| // Copyright 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "media/capture/webm_muxer.h" |
| |
| #include "base/bind.h" |
| #include "media/audio/audio_parameters.h" |
| #include "media/base/limits.h" |
| #include "media/base/video_frame.h" |
| #include "media/filters/opus_constants.h" |
| #include "ui/gfx/geometry/size.h" |
| |
| namespace media { |
| |
| namespace { |
| |
| void WriteOpusHeader(const media::AudioParameters& params, uint8* header) { |
| // See https://wiki.xiph.org/OggOpus#ID_Header. |
| // Set magic signature. |
| std::string label = "OpusHead"; |
| memcpy(header + OPUS_EXTRADATA_LABEL_OFFSET, &label, label.size()); |
| // Set Opus version. |
| header[OPUS_EXTRADATA_VERSION_OFFSET] = 1; |
| // Set channel count. |
| header[OPUS_EXTRADATA_CHANNELS_OFFSET] = params.channels(); |
| // Set pre-skip |
| uint16 skip = 0; |
| memcpy(header + OPUS_EXTRADATA_SKIP_SAMPLES_OFFSET, &skip, sizeof(uint16)); |
| // Set original input sample rate in Hz. |
| uint32 sample_rate = params.sample_rate(); |
| memcpy(header + OPUS_EXTRADATA_SAMPLE_RATE_OFFSET, &sample_rate, |
| sizeof(uint32)); |
| // Set output gain in dB. |
| uint16 gain = 0; |
| memcpy(header + OPUS_EXTRADATA_GAIN_OFFSET, &gain, 2); |
| |
| // Set channel mapping. |
| if (params.channels() > 2) { |
| // Also possible to have a multistream, not supported for now. |
| DCHECK_LE(params.channels(), OPUS_MAX_VORBIS_CHANNELS); |
| header[OPUS_EXTRADATA_CHANNEL_MAPPING_OFFSET] = 1; |
| // Assuming no coupled streams. This should actually be |
| // channels() - |coupled_streams|. |
| header[OPUS_EXTRADATA_NUM_STREAMS_OFFSET] = params.channels(); |
| header[OPUS_EXTRADATA_NUM_COUPLED_OFFSET] = 0; |
| // Set the actual stream map. |
| for (int i = 0; i < params.channels(); ++i) { |
| header[OPUS_EXTRADATA_STREAM_MAP_OFFSET + i] = |
| kOpusVorbisChannelMap[params.channels() - 1][i]; |
| } |
| } else { |
| header[OPUS_EXTRADATA_CHANNEL_MAPPING_OFFSET] = 0; |
| } |
| } |
| |
| static double GetFrameRate(const scoped_refptr<VideoFrame>& video_frame) { |
| const double kZeroFrameRate = 0.0; |
| const double kDefaultFrameRate = 30.0; |
| |
| double frame_rate = kDefaultFrameRate; |
| if (!video_frame->metadata()->GetDouble( |
| VideoFrameMetadata::FRAME_RATE, &frame_rate) || |
| frame_rate <= kZeroFrameRate || |
| frame_rate > media::limits::kMaxFramesPerSecond) { |
| frame_rate = kDefaultFrameRate; |
| } |
| return frame_rate; |
| } |
| |
| } // anonymous namespace |
| |
| WebmMuxer::WebmMuxer(VideoCodec codec, |
| bool has_video, |
| bool has_audio, |
| const WriteDataCB& write_data_callback) |
| : use_vp9_(codec == kCodecVP9), |
| video_track_index_(0), |
| audio_track_index_(0), |
| has_video_(has_video), |
| has_audio_(has_audio), |
| write_data_callback_(write_data_callback), |
| position_(0) { |
| DCHECK(has_video_ || has_audio_); |
| DCHECK(!write_data_callback_.is_null()); |
| DCHECK(codec == kCodecVP8 || codec == kCodecVP9) |
| << " Only Vp8 and VP9 are supported in WebmMuxer"; |
| |
| segment_.Init(this); |
| segment_.set_mode(mkvmuxer::Segment::kLive); |
| segment_.OutputCues(false); |
| |
| mkvmuxer::SegmentInfo* const info = segment_.GetSegmentInfo(); |
| info->set_writing_app("Chrome"); |
| info->set_muxing_app("Chrome"); |
| |
| // Creation is done on a different thread than main activities. |
| thread_checker_.DetachFromThread(); |
| } |
| |
| WebmMuxer::~WebmMuxer() { |
| // No need to segment_.Finalize() since is not Seekable(), i.e. a live |
| // stream, but is a good practice. |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| segment_.Finalize(); |
| } |
| |
| void WebmMuxer::OnEncodedVideo(const scoped_refptr<VideoFrame>& video_frame, |
| scoped_ptr<std::string> encoded_data, |
| base::TimeTicks timestamp, |
| bool is_key_frame) { |
| DVLOG(1) << __FUNCTION__ << " - " << encoded_data->size() << "B"; |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| |
| if (!video_track_index_) { |
| // |track_index_|, cannot be zero (!), initialize WebmMuxer in that case. |
| // http://www.matroska.org/technical/specs/index.html#Tracks |
| AddVideoTrack(video_frame->visible_rect().size(), |
| GetFrameRate(video_frame)); |
| if (first_frame_timestamp_.is_null()) |
| first_frame_timestamp_ = timestamp; |
| } |
| |
| // TODO(ajose): Don't drop data. http://crbug.com/547948 |
| // TODO(ajose): Update this when we support multiple tracks. |
| // http://crbug.com/528523 |
| if (has_audio_ && !audio_track_index_) { |
| DVLOG(1) << __FUNCTION__ << ": delaying until audio track ready."; |
| return; |
| } |
| |
| most_recent_timestamp_ = |
| std::max(most_recent_timestamp_, timestamp - first_frame_timestamp_); |
| segment_.AddFrame(reinterpret_cast<const uint8_t*>(encoded_data->data()), |
| encoded_data->size(), video_track_index_, |
| most_recent_timestamp_.InMicroseconds() * |
| base::Time::kNanosecondsPerMicrosecond, |
| is_key_frame); |
| } |
| |
| void WebmMuxer::OnEncodedAudio(const media::AudioParameters& params, |
| scoped_ptr<std::string> encoded_data, |
| base::TimeTicks timestamp) { |
| DVLOG(1) << __FUNCTION__ << " - " << encoded_data->size() << "B"; |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| |
| if (!audio_track_index_) { |
| AddAudioTrack(params); |
| if (first_frame_timestamp_.is_null()) |
| first_frame_timestamp_ = timestamp; |
| } |
| |
| // TODO(ajose): Don't drop data. http://crbug.com/547948 |
| // TODO(ajose): Update this when we support multiple tracks. |
| // http://crbug.com/528523 |
| if (has_video_ && !video_track_index_) { |
| DVLOG(1) << __FUNCTION__ << ": delaying until video track ready."; |
| return; |
| } |
| |
| most_recent_timestamp_ = |
| std::max(most_recent_timestamp_, timestamp - first_frame_timestamp_); |
| segment_.AddFrame(reinterpret_cast<const uint8_t*>(encoded_data->data()), |
| encoded_data->size(), audio_track_index_, |
| most_recent_timestamp_.InMicroseconds() * |
| base::Time::kNanosecondsPerMicrosecond, |
| true /* is_key_frame -- always true for audio */); |
| } |
| |
| void WebmMuxer::AddVideoTrack(const gfx::Size& frame_size, double frame_rate) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK_EQ(0u, video_track_index_) |
| << "WebmMuxer can only be initialized once."; |
| |
| video_track_index_ = |
| segment_.AddVideoTrack(frame_size.width(), frame_size.height(), 0); |
| DCHECK_GT(video_track_index_, 0u); |
| |
| mkvmuxer::VideoTrack* const video_track = |
| reinterpret_cast<mkvmuxer::VideoTrack*>( |
| segment_.GetTrackByNumber(video_track_index_)); |
| DCHECK(video_track); |
| video_track->set_codec_id(use_vp9_ ? mkvmuxer::Tracks::kVp9CodecId |
| : mkvmuxer::Tracks::kVp8CodecId); |
| DCHECK_EQ(0ull, video_track->crop_right()); |
| DCHECK_EQ(0ull, video_track->crop_left()); |
| DCHECK_EQ(0ull, video_track->crop_top()); |
| DCHECK_EQ(0ull, video_track->crop_bottom()); |
| |
| video_track->set_frame_rate(frame_rate); |
| video_track->set_default_duration(base::Time::kNanosecondsPerSecond / |
| frame_rate); |
| // Segment's timestamps should be in milliseconds, DCHECK it. See |
| // http://www.webmproject.org/docs/container/#muxer-guidelines |
| DCHECK_EQ(1000000ull, segment_.GetSegmentInfo()->timecode_scale()); |
| } |
| |
| void WebmMuxer::AddAudioTrack(const media::AudioParameters& params) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK_EQ(0u, audio_track_index_) |
| << "WebmMuxer audio can only be initialised once."; |
| |
| audio_track_index_ = |
| segment_.AddAudioTrack(params.sample_rate(), params.channels(), 0); |
| DCHECK_GT(audio_track_index_, 0u); |
| |
| mkvmuxer::AudioTrack* const audio_track = |
| reinterpret_cast<mkvmuxer::AudioTrack*>( |
| segment_.GetTrackByNumber(audio_track_index_)); |
| DCHECK(audio_track); |
| audio_track->set_codec_id(mkvmuxer::Tracks::kOpusCodecId); |
| |
| DCHECK_EQ(params.sample_rate(), audio_track->sample_rate()); |
| DCHECK_EQ(params.channels(), static_cast<int>(audio_track->channels())); |
| |
| uint8 opus_header[OPUS_EXTRADATA_SIZE]; |
| WriteOpusHeader(params, opus_header); |
| |
| if (!audio_track->SetCodecPrivate(opus_header, OPUS_EXTRADATA_SIZE)) |
| LOG(ERROR) << __FUNCTION__ << ": failed to set opus header."; |
| |
| // Segment's timestamps should be in milliseconds, DCHECK it. See |
| // http://www.webmproject.org/docs/container/#muxer-guidelines |
| DCHECK_EQ(1000000ull, segment_.GetSegmentInfo()->timecode_scale()); |
| } |
| |
| mkvmuxer::int32 WebmMuxer::Write(const void* buf, mkvmuxer::uint32 len) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(buf); |
| write_data_callback_.Run( |
| base::StringPiece(reinterpret_cast<const char*>(buf), len)); |
| position_ += len; |
| return 0; |
| } |
| |
| mkvmuxer::int64 WebmMuxer::Position() const { |
| return position_.ValueOrDie(); |
| } |
| |
| mkvmuxer::int32 WebmMuxer::Position(mkvmuxer::int64 position) { |
| // The stream is not Seekable() so indicate we cannot set the position. |
| return -1; |
| } |
| |
| bool WebmMuxer::Seekable() const { |
| return false; |
| } |
| |
| void WebmMuxer::ElementStartNotify(mkvmuxer::uint64 element_id, |
| mkvmuxer::int64 position) { |
| // This method gets pinged before items are sent to |write_data_callback_|. |
| DCHECK_GE(position, position_.ValueOrDefault(0)) |
| << "Can't go back in a live WebM stream."; |
| } |
| |
| } // namespace media |