Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

1 files changed, 286 insertions, 0 deletions

diff --git a/third_party/aom/av1/decoder/decodetxb.c b/third_party/aom/av1/decoder/decodetxb.c
new file mode 100644
index 000000000..e1db09775
--- /dev/null
+++ b/third_party/aom/av1/decoder/decodetxb.c
@@ -0,0 +1,286 @@
+/*
+ * 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 "av1/common/scan.h"
+#include "av1/common/idct.h"
+#include "av1/common/txb_common.h"
+#include "av1/decoder/decodemv.h"
+#include "av1/decoder/decodetxb.h"
+#include "av1/decoder/dsubexp.h"
+
+#define ACCT_STR __func__
+
+static int read_golomb(MACROBLOCKD *xd, aom_reader *r) {
+  int x = 1;
+  int length = 0;
+  int i = 0;
+
+  while (!i) {
+    i = aom_read_bit(r, ACCT_STR);
+    ++length;
+    if (length >= 32) {
+      aom_internal_error(xd->error_info, AOM_CODEC_CORRUPT_FRAME,
+                         "Invalid length in read_golomb");
+      break;
+    }
+  }
+
+  for (i = 0; i < length - 1; ++i) {
+    x <<= 1;
+    x += aom_read_bit(r, ACCT_STR);
+  }
+
+  return x - 1;
+}
+
+uint8_t av1_read_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
+                            aom_reader *r, int block, int plane,
+                            tran_low_t *tcoeffs, TXB_CTX *txb_ctx,
+                            int16_t *max_scan_line, int *eob) {
+  FRAME_COUNTS *counts = xd->counts;
+  TX_SIZE tx_size = get_tx_size(plane, xd);
+  PLANE_TYPE plane_type = get_plane_type(plane);
+  aom_prob *nz_map = cm->fc->nz_map[tx_size][plane_type];
+  aom_prob *eob_flag = cm->fc->eob_flag[tx_size][plane_type];
+  MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
+  const int seg_eob = tx_size_2d[tx_size];
+  int c = 0;
+  int update_eob = -1;
+  const int16_t *const dequant = xd->plane[plane].seg_dequant[mbmi->segment_id];
+  const int shift = av1_get_tx_scale(tx_size);
+  const int bwl = b_width_log2_lookup[txsize_to_bsize[tx_size]] + 2;
+  int cul_level = 0;
+  unsigned int(*nz_map_count)[SIG_COEF_CONTEXTS][2];
+  uint8_t txb_mask[32 * 32] = { 0 };
+
+  nz_map_count = (counts) ? &counts->nz_map[tx_size][plane_type] : NULL;
+
+  memset(tcoeffs, 0, sizeof(*tcoeffs) * seg_eob);
+
+  int all_zero =
+      aom_read(r, cm->fc->txb_skip[tx_size][txb_ctx->txb_skip_ctx], ACCT_STR);
+  if (xd->counts)
+    ++xd->counts->txb_skip[tx_size][txb_ctx->txb_skip_ctx][all_zero];
+
+  *eob = 0;
+  if (all_zero) {
+    *max_scan_line = 0;
+    return 0;
+  }
+
+#if CONFIG_TXK_SEL
+  av1_read_tx_type(cm, xd, block, plane, r);
+#endif
+  TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
+  const SCAN_ORDER *const scan_order =
+      get_scan(cm, tx_size, tx_type, is_inter_block(mbmi));
+  const int16_t *scan = scan_order->scan;
+
+  for (c = 0; c < seg_eob; ++c) {
+    int is_nz;
+    int coeff_ctx = get_nz_map_ctx(tcoeffs, txb_mask, scan[c], bwl);
+    int eob_ctx = get_eob_ctx(tcoeffs, scan[c], bwl);
+
+    if (c < seg_eob - 1)
+      is_nz = aom_read(r, nz_map[coeff_ctx], tx_size);
+    else
+      is_nz = 1;
+
+    // set non-zero coefficient map.
+    tcoeffs[scan[c]] = is_nz;
+
+    if (c == seg_eob - 1) {
+      ++c;
+      break;
+    }
+
+    if (counts) ++(*nz_map_count)[coeff_ctx][is_nz];
+
+    if (is_nz) {
+      int is_eob = aom_read(r, eob_flag[eob_ctx], tx_size);
+      if (counts) ++counts->eob_flag[tx_size][plane_type][eob_ctx][is_eob];
+      if (is_eob) break;
+    }
+    txb_mask[scan[c]] = 1;
+  }
+
+  *eob = AOMMIN(seg_eob, c + 1);
+  *max_scan_line = *eob;
+
+  int i;
+  for (i = 0; i < NUM_BASE_LEVELS; ++i) {
+    aom_prob *coeff_base = cm->fc->coeff_base[tx_size][plane_type][i];
+
+    update_eob = 0;
+    for (c = *eob - 1; c >= 0; --c) {
+      tran_low_t *v = &tcoeffs[scan[c]];
+      int sign;
+      int ctx;
+
+      if (*v <= i) continue;
+
+      ctx = get_base_ctx(tcoeffs, scan[c], bwl, i + 1);
+
+      if (aom_read(r, coeff_base[ctx], tx_size)) {
+        *v = i + 1;
+        cul_level += i + 1;
+
+        if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][1];
+
+        if (c == 0) {
+          int dc_sign_ctx = txb_ctx->dc_sign_ctx;
+          sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
+          if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
+        } else {
+          sign = aom_read_bit(r, ACCT_STR);
+        }
+        if (sign) *v = -(*v);
+        continue;
+      }
+      *v = i + 2;
+      if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][0];
+
+      // update the eob flag for coefficients with magnitude above 1.
+      update_eob = AOMMAX(update_eob, c);
+    }
+  }
+
+  for (c = update_eob; c >= 0; --c) {
+    tran_low_t *v = &tcoeffs[scan[c]];
+    int sign;
+    int idx;
+    int ctx;
+
+    if (*v <= NUM_BASE_LEVELS) continue;
+
+    if (c == 0) {
+      int dc_sign_ctx = txb_ctx->dc_sign_ctx;
+      sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
+      if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
+    } else {
+      sign = aom_read_bit(r, ACCT_STR);
+    }
+
+    ctx = get_level_ctx(tcoeffs, scan[c], bwl);
+
+    if (cm->fc->coeff_lps[tx_size][plane_type][ctx] == 0) exit(0);
+
+    for (idx = 0; idx < COEFF_BASE_RANGE; ++idx) {
+      if (aom_read(r, cm->fc->coeff_lps[tx_size][plane_type][ctx], tx_size)) {
+        *v = (idx + 1 + NUM_BASE_LEVELS);
+        if (sign) *v = -(*v);
+        cul_level += abs(*v);
+
+        if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][1];
+        break;
+      }
+      if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][0];
+    }
+    if (idx < COEFF_BASE_RANGE) continue;
+
+    // decode 0-th order Golomb code
+    *v = read_golomb(xd, r) + COEFF_BASE_RANGE + 1 + NUM_BASE_LEVELS;
+    if (sign) *v = -(*v);
+    cul_level += abs(*v);
+  }
+
+  for (c = 0; c < *eob; ++c) {
+    int16_t dqv = (c == 0) ? dequant[0] : dequant[1];
+    tran_low_t *v = &tcoeffs[scan[c]];
+    int sign = (*v) < 0;
+    *v = (abs(*v) * dqv) >> shift;
+    if (sign) *v = -(*v);
+  }
+
+  cul_level = AOMMIN(63, cul_level);
+
+  // DC value
+  set_dc_sign(&cul_level, tcoeffs[0]);
+
+  return cul_level;
+}
+
+uint8_t av1_read_coeffs_txb_facade(AV1_COMMON *cm, MACROBLOCKD *xd,
+                                   aom_reader *r, int row, int col, int block,
+                                   int plane, tran_low_t *tcoeffs,
+                                   int16_t *max_scan_line, int *eob) {
+  MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
+  struct macroblockd_plane *pd = &xd->plane[plane];
+
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+#if CONFIG_CB4X4
+#if CONFIG_CHROMA_2X2
+  const BLOCK_SIZE plane_bsize = get_plane_block_size(bsize, pd);
+#else
+  const BLOCK_SIZE plane_bsize =
+      AOMMAX(BLOCK_4X4, get_plane_block_size(bsize, pd));
+#endif  // CONFIG_CHROMA_2X2
+#else   // CONFIG_CB4X4
+  const BLOCK_SIZE plane_bsize =
+      get_plane_block_size(AOMMAX(BLOCK_8X8, bsize), pd);
+#endif  // CONFIG_CB4X4
+
+  TX_SIZE tx_size = get_tx_size(plane, xd);
+  TXB_CTX txb_ctx;
+  get_txb_ctx(plane_bsize, tx_size, plane, pd->above_context + col,
+              pd->left_context + row, &txb_ctx);
+  uint8_t cul_level = av1_read_coeffs_txb(cm, xd, r, block, plane, tcoeffs,
+                                          &txb_ctx, max_scan_line, eob);
+#if CONFIG_ADAPT_SCAN
+  PLANE_TYPE plane_type = get_plane_type(plane);
+  TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
+  if (xd->counts && *eob > 0)
+    av1_update_scan_count_facade(cm, xd->counts, tx_size, tx_type, pd->dqcoeff,
+                                 *eob);
+#endif
+  av1_set_contexts(xd, pd, plane, tx_size, cul_level, col, row);
+  return cul_level;
+}
+
+static void read_txb_probs(FRAME_CONTEXT *fc, const TX_SIZE tx_size,
+                           aom_reader *r) {
+  int plane, ctx, level;
+
+  if (aom_read_bit(r, ACCT_STR) == 0) return;
+
+  for (ctx = 0; ctx < TXB_SKIP_CONTEXTS; ++ctx)
+    av1_diff_update_prob(r, &fc->txb_skip[tx_size][ctx], ACCT_STR);
+
+  for (plane = 0; plane < PLANE_TYPES; ++plane)
+    for (ctx = 0; ctx < SIG_COEF_CONTEXTS; ++ctx)
+      av1_diff_update_prob(r, &fc->nz_map[tx_size][plane][ctx], ACCT_STR);
+
+  for (plane = 0; plane < PLANE_TYPES; ++plane)
+    for (ctx = 0; ctx < EOB_COEF_CONTEXTS; ++ctx)
+      av1_diff_update_prob(r, &fc->eob_flag[tx_size][plane][ctx], ACCT_STR);
+
+  for (level = 0; level < NUM_BASE_LEVELS; ++level)
+    for (plane = 0; plane < PLANE_TYPES; ++plane)
+      for (ctx = 0; ctx < COEFF_BASE_CONTEXTS; ++ctx)
+        av1_diff_update_prob(r, &fc->coeff_base[tx_size][plane][level][ctx],
+                             ACCT_STR);
+
+  for (plane = 0; plane < PLANE_TYPES; ++plane)
+    for (ctx = 0; ctx < LEVEL_CONTEXTS; ++ctx)
+      av1_diff_update_prob(r, &fc->coeff_lps[tx_size][plane][ctx], ACCT_STR);
+}
+
+void av1_read_txb_probs(FRAME_CONTEXT *fc, TX_MODE tx_mode, aom_reader *r) {
+  const TX_SIZE max_tx_size = tx_mode_to_biggest_tx_size[tx_mode];
+  TX_SIZE tx_size;
+  int ctx, plane;
+  for (plane = 0; plane < PLANE_TYPES; ++plane)
+    for (ctx = 0; ctx < DC_SIGN_CONTEXTS; ++ctx)
+      av1_diff_update_prob(r, &fc->dc_sign[plane][ctx], ACCT_STR);
+
+  for (tx_size = TX_4X4; tx_size <= max_tx_size; ++tx_size)
+    read_txb_probs(fc, tx_size, r);
+}