tor-browser

The Tor Browser
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lookahead.c (7474B)


      1 /*
      2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
      3 *
      4 * This source code is subject to the terms of the BSD 2 Clause License and
      5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6 * was not distributed with this source code in the LICENSE file, you can
      7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8 * Media Patent License 1.0 was not distributed with this source code in the
      9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10 */
     11 #include <assert.h>
     12 #include <stdlib.h>
     13 
     14 #include "config/aom_config.h"
     15 
     16 #include "aom_scale/yv12config.h"
     17 #include "av1/common/common.h"
     18 #include "av1/encoder/encoder.h"
     19 #include "av1/encoder/extend.h"
     20 #include "av1/encoder/lookahead.h"
     21 
     22 /* Return the buffer at the given absolute index and increment the index */
     23 static struct lookahead_entry *pop(struct lookahead_ctx *ctx, int *idx) {
     24  int index = *idx;
     25  struct lookahead_entry *buf = ctx->buf + index;
     26 
     27  assert(index < ctx->max_sz);
     28  if (++index >= ctx->max_sz) index -= ctx->max_sz;
     29  *idx = index;
     30  return buf;
     31 }
     32 
     33 void av1_lookahead_destroy(struct lookahead_ctx *ctx) {
     34  if (ctx) {
     35    if (ctx->buf) {
     36      int i;
     37 
     38      for (i = 0; i < ctx->max_sz; i++) aom_free_frame_buffer(&ctx->buf[i].img);
     39      free(ctx->buf);
     40    }
     41    free(ctx);
     42  }
     43 }
     44 
     45 struct lookahead_ctx *av1_lookahead_init(
     46    int width, int height, int subsampling_x, int subsampling_y,
     47    int use_highbitdepth, int depth, int border_in_pixels, int byte_alignment,
     48    int num_lap_buffers, bool is_all_intra, bool alloc_pyramid) {
     49  int lag_in_frames = AOMMAX(1, depth);
     50 
     51  // For all-intra frame encoding, previous source frames are not required.
     52  // Hence max_pre_frames is set to 0 in this case. As previous source frames
     53  // are accessed using a negative index to av1_lookahead_peek(), setting
     54  // max_pre_frames to 0 will cause av1_lookahead_peek() to return NULL for a
     55  // negative index.
     56  const uint8_t max_pre_frames = is_all_intra ? 0 : MAX_PRE_FRAMES;
     57 
     58  // Add the lags to depth and clamp
     59  depth += num_lap_buffers;
     60  depth = clamp(depth, 1, MAX_TOTAL_BUFFERS);
     61 
     62  // Allocate memory to keep previous source frames available.
     63  depth += max_pre_frames;
     64 
     65  // Allocate the lookahead structures
     66  struct lookahead_ctx *ctx = calloc(1, sizeof(*ctx));
     67  if (ctx) {
     68    ctx->max_sz = depth;
     69    ctx->push_frame_count = 0;
     70    ctx->max_pre_frames = max_pre_frames;
     71    ctx->read_ctxs[ENCODE_STAGE].pop_sz = ctx->max_sz - ctx->max_pre_frames;
     72    ctx->read_ctxs[ENCODE_STAGE].valid = 1;
     73    if (num_lap_buffers) {
     74      ctx->read_ctxs[LAP_STAGE].pop_sz = lag_in_frames;
     75      ctx->read_ctxs[LAP_STAGE].valid = 1;
     76    }
     77    ctx->buf = calloc(depth, sizeof(*ctx->buf));
     78    if (!ctx->buf) goto fail;
     79    for (int i = 0; i < depth; i++) {
     80      if (aom_realloc_frame_buffer(
     81              &ctx->buf[i].img, width, height, subsampling_x, subsampling_y,
     82              use_highbitdepth, border_in_pixels, byte_alignment, NULL, NULL,
     83              NULL, alloc_pyramid, 0)) {
     84        goto fail;
     85      }
     86    }
     87  }
     88  return ctx;
     89 fail:
     90  av1_lookahead_destroy(ctx);
     91  return NULL;
     92 }
     93 
     94 int av1_lookahead_full(const struct lookahead_ctx *ctx) {
     95  // TODO(angiebird): Test this function.
     96  return ctx->read_ctxs[ENCODE_STAGE].sz >= ctx->read_ctxs[ENCODE_STAGE].pop_sz;
     97 }
     98 
     99 int av1_lookahead_push(struct lookahead_ctx *ctx, const YV12_BUFFER_CONFIG *src,
    100                       int64_t ts_start, int64_t ts_end, int use_highbitdepth,
    101                       bool alloc_pyramid, aom_enc_frame_flags_t flags) {
    102  int width = src->y_crop_width;
    103  int height = src->y_crop_height;
    104  int uv_width = src->uv_crop_width;
    105  int uv_height = src->uv_crop_height;
    106  int subsampling_x = src->subsampling_x;
    107  int subsampling_y = src->subsampling_y;
    108  int larger_dimensions, new_dimensions;
    109 
    110  assert(ctx->read_ctxs[ENCODE_STAGE].valid == 1);
    111  if (ctx->read_ctxs[ENCODE_STAGE].sz + ctx->max_pre_frames > ctx->max_sz)
    112    return 1;
    113 
    114  ctx->read_ctxs[ENCODE_STAGE].sz++;
    115  if (ctx->read_ctxs[LAP_STAGE].valid) {
    116    ctx->read_ctxs[LAP_STAGE].sz++;
    117  }
    118 
    119  struct lookahead_entry *buf = pop(ctx, &ctx->write_idx);
    120 
    121  new_dimensions = width != buf->img.y_crop_width ||
    122                   height != buf->img.y_crop_height ||
    123                   uv_width != buf->img.uv_crop_width ||
    124                   uv_height != buf->img.uv_crop_height;
    125  larger_dimensions =
    126      width > buf->img.y_crop_width || height > buf->img.y_crop_height ||
    127      uv_width > buf->img.uv_crop_width || uv_height > buf->img.uv_crop_height;
    128  assert(!larger_dimensions || new_dimensions);
    129 
    130  if (larger_dimensions) {
    131    YV12_BUFFER_CONFIG new_img;
    132    memset(&new_img, 0, sizeof(new_img));
    133    if (aom_alloc_frame_buffer(&new_img, width, height, subsampling_x,
    134                               subsampling_y, use_highbitdepth,
    135                               AOM_BORDER_IN_PIXELS, 0, alloc_pyramid, 0))
    136      return 1;
    137    aom_free_frame_buffer(&buf->img);
    138    buf->img = new_img;
    139  } else if (new_dimensions) {
    140    buf->img.y_width = src->y_width;
    141    buf->img.y_height = src->y_height;
    142    buf->img.uv_width = src->uv_width;
    143    buf->img.uv_height = src->uv_height;
    144    buf->img.y_crop_width = src->y_crop_width;
    145    buf->img.y_crop_height = src->y_crop_height;
    146    buf->img.uv_crop_width = src->uv_crop_width;
    147    buf->img.uv_crop_height = src->uv_crop_height;
    148    buf->img.subsampling_x = src->subsampling_x;
    149    buf->img.subsampling_y = src->subsampling_y;
    150  }
    151  av1_copy_and_extend_frame(src, &buf->img);
    152 
    153  buf->ts_start = ts_start;
    154  buf->ts_end = ts_end;
    155  buf->display_idx = ctx->push_frame_count;
    156  buf->flags = flags;
    157  ++ctx->push_frame_count;
    158  aom_remove_metadata_from_frame_buffer(&buf->img);
    159  if (src->metadata &&
    160      aom_copy_metadata_to_frame_buffer(&buf->img, src->metadata)) {
    161    return 1;
    162  }
    163  return 0;
    164 }
    165 
    166 struct lookahead_entry *av1_lookahead_pop(struct lookahead_ctx *ctx, int drain,
    167                                          COMPRESSOR_STAGE stage) {
    168  struct lookahead_entry *buf = NULL;
    169  if (ctx) {
    170    struct read_ctx *read_ctx = &ctx->read_ctxs[stage];
    171    assert(read_ctx->valid == 1);
    172    if (read_ctx->sz && (drain || read_ctx->sz == read_ctx->pop_sz)) {
    173      buf = pop(ctx, &read_ctx->read_idx);
    174      read_ctx->sz--;
    175    }
    176  }
    177  return buf;
    178 }
    179 
    180 struct lookahead_entry *av1_lookahead_peek(struct lookahead_ctx *ctx, int index,
    181                                           COMPRESSOR_STAGE stage) {
    182  struct lookahead_entry *buf = NULL;
    183  if (ctx == NULL) {
    184    return buf;
    185  }
    186 
    187  struct read_ctx *read_ctx = &ctx->read_ctxs[stage];
    188  assert(read_ctx->valid == 1);
    189  if (index >= 0) {
    190    // Forward peek
    191    if (index < read_ctx->sz) {
    192      index += read_ctx->read_idx;
    193      if (index >= ctx->max_sz) index -= ctx->max_sz;
    194      buf = ctx->buf + index;
    195    }
    196  } else if (index < 0) {
    197    // Backward peek
    198    if (-index <= ctx->max_pre_frames) {
    199      index += (int)(read_ctx->read_idx);
    200      if (index < 0) index += (int)(ctx->max_sz);
    201      buf = ctx->buf + index;
    202    }
    203  }
    204 
    205  return buf;
    206 }
    207 
    208 int av1_lookahead_depth(struct lookahead_ctx *ctx, COMPRESSOR_STAGE stage) {
    209  assert(ctx != NULL);
    210 
    211  struct read_ctx *read_ctx = &ctx->read_ctxs[stage];
    212  assert(read_ctx->valid == 1);
    213  return read_ctx->sz;
    214 }
    215 
    216 int av1_lookahead_pop_sz(struct lookahead_ctx *ctx, COMPRESSOR_STAGE stage) {
    217  assert(ctx != NULL);
    218 
    219  struct read_ctx *read_ctx = &ctx->read_ctxs[stage];
    220  assert(read_ctx->valid == 1);
    221  return read_ctx->pop_sz;
    222 }