/* *  Copyright (c) 2013 The WebM project authors. All Rights Reserved. * *  Use of this source code is governed by a BSD-style license *  that can be found in the LICENSE file in the root of the source *  tree. An additional intellectual property rights grant can be found *  in the file PATENTS.  All contributing project authors may *  be found in the AUTHORS file in the root of the source tree. */ #include "./webmdec.h" #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 VpxInputContext *const vpx_ctx) {  rewind(vpx_ctx->file);  reset(webm_ctx);} }  // namespace int file_is_webm(struct WebmInputContext *webm_ctx,                 struct VpxInputContext *vpx_ctx) {  mkvparser::MkvReader *const reader = new mkvparser::MkvReader(vpx_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, vpx_ctx);    return 0;  }   mkvparser::Segment* segment;  if (mkvparser::Segment::CreateInstance(reader, pos, segment)) {    rewind_and_reset(webm_ctx, vpx_ctx);    return 0;  }  webm_ctx->segment = segment;  if (segment->Load() < 0) {    rewind_and_reset(webm_ctx, vpx_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 = track->GetNumber();      break;    }  }   if (video_track == NULL || video_track->GetCodecId() == NULL) {    rewind_and_reset(webm_ctx, vpx_ctx);    return 0;  }   if (!strncmp(video_track->GetCodecId(), "V_VP8", 5)) {    vpx_ctx->fourcc = VP8_FOURCC;  } else if (!strncmp(video_track->GetCodecId(), "V_VP9", 5)) {    vpx_ctx->fourcc = VP9_FOURCC;  } else {    rewind_and_reset(webm_ctx, vpx_ctx);    return 0;  }   vpx_ctx->framerate.denominator = 0;  vpx_ctx->framerate.numerator = 0;  vpx_ctx->width = static_cast<uint32_t>(video_track->GetWidth());  vpx_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 *buffer_size) {  // 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()) {        *buffer_size = 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();      webm_ctx->block_frame_index = 0;    }  } while (block->GetTrackNumber() != webm_ctx->video_track_index ||           block_entry_eos);   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];    if (*buffer == NULL) {      return -1;    }    webm_ctx->buffer = *buffer;  }  *buffer_size = 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 VpxInputContext *vpx_ctx) {  uint32_t i = 0;  uint8_t *buffer = NULL;  size_t buffer_size = 0;  while (webm_ctx->timestamp_ns < 1000000000 && i < 50) {    if (webm_read_frame(webm_ctx, &buffer, &buffer_size)) {      break;    }    ++i;  }  vpx_ctx->framerate.numerator = (i - 1) * 1000000;  vpx_ctx->framerate.denominator =      static_cast<int>(webm_ctx->timestamp_ns / 1000);  delete[] buffer;   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);}