webmdec.cc

/*
 *  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.hpp"
#include "third_party/libwebm/mkvreader.hpp"

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;
}

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;

  mkvparser::EBMLHeader header;
  long long pos = 0;
  if (header.Parse(reader, pos) < 0) {
    rewind_and_reset(webm_ctx, vpx_ctx);
    return 0;