Update aom to v1.0.0

Update aom to commit id d14c5bb4f336ef1842046089849dee4a301fbbf0.

27 files changed, 4151 insertions, 0 deletions

diff --git a/third_party/aom/common/args.c b/third_party/aom/common/args.c
new file mode 100644
index 000000000..7131e24de
--- /dev/null
+++ b/third_party/aom/common/args.c
@@ -0,0 +1,297 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/args.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#include "aom/aom_integer.h"
+#include "aom_ports/msvc.h"
+
+#if defined(__GNUC__) && __GNUC__
+extern void die(const char *fmt, ...) __attribute__((noreturn));
+#else
+extern void die(const char *fmt, ...);
+#endif
+
+struct arg arg_init(char **argv) {
+  struct arg a;
+
+  a.argv = argv;
+  a.argv_step = 1;
+  a.name = NULL;
+  a.val = NULL;
+  a.def = NULL;
+  return a;
+}
+
+char *ignore_front_spaces(const char *str) {
+  while (str[0] == ' ' || str[0] == '\t') ++str;
+  return (char *)str;
+}
+
+void ignore_end_spaces(char *str) {
+  char *end = str + strlen(str);
+  while (end > str && (end[0] == ' ' || end[0] == '\t' || end[0] == '\n' ||
+                       end[0] == '\r' || end[0] == '\0'))
+    --end;
+  if (end >= str) end[1] = '\0';
+}
+
+int arg_cfg(int *argc, char ***argv, const char *file) {
+  char **argv_local = (char **)*argv;
+  char **argv_org = (char **)*argv;
+  char line[1024 * 10];
+  FILE *f = fopen(file, "r");
+  if (!f) return 1;
+
+  while (fgets(line, sizeof(line) - 1, f)) {
+    char *actual_line = ignore_front_spaces(line);
+    char *left, *right, *comment;
+    size_t length = strlen(actual_line);
+
+    if (length == 0 || actual_line[0] == '#') continue;
+    right = strchr(actual_line, ':');
+    if (right == NULL) continue;
+    right[0] = '\0';
+
+    left = ignore_front_spaces(actual_line);
+    right = ignore_front_spaces(right + 1);
+
+    comment = strchr(right, '#');
+    if (comment != NULL) comment[0] = '\0';
+
+    ignore_end_spaces(left);
+    ignore_end_spaces(right);
+
+    char **new_args = argv_dup(*argc, (const char **)argv_local);
+    char *new_line = (char *)malloc(sizeof(*new_line) * 128);
+
+    if (argv_local != argv_org) free(argv_local);
+
+    if (!strcmp(right, "ON"))
+      snprintf(new_line, sizeof(*new_line) * 128, "--%s", left);
+    else
+      snprintf(new_line, sizeof(*new_line) * 128, "--%s=%s", left, right);
+
+    new_args[(*argc) - 1] = new_args[(*argc) - 2];
+    new_args[(*argc) - 2] = new_line;
+    argv_local = new_args;
+    *argv = new_args;
+    (*argc)++;
+  }
+  fclose(f);
+  return 0;
+}
+
+int arg_match(struct arg *arg_, const struct arg_def *def, char **argv) {
+  struct arg arg;
+
+  if (!argv[0] || argv[0][0] != '-') return 0;
+
+  arg = arg_init(argv);
+
+  if (def->short_name && strlen(arg.argv[0]) == strlen(def->short_name) + 1 &&
+      !strcmp(arg.argv[0] + 1, def->short_name)) {
+    arg.name = arg.argv[0] + 1;
+    arg.val = def->has_val ? arg.argv[1] : NULL;
+    arg.argv_step = def->has_val ? 2 : 1;
+  } else if (def->long_name) {
+    const size_t name_len = strlen(def->long_name);
+
+    if (strlen(arg.argv[0]) >= name_len + 2 && arg.argv[0][1] == '-' &&
+        !strncmp(arg.argv[0] + 2, def->long_name, name_len) &&
+        (arg.argv[0][name_len + 2] == '=' ||
+         arg.argv[0][name_len + 2] == '\0')) {
+      arg.name = arg.argv[0] + 2;
+      arg.val = arg.name[name_len] == '=' ? arg.name + name_len + 1 : NULL;
+      arg.argv_step = 1;
+    }
+  }
+
+  if (arg.name && !arg.val && def->has_val)
+    die("Error: option %s requires argument.\n", arg.name);
+
+  if (arg.name && arg.val && !def->has_val)
+    die("Error: option %s requires no argument.\n", arg.name);
+
+  if (arg.name && (arg.val || !def->has_val)) {
+    arg.def = def;
+    *arg_ = arg;
+    return 1;
+  }
+
+  return 0;
+}
+
+const char *arg_next(struct arg *arg) {
+  if (arg->argv[0]) arg->argv += arg->argv_step;
+
+  return *arg->argv;
+}
+
+char **argv_dup(int argc, const char **argv) {
+  char **new_argv = malloc((argc + 1) * sizeof(*argv));
+
+  memcpy(new_argv, argv, argc * sizeof(*argv));
+  new_argv[argc] = NULL;
+  return new_argv;
+}
+
+void arg_show_usage(FILE *fp, const struct arg_def *const *defs) {
+  char option_text[40] = { 0 };
+
+  for (; *defs; defs++) {
+    const struct arg_def *def = *defs;
+    char *short_val = def->has_val ? " <arg>" : "";
+    char *long_val = def->has_val ? "=<arg>" : "";
+
+    if (def->short_name && def->long_name) {
+      char *comma = def->has_val ? "," : ",      ";
+
+      snprintf(option_text, 37, "-%s%s%s --%s%6s", def->short_name, short_val,
+               comma, def->long_name, long_val);
+    } else if (def->short_name)
+      snprintf(option_text, 37, "-%s%s", def->short_name, short_val);
+    else if (def->long_name)
+      snprintf(option_text, 37, "          --%s%s", def->long_name, long_val);
+
+    fprintf(fp, "  %-37s\t%s\n", option_text, def->desc);
+
+    if (def->enums) {
+      const struct arg_enum_list *listptr;
+
+      fprintf(fp, "  %-37s\t  ", "");
+
+      for (listptr = def->enums; listptr->name; listptr++)
+        fprintf(fp, "%s%s", listptr->name, listptr[1].name ? ", " : "\n");
+    }
+  }
+}
+
+unsigned int arg_parse_uint(const struct arg *arg) {
+  char *endptr;
+  const unsigned long rawval = strtoul(arg->val, &endptr, 10);  // NOLINT
+
+  if (arg->val[0] != '\0' && endptr[0] == '\0') {
+    if (rawval <= UINT_MAX) return (unsigned int)rawval;
+
+    die("Option %s: Value %lu out of range for unsigned int\n", arg->name,
+        rawval);
+  }
+
+  die("Option %s: Invalid character '%c'\n", arg->name, *endptr);
+  return 0;
+}
+
+int arg_parse_int(const struct arg *arg) {
+  char *endptr;
+  const long rawval = strtol(arg->val, &endptr, 10);  // NOLINT
+
+  if (arg->val[0] != '\0' && endptr[0] == '\0') {
+    if (rawval >= INT_MIN && rawval <= INT_MAX) return (int)rawval;
+
+    die("Option %s: Value %ld out of range for signed int\n", arg->name,
+        rawval);
+  }
+
+  die("Option %s: Invalid character '%c'\n", arg->name, *endptr);
+  return 0;
+}
+
+struct aom_rational {
+  int num; /**< fraction numerator */
+  int den; /**< fraction denominator */
+};
+struct aom_rational arg_parse_rational(const struct arg *arg) {
+  long int rawval;
+  char *endptr;
+  struct aom_rational rat;
+
+  /* parse numerator */
+  rawval = strtol(arg->val, &endptr, 10);
+
+  if (arg->val[0] != '\0' && endptr[0] == '/') {
+    if (rawval >= INT_MIN && rawval <= INT_MAX)
+      rat.num = (int)rawval;
+    else
+      die("Option %s: Value %ld out of range for signed int\n", arg->name,
+          rawval);
+  } else
+    die("Option %s: Expected / at '%c'\n", arg->name, *endptr);
+
+  /* parse denominator */
+  rawval = strtol(endptr + 1, &endptr, 10);
+
+  if (arg->val[0] != '\0' && endptr[0] == '\0') {
+    if (rawval >= INT_MIN && rawval <= INT_MAX)
+      rat.den = (int)rawval;
+    else
+      die("Option %s: Value %ld out of range for signed int\n", arg->name,
+          rawval);
+  } else
+    die("Option %s: Invalid character '%c'\n", arg->name, *endptr);
+
+  return rat;
+}
+
+int arg_parse_enum(const struct arg *arg) {
+  const struct arg_enum_list *listptr;
+  long int rawval;
+  char *endptr;
+
+  /* First see if the value can be parsed as a raw value */
+  rawval = strtol(arg->val, &endptr, 10);
+  if (arg->val[0] != '\0' && endptr[0] == '\0') {
+    /* Got a raw value, make sure it's valid */
+    for (listptr = arg->def->enums; listptr->name; listptr++)
+      if (listptr->val == rawval) return (int)rawval;
+  }
+
+  /* Next see if it can be parsed as a string */
+  for (listptr = arg->def->enums; listptr->name; listptr++)
+    if (!strcmp(arg->val, listptr->name)) return listptr->val;
+
+  die("Option %s: Invalid value '%s'\n", arg->name, arg->val);
+  return 0;
+}
+
+int arg_parse_enum_or_int(const struct arg *arg) {
+  if (arg->def->enums) return arg_parse_enum(arg);
+  return arg_parse_int(arg);
+}
+
+// parse a comma separated list of at most n integers
+// return the number of elements in the list
+int arg_parse_list(const struct arg *arg, int *list, int n) {
+  const char *ptr = arg->val;
+  char *endptr;
+  int i = 0;
+
+  while (ptr[0] != '\0') {
+    int32_t rawval = (int32_t)strtol(ptr, &endptr, 10);
+    if (rawval < INT_MIN || rawval > INT_MAX) {
+      die("Option %s: Value %ld out of range for signed int\n", arg->name,
+          rawval);
+    } else if (i >= n) {
+      die("Option %s: List has more than %d entries\n", arg->name, n);
+    } else if (*endptr == ',') {
+      endptr++;
+    } else if (*endptr != '\0') {
+      die("Option %s: Bad list separator '%c'\n", arg->name, *endptr);
+    }
+    list[i++] = (int)rawval;
+    ptr = endptr;
+  }
+  return i;
+}
diff --git a/third_party/aom/common/args.h b/third_party/aom/common/args.h
new file mode 100644
index 000000000..d12973666
--- /dev/null
+++ b/third_party/aom/common/args.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef ARGS_H_
+#define ARGS_H_
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct arg {
+  char **argv;
+  const char *name;
+  const char *val;
+  unsigned int argv_step;
+  const struct arg_def *def;
+};
+
+struct arg_enum_list {
+  const char *name;
+  int val;
+};
+#define ARG_ENUM_LIST_END \
+  { 0 }
+
+typedef struct arg_def {
+  const char *short_name;
+  const char *long_name;
+  int has_val;
+  const char *desc;
+  const struct arg_enum_list *enums;
+} arg_def_t;
+#define ARG_DEF(s, l, v, d) \
+  { s, l, v, d, NULL }
+#define ARG_DEF_ENUM(s, l, v, d, e) \
+  { s, l, v, d, e }
+#define ARG_DEF_LIST_END \
+  { 0 }
+
+struct arg arg_init(char **argv);
+int arg_match(struct arg *arg_, const struct arg_def *def, char **argv);
+char *ignore_front_spaces(const char *str);
+void ignore_end_spaces(char *str);
+int arg_cfg(int *argc, char ***argv, const char *file);
+const char *arg_next(struct arg *arg);
+void arg_show_usage(FILE *fp, const struct arg_def *const *defs);
+char **argv_dup(int argc, const char **argv);
+
+unsigned int arg_parse_uint(const struct arg *arg);
+int arg_parse_int(const struct arg *arg);
+struct aom_rational arg_parse_rational(const struct arg *arg);
+int arg_parse_enum(const struct arg *arg);
+int arg_parse_enum_or_int(const struct arg *arg);
+int arg_parse_list(const struct arg *arg, int *list, int n);
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // ARGS_H_
diff --git a/third_party/aom/common/ivfdec.c b/third_party/aom/common/ivfdec.c
new file mode 100644
index 000000000..80d73b04c
--- /dev/null
+++ b/third_party/aom/common/ivfdec.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/ivfdec.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aom_ports/mem_ops.h"
+#include "aom_ports/sanitizer.h"
+
+static const char *IVF_SIGNATURE = "DKIF";
+
+static void fix_framerate(int *num, int *den) {
+  if (*den <= 0 || *den >= 1000000000 || *num <= 0 || *num >= 1000) {
+    // framerate seems to be invalid, just default to 30fps.
+    *num = 30;
+    *den = 1;
+  }
+}
+
+int file_is_ivf(struct AvxInputContext *input_ctx) {
+  char raw_hdr[32];
+  int is_ivf = 0;
+
+  if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {
+    if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {
+      is_ivf = 1;
+
+      if (mem_get_le16(raw_hdr + 4) != 0) {
+        fprintf(stderr,
+                "Error: Unrecognized IVF version! This file may not"
+                " decode properly.");
+      }
+
+      input_ctx->fourcc = mem_get_le32(raw_hdr + 8);
+      input_ctx->width = mem_get_le16(raw_hdr + 12);
+      input_ctx->height = mem_get_le16(raw_hdr + 14);
+      input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);
+      input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);
+      fix_framerate(&input_ctx->framerate.numerator,
+                    &input_ctx->framerate.denominator);
+    }
+  }
+
+  if (!is_ivf) {
+    rewind(input_ctx->file);
+    input_ctx->detect.buf_read = 0;
+  } else {
+    input_ctx->detect.position = 4;
+  }
+  return is_ivf;
+}
+
+int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read,
+                   size_t *buffer_size, aom_codec_pts_t *pts) {
+  char raw_header[IVF_FRAME_HDR_SZ] = { 0 };
+  size_t frame_size = 0;
+
+  if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
+    if (!feof(infile)) warn("Failed to read frame size");
+  } else {
+    frame_size = mem_get_le32(raw_header);
+
+    if (frame_size > 256 * 1024 * 1024) {
+      warn("Read invalid frame size (%u)", (unsigned int)frame_size);
+      frame_size = 0;
+    }
+
+    if (frame_size > *buffer_size) {
+      uint8_t *new_buffer = (uint8_t *)realloc(*buffer, 2 * frame_size);
+
+      if (new_buffer) {
+        *buffer = new_buffer;
+        *buffer_size = 2 * frame_size;
+      } else {
+        warn("Failed to allocate compressed data buffer");
+        frame_size = 0;
+      }
+    }
+
+    if (pts) {
+      *pts = mem_get_le32(&raw_header[4]);
+      *pts += ((aom_codec_pts_t)mem_get_le32(&raw_header[8]) << 32);
+    }
+  }
+
+  if (!feof(infile)) {
+    ASAN_UNPOISON_MEMORY_REGION(*buffer, *buffer_size);
+    if (fread(*buffer, 1, frame_size, infile) != frame_size) {
+      warn("Failed to read full frame");
+      return 1;
+    }
+
+    ASAN_POISON_MEMORY_REGION(*buffer + frame_size, *buffer_size - frame_size);
+    *bytes_read = frame_size;
+    return 0;
+  }
+
+  return 1;
+}
diff --git a/third_party/aom/common/ivfdec.h b/third_party/aom/common/ivfdec.h
new file mode 100644
index 000000000..9013dea64
--- /dev/null
+++ b/third_party/aom/common/ivfdec.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef IVFDEC_H_
+#define IVFDEC_H_
+
+#include "common/tools_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int file_is_ivf(struct AvxInputContext *input);
+
+typedef int64_t aom_codec_pts_t;
+int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read,
+                   size_t *buffer_size, aom_codec_pts_t *pts);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif  // IVFDEC_H_
diff --git a/third_party/aom/common/ivfenc.c b/third_party/aom/common/ivfenc.c
new file mode 100644
index 000000000..64715f4d7
--- /dev/null
+++ b/third_party/aom/common/ivfenc.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/ivfenc.h"
+
+#include "aom/aom_encoder.h"
+#include "aom_ports/mem_ops.h"
+
+void ivf_write_file_header(FILE *outfile, const struct aom_codec_enc_cfg *cfg,
+                           unsigned int fourcc, int frame_cnt) {
+  char header[32];
+
+  header[0] = 'D';
+  header[1] = 'K';
+  header[2] = 'I';
+  header[3] = 'F';
+  mem_put_le16(header + 4, 0);                     // version
+  mem_put_le16(header + 6, 32);                    // header size
+  mem_put_le32(header + 8, fourcc);                // fourcc
+  mem_put_le16(header + 12, cfg->g_w);             // width
+  mem_put_le16(header + 14, cfg->g_h);             // height
+  mem_put_le32(header + 16, cfg->g_timebase.den);  // rate
+  mem_put_le32(header + 20, cfg->g_timebase.num);  // scale
+  mem_put_le32(header + 24, frame_cnt);            // length
+  mem_put_le32(header + 28, 0);                    // unused
+
+  fwrite(header, 1, 32, outfile);
+}
+
+void ivf_write_frame_header(FILE *outfile, int64_t pts, size_t frame_size) {
+  char header[12];
+
+  mem_put_le32(header, (int)frame_size);
+  mem_put_le32(header + 4, (int)(pts & 0xFFFFFFFF));
+  mem_put_le32(header + 8, (int)(pts >> 32));
+  fwrite(header, 1, 12, outfile);
+}
+
+void ivf_write_frame_size(FILE *outfile, size_t frame_size) {
+  char header[4];
+
+  mem_put_le32(header, (int)frame_size);
+  fwrite(header, 1, 4, outfile);
+}
diff --git a/third_party/aom/common/ivfenc.h b/third_party/aom/common/ivfenc.h
new file mode 100644
index 000000000..f0cab8178
--- /dev/null
+++ b/third_party/aom/common/ivfenc.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef IVFENC_H_
+#define IVFENC_H_
+
+#include "common/tools_common.h"
+
+struct aom_codec_enc_cfg;
+struct aom_codec_cx_pkt;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void ivf_write_file_header(FILE *outfile, const struct aom_codec_enc_cfg *cfg,
+                           uint32_t fourcc, int frame_cnt);
+
+void ivf_write_frame_header(FILE *outfile, int64_t pts, size_t frame_size);
+
+void ivf_write_frame_size(FILE *outfile, size_t frame_size);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif  // IVFENC_H_
diff --git a/third_party/aom/common/md5_utils.c b/third_party/aom/common/md5_utils.c
new file mode 100644
index 000000000..b69e1cc72
--- /dev/null
+++ b/third_party/aom/common/md5_utils.c
@@ -0,0 +1,249 @@
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ *
+ * Changed so as no longer to depend on Colin Plumb's `usual.h' header
+ * definitions
+ *  - Ian Jackson <ian@chiark.greenend.org.uk>.
+ * Still in the public domain.
+ */
+
+#include <string.h> /* for memcpy() */
+
+#include "common/md5_utils.h"
+
+static void byteSwap(UWORD32 *buf, unsigned words) {
+  md5byte *p;
+
+  /* Only swap bytes for big endian machines */
+  int i = 1;
+
+  if (*(char *)&i == 1) return;
+
+  p = (md5byte *)buf;
+
+  do {
+    *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
+             ((unsigned)p[1] << 8 | p[0]);
+    p += 4;
+  } while (--words);
+}
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+void MD5Init(struct MD5Context *ctx) {
+  ctx->buf[0] = 0x67452301;
+  ctx->buf[1] = 0xefcdab89;
+  ctx->buf[2] = 0x98badcfe;
+  ctx->buf[3] = 0x10325476;
+
+  ctx->bytes[0] = 0;
+  ctx->bytes[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+void MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len) {
+  UWORD32 t;
+
+  /* Update byte count */
+
+  t = ctx->bytes[0];
+
+  if ((ctx->bytes[0] = t + len) < t)
+    ctx->bytes[1]++; /* Carry from low to high */
+
+  t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
+
+  if (t > len) {
+    memcpy((md5byte *)ctx->in + 64 - t, buf, len);
+    return;
+  }
+
+  /* First chunk is an odd size */
+  memcpy((md5byte *)ctx->in + 64 - t, buf, t);
+  byteSwap(ctx->in, 16);
+  MD5Transform(ctx->buf, ctx->in);
+  buf += t;
+  len -= t;
+
+  /* Process data in 64-byte chunks */
+  while (len >= 64) {
+    memcpy(ctx->in, buf, 64);
+    byteSwap(ctx->in, 16);
+    MD5Transform(ctx->buf, ctx->in);
+    buf += 64;
+    len -= 64;
+  }
+
+  /* Handle any remaining bytes of data. */
+  memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+void MD5Final(md5byte digest[16], struct MD5Context *ctx) {
+  int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
+  md5byte *p = (md5byte *)ctx->in + count;
+
+  /* Set the first char of padding to 0x80.  There is always room. */
+  *p++ = 0x80;
+
+  /* Bytes of padding needed to make 56 bytes (-8..55) */
+  count = 56 - 1 - count;
+
+  if (count < 0) { /* Padding forces an extra block */
+    memset(p, 0, count + 8);
+    byteSwap(ctx->in, 16);
+    MD5Transform(ctx->buf, ctx->in);
+    p = (md5byte *)ctx->in;
+    count = 56;
+  }
+
+  memset(p, 0, count);
+  byteSwap(ctx->in, 14);
+
+  /* Append length in bits and transform */
+  ctx->in[14] = ctx->bytes[0] << 3;
+  ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
+  MD5Transform(ctx->buf, ctx->in);
+
+  byteSwap(ctx->buf, 4);
+  memcpy(digest, ctx->buf, 16);
+  memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
+}
+
+#ifndef ASM_MD5
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, in, s) \
+  (w += f(x, y, z) + in, w = (w << s | w >> (32 - s)) + x)
+
+#if defined(__clang__) && defined(__has_attribute)
+#if __has_attribute(no_sanitize)
+#define AOM_NO_UNSIGNED_OVERFLOW_CHECK \
+  __attribute__((no_sanitize("unsigned-integer-overflow")))
+#endif
+#endif
+
+#ifndef AOM_NO_UNSIGNED_OVERFLOW_CHECK
+#define AOM_NO_UNSIGNED_OVERFLOW_CHECK
+#endif
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+AOM_NO_UNSIGNED_OVERFLOW_CHECK void MD5Transform(UWORD32 buf[4],
+                                                 UWORD32 const in[16]) {
+  register UWORD32 a, b, c, d;
+
+  a = buf[0];
+  b = buf[1];
+  c = buf[2];
+  d = buf[3];
+
+  MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+  MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+  MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+  MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+  MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+  MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+  MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+  MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+  MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+  MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+  MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+  MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+  MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+  MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+  MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+  MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+  MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+  MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+  MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+  MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+  MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+  MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+  MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+  MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+  MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+  MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+  MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+  MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+  MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+  MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+  MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+  MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+  MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+  MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+  MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+  MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+  MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+  MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+  MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+  MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+  MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+  MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+  MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+  MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+  MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+  MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+  MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+  MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+  MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+  MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+  MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+  MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+  MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+  MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+  MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+  MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+  MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+  MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+  MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+  MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+  MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+  MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+  MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+  MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+  buf[0] += a;
+  buf[1] += b;
+  buf[2] += c;
+  buf[3] += d;
+}
+
+#undef AOM_NO_UNSIGNED_OVERFLOW_CHECK
+
+#endif
diff --git a/third_party/aom/common/md5_utils.h b/third_party/aom/common/md5_utils.h
new file mode 100644
index 000000000..bd4991b3a
--- /dev/null
+++ b/third_party/aom/common/md5_utils.h
@@ -0,0 +1,49 @@
+/*
+ * This is the header file for the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ *
+ * Changed so as no longer to depend on Colin Plumb's `usual.h'
+ * header definitions
+ *  - Ian Jackson <ian@chiark.greenend.org.uk>.
+ * Still in the public domain.
+ */
+
+#ifndef MD5_UTILS_H_
+#define MD5_UTILS_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define md5byte unsigned char
+#define UWORD32 unsigned int
+
+typedef struct MD5Context MD5Context;
+struct MD5Context {
+  UWORD32 buf[4];
+  UWORD32 bytes[2];
+  UWORD32 in[16];
+};
+
+void MD5Init(struct MD5Context *context);
+void MD5Update(struct MD5Context *context, md5byte const *buf, unsigned len);
+void MD5Final(unsigned char digest[16], struct MD5Context *context);
+void MD5Transform(UWORD32 buf[4], UWORD32 const in[16]);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // MD5_UTILS_H_
diff --git a/third_party/aom/common/obudec.c b/third_party/aom/common/obudec.c
new file mode 100644
index 000000000..cd88f1648
--- /dev/null
+++ b/third_party/aom/common/obudec.c
@@ -0,0 +1,448 @@
+/*
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common/obudec.h"
+
+#include "aom_ports/mem_ops.h"
+#include "av1/common/common.h"
+#include "av1/decoder/obu.h"
+
+#define OBU_BUFFER_SIZE (500 * 1024)
+
+#define OBU_HEADER_SIZE 1
+#define OBU_EXTENSION_SIZE 1
+#define OBU_MAX_LENGTH_FIELD_SIZE 8
+#define OBU_DETECTION_SIZE \
+  (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE + 3 * OBU_MAX_LENGTH_FIELD_SIZE)
+
+// Reads unsigned LEB128 integer and returns 0 upon successful read and decode.
+// Stores raw bytes in 'value_buffer', length of the number in 'value_length',
+// and decoded value in 'value'.
+static int obudec_read_leb128(FILE *f, uint8_t *value_buffer,
+                              size_t *value_length, uint64_t *value) {
+  if (!f || !value_buffer || !value_length || !value) return -1;
+  size_t len;
+  for (len = 0; len < OBU_MAX_LENGTH_FIELD_SIZE; ++len) {
+    const size_t num_read = fread(&value_buffer[len], 1, 1, f);
+    if (num_read == 0) {
+      if (len == 0 && feof(f)) {
+        *value_length = 0;
+        return 0;
+      }
+      // Ran out of data before completing read of value.
+      return -1;
+    }
+    if ((value_buffer[len] >> 7) == 0) {
+      ++len;
+      *value_length = len;
+      break;
+    }
+  }
+
+  return aom_uleb_decode(value_buffer, len, value, NULL);
+}
+
+// Reads OBU header from 'f'. The 'buffer_capacity' passed in must be large
+// enough to store an OBU header with extension (2 bytes). Raw OBU data is
+// written to 'obu_data', parsed OBU header values are written to 'obu_header',
+// and total bytes read from file are written to 'bytes_read'. Returns 0 for
+// success, and non-zero on failure. When end of file is reached, the return
+// value is 0 and the 'bytes_read' value is set to 0.
+static int obudec_read_obu_header(FILE *f, size_t buffer_capacity,
+                                  int is_annexb, uint8_t *obu_data,
+                                  ObuHeader *obu_header, size_t *bytes_read) {
+  if (!f || buffer_capacity < (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE) ||
+      !obu_data || !obu_header || !bytes_read) {
+    return -1;
+  }
+  *bytes_read = fread(obu_data, 1, 1, f);
+
+  if (feof(f) && *bytes_read == 0) {
+    return 0;
+  } else if (*bytes_read != 1) {
+    fprintf(stderr, "obudec: Failure reading OBU header.\n");
+    return -1;
+  }
+
+  const int has_extension = (obu_data[0] >> 2) & 0x1;
+  if (has_extension) {
+    if (fread(&obu_data[1], 1, 1, f) != 1) {
+      fprintf(stderr, "obudec: Failure reading OBU extension.");
+      return -1;
+    }
+    ++*bytes_read;
+  }
+
+  size_t obu_bytes_parsed = 0;
+  const aom_codec_err_t parse_result = aom_read_obu_header(
+      obu_data, *bytes_read, &obu_bytes_parsed, obu_header, is_annexb);
+  if (parse_result != AOM_CODEC_OK || *bytes_read != obu_bytes_parsed) {
+    fprintf(stderr, "obudec: Error parsing OBU header.\n");
+    return -1;
+  }
+
+  return 0;
+}
+
+// Reads OBU payload from 'f' and returns 0 for success when all payload bytes
+// are read from the file. Payload data is written to 'obu_data', and actual
+// bytes read added to 'bytes_read'.
+static int obudec_read_obu_payload(FILE *f, size_t payload_length,
+                                   uint8_t *obu_data, size_t *bytes_read) {
+  if (!f || payload_length == 0 || !obu_data || !bytes_read) return -1;
+
+  if (fread(obu_data, 1, payload_length, f) != payload_length) {
+    fprintf(stderr, "obudec: Failure reading OBU payload.\n");
+    return -1;
+  }
+
+  *bytes_read += payload_length;
+  return 0;
+}
+
+static int obudec_read_obu_header_and_size(FILE *f, size_t buffer_capacity,
+                                           int is_annexb, uint8_t *buffer,
+                                           size_t *bytes_read,
+                                           size_t *payload_length,
+                                           ObuHeader *obu_header) {
+  const size_t kMinimumBufferSize =
+      (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE + OBU_MAX_LENGTH_FIELD_SIZE);
+  if (!f || !buffer || !bytes_read || !payload_length || !obu_header ||
+      buffer_capacity < kMinimumBufferSize) {
+    return -1;
+  }
+
+  size_t leb128_length = 0;
+  uint64_t obu_size = 0;
+  if (is_annexb) {
+    if (obudec_read_leb128(f, &buffer[0], &leb128_length, &obu_size) != 0) {
+      fprintf(stderr, "obudec: Failure reading OBU size length.\n");
+      return -1;
+    } else if (leb128_length == 0) {
+      *payload_length = 0;
+      return 0;
+    }
+    if (obu_size > UINT32_MAX) {
+      fprintf(stderr, "obudec: OBU payload length too large.\n");
+      return -1;
+    }
+  }
+
+  size_t header_size = 0;
+  if (obudec_read_obu_header(f, buffer_capacity - leb128_length, is_annexb,
+                             buffer + leb128_length, obu_header,
+                             &header_size) != 0) {
+    return -1;
+  } else if (header_size == 0) {
+    *payload_length = 0;
+    return 0;
+  }
+
+  if (is_annexb) {
+    if (obu_size < header_size) {
+      fprintf(stderr, "obudec: OBU size is too small.\n");
+      return -1;
+    }
+    *payload_length = (size_t)obu_size - header_size;
+  } else {
+    uint64_t u64_payload_length = 0;
+    if (obudec_read_leb128(f, &buffer[header_size], &leb128_length,
+                           &u64_payload_length) != 0) {
+      fprintf(stderr, "obudec: Failure reading OBU payload length.\n");
+      return -1;
+    }
+    if (u64_payload_length > UINT32_MAX) {
+      fprintf(stderr, "obudec: OBU payload length too large.\n");
+      return -1;
+    }
+
+    *payload_length = (size_t)u64_payload_length;
+  }
+
+  *bytes_read = leb128_length + header_size;
+  return 0;
+}
+
+static int obudec_read_one_obu(FILE *f, uint8_t **obu_buffer,
+                               size_t obu_bytes_buffered,
+                               size_t *obu_buffer_capacity, size_t *obu_length,
+                               ObuHeader *obu_header, int is_annexb) {
+  size_t available_buffer_capacity = *obu_buffer_capacity - obu_bytes_buffered;
+
+  if (!(*obu_buffer)) return -1;
+
+  size_t bytes_read = 0;
+  size_t obu_payload_length = 0;
+  const int status = obudec_read_obu_header_and_size(
+      f, available_buffer_capacity, is_annexb, *obu_buffer + obu_bytes_buffered,
+      &bytes_read, &obu_payload_length, obu_header);
+  if (status < 0) return status;
+
+  if (obu_payload_length > SIZE_MAX - bytes_read) return -1;
+
+  if (obu_payload_length > 256 * 1024 * 1024) {
+    fprintf(stderr, "obudec: Read invalid OBU size (%u)\n",
+            (unsigned int)obu_payload_length);
+    *obu_length = bytes_read + obu_payload_length;
+    return -1;
+  }
+
+  if (bytes_read + obu_payload_length > available_buffer_capacity) {
+    // TODO(tomfinegan): Add overflow check.
+    const size_t new_capacity =
+        obu_bytes_buffered + bytes_read + 2 * obu_payload_length;
+
+#if defined AOM_MAX_ALLOCABLE_MEMORY
+    if (new_capacity > AOM_MAX_ALLOCABLE_MEMORY) {
+      fprintf(stderr, "obudec: OBU size exceeds max alloc size.\n");
+      return -1;
+    }
+#endif
+
+    uint8_t *new_buffer = (uint8_t *)realloc(*obu_buffer, new_capacity);
+
+    if (new_buffer) {
+      *obu_buffer = new_buffer;
+      *obu_buffer_capacity = new_capacity;
+    } else {
+      fprintf(stderr, "obudec: Failed to allocate compressed data buffer\n");
+      *obu_length = bytes_read + obu_payload_length;
+      return -1;
+    }
+  }
+
+  if (obu_payload_length > 0 &&
+      obudec_read_obu_payload(f, obu_payload_length,
+                              *obu_buffer + obu_bytes_buffered + bytes_read,
+                              &bytes_read) != 0) {
+    return -1;
+  }
+
+  *obu_length = bytes_read;
+  return 0;
+}
+
+int file_is_obu(struct ObuDecInputContext *obu_ctx) {
+  if (!obu_ctx || !obu_ctx->avx_ctx) return 0;
+
+  struct AvxInputContext *avx_ctx = obu_ctx->avx_ctx;
+  uint8_t detect_buf[OBU_DETECTION_SIZE] = { 0 };
+  const int is_annexb = obu_ctx->is_annexb;
+  FILE *f = avx_ctx->file;
+  size_t payload_length = 0;
+  ObuHeader obu_header;
+  memset(&obu_header, 0, sizeof(obu_header));
+  size_t length_of_unit_size = 0;
+  size_t annexb_header_length = 0;
+  uint64_t unit_size = 0;
+
+  if (is_annexb) {
+    // read the size of first temporal unit
+    if (obudec_read_leb128(f, &detect_buf[0], &length_of_unit_size,
+                           &unit_size) != 0) {
+      fprintf(stderr, "obudec: Failure reading temporal unit header\n");
+      return 0;
+    }
+
+    // read the size of first frame unit
+    if (obudec_read_leb128(f, &detect_buf[length_of_unit_size],
+                           &annexb_header_length, &unit_size) != 0) {
+      fprintf(stderr, "obudec: Failure reading frame unit header\n");
+      return 0;
+    }
+    annexb_header_length += length_of_unit_size;
+  }
+
+  size_t bytes_read = 0;
+  if (obudec_read_obu_header_and_size(
+          f, OBU_DETECTION_SIZE - annexb_header_length, is_annexb,
+          &detect_buf[annexb_header_length], &bytes_read, &payload_length,
+          &obu_header) != 0) {
+    fprintf(stderr, "obudec: Failure reading first OBU.\n");
+    rewind(f);
+    return 0;
+  }
+
+  if (is_annexb) {
+    bytes_read += annexb_header_length;
+  }
+
+  if (obu_header.type != OBU_TEMPORAL_DELIMITER &&
+      obu_header.type != OBU_SEQUENCE_HEADER) {
+    return 0;
+  }
+
+  if (obu_header.has_size_field) {
+    if (obu_header.type == OBU_TEMPORAL_DELIMITER && payload_length != 0) {
+      fprintf(
+          stderr,
+          "obudec: Invalid OBU_TEMPORAL_DELIMITER payload length (non-zero).");
+      rewind(f);
+      return 0;
+    }
+  } else if (!is_annexb) {
+    fprintf(stderr, "obudec: OBU size fields required, cannot decode input.\n");
+    rewind(f);
+    return 0;
+  }
+
+  // Appears that input is valid Section 5 AV1 stream.
+  obu_ctx->buffer = (uint8_t *)malloc(OBU_BUFFER_SIZE);
+  if (!obu_ctx->buffer) {
+    fprintf(stderr, "Out of memory.\n");
+    rewind(f);
+    return 0;
+  }
+  obu_ctx->buffer_capacity = OBU_BUFFER_SIZE;
+
+  memcpy(obu_ctx->buffer, &detect_buf[0], bytes_read);
+  obu_ctx->bytes_buffered = bytes_read;
+  // If the first OBU is a SEQUENCE_HEADER, then it will have a payload.
+  // We need to read this in so that our buffer only contains complete OBUs.
+  if (payload_length > 0) {
+    if (payload_length > (obu_ctx->buffer_capacity - bytes_read)) {
+      fprintf(stderr, "obudec: First OBU's payload is too large\n");
+      rewind(f);
+      return 0;
+    }
+
+    size_t payload_bytes = 0;
+    const int status = obudec_read_obu_payload(
+        f, payload_length, &obu_ctx->buffer[bytes_read], &payload_bytes);
+    if (status < 0) {
+      rewind(f);
+      return 0;
+    }
+    obu_ctx->bytes_buffered += payload_bytes;
+  }
+  return 1;
+}
+
+int obudec_read_temporal_unit(struct ObuDecInputContext *obu_ctx,
+                              uint8_t **buffer, size_t *bytes_read,
+                              size_t *buffer_size) {
+  FILE *f = obu_ctx->avx_ctx->file;
+  if (!f) return -1;
+
+  *buffer_size = 0;
+  *bytes_read = 0;
+
+  if (feof(f)) {
+    return 1;
+  }
+
+  size_t tu_size;
+  size_t obu_size = 0;
+  size_t length_of_temporal_unit_size = 0;
+  uint8_t tuheader[OBU_MAX_LENGTH_FIELD_SIZE] = { 0 };
+
+  if (obu_ctx->is_annexb) {
+    uint64_t size = 0;
+
+    if (obu_ctx->bytes_buffered == 0) {
+      if (obudec_read_leb128(f, &tuheader[0], &length_of_temporal_unit_size,
+                             &size) != 0) {
+        fprintf(stderr, "obudec: Failure reading temporal unit header\n");
+        return -1;
+      }
+      if (size == 0 && feof(f)) {
+        return 1;
+      }
+    } else {
+      // temporal unit size was already stored in buffer
+      if (aom_uleb_decode(obu_ctx->buffer, obu_ctx->bytes_buffered, &size,
+                          &length_of_temporal_unit_size) != 0) {
+        fprintf(stderr, "obudec: Failure reading temporal unit header\n");
+        return -1;
+      }
+    }
+
+    if (size > UINT32_MAX || size + length_of_temporal_unit_size > UINT32_MAX) {
+      fprintf(stderr, "obudec: TU too large.\n");
+      return -1;
+    }
+
+    size += length_of_temporal_unit_size;
+    tu_size = (size_t)size;
+  } else {
+    while (1) {
+      ObuHeader obu_header;
+      memset(&obu_header, 0, sizeof(obu_header));
+
+      if (obudec_read_one_obu(f, &obu_ctx->buffer, obu_ctx->bytes_buffered,
+                              &obu_ctx->buffer_capacity, &obu_size, &obu_header,
+                              0) != 0) {
+        fprintf(stderr, "obudec: read_one_obu failed in TU loop\n");
+        return -1;
+      }
+
+      if (obu_header.type == OBU_TEMPORAL_DELIMITER || obu_size == 0) {
+        tu_size = obu_ctx->bytes_buffered;
+        break;
+      } else {
+        obu_ctx->bytes_buffered += obu_size;
+      }
+    }
+  }
+
+#if defined AOM_MAX_ALLOCABLE_MEMORY
+  if (tu_size > AOM_MAX_ALLOCABLE_MEMORY) {
+    fprintf(stderr, "obudec: Temporal Unit size exceeds max alloc size.\n");
+    return -1;
+  }
+#endif
+  uint8_t *new_buffer = (uint8_t *)realloc(*buffer, tu_size);
+  if (!new_buffer) {
+    free(*buffer);
+    fprintf(stderr, "obudec: Out of memory.\n");
+    return -1;
+  }
+  *buffer = new_buffer;
+  *bytes_read = tu_size;
+  *buffer_size = tu_size;
+
+  if (!obu_ctx->is_annexb) {
+    memcpy(*buffer, obu_ctx->buffer, tu_size);
+
+    // At this point, (obu_ctx->buffer + obu_ctx->bytes_buffered + obu_size)
+    // points to the end of the buffer.
+    memmove(obu_ctx->buffer, obu_ctx->buffer + obu_ctx->bytes_buffered,
+            obu_size);
+    obu_ctx->bytes_buffered = obu_size;
+  } else {
+    if (!feof(f)) {
+      size_t data_size;
+      size_t offset;
+      if (!obu_ctx->bytes_buffered) {
+        data_size = tu_size - length_of_temporal_unit_size;
+        memcpy(*buffer, &tuheader[0], length_of_temporal_unit_size);
+        offset = length_of_temporal_unit_size;
+      } else {
+        memcpy(*buffer, obu_ctx->buffer, obu_ctx->bytes_buffered);
+        offset = obu_ctx->bytes_buffered;
+        data_size = tu_size - obu_ctx->bytes_buffered;
+        obu_ctx->bytes_buffered = 0;
+      }
+
+      if (fread(*buffer + offset, 1, data_size, f) != data_size) {
+        fprintf(stderr, "obudec: Failed to read full temporal unit\n");
+        return -1;
+      }
+    }
+  }
+  return 0;
+}
+
+void obudec_free(struct ObuDecInputContext *obu_ctx) { free(obu_ctx->buffer); }
diff --git a/third_party/aom/common/obudec.h b/third_party/aom/common/obudec.h
new file mode 100644
index 000000000..c52a94e9d
--- /dev/null
+++ b/third_party/aom/common/obudec.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef OBUDEC_H_
+#define OBUDEC_H_
+
+#include "common/tools_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ObuDecInputContext {
+  struct AvxInputContext *avx_ctx;
+  uint8_t *buffer;
+  size_t buffer_capacity;
+  size_t bytes_buffered;
+  int is_annexb;
+};
+
+// Returns 1 when file data starts (if Annex B stream, after reading the
+// size of the OBU) with what appears to be a Temporal Delimiter
+// OBU as defined by Section 5 of the AV1 bitstream specification.
+int file_is_obu(struct ObuDecInputContext *obu_ctx);
+
+// Reads one Temporal Unit from the input file. Returns 0 when a TU is
+// successfully read, 1 when end of file is reached, and less than 0 when an
+// error occurs. Stores TU data in 'buffer'. Reallocs buffer to match TU size,
+// returns buffer capacity via 'buffer_size', and returns size of buffered data
+// via 'bytes_read'.
+int obudec_read_temporal_unit(struct ObuDecInputContext *obu_ctx,
+                              uint8_t **buffer, size_t *bytes_read,
+                              size_t *buffer_size);
+
+void obudec_free(struct ObuDecInputContext *obu_ctx);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif  // OBUDEC_H_
diff --git a/third_party/aom/common/tools_common.c b/third_party/aom/common/tools_common.c
new file mode 100644
index 000000000..359ec7341
--- /dev/null
+++ b/third_party/aom/common/tools_common.c
@@ -0,0 +1,423 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/tools_common.h"
+
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if CONFIG_AV1_ENCODER
+#include "aom/aomcx.h"
+#endif
+
+#if CONFIG_AV1_DECODER
+#include "aom/aomdx.h"
+#endif
+
+#if defined(_WIN32) || defined(__OS2__)
+#include <io.h>
+#include <fcntl.h>
+
+#ifdef __OS2__
+#define _setmode setmode
+#define _fileno fileno
+#define _O_BINARY O_BINARY
+#endif
+#endif
+
+#define LOG_ERROR(label)               \
+  do {                                 \
+    const char *l = label;             \
+    va_list ap;                        \
+    va_start(ap, fmt);                 \
+    if (l) fprintf(stderr, "%s: ", l); \
+    vfprintf(stderr, fmt, ap);         \
+    fprintf(stderr, "\n");             \
+    va_end(ap);                        \
+  } while (0)
+
+FILE *set_binary_mode(FILE *stream) {
+  (void)stream;
+#if defined(_WIN32) || defined(__OS2__)
+  _setmode(_fileno(stream), _O_BINARY);
+#endif
+  return stream;
+}
+
+void die(const char *fmt, ...) {
+  LOG_ERROR(NULL);
+  usage_exit();
+}
+
+void fatal(const char *fmt, ...) {
+  LOG_ERROR("Fatal");
+  exit(EXIT_FAILURE);
+}
+
+void warn(const char *fmt, ...) { LOG_ERROR("Warning"); }
+
+void die_codec(aom_codec_ctx_t *ctx, const char *s) {
+  const char *detail = aom_codec_error_detail(ctx);
+
+  printf("%s: %s\n", s, aom_codec_error(ctx));
+  if (detail) printf("    %s\n", detail);
+  exit(EXIT_FAILURE);
+}
+
+int read_yuv_frame(struct AvxInputContext *input_ctx, aom_image_t *yuv_frame) {
+  FILE *f = input_ctx->file;
+  struct FileTypeDetectionBuffer *detect = &input_ctx->detect;
+  int plane = 0;
+  int shortread = 0;
+  const int bytespp = (yuv_frame->fmt & AOM_IMG_FMT_HIGHBITDEPTH) ? 2 : 1;
+
+  for (plane = 0; plane < 3; ++plane) {
+    uint8_t *ptr;
+    const int w = aom_img_plane_width(yuv_frame, plane);
+    const int h = aom_img_plane_height(yuv_frame, plane);
+    int r;
+
+    /* Determine the correct plane based on the image format. The for-loop
+     * always counts in Y,U,V order, but this may not match the order of
+     * the data on disk.
+     */
+    switch (plane) {
+      case 1:
+        ptr =
+            yuv_frame->planes[yuv_frame->fmt == AOM_IMG_FMT_YV12 ? AOM_PLANE_V
+                                                                 : AOM_PLANE_U];
+        break;
+      case 2:
+        ptr =
+            yuv_frame->planes[yuv_frame->fmt == AOM_IMG_FMT_YV12 ? AOM_PLANE_U
+                                                                 : AOM_PLANE_V];
+        break;
+      default: ptr = yuv_frame->planes[plane];
+    }
+
+    for (r = 0; r < h; ++r) {
+      size_t needed = w * bytespp;
+      size_t buf_position = 0;
+      const size_t left = detect->buf_read - detect->position;
+      if (left > 0) {
+        const size_t more = (left < needed) ? left : needed;
+        memcpy(ptr, detect->buf + detect->position, more);
+        buf_position = more;
+        needed -= more;
+        detect->position += more;
+      }
+      if (needed > 0) {
+        shortread |= (fread(ptr + buf_position, 1, needed, f) < needed);
+      }
+
+      ptr += yuv_frame->stride[plane];
+    }
+  }
+
+  return shortread;
+}
+
+#if CONFIG_AV1_ENCODER
+static const AvxInterface aom_encoders[] = {
+  { "av1", AV1_FOURCC, &aom_codec_av1_cx },
+};
+
+int get_aom_encoder_count(void) {
+  return sizeof(aom_encoders) / sizeof(aom_encoders[0]);
+}
+
+const AvxInterface *get_aom_encoder_by_index(int i) { return &aom_encoders[i]; }
+
+const AvxInterface *get_aom_encoder_by_name(const char *name) {
+  int i;
+
+  for (i = 0; i < get_aom_encoder_count(); ++i) {
+    const AvxInterface *encoder = get_aom_encoder_by_index(i);
+    if (strcmp(encoder->name, name) == 0) return encoder;
+  }
+
+  return NULL;
+}
+#endif  // CONFIG_AV1_ENCODER
+
+#if CONFIG_AV1_DECODER
+static const AvxInterface aom_decoders[] = {
+  { "av1", AV1_FOURCC, &aom_codec_av1_dx },
+};
+
+int get_aom_decoder_count(void) {
+  return sizeof(aom_decoders) / sizeof(aom_decoders[0]);
+}
+
+const AvxInterface *get_aom_decoder_by_index(int i) { return &aom_decoders[i]; }
+
+const AvxInterface *get_aom_decoder_by_name(const char *name) {
+  int i;
+
+  for (i = 0; i < get_aom_decoder_count(); ++i) {
+    const AvxInterface *const decoder = get_aom_decoder_by_index(i);
+    if (strcmp(decoder->name, name) == 0) return decoder;
+  }
+
+  return NULL;
+}
+
+const AvxInterface *get_aom_decoder_by_fourcc(uint32_t fourcc) {
+  int i;
+
+  for (i = 0; i < get_aom_decoder_count(); ++i) {
+    const AvxInterface *const decoder = get_aom_decoder_by_index(i);
+    if (decoder->fourcc == fourcc) return decoder;
+  }
+
+  return NULL;
+}
+#endif  // CONFIG_AV1_DECODER
+
+void aom_img_write(const aom_image_t *img, FILE *file) {
+  int plane;
+
+  for (plane = 0; plane < 3; ++plane) {
+    const unsigned char *buf = img->planes[plane];
+    const int stride = img->stride[plane];
+    const int w = aom_img_plane_width(img, plane) *
+                  ((img->fmt & AOM_IMG_FMT_HIGHBITDEPTH) ? 2 : 1);
+    const int h = aom_img_plane_height(img, plane);
+    int y;
+
+    for (y = 0; y < h; ++y) {
+      fwrite(buf, 1, w, file);
+      buf += stride;
+    }
+  }
+}
+
+int aom_img_read(aom_image_t *img, FILE *file) {
+  int plane;
+
+  for (plane = 0; plane < 3; ++plane) {
+    unsigned char *buf = img->planes[plane];
+    const int stride = img->stride[plane];
+    const int w = aom_img_plane_width(img, plane) *
+                  ((img->fmt & AOM_IMG_FMT_HIGHBITDEPTH) ? 2 : 1);
+    const int h = aom_img_plane_height(img, plane);
+    int y;
+
+    for (y = 0; y < h; ++y) {
+      if (fread(buf, 1, w, file) != (size_t)w) return 0;
+      buf += stride;
+    }
+  }
+
+  return 1;
+}
+
+// TODO(dkovalev) change sse_to_psnr signature: double -> int64_t
+double sse_to_psnr(double samples, double peak, double sse) {
+  static const double kMaxPSNR = 100.0;
+
+  if (sse > 0.0) {
+    const double psnr = 10.0 * log10(samples * peak * peak / sse);
+    return psnr > kMaxPSNR ? kMaxPSNR : psnr;
+  } else {
+    return kMaxPSNR;
+  }
+}
+
+// TODO(debargha): Consolidate the functions below into a separate file.
+static void highbd_img_upshift(aom_image_t *dst, aom_image_t *src,
+                               int input_shift) {
+  // Note the offset is 1 less than half.
+  const int offset = input_shift > 0 ? (1 << (input_shift - 1)) - 1 : 0;
+  int plane;
+  if (dst->d_w != src->d_w || dst->d_h != src->d_h ||
+      dst->x_chroma_shift != src->x_chroma_shift ||
+      dst->y_chroma_shift != src->y_chroma_shift || dst->fmt != src->fmt ||
+      input_shift < 0) {
+    fatal("Unsupported image conversion");
+  }
+  switch (src->fmt) {
+    case AOM_IMG_FMT_I42016:
+    case AOM_IMG_FMT_I42216:
+    case AOM_IMG_FMT_I44416: break;
+    default: fatal("Unsupported image conversion"); break;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint16_t *p_src =
+          (uint16_t *)(src->planes[plane] + y * src->stride[plane]);
+      uint16_t *p_dst =
+          (uint16_t *)(dst->planes[plane] + y * dst->stride[plane]);
+      for (x = 0; x < w; x++) *p_dst++ = (*p_src++ << input_shift) + offset;
+    }
+  }
+}
+
+static void lowbd_img_upshift(aom_image_t *dst, aom_image_t *src,
+                              int input_shift) {
+  // Note the offset is 1 less than half.
+  const int offset = input_shift > 0 ? (1 << (input_shift - 1)) - 1 : 0;
+  int plane;
+  if (dst->d_w != src->d_w || dst->d_h != src->d_h ||
+      dst->x_chroma_shift != src->x_chroma_shift ||
+      dst->y_chroma_shift != src->y_chroma_shift ||
+      dst->fmt != src->fmt + AOM_IMG_FMT_HIGHBITDEPTH || input_shift < 0) {
+    fatal("Unsupported image conversion");
+  }
+  switch (src->fmt) {
+    case AOM_IMG_FMT_I420:
+    case AOM_IMG_FMT_I422:
+    case AOM_IMG_FMT_I444: break;
+    default: fatal("Unsupported image conversion"); break;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint8_t *p_src = src->planes[plane] + y * src->stride[plane];
+      uint16_t *p_dst =
+          (uint16_t *)(dst->planes[plane] + y * dst->stride[plane]);
+      for (x = 0; x < w; x++) {
+        *p_dst++ = (*p_src++ << input_shift) + offset;
+      }
+    }
+  }
+}
+
+void aom_img_upshift(aom_image_t *dst, aom_image_t *src, int input_shift) {
+  if (src->fmt & AOM_IMG_FMT_HIGHBITDEPTH) {
+    highbd_img_upshift(dst, src, input_shift);
+  } else {
+    lowbd_img_upshift(dst, src, input_shift);
+  }
+}
+
+void aom_img_truncate_16_to_8(aom_image_t *dst, aom_image_t *src) {
+  int plane;
+  if (dst->fmt + AOM_IMG_FMT_HIGHBITDEPTH != src->fmt || dst->d_w != src->d_w ||
+      dst->d_h != src->d_h || dst->x_chroma_shift != src->x_chroma_shift ||
+      dst->y_chroma_shift != src->y_chroma_shift) {
+    fatal("Unsupported image conversion");
+  }
+  switch (dst->fmt) {
+    case AOM_IMG_FMT_I420:
+    case AOM_IMG_FMT_I422:
+    case AOM_IMG_FMT_I444: break;
+    default: fatal("Unsupported image conversion"); break;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint16_t *p_src =
+          (uint16_t *)(src->planes[plane] + y * src->stride[plane]);
+      uint8_t *p_dst = dst->planes[plane] + y * dst->stride[plane];
+      for (x = 0; x < w; x++) {
+        *p_dst++ = (uint8_t)(*p_src++);
+      }
+    }
+  }
+}
+
+static void highbd_img_downshift(aom_image_t *dst, aom_image_t *src,
+                                 int down_shift) {
+  int plane;
+  if (dst->d_w != src->d_w || dst->d_h != src->d_h ||
+      dst->x_chroma_shift != src->x_chroma_shift ||
+      dst->y_chroma_shift != src->y_chroma_shift || dst->fmt != src->fmt ||
+      down_shift < 0) {
+    fatal("Unsupported image conversion");
+  }
+  switch (src->fmt) {
+    case AOM_IMG_FMT_I42016:
+    case AOM_IMG_FMT_I42216:
+    case AOM_IMG_FMT_I44416: break;
+    default: fatal("Unsupported image conversion"); break;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint16_t *p_src =
+          (uint16_t *)(src->planes[plane] + y * src->stride[plane]);
+      uint16_t *p_dst =
+          (uint16_t *)(dst->planes[plane] + y * dst->stride[plane]);
+      for (x = 0; x < w; x++) *p_dst++ = *p_src++ >> down_shift;
+    }
+  }
+}
+
+static void lowbd_img_downshift(aom_image_t *dst, aom_image_t *src,
+                                int down_shift) {
+  int plane;
+  if (dst->d_w != src->d_w || dst->d_h != src->d_h ||
+      dst->x_chroma_shift != src->x_chroma_shift ||
+      dst->y_chroma_shift != src->y_chroma_shift ||
+      src->fmt != dst->fmt + AOM_IMG_FMT_HIGHBITDEPTH || down_shift < 0) {
+    fatal("Unsupported image conversion");
+  }
+  switch (dst->fmt) {
+    case AOM_IMG_FMT_I420:
+    case AOM_IMG_FMT_I422:
+    case AOM_IMG_FMT_I444: break;
+    default: fatal("Unsupported image conversion"); break;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint16_t *p_src =
+          (uint16_t *)(src->planes[plane] + y * src->stride[plane]);
+      uint8_t *p_dst = dst->planes[plane] + y * dst->stride[plane];
+      for (x = 0; x < w; x++) {
+        *p_dst++ = *p_src++ >> down_shift;
+      }
+    }
+  }
+}
+
+void aom_img_downshift(aom_image_t *dst, aom_image_t *src, int down_shift) {
+  if (dst->fmt & AOM_IMG_FMT_HIGHBITDEPTH) {
+    highbd_img_downshift(dst, src, down_shift);
+  } else {
+    lowbd_img_downshift(dst, src, down_shift);
+  }
+}
diff --git a/third_party/aom/common/tools_common.h b/third_party/aom/common/tools_common.h
new file mode 100644
index 000000000..abee4ea63
--- /dev/null
+++ b/third_party/aom/common/tools_common.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef TOOLS_COMMON_H_
+#define TOOLS_COMMON_H_
+
+#include <stdio.h>
+
+#include "config/aom_config.h"
+
+#include "aom/aom_codec.h"
+#include "aom/aom_image.h"
+#include "aom/aom_integer.h"
+#include "aom_ports/msvc.h"
+
+#if CONFIG_AV1_ENCODER
+#include "common/y4minput.h"
+#endif
+
+#if defined(_MSC_VER)
+/* MSVS uses _f{seek,tell}i64. */
+#define fseeko _fseeki64
+#define ftello _ftelli64
+typedef int64_t FileOffset;
+#elif defined(_WIN32)
+#include <sys/types.h> /* NOLINT*/
+/* MinGW uses f{seek,tell}o64 for large files. */
+#define fseeko fseeko64
+#define ftello ftello64
+typedef off64_t FileOffset;
+#elif CONFIG_OS_SUPPORT
+#include <sys/types.h> /* NOLINT*/
+typedef off_t FileOffset;
+/* Use 32-bit file operations in WebM file format when building ARM
+ * executables (.axf) with RVCT. */
+#else
+#define fseeko fseek
+#define ftello ftell
+typedef long FileOffset; /* NOLINT */
+#endif /* CONFIG_OS_SUPPORT */
+
+#if CONFIG_OS_SUPPORT
+#if defined(_MSC_VER)
+#include <io.h> /* NOLINT */
+#define isatty _isatty
+#define fileno _fileno
+#else
+#include <unistd.h> /* NOLINT */
+#endif              /* _MSC_VER */
+#endif              /* CONFIG_OS_SUPPORT */
+
+#define LITERALU64(hi, lo) ((((uint64_t)hi) << 32) | lo)
+
+#ifndef PATH_MAX
+#define PATH_MAX 512
+#endif
+
+#define IVF_FRAME_HDR_SZ (4 + 8) /* 4 byte size + 8 byte timestamp */
+#define IVF_FILE_HDR_SZ 32
+
+#define RAW_FRAME_HDR_SZ sizeof(uint32_t)
+
+#define AV1_FOURCC 0x31305641
+
+enum VideoFileType {
+  FILE_TYPE_OBU,
+  FILE_TYPE_RAW,
+  FILE_TYPE_IVF,
+  FILE_TYPE_Y4M,
+  FILE_TYPE_WEBM
+};
+
+struct FileTypeDetectionBuffer {
+  char buf[4];
+  size_t buf_read;
+  size_t position;
+};
+
+struct AvxRational {
+  int numerator;
+  int denominator;
+};
+
+struct AvxInputContext {
+  const char *filename;
+  FILE *file;
+  int64_t length;
+  struct FileTypeDetectionBuffer detect;
+  enum VideoFileType file_type;
+  uint32_t width;
+  uint32_t height;
+  struct AvxRational pixel_aspect_ratio;
+  aom_img_fmt_t fmt;
+  aom_bit_depth_t bit_depth;
+  int only_i420;
+  uint32_t fourcc;
+  struct AvxRational framerate;
+#if CONFIG_AV1_ENCODER
+  y4m_input y4m;
+#endif
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(__GNUC__)
+#define AOM_NO_RETURN __attribute__((noreturn))
+#else
+#define AOM_NO_RETURN
+#endif
+
+/* Sets a stdio stream into binary mode */
+FILE *set_binary_mode(FILE *stream);
+
+void die(const char *fmt, ...) AOM_NO_RETURN;
+void fatal(const char *fmt, ...) AOM_NO_RETURN;
+void warn(const char *fmt, ...);
+
+void die_codec(aom_codec_ctx_t *ctx, const char *s) AOM_NO_RETURN;
+
+/* The tool including this file must define usage_exit() */
+void usage_exit(void) AOM_NO_RETURN;
+
+#undef AOM_NO_RETURN
+
+int read_yuv_frame(struct AvxInputContext *input_ctx, aom_image_t *yuv_frame);
+
+typedef struct AvxInterface {
+  const char *const name;
+  const uint32_t fourcc;
+  aom_codec_iface_t *(*const codec_interface)();
+} AvxInterface;
+
+int get_aom_encoder_count(void);
+const AvxInterface *get_aom_encoder_by_index(int i);
+const AvxInterface *get_aom_encoder_by_name(const char *name);
+
+int get_aom_decoder_count(void);
+const AvxInterface *get_aom_decoder_by_index(int i);
+const AvxInterface *get_aom_decoder_by_name(const char *name);
+const AvxInterface *get_aom_decoder_by_fourcc(uint32_t fourcc);
+
+void aom_img_write(const aom_image_t *img, FILE *file);
+int aom_img_read(aom_image_t *img, FILE *file);
+
+double sse_to_psnr(double samples, double peak, double mse);
+void aom_img_upshift(aom_image_t *dst, aom_image_t *src, int input_shift);
+void aom_img_downshift(aom_image_t *dst, aom_image_t *src, int down_shift);
+void aom_img_truncate_16_to_8(aom_image_t *dst, aom_image_t *src);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif  // TOOLS_COMMON_H_
diff --git a/third_party/aom/common/video_common.h b/third_party/aom/common/video_common.h
new file mode 100644
index 000000000..f96af4b7e
--- /dev/null
+++ b/third_party/aom/common/video_common.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef VIDEO_COMMON_H_
+#define VIDEO_COMMON_H_
+
+#include "common/tools_common.h"
+
+typedef struct {
+  uint32_t codec_fourcc;
+  int frame_width;
+  int frame_height;
+  struct AvxRational time_base;
+} AvxVideoInfo;
+
+#endif  // VIDEO_COMMON_H_
diff --git a/third_party/aom/common/video_reader.c b/third_party/aom/common/video_reader.c
new file mode 100644
index 000000000..f5327c928
--- /dev/null
+++ b/third_party/aom/common/video_reader.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#include "common/video_reader.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "aom_ports/mem_ops.h"
+#include "common/ivfdec.h"
+
+static const char *const kIVFSignature = "DKIF";
+
+struct AvxVideoReaderStruct {
+  AvxVideoInfo info;
+  FILE *file;
+  uint8_t *buffer;
+  size_t buffer_size;
+  size_t frame_size;
+  aom_codec_pts_t pts;
+};
+
+AvxVideoReader *aom_video_reader_open(const char *filename) {
+  char header[32];
+  AvxVideoReader *reader = NULL;
+  FILE *const file = fopen(filename, "rb");
+  if (!file) return NULL;  // Can't open file
+
+  if (fread(header, 1, 32, file) != 32) return NULL;  // Can't read file header
+
+  if (memcmp(kIVFSignature, header, 4) != 0)
+    return NULL;  // Wrong IVF signature
+
+  if (mem_get_le16(header + 4) != 0) return NULL;  // Wrong IVF version
+
+  reader = (AvxVideoReader *)calloc(1, sizeof(*reader));
+  if (!reader) return NULL;  // Can't allocate AvxVideoReader
+
+  reader->file = file;
+  reader->info.codec_fourcc = mem_get_le32(header + 8);
+  reader->info.frame_width = mem_get_le16(header + 12);
+  reader->info.frame_height = mem_get_le16(header + 14);
+  reader->info.time_base.numerator = mem_get_le32(header + 16);
+  reader->info.time_base.denominator = mem_get_le32(header + 20);
+
+  return reader;
+}
+
+void aom_video_reader_close(AvxVideoReader *reader) {
+  if (reader) {
+    fclose(reader->file);
+    free(reader->buffer);
+    free(reader);
+  }
+}
+
+int aom_video_reader_read_frame(AvxVideoReader *reader) {
+  return !ivf_read_frame(reader->file, &reader->buffer, &reader->frame_size,
+                         &reader->buffer_size, &reader->pts);
+}
+
+const uint8_t *aom_video_reader_get_frame(AvxVideoReader *reader,
+                                          size_t *size) {
+  if (size) *size = reader->frame_size;
+
+  return reader->buffer;
+}
+
+int64_t aom_video_reader_get_frame_pts(AvxVideoReader *reader) {
+  return (int64_t)reader->pts;
+}
+
+FILE *aom_video_reader_get_file(AvxVideoReader *reader) { return reader->file; }
+
+const AvxVideoInfo *aom_video_reader_get_info(AvxVideoReader *reader) {
+  return &reader->info;
+}
diff --git a/third_party/aom/common/video_reader.h b/third_party/aom/common/video_reader.h
new file mode 100644
index 000000000..1eb33831a
--- /dev/null
+++ b/third_party/aom/common/video_reader.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef VIDEO_READER_H_
+#define VIDEO_READER_H_
+
+#include "common/video_common.h"
+
+// The following code is work in progress. It is going to  support transparent
+// reading of input files. Right now only IVF format is supported for
+// simplicity. The main goal the API is to be simple and easy to use in example
+// code and in aomenc/aomdec later. All low-level details like memory
+// buffer management are hidden from API users.
+struct AvxVideoReaderStruct;
+typedef struct AvxVideoReaderStruct AvxVideoReader;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Opens the input file for reading and inspects it to determine file type.
+// Returns an opaque AvxVideoReader* upon success, or NULL upon failure.
+// Right now only IVF format is supported.
+AvxVideoReader *aom_video_reader_open(const char *filename);
+
+// Frees all resources associated with AvxVideoReader* returned from
+// aom_video_reader_open() call.
+void aom_video_reader_close(AvxVideoReader *reader);
+
+// Reads frame from the file and stores it in internal buffer.
+int aom_video_reader_read_frame(AvxVideoReader *reader);
+
+// Returns the pointer to memory buffer with frame data read by last call to
+// aom_video_reader_read_frame().
+const uint8_t *aom_video_reader_get_frame(AvxVideoReader *reader, size_t *size);
+
+// Returns the pts of the frame.
+int64_t aom_video_reader_get_frame_pts(AvxVideoReader *reader);
+// Return the reader file.
+FILE *aom_video_reader_get_file(AvxVideoReader *reader);
+
+// Fills AvxVideoInfo with information from opened video file.
+const AvxVideoInfo *aom_video_reader_get_info(AvxVideoReader *reader);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VIDEO_READER_H_
diff --git a/third_party/aom/common/video_writer.c b/third_party/aom/common/video_writer.c
new file mode 100644
index 000000000..a7ec309fc
--- /dev/null
+++ b/third_party/aom/common/video_writer.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#include "common/video_writer.h"
+
+#include <stdlib.h>
+
+#include "aom/aom_encoder.h"
+#include "common/ivfenc.h"
+
+struct AvxVideoWriterStruct {
+  AvxVideoInfo info;
+  FILE *file;
+  int frame_count;
+};
+
+static void write_header(FILE *file, const AvxVideoInfo *info,
+                         int frame_count) {
+  struct aom_codec_enc_cfg cfg;
+  cfg.g_w = info->frame_width;
+  cfg.g_h = info->frame_height;
+  cfg.g_timebase.num = info->time_base.numerator;
+  cfg.g_timebase.den = info->time_base.denominator;
+
+  ivf_write_file_header(file, &cfg, info->codec_fourcc, frame_count);
+}
+
+AvxVideoWriter *aom_video_writer_open(const char *filename,
+                                      AvxContainer container,
+                                      const AvxVideoInfo *info) {
+  if (container == kContainerIVF) {
+    AvxVideoWriter *writer = NULL;
+    FILE *const file = fopen(filename, "wb");
+    if (!file) return NULL;
+
+    writer = malloc(sizeof(*writer));
+    if (!writer) return NULL;
+
+    writer->frame_count = 0;
+    writer->info = *info;
+    writer->file = file;
+
+    write_header(writer->file, info, 0);
+
+    return writer;
+  }
+
+  return NULL;
+}
+
+void aom_video_writer_close(AvxVideoWriter *writer) {
+  if (writer) {
+    // Rewriting frame header with real frame count
+    rewind(writer->file);
+    write_header(writer->file, &writer->info, writer->frame_count);
+
+    fclose(writer->file);
+    free(writer);
+  }
+}
+
+int aom_video_writer_write_frame(AvxVideoWriter *writer, const uint8_t *buffer,
+                                 size_t size, int64_t pts) {
+  ivf_write_frame_header(writer->file, pts, size);
+  if (fwrite(buffer, 1, size, writer->file) != size) return 0;
+
+  ++writer->frame_count;
+
+  return 1;
+}
diff --git a/third_party/aom/common/video_writer.h b/third_party/aom/common/video_writer.h
new file mode 100644
index 000000000..16655d3a6
--- /dev/null
+++ b/third_party/aom/common/video_writer.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef VIDEO_WRITER_H_
+#define VIDEO_WRITER_H_
+
+#include "common/video_common.h"
+
+typedef enum { kContainerIVF } AvxContainer;
+
+struct AvxVideoWriterStruct;
+typedef struct AvxVideoWriterStruct AvxVideoWriter;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Finds and opens writer for specified container format.
+// Returns an opaque AvxVideoWriter* upon success, or NULL upon failure.
+// Right now only IVF format is supported.
+AvxVideoWriter *aom_video_writer_open(const char *filename,
+                                      AvxContainer container,
+                                      const AvxVideoInfo *info);
+
+// Frees all resources associated with AvxVideoWriter* returned from
+// aom_video_writer_open() call.
+void aom_video_writer_close(AvxVideoWriter *writer);
+
+// Writes frame bytes to the file.
+int aom_video_writer_write_frame(AvxVideoWriter *writer, const uint8_t *buffer,
+                                 size_t size, int64_t pts);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VIDEO_WRITER_H_
diff --git a/third_party/aom/common/warnings.c b/third_party/aom/common/warnings.c
new file mode 100644
index 000000000..2facee252
--- /dev/null
+++ b/third_party/aom/common/warnings.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/warnings.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aom/aom_encoder.h"
+#include "apps/aomenc.h"
+#include "common/tools_common.h"
+
+static const char quantizer_warning_string[] =
+    "Bad quantizer values. Quantizer values should not be equal, and should "
+    "differ by at least 8.";
+
+struct WarningListNode {
+  const char *warning_string;
+  struct WarningListNode *next_warning;
+};
+
+struct WarningList {
+  struct WarningListNode *warning_node;
+};
+
+static void add_warning(const char *warning_string,
+                        struct WarningList *warning_list) {
+  struct WarningListNode **node = &warning_list->warning_node;
+
+  struct WarningListNode *new_node = malloc(sizeof(*new_node));
+  if (new_node == NULL) {
+    fatal("Unable to allocate warning node.");
+  }
+
+  new_node->warning_string = warning_string;
+  new_node->next_warning = NULL;
+
+  while (*node != NULL) node = &(*node)->next_warning;
+
+  *node = new_node;
+}
+
+static void free_warning_list(struct WarningList *warning_list) {
+  while (warning_list->warning_node != NULL) {
+    struct WarningListNode *const node = warning_list->warning_node;
+    warning_list->warning_node = node->next_warning;
+    free(node);
+  }
+}
+
+static int continue_prompt(int num_warnings) {
+  int c;
+  fprintf(stderr,
+          "%d encoder configuration warning(s). Continue? (y to continue) ",
+          num_warnings);
+  c = getchar();
+  return c == 'y';
+}
+
+static void check_quantizer(int min_q, int max_q,
+                            struct WarningList *warning_list) {
+  const int lossless = min_q == 0 && max_q == 0;
+  if (!lossless && (min_q == max_q || abs(max_q - min_q) < 8))
+    add_warning(quantizer_warning_string, warning_list);
+}
+
+void check_encoder_config(int disable_prompt,
+                          const struct AvxEncoderConfig *global_config,
+                          const struct aom_codec_enc_cfg *stream_config) {
+  int num_warnings = 0;
+  struct WarningListNode *warning = NULL;
+  struct WarningList warning_list = { 0 };
+  (void)global_config;
+  check_quantizer(stream_config->rc_min_quantizer,
+                  stream_config->rc_max_quantizer, &warning_list);
+  /* Count and print warnings. */
+  for (warning = warning_list.warning_node; warning != NULL;
+       warning = warning->next_warning, ++num_warnings) {
+    warn(warning->warning_string);
+  }
+
+  free_warning_list(&warning_list);
+
+  if (num_warnings) {
+    if (!disable_prompt && !continue_prompt(num_warnings)) exit(EXIT_FAILURE);
+  }
+}
diff --git a/third_party/aom/common/warnings.h b/third_party/aom/common/warnings.h
new file mode 100644
index 000000000..61db2dcf8
--- /dev/null
+++ b/third_party/aom/common/warnings.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef WARNINGS_H_
+#define WARNINGS_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct aom_codec_enc_cfg;
+struct AvxEncoderConfig;
+
+/*
+ * Checks config for improperly used settings. Warns user upon encountering
+ * settings that will lead to poor output quality. Prompts user to continue
+ * when warnings are issued.
+ */
+void check_encoder_config(int disable_prompt,
+                          const struct AvxEncoderConfig *global_config,
+                          const struct aom_codec_enc_cfg *stream_config);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // WARNINGS_H_
diff --git a/third_party/aom/common/webmdec.cc b/third_party/aom/common/webmdec.cc
new file mode 100644
index 000000000..17ac53c93
--- /dev/null
+++ b/third_party/aom/common/webmdec.cc
@@ -0,0 +1,229 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/webmdec.h"
+
+#include <cassert>
+#include <cstring>
+#include <cstdio>
+
+#include "third_party/libwebm/mkvparser/mkvparser.h"
+#include "third_party/libwebm/mkvparser/mkvreader.h"
+
+namespace {
+
+void reset(struct WebmInputContext *const webm_ctx) {
+  if (webm_ctx->reader != NULL) {
+    mkvparser::MkvReader *const reader =
+        reinterpret_cast<mkvparser::MkvReader *>(webm_ctx->reader);
+    delete reader;
+  }
+  if (webm_ctx->segment != NULL) {
+    mkvparser::Segment *const segment =
+        reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment);
+    delete segment;
+  }
+  if (webm_ctx->buffer != NULL) {
+    delete[] webm_ctx->buffer;
+  }
+  webm_ctx->reader = NULL;
+  webm_ctx->segment = NULL;
+  webm_ctx->buffer = NULL;
+  webm_ctx->cluster = NULL;
+  webm_ctx->block_entry = NULL;
+  webm_ctx->block = NULL;
+  webm_ctx->block_frame_index = 0;
+  webm_ctx->video_track_index = 0;
+  webm_ctx->timestamp_ns = 0;
+  webm_ctx->is_key_frame = false;
+}
+
+void get_first_cluster(struct WebmInputContext *const webm_ctx) {
+  mkvparser::Segment *const segment =
+      reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment);
+  const mkvparser::Cluster *const cluster = segment->GetFirst();
+  webm_ctx->cluster = cluster;
+}
+
+void rewind_and_reset(struct WebmInputContext *const webm_ctx,
+                      struct AvxInputContext *const aom_ctx) {
+  rewind(aom_ctx->file);
+  reset(webm_ctx);
+}
+
+}  // namespace
+
+int file_is_webm(struct WebmInputContext *webm_ctx,
+                 struct AvxInputContext *aom_ctx) {
+  mkvparser::MkvReader *const reader = new mkvparser::MkvReader(aom_ctx->file);
+  webm_ctx->reader = reader;
+  webm_ctx->reached_eos = 0;
+
+  mkvparser::EBMLHeader header;
+  long long pos = 0;
+  if (header.Parse(reader, pos) < 0) {
+    rewind_and_reset(webm_ctx, aom_ctx);
+    return 0;
+  }
+
+  mkvparser::Segment *segment;
+  if (mkvparser::Segment::CreateInstance(reader, pos, segment)) {
+    rewind_and_reset(webm_ctx, aom_ctx);
+    return 0;
+  }
+  webm_ctx->segment = segment;
+  if (segment->Load() < 0) {
+    rewind_and_reset(webm_ctx, aom_ctx);
+    return 0;
+  }
+
+  const mkvparser::Tracks *const tracks = segment->GetTracks();
+  const mkvparser::VideoTrack *video_track = NULL;
+  for (unsigned long i = 0; i < tracks->GetTracksCount(); ++i) {
+    const mkvparser::Track *const track = tracks->GetTrackByIndex(i);
+    if (track->GetType() == mkvparser::Track::kVideo) {
+      video_track = static_cast<const mkvparser::VideoTrack *>(track);
+      webm_ctx->video_track_index = static_cast<int>(track->GetNumber());
+      break;
+    }
+  }
+
+  if (video_track == NULL || video_track->GetCodecId() == NULL) {
+    rewind_and_reset(webm_ctx, aom_ctx);
+    return 0;
+  }
+
+  if (!strncmp(video_track->GetCodecId(), "V_AV1", 5)) {
+    aom_ctx->fourcc = AV1_FOURCC;
+  } else {
+    rewind_and_reset(webm_ctx, aom_ctx);
+    return 0;
+  }
+
+  aom_ctx->framerate.denominator = 0;
+  aom_ctx->framerate.numerator = 0;
+  aom_ctx->width = static_cast<uint32_t>(video_track->GetWidth());
+  aom_ctx->height = static_cast<uint32_t>(video_track->GetHeight());
+
+  get_first_cluster(webm_ctx);
+
+  return 1;
+}
+
+int webm_read_frame(struct WebmInputContext *webm_ctx, uint8_t **buffer,
+                    size_t *bytes_read, size_t *buffer_size) {
+  assert(webm_ctx->buffer == *buffer);
+  // This check is needed for frame parallel decoding, in which case this
+  // function could be called even after it has reached end of input stream.
+  if (webm_ctx->reached_eos) {
+    return 1;
+  }
+  mkvparser::Segment *const segment =
+      reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment);
+  const mkvparser::Cluster *cluster =
+      reinterpret_cast<const mkvparser::Cluster *>(webm_ctx->cluster);
+  const mkvparser::Block *block =
+      reinterpret_cast<const mkvparser::Block *>(webm_ctx->block);
+  const mkvparser::BlockEntry *block_entry =
+      reinterpret_cast<const mkvparser::BlockEntry *>(webm_ctx->block_entry);
+  bool block_entry_eos = false;
+  do {
+    long status = 0;
+    bool get_new_block = false;
+    if (block_entry == NULL && !block_entry_eos) {
+      status = cluster->GetFirst(block_entry);
+      get_new_block = true;
+    } else if (block_entry_eos || block_entry->EOS()) {
+      cluster = segment->GetNext(cluster);
+      if (cluster == NULL || cluster->EOS()) {
+        *bytes_read = 0;
+        webm_ctx->reached_eos = 1;
+        return 1;
+      }
+      status = cluster->GetFirst(block_entry);
+      block_entry_eos = false;
+      get_new_block = true;
+    } else if (block == NULL ||
+               webm_ctx->block_frame_index == block->GetFrameCount() ||
+               block->GetTrackNumber() != webm_ctx->video_track_index) {
+      status = cluster->GetNext(block_entry, block_entry);
+      if (block_entry == NULL || block_entry->EOS()) {
+        block_entry_eos = true;
+        continue;
+      }
+      get_new_block = true;
+    }
+    if (status || block_entry == NULL) {
+      return -1;
+    }
+    if (get_new_block) {
+      block = block_entry->GetBlock();
+      if (block == NULL) return -1;
+      webm_ctx->block_frame_index = 0;
+    }
+  } while (block_entry_eos ||
+           block->GetTrackNumber() != webm_ctx->video_track_index);
+
+  webm_ctx->cluster = cluster;
+  webm_ctx->block_entry = block_entry;
+  webm_ctx->block = block;
+
+  const mkvparser::Block::Frame &frame =
+      block->GetFrame(webm_ctx->block_frame_index);
+  ++webm_ctx->block_frame_index;
+  if (frame.len > static_cast<long>(*buffer_size)) {
+    delete[] * buffer;
+    *buffer = new uint8_t[frame.len];
+    webm_ctx->buffer = *buffer;
+    if (*buffer == NULL) {
+      return -1;
+    }
+    *buffer_size = frame.len;
+  }
+  *bytes_read = frame.len;
+  webm_ctx->timestamp_ns = block->GetTime(cluster);
+  webm_ctx->is_key_frame = block->IsKey();
+
+  mkvparser::MkvReader *const reader =
+      reinterpret_cast<mkvparser::MkvReader *>(webm_ctx->reader);
+  return frame.Read(reader, *buffer) ? -1 : 0;
+}
+
+int webm_guess_framerate(struct WebmInputContext *webm_ctx,
+                         struct AvxInputContext *aom_ctx) {
+  uint32_t i = 0;
+  uint8_t *buffer = NULL;
+  size_t buffer_size = 0;
+  size_t bytes_read = 0;
+  assert(webm_ctx->buffer == NULL);
+  while (webm_ctx->timestamp_ns < 1000000000 && i < 50) {
+    if (webm_read_frame(webm_ctx, &buffer, &bytes_read, &buffer_size)) {
+      break;
+    }
+    ++i;
+  }
+  aom_ctx->framerate.numerator = (i - 1) * 1000000;
+  aom_ctx->framerate.denominator =
+      static_cast<int>(webm_ctx->timestamp_ns / 1000);
+  delete[] buffer;
+  webm_ctx->buffer = NULL;
+
+  get_first_cluster(webm_ctx);
+  webm_ctx->block = NULL;
+  webm_ctx->block_entry = NULL;
+  webm_ctx->block_frame_index = 0;
+  webm_ctx->timestamp_ns = 0;
+  webm_ctx->reached_eos = 0;
+
+  return 0;
+}
+
+void webm_free(struct WebmInputContext *webm_ctx) { reset(webm_ctx); }
diff --git a/third_party/aom/common/webmdec.h b/third_party/aom/common/webmdec.h
new file mode 100644
index 000000000..d5b472a01
--- /dev/null
+++ b/third_party/aom/common/webmdec.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef WEBMDEC_H_
+#define WEBMDEC_H_
+
+#include "common/tools_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct AvxInputContext;
+
+struct WebmInputContext {
+  void *reader;
+  void *segment;
+  uint8_t *buffer;
+  const void *cluster;
+  const void *block_entry;
+  const void *block;
+  int block_frame_index;
+  int video_track_index;
+  uint64_t timestamp_ns;
+  int is_key_frame;
+  int reached_eos;
+};
+
+// Checks if the input is a WebM file. If so, initializes WebMInputContext so
+// that webm_read_frame can be called to retrieve a video frame.
+// Returns 1 on success and 0 on failure or input is not WebM file.
+// TODO(vigneshv): Refactor this function into two smaller functions specific
+// to their task.
+int file_is_webm(struct WebmInputContext *webm_ctx,
+                 struct AvxInputContext *aom_ctx);
+
+// Reads a WebM Video Frame. Memory for the buffer is created, owned and managed
+// by this function. For the first call, |buffer| should be NULL and
+// |*buffer_size| should be 0. Once all the frames are read and used,
+// webm_free() should be called, otherwise there will be a leak.
+// Parameters:
+//      webm_ctx - WebmInputContext object
+//      buffer - pointer where the frame data will be filled.
+//      bytes_read - pointer to bytes read.
+//      buffer_size - pointer to buffer size.
+// Return values:
+//      0 - Success
+//      1 - End of Stream
+//     -1 - Error
+int webm_read_frame(struct WebmInputContext *webm_ctx, uint8_t **buffer,
+                    size_t *bytes_read, size_t *buffer_size);
+
+// Guesses the frame rate of the input file based on the container timestamps.
+int webm_guess_framerate(struct WebmInputContext *webm_ctx,
+                         struct AvxInputContext *aom_ctx);
+
+// Resets the WebMInputContext.
+void webm_free(struct WebmInputContext *webm_ctx);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // WEBMDEC_H_
diff --git a/third_party/aom/common/webmenc.cc b/third_party/aom/common/webmenc.cc
new file mode 100644
index 000000000..58ab33670
--- /dev/null
+++ b/third_party/aom/common/webmenc.cc
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "common/webmenc.h"
+
+#include <string>
+
+#include "third_party/libwebm/mkvmuxer/mkvmuxer.h"
+#include "third_party/libwebm/mkvmuxer/mkvmuxerutil.h"
+#include "third_party/libwebm/mkvmuxer/mkvwriter.h"
+
+namespace {
+const uint64_t kDebugTrackUid = 0xDEADBEEF;
+const int kVideoTrackNumber = 1;
+}  // namespace
+
+void write_webm_file_header(struct WebmOutputContext *webm_ctx,
+                            const aom_codec_enc_cfg_t *cfg,
+                            stereo_format_t stereo_fmt, unsigned int fourcc,
+                            const struct AvxRational *par) {
+  mkvmuxer::MkvWriter *const writer = new mkvmuxer::MkvWriter(webm_ctx->stream);
+  mkvmuxer::Segment *const segment = new mkvmuxer::Segment();
+  segment->Init(writer);
+  segment->set_mode(mkvmuxer::Segment::kFile);
+  segment->OutputCues(true);
+
+  mkvmuxer::SegmentInfo *const info = segment->GetSegmentInfo();
+  const uint64_t kTimecodeScale = 1000000;
+  info->set_timecode_scale(kTimecodeScale);
+  std::string version = "aomenc";
+  if (!webm_ctx->debug) {
+    version.append(std::string(" ") + aom_codec_version_str());
+  }
+  info->set_writing_app(version.c_str());
+
+  const uint64_t video_track_id =
+      segment->AddVideoTrack(static_cast<int>(cfg->g_w),
+                             static_cast<int>(cfg->g_h), kVideoTrackNumber);
+  mkvmuxer::VideoTrack *const video_track = static_cast<mkvmuxer::VideoTrack *>(
+      segment->GetTrackByNumber(video_track_id));
+  video_track->SetStereoMode(stereo_fmt);
+  const char *codec_id;
+  switch (fourcc) {
+    case AV1_FOURCC: codec_id = "V_AV1"; break;
+    default: codec_id = "V_AV1"; break;
+  }
+  video_track->set_codec_id(codec_id);
+  if (par->numerator > 1 || par->denominator > 1) {
+    // TODO(fgalligan): Add support of DisplayUnit, Display Aspect Ratio type
+    // to WebM format.
+    const uint64_t display_width = static_cast<uint64_t>(
+        ((cfg->g_w * par->numerator * 1.0) / par->denominator) + .5);
+    video_track->set_display_width(display_width);
+    video_track->set_display_height(cfg->g_h);
+  }
+  if (webm_ctx->debug) {
+    video_track->set_uid(kDebugTrackUid);
+  }
+  webm_ctx->writer = writer;
+  webm_ctx->segment = segment;
+}
+
+void write_webm_block(struct WebmOutputContext *webm_ctx,
+                      const aom_codec_enc_cfg_t *cfg,
+                      const aom_codec_cx_pkt_t *pkt) {
+  mkvmuxer::Segment *const segment =
+      reinterpret_cast<mkvmuxer::Segment *>(webm_ctx->segment);
+  int64_t pts_ns = pkt->data.frame.pts * 1000000000ll * cfg->g_timebase.num /
+                   cfg->g_timebase.den;
+  if (pts_ns <= webm_ctx->last_pts_ns) pts_ns = webm_ctx->last_pts_ns + 1000000;
+  webm_ctx->last_pts_ns = pts_ns;
+
+  segment->AddFrame(static_cast<uint8_t *>(pkt->data.frame.buf),
+                    pkt->data.frame.sz, kVideoTrackNumber, pts_ns,
+                    pkt->data.frame.flags & AOM_FRAME_IS_KEY);
+}
+
+void write_webm_file_footer(struct WebmOutputContext *webm_ctx) {
+  mkvmuxer::MkvWriter *const writer =
+      reinterpret_cast<mkvmuxer::MkvWriter *>(webm_ctx->writer);
+  mkvmuxer::Segment *const segment =
+      reinterpret_cast<mkvmuxer::Segment *>(webm_ctx->segment);
+  segment->Finalize();
+  delete segment;
+  delete writer;
+  webm_ctx->writer = NULL;
+  webm_ctx->segment = NULL;
+}
diff --git a/third_party/aom/common/webmenc.h b/third_party/aom/common/webmenc.h
new file mode 100644
index 000000000..74387fb8d
--- /dev/null
+++ b/third_party/aom/common/webmenc.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+#ifndef WEBMENC_H_
+#define WEBMENC_H_
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "tools_common.h"
+#include "aom/aom_encoder.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct WebmOutputContext {
+  int debug;
+  FILE *stream;
+  int64_t last_pts_ns;
+  void *writer;
+  void *segment;
+};
+
+/* Stereo 3D packed frame format */
+typedef enum stereo_format {
+  STEREO_FORMAT_MONO = 0,
+  STEREO_FORMAT_LEFT_RIGHT = 1,
+  STEREO_FORMAT_BOTTOM_TOP = 2,
+  STEREO_FORMAT_TOP_BOTTOM = 3,
+  STEREO_FORMAT_RIGHT_LEFT = 11
+} stereo_format_t;
+
+void write_webm_file_header(struct WebmOutputContext *webm_ctx,
+                            const aom_codec_enc_cfg_t *cfg,
+                            stereo_format_t stereo_fmt, unsigned int fourcc,
+                            const struct AvxRational *par);
+
+void write_webm_block(struct WebmOutputContext *webm_ctx,
+                      const aom_codec_enc_cfg_t *cfg,
+                      const aom_codec_cx_pkt_t *pkt);
+
+void write_webm_file_footer(struct WebmOutputContext *webm_ctx);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // WEBMENC_H_
diff --git a/third_party/aom/common/y4menc.c b/third_party/aom/common/y4menc.c
new file mode 100644
index 000000000..d33d0313e
--- /dev/null
+++ b/third_party/aom/common/y4menc.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <assert.h>
+
+#include "common/y4menc.h"
+
+int y4m_write_file_header(char *buf, size_t len, int width, int height,
+                          const struct AvxRational *framerate,
+                          aom_img_fmt_t fmt, unsigned int bit_depth) {
+  const char *color;
+  switch (bit_depth) {
+    case 8:
+      color = fmt == AOM_IMG_FMT_444A
+                  ? "C444alpha\n"
+                  : fmt == AOM_IMG_FMT_I444
+                        ? "C444\n"
+                        : fmt == AOM_IMG_FMT_I422 ? "C422\n" : "C420jpeg\n";
+      break;
+    case 9:
+      color = fmt == AOM_IMG_FMT_I44416
+                  ? "C444p9 XYSCSS=444P9\n"
+                  : fmt == AOM_IMG_FMT_I42216 ? "C422p9 XYSCSS=422P9\n"
+                                              : "C420p9 XYSCSS=420P9\n";
+      break;
+    case 10:
+      color = fmt == AOM_IMG_FMT_I44416
+                  ? "C444p10 XYSCSS=444P10\n"
+                  : fmt == AOM_IMG_FMT_I42216 ? "C422p10 XYSCSS=422P10\n"
+                                              : "C420p10 XYSCSS=420P10\n";
+      break;
+    case 12:
+      color = fmt == AOM_IMG_FMT_I44416
+                  ? "C444p12 XYSCSS=444P12\n"
+                  : fmt == AOM_IMG_FMT_I42216 ? "C422p12 XYSCSS=422P12\n"
+                                              : "C420p12 XYSCSS=420P12\n";
+      break;
+    case 14:
+      color = fmt == AOM_IMG_FMT_I44416
+                  ? "C444p14 XYSCSS=444P14\n"
+                  : fmt == AOM_IMG_FMT_I42216 ? "C422p14 XYSCSS=422P14\n"
+                                              : "C420p14 XYSCSS=420P14\n";
+      break;
+    case 16:
+      color = fmt == AOM_IMG_FMT_I44416
+                  ? "C444p16 XYSCSS=444P16\n"
+                  : fmt == AOM_IMG_FMT_I42216 ? "C422p16 XYSCSS=422P16\n"
+                                              : "C420p16 XYSCSS=420P16\n";
+      break;
+    default: color = NULL; assert(0);
+  }
+  return snprintf(buf, len, "YUV4MPEG2 W%u H%u F%u:%u I%c %s", width, height,
+                  framerate->numerator, framerate->denominator, 'p', color);
+}
+
+int y4m_write_frame_header(char *buf, size_t len) {
+  return snprintf(buf, len, "FRAME\n");
+}
diff --git a/third_party/aom/common/y4menc.h b/third_party/aom/common/y4menc.h
new file mode 100644
index 000000000..6344176ba
--- /dev/null
+++ b/third_party/aom/common/y4menc.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef Y4MENC_H_
+#define Y4MENC_H_
+
+#include "aom/aom_decoder.h"
+#include "common/tools_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define Y4M_BUFFER_SIZE 128
+
+int y4m_write_file_header(char *buf, size_t len, int width, int height,
+                          const struct AvxRational *framerate,
+                          aom_img_fmt_t fmt, unsigned int bit_depth);
+int y4m_write_frame_header(char *buf, size_t len);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // Y4MENC_H_
diff --git a/third_party/aom/common/y4minput.c b/third_party/aom/common/y4minput.c
new file mode 100644
index 000000000..a1dca10cd
--- /dev/null
+++ b/third_party/aom/common/y4minput.c
@@ -0,0 +1,1142 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ *
+ * Based on code from the OggTheora software codec source code,
+ * Copyright (C) 2002-2010 The Xiph.Org Foundation and contributors.
+ */
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aom/aom_integer.h"
+#include "y4minput.h"
+
+// Reads 'size' bytes from 'file' into 'buf' with some fault tolerance.
+// Returns true on success.
+static int file_read(void *buf, size_t size, FILE *file) {
+  const int kMaxRetries = 5;
+  int retry_count = 0;
+  int file_error;
+  size_t len = 0;
+  do {
+    const size_t n = fread((uint8_t *)buf + len, 1, size - len, file);
+    len += n;
+    file_error = ferror(file);
+    if (file_error) {
+      if (errno == EINTR || errno == EAGAIN) {
+        clearerr(file);
+        continue;
+      } else {
+        fprintf(stderr, "Error reading file: %u of %u bytes read, %d: %s\n",
+                (uint32_t)len, (uint32_t)size, errno, strerror(errno));
+        return 0;
+      }
+    }
+  } while (!feof(file) && len < size && ++retry_count < kMaxRetries);
+
+  if (!feof(file) && len != size) {
+    fprintf(stderr,
+            "Error reading file: %u of %u bytes read,"
+            " error: %d, retries: %d, %d: %s\n",
+            (uint32_t)len, (uint32_t)size, file_error, retry_count, errno,
+            strerror(errno));
+  }
+  return len == size;
+}
+
+static int y4m_parse_tags(y4m_input *_y4m, char *_tags) {
+  int got_w;
+  int got_h;
+  int got_fps;
+  int got_interlace;
+  int got_par;
+  int got_chroma;
+  char *p;
+  char *q;
+  got_w = got_h = got_fps = got_interlace = got_par = got_chroma = 0;
+  for (p = _tags;; p = q) {
+    /*Skip any leading spaces.*/
+    while (*p == ' ') p++;
+    /*If that's all we have, stop.*/
+    if (p[0] == '\0') break;
+    /*Find the end of this tag.*/
+    for (q = p + 1; *q != '\0' && *q != ' '; q++) {
+    }
+    /*Process the tag.*/
+    switch (p[0]) {
+      case 'W': {
+        if (sscanf(p + 1, "%d", &_y4m->pic_w) != 1) return -1;
+        got_w = 1;
+      } break;
+      case 'H': {
+        if (sscanf(p + 1, "%d", &_y4m->pic_h) != 1) return -1;
+        got_h = 1;
+      } break;
+      case 'F': {
+        if (sscanf(p + 1, "%d:%d", &_y4m->fps_n, &_y4m->fps_d) != 2) {
+          return -1;
+        }
+        got_fps = 1;
+      } break;
+      case 'I': {
+        _y4m->interlace = p[1];
+        got_interlace = 1;
+      } break;
+      case 'A': {
+        if (sscanf(p + 1, "%d:%d", &_y4m->par_n, &_y4m->par_d) != 2) {
+          return -1;
+        }
+        got_par = 1;
+      } break;
+      case 'C': {
+        if (q - p > 16) return -1;
+        memcpy(_y4m->chroma_type, p + 1, q - p - 1);
+        _y4m->chroma_type[q - p - 1] = '\0';
+        got_chroma = 1;
+      } break;
+        /*Ignore unknown tags.*/
+    }
+  }
+  if (!got_w || !got_h || !got_fps) return -1;
+  if (!got_interlace) _y4m->interlace = '?';
+  if (!got_par) _y4m->par_n = _y4m->par_d = 0;
+  /*Chroma-type is not specified in older files, e.g., those generated by
+     mplayer.*/
+  if (!got_chroma) strcpy(_y4m->chroma_type, "420");
+  return 0;
+}
+
+/*All anti-aliasing filters in the following conversion functions are based on
+   one of two window functions:
+  The 6-tap Lanczos window (for down-sampling and shifts):
+   sinc(\pi*t)*sinc(\pi*t/3), |t|<3  (sinc(t)==sin(t)/t)
+   0,                         |t|>=3
+  The 4-tap Mitchell window (for up-sampling):
+   7|t|^3-12|t|^2+16/3,             |t|<1
+   -(7/3)|x|^3+12|x|^2-20|x|+32/3,  |t|<2
+   0,                               |t|>=2
+  The number of taps is intentionally kept small to reduce computational
+   overhead and limit ringing.
+
+  The taps from these filters are scaled so that their sum is 1, and the
+  result is scaled by 128 and rounded to integers to create a filter whose
+   intermediate values fit inside 16 bits.
+  Coefficients are rounded in such a way as to ensure their sum is still 128,
+   which is usually equivalent to normal rounding.
+
+  Conversions which require both horizontal and vertical filtering could
+   have these steps pipelined, for less memory consumption and better cache
+   performance, but we do them separately for simplicity.*/
+#define OC_MINI(_a, _b) ((_a) > (_b) ? (_b) : (_a))
+#define OC_MAXI(_a, _b) ((_a) < (_b) ? (_b) : (_a))
+#define OC_CLAMPI(_a, _b, _c) (OC_MAXI(_a, OC_MINI(_b, _c)))
+
+/*420jpeg chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  420mpeg2 chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  BR      |       BR      |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  BR      |       BR      |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  We use a resampling filter to shift the site locations one quarter pixel (at
+   the chroma plane's resolution) to the right.
+  The 4:2:2 modes look exactly the same, except there are twice as many chroma
+   lines, and they are vertically co-sited with the luma samples in both the
+   mpeg2 and jpeg cases (thus requiring no vertical resampling).*/
+static void y4m_42xmpeg2_42xjpeg_helper(unsigned char *_dst,
+                                        const unsigned char *_src, int _c_w,
+                                        int _c_h) {
+  int y;
+  int x;
+  for (y = 0; y < _c_h; y++) {
+    /*Filter: [4 -17 114 35 -9 1]/128, derived from a 6-tap Lanczos
+       window.*/
+    for (x = 0; x < OC_MINI(_c_w, 2); x++) {
+      _dst[x] = (unsigned char)OC_CLAMPI(
+          0,
+          (4 * _src[0] - 17 * _src[OC_MAXI(x - 1, 0)] + 114 * _src[x] +
+           35 * _src[OC_MINI(x + 1, _c_w - 1)] -
+           9 * _src[OC_MINI(x + 2, _c_w - 1)] + _src[OC_MINI(x + 3, _c_w - 1)] +
+           64) >>
+              7,
+          255);
+    }
+    for (; x < _c_w - 3; x++) {
+      _dst[x] = (unsigned char)OC_CLAMPI(
+          0,
+          (4 * _src[x - 2] - 17 * _src[x - 1] + 114 * _src[x] +
+           35 * _src[x + 1] - 9 * _src[x + 2] + _src[x + 3] + 64) >>
+              7,
+          255);
+    }
+    for (; x < _c_w; x++) {
+      _dst[x] = (unsigned char)OC_CLAMPI(
+          0,
+          (4 * _src[x - 2] - 17 * _src[x - 1] + 114 * _src[x] +
+           35 * _src[OC_MINI(x + 1, _c_w - 1)] -
+           9 * _src[OC_MINI(x + 2, _c_w - 1)] + _src[_c_w - 1] + 64) >>
+              7,
+          255);
+    }
+    _dst += _c_w;
+    _src += _c_w;
+  }
+}
+
+/*Handles both 422 and 420mpeg2 to 422jpeg and 420jpeg, respectively.*/
+static void y4m_convert_42xmpeg2_42xjpeg(y4m_input *_y4m, unsigned char *_dst,
+                                         unsigned char *_aux) {
+  int c_w;
+  int c_h;
+  int c_sz;
+  int pli;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  for (pli = 1; pli < 3; pli++) {
+    y4m_42xmpeg2_42xjpeg_helper(_dst, _aux, c_w, c_h);
+    _dst += c_sz;
+    _aux += c_sz;
+  }
+}
+
+/*This format is only used for interlaced content, but is included for
+   completeness.
+
+  420jpeg chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  420paldv chroma samples are sited like:
+  YR------Y-------YR------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YB------Y-------YB------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YR------Y-------YR------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YB------Y-------YB------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  We use a resampling filter to shift the site locations one quarter pixel (at
+   the chroma plane's resolution) to the right.
+  Then we use another filter to move the C_r location down one quarter pixel,
+   and the C_b location up one quarter pixel.*/
+static void y4m_convert_42xpaldv_42xjpeg(y4m_input *_y4m, unsigned char *_dst,
+                                         unsigned char *_aux) {
+  unsigned char *tmp;
+  int c_w;
+  int c_h;
+  int c_sz;
+  int pli;
+  int y;
+  int x;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + 1) / 2;
+  c_h = (_y4m->pic_h + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  c_sz = c_w * c_h;
+  tmp = _aux + 2 * c_sz;
+  for (pli = 1; pli < 3; pli++) {
+    /*First do the horizontal re-sampling.
+      This is the same as the mpeg2 case, except that after the horizontal
+       case, we need to apply a second vertical filter.*/
+    y4m_42xmpeg2_42xjpeg_helper(tmp, _aux, c_w, c_h);
+    _aux += c_sz;
+    switch (pli) {
+      case 1: {
+        /*Slide C_b up a quarter-pel.
+          This is the same filter used above, but in the other order.*/
+        for (x = 0; x < c_w; x++) {
+          for (y = 0; y < OC_MINI(c_h, 3); y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (tmp[0] - 9 * tmp[OC_MAXI(y - 2, 0) * c_w] +
+                 35 * tmp[OC_MAXI(y - 1, 0) * c_w] + 114 * tmp[y * c_w] -
+                 17 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] +
+                 4 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] + 64) >>
+                    7,
+                255);
+          }
+          for (; y < c_h - 2; y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (tmp[(y - 3) * c_w] - 9 * tmp[(y - 2) * c_w] +
+                 35 * tmp[(y - 1) * c_w] + 114 * tmp[y * c_w] -
+                 17 * tmp[(y + 1) * c_w] + 4 * tmp[(y + 2) * c_w] + 64) >>
+                    7,
+                255);
+          }
+          for (; y < c_h; y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (tmp[(y - 3) * c_w] - 9 * tmp[(y - 2) * c_w] +
+                 35 * tmp[(y - 1) * c_w] + 114 * tmp[y * c_w] -
+                 17 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] +
+                 4 * tmp[(c_h - 1) * c_w] + 64) >>
+                    7,
+                255);
+          }
+          _dst++;
+          tmp++;
+        }
+        _dst += c_sz - c_w;
+        tmp -= c_w;
+      } break;
+      case 2: {
+        /*Slide C_r down a quarter-pel.
+          This is the same as the horizontal filter.*/
+        for (x = 0; x < c_w; x++) {
+          for (y = 0; y < OC_MINI(c_h, 2); y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (4 * tmp[0] - 17 * tmp[OC_MAXI(y - 1, 0) * c_w] +
+                 114 * tmp[y * c_w] + 35 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] -
+                 9 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] +
+                 tmp[OC_MINI(y + 3, c_h - 1) * c_w] + 64) >>
+                    7,
+                255);
+          }
+          for (; y < c_h - 3; y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (4 * tmp[(y - 2) * c_w] - 17 * tmp[(y - 1) * c_w] +
+                 114 * tmp[y * c_w] + 35 * tmp[(y + 1) * c_w] -
+                 9 * tmp[(y + 2) * c_w] + tmp[(y + 3) * c_w] + 64) >>
+                    7,
+                255);
+          }
+          for (; y < c_h; y++) {
+            _dst[y * c_w] = (unsigned char)OC_CLAMPI(
+                0,
+                (4 * tmp[(y - 2) * c_w] - 17 * tmp[(y - 1) * c_w] +
+                 114 * tmp[y * c_w] + 35 * tmp[OC_MINI(y + 1, c_h - 1) * c_w] -
+                 9 * tmp[OC_MINI(y + 2, c_h - 1) * c_w] + tmp[(c_h - 1) * c_w] +
+                 64) >>
+                    7,
+                255);
+          }
+          _dst++;
+          tmp++;
+        }
+      } break;
+    }
+    /*For actual interlaced material, this would have to be done separately on
+       each field, and the shift amounts would be different.
+      C_r moves down 1/8, C_b up 3/8 in the top field, and C_r moves down 3/8,
+       C_b up 1/8 in the bottom field.
+      The corresponding filters would be:
+       Down 1/8 (reverse order for up): [3 -11 125 15 -4 0]/128
+       Down 3/8 (reverse order for up): [4 -19 98 56 -13 2]/128*/
+  }
+}
+
+/*Perform vertical filtering to reduce a single plane from 4:2:2 to 4:2:0.
+  This is used as a helper by several converation routines.*/
+static void y4m_422jpeg_420jpeg_helper(unsigned char *_dst,
+                                       const unsigned char *_src, int _c_w,
+                                       int _c_h) {
+  int y;
+  int x;
+  /*Filter: [3 -17 78 78 -17 3]/128, derived from a 6-tap Lanczos window.*/
+  for (x = 0; x < _c_w; x++) {
+    for (y = 0; y < OC_MINI(_c_h, 2); y += 2) {
+      _dst[(y >> 1) * _c_w] =
+          OC_CLAMPI(0,
+                    (64 * _src[0] + 78 * _src[OC_MINI(1, _c_h - 1) * _c_w] -
+                     17 * _src[OC_MINI(2, _c_h - 1) * _c_w] +
+                     3 * _src[OC_MINI(3, _c_h - 1) * _c_w] + 64) >>
+                        7,
+                    255);
+    }
+    for (; y < _c_h - 3; y += 2) {
+      _dst[(y >> 1) * _c_w] =
+          OC_CLAMPI(0,
+                    (3 * (_src[(y - 2) * _c_w] + _src[(y + 3) * _c_w]) -
+                     17 * (_src[(y - 1) * _c_w] + _src[(y + 2) * _c_w]) +
+                     78 * (_src[y * _c_w] + _src[(y + 1) * _c_w]) + 64) >>
+                        7,
+                    255);
+    }
+    for (; y < _c_h; y += 2) {
+      _dst[(y >> 1) * _c_w] = OC_CLAMPI(
+          0,
+          (3 * (_src[(y - 2) * _c_w] + _src[(_c_h - 1) * _c_w]) -
+           17 * (_src[(y - 1) * _c_w] + _src[OC_MINI(y + 2, _c_h - 1) * _c_w]) +
+           78 * (_src[y * _c_w] + _src[OC_MINI(y + 1, _c_h - 1) * _c_w]) +
+           64) >>
+              7,
+          255);
+    }
+    _src++;
+    _dst++;
+  }
+}
+
+/*420jpeg chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  422jpeg chroma samples are sited like:
+  Y---BR--Y-------Y---BR--Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y---BR--Y-------Y---BR--Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y---BR--Y-------Y---BR--Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y---BR--Y-------Y---BR--Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  We use a resampling filter to decimate the chroma planes by two in the
+   vertical direction.*/
+static void y4m_convert_422jpeg_420jpeg(y4m_input *_y4m, unsigned char *_dst,
+                                        unsigned char *_aux) {
+  int c_w;
+  int c_h;
+  int c_sz;
+  int dst_c_w;
+  int dst_c_h;
+  int dst_c_sz;
+  int pli;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
+  c_h = _y4m->pic_h;
+  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  dst_c_sz = dst_c_w * dst_c_h;
+  for (pli = 1; pli < 3; pli++) {
+    y4m_422jpeg_420jpeg_helper(_dst, _aux, c_w, c_h);
+    _aux += c_sz;
+    _dst += dst_c_sz;
+  }
+}
+
+/*420jpeg chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  422 chroma samples are sited like:
+  YBR-----Y-------YBR-----Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------YBR-----Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------YBR-----Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------YBR-----Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  We use a resampling filter to shift the original site locations one quarter
+   pixel (at the original chroma resolution) to the right.
+  Then we use a second resampling filter to decimate the chroma planes by two
+   in the vertical direction.*/
+static void y4m_convert_422_420jpeg(y4m_input *_y4m, unsigned char *_dst,
+                                    unsigned char *_aux) {
+  unsigned char *tmp;
+  int c_w;
+  int c_h;
+  int c_sz;
+  int dst_c_h;
+  int dst_c_sz;
+  int pli;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
+  c_h = _y4m->pic_h;
+  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  dst_c_sz = c_w * dst_c_h;
+  tmp = _aux + 2 * c_sz;
+  for (pli = 1; pli < 3; pli++) {
+    /*In reality, the horizontal and vertical steps could be pipelined, for
+       less memory consumption and better cache performance, but we do them
+       separately for simplicity.*/
+    /*First do horizontal filtering (convert to 422jpeg)*/
+    y4m_42xmpeg2_42xjpeg_helper(tmp, _aux, c_w, c_h);
+    /*Now do the vertical filtering.*/
+    y4m_422jpeg_420jpeg_helper(_dst, tmp, c_w, c_h);
+    _aux += c_sz;
+    _dst += dst_c_sz;
+  }
+}
+
+/*420jpeg chroma samples are sited like:
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |   BR  |       |   BR  |
+  |       |       |       |
+  Y-------Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  411 chroma samples are sited like:
+  YBR-----Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+  YBR-----Y-------Y-------Y-------
+  |       |       |       |
+  |       |       |       |
+  |       |       |       |
+
+  We use a filter to resample at site locations one eighth pixel (at the source
+   chroma plane's horizontal resolution) and five eighths of a pixel to the
+   right.
+  Then we use another filter to decimate the planes by 2 in the vertical
+   direction.*/
+static void y4m_convert_411_420jpeg(y4m_input *_y4m, unsigned char *_dst,
+                                    unsigned char *_aux) {
+  unsigned char *tmp;
+  int c_w;
+  int c_h;
+  int c_sz;
+  int dst_c_w;
+  int dst_c_h;
+  int dst_c_sz;
+  int tmp_sz;
+  int pli;
+  int y;
+  int x;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
+  c_h = _y4m->pic_h;
+  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  dst_c_sz = dst_c_w * dst_c_h;
+  tmp_sz = dst_c_w * c_h;
+  tmp = _aux + 2 * c_sz;
+  for (pli = 1; pli < 3; pli++) {
+    /*In reality, the horizontal and vertical steps could be pipelined, for
+       less memory consumption and better cache performance, but we do them
+       separately for simplicity.*/
+    /*First do horizontal filtering (convert to 422jpeg)*/
+    for (y = 0; y < c_h; y++) {
+      /*Filters: [1 110 18 -1]/128 and [-3 50 86 -5]/128, both derived from a
+         4-tap Mitchell window.*/
+      for (x = 0; x < OC_MINI(c_w, 1); x++) {
+        tmp[x << 1] = (unsigned char)OC_CLAMPI(
+            0,
+            (111 * _aux[0] + 18 * _aux[OC_MINI(1, c_w - 1)] -
+             _aux[OC_MINI(2, c_w - 1)] + 64) >>
+                7,
+            255);
+        tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
+            0,
+            (47 * _aux[0] + 86 * _aux[OC_MINI(1, c_w - 1)] -
+             5 * _aux[OC_MINI(2, c_w - 1)] + 64) >>
+                7,
+            255);
+      }
+      for (; x < c_w - 2; x++) {
+        tmp[x << 1] =
+            (unsigned char)OC_CLAMPI(0,
+                                     (_aux[x - 1] + 110 * _aux[x] +
+                                      18 * _aux[x + 1] - _aux[x + 2] + 64) >>
+                                         7,
+                                     255);
+        tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
+            0,
+            (-3 * _aux[x - 1] + 50 * _aux[x] + 86 * _aux[x + 1] -
+             5 * _aux[x + 2] + 64) >>
+                7,
+            255);
+      }
+      for (; x < c_w; x++) {
+        tmp[x << 1] = (unsigned char)OC_CLAMPI(
+            0,
+            (_aux[x - 1] + 110 * _aux[x] + 18 * _aux[OC_MINI(x + 1, c_w - 1)] -
+             _aux[c_w - 1] + 64) >>
+                7,
+            255);
+        if ((x << 1 | 1) < dst_c_w) {
+          tmp[x << 1 | 1] = (unsigned char)OC_CLAMPI(
+              0,
+              (-3 * _aux[x - 1] + 50 * _aux[x] +
+               86 * _aux[OC_MINI(x + 1, c_w - 1)] - 5 * _aux[c_w - 1] + 64) >>
+                  7,
+              255);
+        }
+      }
+      tmp += dst_c_w;
+      _aux += c_w;
+    }
+    tmp -= tmp_sz;
+    /*Now do the vertical filtering.*/
+    y4m_422jpeg_420jpeg_helper(_dst, tmp, dst_c_w, c_h);
+    _dst += dst_c_sz;
+  }
+}
+
+/*Convert 444 to 420jpeg.*/
+static void y4m_convert_444_420jpeg(y4m_input *_y4m, unsigned char *_dst,
+                                    unsigned char *_aux) {
+  unsigned char *tmp;
+  int c_w;
+  int c_h;
+  int c_sz;
+  int dst_c_w;
+  int dst_c_h;
+  int dst_c_sz;
+  int tmp_sz;
+  int pli;
+  int y;
+  int x;
+  /*Skip past the luma data.*/
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  /*Compute the size of each chroma plane.*/
+  c_w = (_y4m->pic_w + _y4m->src_c_dec_h - 1) / _y4m->src_c_dec_h;
+  c_h = _y4m->pic_h;
+  dst_c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  dst_c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  dst_c_sz = dst_c_w * dst_c_h;
+  tmp_sz = dst_c_w * c_h;
+  tmp = _aux + 2 * c_sz;
+  for (pli = 1; pli < 3; pli++) {
+    /*Filter: [3 -17 78 78 -17 3]/128, derived from a 6-tap Lanczos window.*/
+    for (y = 0; y < c_h; y++) {
+      for (x = 0; x < OC_MINI(c_w, 2); x += 2) {
+        tmp[x >> 1] = OC_CLAMPI(0,
+                                (64 * _aux[0] + 78 * _aux[OC_MINI(1, c_w - 1)] -
+                                 17 * _aux[OC_MINI(2, c_w - 1)] +
+                                 3 * _aux[OC_MINI(3, c_w - 1)] + 64) >>
+                                    7,
+                                255);
+      }
+      for (; x < c_w - 3; x += 2) {
+        tmp[x >> 1] = OC_CLAMPI(0,
+                                (3 * (_aux[x - 2] + _aux[x + 3]) -
+                                 17 * (_aux[x - 1] + _aux[x + 2]) +
+                                 78 * (_aux[x] + _aux[x + 1]) + 64) >>
+                                    7,
+                                255);
+      }
+      for (; x < c_w; x += 2) {
+        tmp[x >> 1] =
+            OC_CLAMPI(0,
+                      (3 * (_aux[x - 2] + _aux[c_w - 1]) -
+                       17 * (_aux[x - 1] + _aux[OC_MINI(x + 2, c_w - 1)]) +
+                       78 * (_aux[x] + _aux[OC_MINI(x + 1, c_w - 1)]) + 64) >>
+                          7,
+                      255);
+      }
+      tmp += dst_c_w;
+      _aux += c_w;
+    }
+    tmp -= tmp_sz;
+    /*Now do the vertical filtering.*/
+    y4m_422jpeg_420jpeg_helper(_dst, tmp, dst_c_w, c_h);
+    _dst += dst_c_sz;
+  }
+}
+
+/*The image is padded with empty chroma components at 4:2:0.*/
+static void y4m_convert_mono_420jpeg(y4m_input *_y4m, unsigned char *_dst,
+                                     unsigned char *_aux) {
+  int c_sz;
+  (void)_aux;
+  _dst += _y4m->pic_w * _y4m->pic_h;
+  c_sz = ((_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h) *
+         ((_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v);
+  memset(_dst, 128, c_sz * 2);
+}
+
+/*No conversion function needed.*/
+static void y4m_convert_null(y4m_input *_y4m, unsigned char *_dst,
+                             unsigned char *_aux) {
+  (void)_y4m;
+  (void)_dst;
+  (void)_aux;
+}
+
+int y4m_input_open(y4m_input *_y4m, FILE *_fin, char *_skip, int _nskip,
+                   int only_420) {
+  char buffer[80] = { 0 };
+  int ret;
+  int i;
+  /*Read until newline, or 80 cols, whichever happens first.*/
+  for (i = 0; i < 79; i++) {
+    if (_nskip > 0) {
+      buffer[i] = *_skip++;
+      _nskip--;
+    } else {
+      if (!file_read(buffer + i, 1, _fin)) return -1;
+    }
+    if (buffer[i] == '\n') break;
+  }
+  /*We skipped too much header data.*/
+  if (_nskip > 0) return -1;
+  if (i == 79) {
+    fprintf(stderr, "Error parsing header; not a YUV2MPEG2 file?\n");
+    return -1;
+  }
+  buffer[i] = '\0';
+  if (memcmp(buffer, "YUV4MPEG", 8)) {
+    fprintf(stderr, "Incomplete magic for YUV4MPEG file.\n");
+    return -1;
+  }
+  if (buffer[8] != '2') {
+    fprintf(stderr, "Incorrect YUV input file version; YUV4MPEG2 required.\n");
+  }
+  ret = y4m_parse_tags(_y4m, buffer + 5);
+  if (ret < 0) {
+    fprintf(stderr, "Error parsing YUV4MPEG2 header.\n");
+    return ret;
+  }
+  if (_y4m->interlace == '?') {
+    fprintf(stderr,
+            "Warning: Input video interlacing format unknown; "
+            "assuming progressive scan.\n");
+  } else if (_y4m->interlace != 'p') {
+    fprintf(stderr,
+            "Input video is interlaced; "
+            "Only progressive scan handled.\n");
+    return -1;
+  }
+  _y4m->aom_fmt = AOM_IMG_FMT_I420;
+  _y4m->bps = 12;
+  _y4m->bit_depth = 8;
+  if (strcmp(_y4m->chroma_type, "420") == 0 ||
+      strcmp(_y4m->chroma_type, "420jpeg") == 0) {
+    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
+        _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz =
+        _y4m->pic_w * _y4m->pic_h +
+        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
+    /* Natively supported: no conversion required. */
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+  } else if (strcmp(_y4m->chroma_type, "420p10") == 0) {
+    _y4m->src_c_dec_h = 2;
+    _y4m->dst_c_dec_h = 2;
+    _y4m->src_c_dec_v = 2;
+    _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz =
+        2 * (_y4m->pic_w * _y4m->pic_h +
+             2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2));
+    /* Natively supported: no conversion required. */
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    _y4m->bit_depth = 10;
+    _y4m->bps = 15;
+    _y4m->aom_fmt = AOM_IMG_FMT_I42016;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 420p10 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "420p12") == 0) {
+    _y4m->src_c_dec_h = 2;
+    _y4m->dst_c_dec_h = 2;
+    _y4m->src_c_dec_v = 2;
+    _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz =
+        2 * (_y4m->pic_w * _y4m->pic_h +
+             2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2));
+    /* Natively supported: no conversion required. */
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    _y4m->bit_depth = 12;
+    _y4m->bps = 18;
+    _y4m->aom_fmt = AOM_IMG_FMT_I42016;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 420p12 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "420mpeg2") == 0) {
+    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
+        _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+    /*Chroma filter required: read into the aux buf first.*/
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz =
+        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
+    _y4m->convert = y4m_convert_42xmpeg2_42xjpeg;
+  } else if (strcmp(_y4m->chroma_type, "420paldv") == 0) {
+    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = _y4m->src_c_dec_v =
+        _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+    /*Chroma filter required: read into the aux buf first.
+      We need to make two filter passes, so we need some extra space in the
+       aux buffer.*/
+    _y4m->aux_buf_sz = 3 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
+    _y4m->aux_buf_read_sz =
+        2 * ((_y4m->pic_w + 1) / 2) * ((_y4m->pic_h + 1) / 2);
+    _y4m->convert = y4m_convert_42xpaldv_42xjpeg;
+  } else if (strcmp(_y4m->chroma_type, "422jpeg") == 0) {
+    _y4m->src_c_dec_h = _y4m->dst_c_dec_h = 2;
+    _y4m->src_c_dec_v = 1;
+    _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+    /*Chroma filter required: read into the aux buf first.*/
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz =
+        2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+    _y4m->convert = y4m_convert_422jpeg_420jpeg;
+  } else if (strcmp(_y4m->chroma_type, "422") == 0) {
+    _y4m->src_c_dec_h = 2;
+    _y4m->src_c_dec_v = 1;
+    if (only_420) {
+      _y4m->dst_c_dec_h = 2;
+      _y4m->dst_c_dec_v = 2;
+      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+      /*Chroma filter required: read into the aux buf first.
+        We need to make two filter passes, so we need some extra space in the
+         aux buffer.*/
+      _y4m->aux_buf_read_sz = 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+      _y4m->aux_buf_sz =
+          _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+      _y4m->convert = y4m_convert_422_420jpeg;
+    } else {
+      _y4m->aom_fmt = AOM_IMG_FMT_I422;
+      _y4m->bps = 16;
+      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+      _y4m->dst_buf_read_sz =
+          _y4m->pic_w * _y4m->pic_h + 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+      /*Natively supported: no conversion required.*/
+      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+      _y4m->convert = y4m_convert_null;
+    }
+  } else if (strcmp(_y4m->chroma_type, "422p10") == 0) {
+    _y4m->src_c_dec_h = 2;
+    _y4m->src_c_dec_v = 1;
+    _y4m->aom_fmt = AOM_IMG_FMT_I42216;
+    _y4m->bps = 20;
+    _y4m->bit_depth = 10;
+    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+    _y4m->dst_buf_read_sz = 2 * (_y4m->pic_w * _y4m->pic_h +
+                                 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h);
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 422p10 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "422p12") == 0) {
+    _y4m->src_c_dec_h = 2;
+    _y4m->src_c_dec_v = 1;
+    _y4m->aom_fmt = AOM_IMG_FMT_I42216;
+    _y4m->bps = 24;
+    _y4m->bit_depth = 12;
+    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+    _y4m->dst_buf_read_sz = 2 * (_y4m->pic_w * _y4m->pic_h +
+                                 2 * ((_y4m->pic_w + 1) / 2) * _y4m->pic_h);
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 422p12 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "411") == 0) {
+    _y4m->src_c_dec_h = 4;
+    _y4m->dst_c_dec_h = 2;
+    _y4m->src_c_dec_v = 1;
+    _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+    /*Chroma filter required: read into the aux buf first.
+      We need to make two filter passes, so we need some extra space in the
+       aux buffer.*/
+    _y4m->aux_buf_read_sz = 2 * ((_y4m->pic_w + 3) / 4) * _y4m->pic_h;
+    _y4m->aux_buf_sz =
+        _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+    _y4m->convert = y4m_convert_411_420jpeg;
+  } else if (strcmp(_y4m->chroma_type, "444") == 0) {
+    _y4m->src_c_dec_h = 1;
+    _y4m->src_c_dec_v = 1;
+    if (only_420) {
+      _y4m->dst_c_dec_h = 2;
+      _y4m->dst_c_dec_v = 2;
+      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+      /*Chroma filter required: read into the aux buf first.
+        We need to make two filter passes, so we need some extra space in the
+         aux buffer.*/
+      _y4m->aux_buf_read_sz = 2 * _y4m->pic_w * _y4m->pic_h;
+      _y4m->aux_buf_sz =
+          _y4m->aux_buf_read_sz + ((_y4m->pic_w + 1) / 2) * _y4m->pic_h;
+      _y4m->convert = y4m_convert_444_420jpeg;
+    } else {
+      _y4m->aom_fmt = AOM_IMG_FMT_I444;
+      _y4m->bps = 24;
+      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+      _y4m->dst_buf_read_sz = 3 * _y4m->pic_w * _y4m->pic_h;
+      /*Natively supported: no conversion required.*/
+      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+      _y4m->convert = y4m_convert_null;
+    }
+  } else if (strcmp(_y4m->chroma_type, "444p10") == 0) {
+    _y4m->src_c_dec_h = 1;
+    _y4m->src_c_dec_v = 1;
+    _y4m->aom_fmt = AOM_IMG_FMT_I44416;
+    _y4m->bps = 30;
+    _y4m->bit_depth = 10;
+    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+    _y4m->dst_buf_read_sz = 2 * 3 * _y4m->pic_w * _y4m->pic_h;
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 444p10 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "444p12") == 0) {
+    _y4m->src_c_dec_h = 1;
+    _y4m->src_c_dec_v = 1;
+    _y4m->aom_fmt = AOM_IMG_FMT_I44416;
+    _y4m->bps = 36;
+    _y4m->bit_depth = 12;
+    _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+    _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+    _y4m->dst_buf_read_sz = 2 * 3 * _y4m->pic_w * _y4m->pic_h;
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_null;
+    if (only_420) {
+      fprintf(stderr, "Unsupported conversion from 444p12 to 420jpeg\n");
+      return -1;
+    }
+  } else if (strcmp(_y4m->chroma_type, "444alpha") == 0) {
+    _y4m->src_c_dec_h = 1;
+    _y4m->src_c_dec_v = 1;
+    if (only_420) {
+      _y4m->dst_c_dec_h = 2;
+      _y4m->dst_c_dec_v = 2;
+      _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+      /*Chroma filter required: read into the aux buf first.
+        We need to make two filter passes, so we need some extra space in the
+         aux buffer.
+        The extra plane also gets read into the aux buf.
+        It will be discarded.*/
+      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 3 * _y4m->pic_w * _y4m->pic_h;
+      _y4m->convert = y4m_convert_444_420jpeg;
+    } else {
+      _y4m->aom_fmt = AOM_IMG_FMT_444A;
+      _y4m->bps = 32;
+      _y4m->dst_c_dec_h = _y4m->src_c_dec_h;
+      _y4m->dst_c_dec_v = _y4m->src_c_dec_v;
+      _y4m->dst_buf_read_sz = 4 * _y4m->pic_w * _y4m->pic_h;
+      /*Natively supported: no conversion required.*/
+      _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+      _y4m->convert = y4m_convert_null;
+    }
+  } else if (strcmp(_y4m->chroma_type, "mono") == 0) {
+    _y4m->src_c_dec_h = _y4m->src_c_dec_v = 0;
+    _y4m->dst_c_dec_h = _y4m->dst_c_dec_v = 2;
+    _y4m->dst_buf_read_sz = _y4m->pic_w * _y4m->pic_h;
+    /*No extra space required, but we need to clear the chroma planes.*/
+    _y4m->aux_buf_sz = _y4m->aux_buf_read_sz = 0;
+    _y4m->convert = y4m_convert_mono_420jpeg;
+  } else {
+    fprintf(stderr, "Unknown chroma sampling type: %s\n", _y4m->chroma_type);
+    return -1;
+  }
+  /*The size of the final frame buffers is always computed from the
+     destination chroma decimation type.*/
+  _y4m->dst_buf_sz =
+      _y4m->pic_w * _y4m->pic_h +
+      2 * ((_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h) *
+          ((_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v);
+  if (_y4m->bit_depth == 8)
+    _y4m->dst_buf = (unsigned char *)malloc(_y4m->dst_buf_sz);
+  else
+    _y4m->dst_buf = (unsigned char *)malloc(2 * _y4m->dst_buf_sz);
+
+  if (_y4m->aux_buf_sz > 0)
+    _y4m->aux_buf = (unsigned char *)malloc(_y4m->aux_buf_sz);
+  return 0;
+}
+
+void y4m_input_close(y4m_input *_y4m) {
+  free(_y4m->dst_buf);
+  free(_y4m->aux_buf);
+}
+
+int y4m_input_fetch_frame(y4m_input *_y4m, FILE *_fin, aom_image_t *_img) {
+  char frame[6];
+  int pic_sz;
+  int c_w;
+  int c_h;
+  int c_sz;
+  int bytes_per_sample = _y4m->bit_depth > 8 ? 2 : 1;
+  /*Read and skip the frame header.*/
+  if (!file_read(frame, 6, _fin)) return 0;
+  if (memcmp(frame, "FRAME", 5)) {
+    fprintf(stderr, "Loss of framing in Y4M input data\n");
+    return -1;
+  }
+  if (frame[5] != '\n') {
+    char c;
+    int j;
+    for (j = 0; j < 79 && file_read(&c, 1, _fin) && c != '\n'; j++) {
+    }
+    if (j == 79) {
+      fprintf(stderr, "Error parsing Y4M frame header\n");
+      return -1;
+    }
+  }
+  /*Read the frame data that needs no conversion.*/
+  if (!file_read(_y4m->dst_buf, _y4m->dst_buf_read_sz, _fin)) {
+    fprintf(stderr, "Error reading Y4M frame data.\n");
+    return -1;
+  }
+  /*Read the frame data that does need conversion.*/
+  if (!file_read(_y4m->aux_buf, _y4m->aux_buf_read_sz, _fin)) {
+    fprintf(stderr, "Error reading Y4M frame data.\n");
+    return -1;
+  }
+  /*Now convert the just read frame.*/
+  (*_y4m->convert)(_y4m, _y4m->dst_buf, _y4m->aux_buf);
+  /*Fill in the frame buffer pointers.
+    We don't use aom_img_wrap() because it forces padding for odd picture
+     sizes, which would require a separate fread call for every row.*/
+  memset(_img, 0, sizeof(*_img));
+  /*Y4M has the planes in Y'CbCr order, which libaom calls Y, U, and V.*/
+  _img->fmt = _y4m->aom_fmt;
+  _img->w = _img->d_w = _y4m->pic_w;
+  _img->h = _img->d_h = _y4m->pic_h;
+  _img->x_chroma_shift = _y4m->dst_c_dec_h >> 1;
+  _img->y_chroma_shift = _y4m->dst_c_dec_v >> 1;
+  _img->bps = _y4m->bps;
+
+  /*Set up the buffer pointers.*/
+  pic_sz = _y4m->pic_w * _y4m->pic_h * bytes_per_sample;
+  c_w = (_y4m->pic_w + _y4m->dst_c_dec_h - 1) / _y4m->dst_c_dec_h;
+  c_w *= bytes_per_sample;
+  c_h = (_y4m->pic_h + _y4m->dst_c_dec_v - 1) / _y4m->dst_c_dec_v;
+  c_sz = c_w * c_h;
+  _img->stride[AOM_PLANE_Y] = _img->stride[AOM_PLANE_ALPHA] =
+      _y4m->pic_w * bytes_per_sample;
+  _img->stride[AOM_PLANE_U] = _img->stride[AOM_PLANE_V] = c_w;
+  _img->planes[AOM_PLANE_Y] = _y4m->dst_buf;
+  _img->planes[AOM_PLANE_U] = _y4m->dst_buf + pic_sz;
+  _img->planes[AOM_PLANE_V] = _y4m->dst_buf + pic_sz + c_sz;
+  _img->planes[AOM_PLANE_ALPHA] = _y4m->dst_buf + pic_sz + 2 * c_sz;
+  return 1;
+}
diff --git a/third_party/aom/common/y4minput.h b/third_party/aom/common/y4minput.h
new file mode 100644
index 000000000..db20190db
--- /dev/null
+++ b/third_party/aom/common/y4minput.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ *
+ * Based on code from the OggTheora software codec source code,
+ * Copyright (C) 2002-2010 The Xiph.Org Foundation and contributors.
+ */
+
+#ifndef Y4MINPUT_H_
+#define Y4MINPUT_H_
+
+#include <stdio.h>
+#include "aom/aom_image.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct y4m_input y4m_input;
+
+/*The function used to perform chroma conversion.*/
+typedef void (*y4m_convert_func)(y4m_input *_y4m, unsigned char *_dst,
+                                 unsigned char *_src);
+
+struct y4m_input {
+  int pic_w;
+  int pic_h;
+  int fps_n;
+  int fps_d;
+  int par_n;
+  int par_d;
+  char interlace;
+  int src_c_dec_h;
+  int src_c_dec_v;
+  int dst_c_dec_h;
+  int dst_c_dec_v;
+  char chroma_type[16];
+  /*The size of each converted frame buffer.*/
+  size_t dst_buf_sz;
+  /*The amount to read directly into the converted frame buffer.*/
+  size_t dst_buf_read_sz;
+  /*The size of the auxilliary buffer.*/
+  size_t aux_buf_sz;
+  /*The amount to read into the auxilliary buffer.*/
+  size_t aux_buf_read_sz;
+  y4m_convert_func convert;
+  unsigned char *dst_buf;
+  unsigned char *aux_buf;
+  enum aom_img_fmt aom_fmt;
+  int bps;
+  unsigned int bit_depth;
+};
+
+int y4m_input_open(y4m_input *_y4m, FILE *_fin, char *_skip, int _nskip,
+                   int only_420);
+void y4m_input_close(y4m_input *_y4m);
+int y4m_input_fetch_frame(y4m_input *_y4m, FILE *_fin, aom_image_t *img);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // Y4MINPUT_H_