1 files changed, 110 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/dkboolreader.c b/third_party/aom/aom_dsp/dkboolreader.c
new file mode 100644
index 000000000..288d5f1ce
--- /dev/null
+++ b/third_party/aom/aom_dsp/dkboolreader.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 <stdlib.h>
+
+#include "./aom_config.h"
+
+#include "aom_dsp/dkboolreader.h"
+#include "aom_dsp/prob.h"
+#include "aom_dsp/aom_dsp_common.h"
+#include "aom_ports/mem.h"
+#include "aom_mem/aom_mem.h"
+#include "aom_util/endian_inl.h"
+
+static INLINE int aom_dk_read_bit(struct aom_dk_reader *r) {
+  return aom_dk_read(r, 128);  // aom_prob_half
+}
+
+int aom_dk_reader_init(struct aom_dk_reader *r, const uint8_t *buffer,
+                       size_t size, aom_decrypt_cb decrypt_cb,
+                       void *decrypt_state) {
+  if (size && !buffer) {
+    return 1;
+  } else {
+    r->buffer_end = buffer + size;
+    r->buffer_start = r->buffer = buffer;
+    r->value = 0;
+    r->count = -8;
+    r->range = 255;
+    r->decrypt_cb = decrypt_cb;
+    r->decrypt_state = decrypt_state;
+    aom_dk_reader_fill(r);
+#if CONFIG_ACCOUNTING
+    r->accounting = NULL;
+#endif
+    return aom_dk_read_bit(r) != 0;  // marker bit
+  }
+}
+
+void aom_dk_reader_fill(struct aom_dk_reader *r) {
+  const uint8_t *const buffer_end = r->buffer_end;
+  const uint8_t *buffer = r->buffer;
+  const uint8_t *buffer_start = buffer;
+  BD_VALUE value = r->value;
+  int count = r->count;
+  const size_t bytes_left = buffer_end - buffer;
+  const size_t bits_left = bytes_left * CHAR_BIT;
+  int shift = BD_VALUE_SIZE - CHAR_BIT - (count + CHAR_BIT);
+
+  if (r->decrypt_cb) {
+    size_t n = AOMMIN(sizeof(r->clear_buffer), bytes_left);
+    r->decrypt_cb(r->decrypt_state, buffer, r->clear_buffer, (int)n);
+    buffer = r->clear_buffer;
+    buffer_start = r->clear_buffer;
+  }
+  if (bits_left > BD_VALUE_SIZE) {
+    const int bits = (shift & 0xfffffff8) + CHAR_BIT;
+    BD_VALUE nv;
+    BD_VALUE big_endian_values;
+    memcpy(&big_endian_values, buffer, sizeof(BD_VALUE));
+#if SIZE_MAX == 0xffffffffffffffffULL
+    big_endian_values = HToBE64(big_endian_values);
+#else
+    big_endian_values = HToBE32(big_endian_values);
+#endif
+    nv = big_endian_values >> (BD_VALUE_SIZE - bits);
+    count += bits;
+    buffer += (bits >> 3);
+    value = r->value | (nv << (shift & 0x7));
+  } else {
+    const int bits_over = (int)(shift + CHAR_BIT - (int)bits_left);
+    int loop_end = 0;
+    if (bits_over >= 0) {
+      count += LOTS_OF_BITS;
+      loop_end = bits_over;
+    }
+
+    if (bits_over < 0 || bits_left) {
+      while (shift >= loop_end) {
+        count += CHAR_BIT;
+        value |= (BD_VALUE)*buffer++ << shift;
+        shift -= CHAR_BIT;
+      }
+    }
+  }
+
+  // NOTE: Variable 'buffer' may not relate to 'r->buffer' after decryption,
+  // so we increase 'r->buffer' by the amount that 'buffer' moved, rather than
+  // assign 'buffer' to 'r->buffer'.
+  r->buffer += buffer - buffer_start;
+  r->value = value;
+  r->count = count;
+}
+
+const uint8_t *aom_dk_reader_find_end(struct aom_dk_reader *r) {
+  // Find the end of the coded buffer
+  while (r->count > CHAR_BIT && r->count < BD_VALUE_SIZE) {
+    r->count -= CHAR_BIT;
+    r->buffer--;
+  }
+  return r->buffer;
+}