gecko-dev/dom/media/ogg/OggDecoder.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "OggDecoder.h"
#include "MediaContainerType.h"
#include "MediaDecoder.h"
#include "mozilla/StaticPrefs_media.h"
#include "nsMimeTypes.h"

namespace mozilla {

/* static */
bool OggDecoder::IsSupportedType(const MediaContainerType& aContainerType) {
  if (!StaticPrefs::media_ogg_enabled()) {
    return false;
  }

  if (aContainerType.Type() != MEDIAMIMETYPE(AUDIO_OGG) &&
      aContainerType.Type() != MEDIAMIMETYPE(VIDEO_OGG) &&
      aContainerType.Type() != MEDIAMIMETYPE("application/ogg")) {
    return false;
  }

  const bool isOggVideo = (aContainerType.Type() != MEDIAMIMETYPE(AUDIO_OGG));

  const MediaCodecs& codecs = aContainerType.ExtendedType().Codecs();
  if (codecs.IsEmpty()) {
    // Ogg guarantees that the only codecs it contained are supported.
    return true;
  }
  // Verify that all the codecs specified are ones that we expect that
  // we can play.
  for (const auto& codec : codecs.Range()) {
    if ((MediaDecoder::IsOpusEnabled() && codec.EqualsLiteral("opus")) ||
        codec.EqualsLiteral("vorbis") || codec.EqualsLiteral("flac")) {
      continue;
    }
    // Note: Only accept Theora in a video container type, not in an audio
    // container type.
    if (isOggVideo && codec.EqualsLiteral("theora")) {
      continue;
    }
    // Some unsupported codec.
    return false;
  }
  return true;
}

/* static */
nsTArray<UniquePtr<TrackInfo>> OggDecoder::GetTracksInfo(
    const MediaContainerType& aType) {
  nsTArray<UniquePtr<TrackInfo>> tracks;
  if (!IsSupportedType(aType)) {
    return tracks;
  }

  const MediaCodecs& codecs = aType.ExtendedType().Codecs();
  if (codecs.IsEmpty()) {
    // Codecs must be specified for ogg as it can't be implied.
    return tracks;
  }

  for (const auto& codec : codecs.Range()) {
    if (codec.EqualsLiteral("opus") || codec.EqualsLiteral("vorbis") ||
        codec.EqualsLiteral("flac")) {
      tracks.AppendElement(
          CreateTrackInfoWithMIMETypeAndContainerTypeExtraParameters(
              "audio/"_ns + NS_ConvertUTF16toUTF8(codec), aType));
    } else {
      MOZ_ASSERT(codec.EqualsLiteral("theora"));
      tracks.AppendElement(
          CreateTrackInfoWithMIMETypeAndContainerTypeExtraParameters(
              "video/"_ns + NS_ConvertUTF16toUTF8(codec), aType));
    }
  }
  return tracks;
}

}  // namespace mozilla