| // Copyright (c) 2012 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/filters/opus_audio_decoder.h" |
| |
| #include <cmath> |
| |
| #include "base/single_thread_task_runner.h" |
| #include "base/sys_byteorder.h" |
| #include "media/base/audio_buffer.h" |
| #include "media/base/audio_decoder_config.h" |
| #include "media/base/audio_discard_helper.h" |
| #include "media/base/bind_to_current_loop.h" |
| #include "media/base/buffers.h" |
| #include "media/base/decoder_buffer.h" |
| #include "third_party/opus/src/include/opus.h" |
| #include "third_party/opus/src/include/opus_multistream.h" |
| |
| namespace media { |
| |
| static uint16 ReadLE16(const uint8* data, size_t data_size, int read_offset) { |
| uint16 value = 0; |
| DCHECK_LE(read_offset + sizeof(value), data_size); |
| memcpy(&value, data + read_offset, sizeof(value)); |
| return base::ByteSwapToLE16(value); |
| } |
| |
| // The Opus specification is part of IETF RFC 6716: |
| // http://tools.ietf.org/html/rfc6716 |
| |
| // Opus uses Vorbis channel mapping, and Vorbis channel mapping specifies |
| // mappings for up to 8 channels. This information is part of the Vorbis I |
| // Specification: |
| // http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html |
| static const int kMaxVorbisChannels = 8; |
| |
| // Maximum packet size used in Xiph's opusdec and FFmpeg's libopusdec. |
| static const int kMaxOpusOutputPacketSizeSamples = 960 * 6; |
| |
| static void RemapOpusChannelLayout(const uint8* opus_mapping, |
| int num_channels, |
| uint8* channel_layout) { |
| DCHECK_LE(num_channels, kMaxVorbisChannels); |
| |
| // Opus uses Vorbis channel layout. |
| const int32 num_layouts = kMaxVorbisChannels; |
| const int32 num_layout_values = kMaxVorbisChannels; |
| |
| // Vorbis channel ordering for streams with >= 2 channels: |
| // 2 Channels |
| // L, R |
| // 3 Channels |
| // L, Center, R |
| // 4 Channels |
| // Front L, Front R, Back L, Back R |
| // 5 Channels |
| // Front L, Center, Front R, Back L, Back R |
| // 6 Channels (5.1) |
| // Front L, Center, Front R, Back L, Back R, LFE |
| // 7 channels (6.1) |
| // Front L, Front Center, Front R, Side L, Side R, Back Center, LFE |
| // 8 Channels (7.1) |
| // Front L, Center, Front R, Side L, Side R, Back L, Back R, LFE |
| // |
| // Channel ordering information is taken from section 4.3.9 of the Vorbis I |
| // Specification: |
| // http://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-800004.3.9 |
| |
| // These are the FFmpeg channel layouts expressed using the position of each |
| // channel in the output stream from libopus. |
| const uint8 kFFmpegChannelLayouts[num_layouts][num_layout_values] = { |
| { 0 }, |
| |
| // Stereo: No reorder. |
| { 0, 1 }, |
| |
| // 3 Channels, from Vorbis order to: |
| // L, R, Center |
| { 0, 2, 1 }, |
| |
| // 4 Channels: No reorder. |
| { 0, 1, 2, 3 }, |
| |
| // 5 Channels, from Vorbis order to: |
| // Front L, Front R, Center, Back L, Back R |
| { 0, 2, 1, 3, 4 }, |
| |
| // 6 Channels (5.1), from Vorbis order to: |
| // Front L, Front R, Center, LFE, Back L, Back R |
| { 0, 2, 1, 5, 3, 4 }, |
| |
| // 7 Channels (6.1), from Vorbis order to: |
| // Front L, Front R, Front Center, LFE, Side L, Side R, Back Center |
| { 0, 2, 1, 6, 3, 4, 5 }, |
| |
| // 8 Channels (7.1), from Vorbis order to: |
| // Front L, Front R, Center, LFE, Back L, Back R, Side L, Side R |
| { 0, 2, 1, 7, 5, 6, 3, 4 }, |
| }; |
| |
| // Reorder the channels to produce the same ordering as FFmpeg, which is |
| // what the pipeline expects. |
| const uint8* vorbis_layout_offset = kFFmpegChannelLayouts[num_channels - 1]; |
| for (int channel = 0; channel < num_channels; ++channel) |
| channel_layout[channel] = opus_mapping[vorbis_layout_offset[channel]]; |
| } |
| |
| // Opus Extra Data contents: |
| // - "OpusHead" (64 bits) |
| // - version number (8 bits) |
| // - Channels C (8 bits) |
| // - Pre-skip (16 bits) |
| // - Sampling rate (32 bits) |
| // - Gain in dB (16 bits, S7.8) |
| // - Mapping (8 bits, 0=single stream (mono/stereo) 1=Vorbis mapping, |
| // 2..254: reserved, 255: multistream with no mapping) |
| // |
| // - if (mapping != 0) |
| // - N = totel number of streams (8 bits) |
| // - M = number of paired streams (8 bits) |
| // - C times channel origin |
| // - if (C<2*M) |
| // - stream = byte/2 |
| // - if (byte&0x1 == 0) |
| // - left |
| // else |
| // - right |
| // - else |
| // - stream = byte-M |
| |
| // Default audio output channel layout. Used to initialize |stream_map| in |
| // OpusExtraData, and passed to opus_multistream_decoder_create() when the |
| // extra data does not contain mapping information. The values are valid only |
| // for mono and stereo output: Opus streams with more than 2 channels require a |
| // stream map. |
| static const int kMaxChannelsWithDefaultLayout = 2; |
| static const uint8 kDefaultOpusChannelLayout[kMaxChannelsWithDefaultLayout] = { |
| 0, 1 }; |
| |
| // Size of the Opus extra data excluding optional mapping information. |
| static const int kOpusExtraDataSize = 19; |
| |
| // Offset to the channel count byte in the Opus extra data. |
| static const int kOpusExtraDataChannelsOffset = 9; |
| |
| // Offset to the pre-skip value in the Opus extra data. |
| static const int kOpusExtraDataSkipSamplesOffset = 10; |
| |
| // Offset to the gain value in the Opus extra data. |
| static const int kOpusExtraDataGainOffset = 16; |
| |
| // Offset to the channel mapping byte in the Opus extra data. |
| static const int kOpusExtraDataChannelMappingOffset = 18; |
| |
| // Extra Data contains a stream map. The mapping values are in extra data beyond |
| // the always present |kOpusExtraDataSize| bytes of data. The mapping data |
| // contains stream count, coupling information, and per channel mapping values: |
| // - Byte 0: Number of streams. |
| // - Byte 1: Number coupled. |
| // - Byte 2: Starting at byte 2 are |extra_data->channels| uint8 mapping |
| // values. |
| static const int kOpusExtraDataNumStreamsOffset = kOpusExtraDataSize; |
| static const int kOpusExtraDataNumCoupledOffset = |
| kOpusExtraDataNumStreamsOffset + 1; |
| static const int kOpusExtraDataStreamMapOffset = |
| kOpusExtraDataNumStreamsOffset + 2; |
| |
| struct OpusExtraData { |
| OpusExtraData() |
| : channels(0), |
| skip_samples(0), |
| channel_mapping(0), |
| num_streams(0), |
| num_coupled(0), |
| gain_db(0), |
| stream_map() { |
| memcpy(stream_map, |
| kDefaultOpusChannelLayout, |
| kMaxChannelsWithDefaultLayout); |
| } |
| int channels; |
| uint16 skip_samples; |
| int channel_mapping; |
| int num_streams; |
| int num_coupled; |
| int16 gain_db; |
| uint8 stream_map[kMaxVorbisChannels]; |
| }; |
| |
| // Returns true when able to successfully parse and store Opus extra data in |
| // |extra_data|. Based on opus header parsing code in libopusdec from FFmpeg, |
| // and opus_header from Xiph's opus-tools project. |
| static bool ParseOpusExtraData(const uint8* data, int data_size, |
| const AudioDecoderConfig& config, |
| OpusExtraData* extra_data) { |
| if (data_size < kOpusExtraDataSize) { |
| DLOG(ERROR) << "Extra data size is too small:" << data_size; |
| return false; |
| } |
| |
| extra_data->channels = *(data + kOpusExtraDataChannelsOffset); |
| |
| if (extra_data->channels <= 0 || extra_data->channels > kMaxVorbisChannels) { |
| DLOG(ERROR) << "invalid channel count in extra data: " |
| << extra_data->channels; |
| return false; |
| } |
| |
| extra_data->skip_samples = |
| ReadLE16(data, data_size, kOpusExtraDataSkipSamplesOffset); |
| extra_data->gain_db = static_cast<int16>( |
| ReadLE16(data, data_size, kOpusExtraDataGainOffset)); |
| |
| extra_data->channel_mapping = *(data + kOpusExtraDataChannelMappingOffset); |
| |
| if (!extra_data->channel_mapping) { |
| if (extra_data->channels > kMaxChannelsWithDefaultLayout) { |
| DLOG(ERROR) << "Invalid extra data, missing stream map."; |
| return false; |
| } |
| |
| extra_data->num_streams = 1; |
| extra_data->num_coupled = |
| (ChannelLayoutToChannelCount(config.channel_layout()) > 1) ? 1 : 0; |
| return true; |
| } |
| |
| if (data_size < kOpusExtraDataStreamMapOffset + extra_data->channels) { |
| DLOG(ERROR) << "Invalid stream map; insufficient data for current channel " |
| << "count: " << extra_data->channels; |
| return false; |
| } |
| |
| extra_data->num_streams = *(data + kOpusExtraDataNumStreamsOffset); |
| extra_data->num_coupled = *(data + kOpusExtraDataNumCoupledOffset); |
| |
| if (extra_data->num_streams + extra_data->num_coupled != extra_data->channels) |
| DVLOG(1) << "Inconsistent channel mapping."; |
| |
| for (int i = 0; i < extra_data->channels; ++i) |
| extra_data->stream_map[i] = *(data + kOpusExtraDataStreamMapOffset + i); |
| return true; |
| } |
| |
| OpusAudioDecoder::OpusAudioDecoder( |
| const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) |
| : task_runner_(task_runner), |
| opus_decoder_(NULL), |
| start_input_timestamp_(kNoTimestamp()) {} |
| |
| void OpusAudioDecoder::Initialize(const AudioDecoderConfig& config, |
| const PipelineStatusCB& status_cb, |
| const OutputCB& output_cb) { |
| DCHECK(task_runner_->BelongsToCurrentThread()); |
| PipelineStatusCB initialize_cb = BindToCurrentLoop(status_cb); |
| |
| config_ = config; |
| output_cb_ = BindToCurrentLoop(output_cb); |
| |
| if (!ConfigureDecoder()) { |
| initialize_cb.Run(DECODER_ERROR_NOT_SUPPORTED); |
| return; |
| } |
| |
| initialize_cb.Run(PIPELINE_OK); |
| } |
| |
| void OpusAudioDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer, |
| const DecodeCB& decode_cb) { |
| DCHECK(task_runner_->BelongsToCurrentThread()); |
| DCHECK(!decode_cb.is_null()); |
| |
| DecodeBuffer(buffer, BindToCurrentLoop(decode_cb)); |
| } |
| |
| void OpusAudioDecoder::Reset(const base::Closure& closure) { |
| DCHECK(task_runner_->BelongsToCurrentThread()); |
| |
| opus_multistream_decoder_ctl(opus_decoder_, OPUS_RESET_STATE); |
| ResetTimestampState(); |
| task_runner_->PostTask(FROM_HERE, closure); |
| } |
| |
| void OpusAudioDecoder::Stop() { |
| DCHECK(task_runner_->BelongsToCurrentThread()); |
| |
| if (!opus_decoder_) |
| return; |
| |
| opus_multistream_decoder_ctl(opus_decoder_, OPUS_RESET_STATE); |
| ResetTimestampState(); |
| CloseDecoder(); |
| } |
| |
| OpusAudioDecoder::~OpusAudioDecoder() {} |
| |
| void OpusAudioDecoder::DecodeBuffer( |
| const scoped_refptr<DecoderBuffer>& input, |
| const DecodeCB& decode_cb) { |
| DCHECK(task_runner_->BelongsToCurrentThread()); |
| DCHECK(!decode_cb.is_null()); |
| |
| DCHECK(input.get()); |
| |
| // Libopus does not buffer output. Decoding is complete when an end of stream |
| // input buffer is received. |
| if (input->end_of_stream()) { |
| decode_cb.Run(kOk); |
| return; |
| } |
| |
| // Make sure we are notified if http://crbug.com/49709 returns. Issue also |
| // occurs with some damaged files. |
| if (input->timestamp() == kNoTimestamp()) { |
| DLOG(ERROR) << "Received a buffer without timestamps!"; |
| decode_cb.Run(kDecodeError); |
| return; |
| } |
| |
| // Apply the necessary codec delay. |
| if (start_input_timestamp_ == kNoTimestamp()) |
| start_input_timestamp_ = input->timestamp(); |
| if (!discard_helper_->initialized() && |
| input->timestamp() == start_input_timestamp_) { |
| discard_helper_->Reset(config_.codec_delay()); |
| } |
| |
| scoped_refptr<AudioBuffer> output_buffer; |
| |
| if (!Decode(input, &output_buffer)) { |
| decode_cb.Run(kDecodeError); |
| return; |
| } |
| |
| if (output_buffer) { |
| output_cb_.Run(output_buffer); |
| } |
| |
| decode_cb.Run(kOk); |
| } |
| |
| bool OpusAudioDecoder::ConfigureDecoder() { |
| if (config_.codec() != kCodecOpus) { |
| DVLOG(1) << "Codec must be kCodecOpus."; |
| return false; |
| } |
| |
| const int channel_count = |
| ChannelLayoutToChannelCount(config_.channel_layout()); |
| if (!config_.IsValidConfig() || channel_count > kMaxVorbisChannels) { |
| DLOG(ERROR) << "Invalid or unsupported audio stream -" |
| << " codec: " << config_.codec() |
| << " channel count: " << channel_count |
| << " channel layout: " << config_.channel_layout() |
| << " bits per channel: " << config_.bits_per_channel() |
| << " samples per second: " << config_.samples_per_second(); |
| return false; |
| } |
| |
| if (config_.is_encrypted()) { |
| DLOG(ERROR) << "Encrypted audio stream not supported."; |
| return false; |
| } |
| |
| // Clean up existing decoder if necessary. |
| CloseDecoder(); |
| |
| // Parse the Opus Extra Data. |
| OpusExtraData opus_extra_data; |
| if (!ParseOpusExtraData(config_.extra_data(), config_.extra_data_size(), |
| config_, |
| &opus_extra_data)) |
| return false; |
| |
| if (config_.codec_delay() < 0) { |
| DLOG(ERROR) << "Invalid file. Incorrect value for codec delay: " |
| << config_.codec_delay(); |
| return false; |
| } |
| |
| if (config_.codec_delay() != opus_extra_data.skip_samples) { |
| DLOG(ERROR) << "Invalid file. Codec Delay in container does not match the " |
| << "value in Opus Extra Data. " << config_.codec_delay() |
| << " vs " << opus_extra_data.skip_samples; |
| return false; |
| } |
| |
| uint8 channel_mapping[kMaxVorbisChannels] = {0}; |
| memcpy(&channel_mapping, |
| kDefaultOpusChannelLayout, |
| kMaxChannelsWithDefaultLayout); |
| |
| if (channel_count > kMaxChannelsWithDefaultLayout) { |
| RemapOpusChannelLayout(opus_extra_data.stream_map, |
| channel_count, |
| channel_mapping); |
| } |
| |
| // Init Opus. |
| int status = OPUS_INVALID_STATE; |
| opus_decoder_ = opus_multistream_decoder_create(config_.samples_per_second(), |
| channel_count, |
| opus_extra_data.num_streams, |
| opus_extra_data.num_coupled, |
| channel_mapping, |
| &status); |
| if (!opus_decoder_ || status != OPUS_OK) { |
| DLOG(ERROR) << "opus_multistream_decoder_create failed status=" |
| << opus_strerror(status); |
| return false; |
| } |
| |
| status = opus_multistream_decoder_ctl( |
| opus_decoder_, OPUS_SET_GAIN(opus_extra_data.gain_db)); |
| if (status != OPUS_OK) { |
| DLOG(ERROR) << "Failed to set OPUS header gain; status=" |
| << opus_strerror(status); |
| return false; |
| } |
| |
| discard_helper_.reset( |
| new AudioDiscardHelper(config_.samples_per_second(), 0)); |
| start_input_timestamp_ = kNoTimestamp(); |
| return true; |
| } |
| |
| void OpusAudioDecoder::CloseDecoder() { |
| if (opus_decoder_) { |
| opus_multistream_decoder_destroy(opus_decoder_); |
| opus_decoder_ = NULL; |
| } |
| } |
| |
| void OpusAudioDecoder::ResetTimestampState() { |
| discard_helper_->Reset( |
| discard_helper_->TimeDeltaToFrames(config_.seek_preroll())); |
| } |
| |
| bool OpusAudioDecoder::Decode(const scoped_refptr<DecoderBuffer>& input, |
| scoped_refptr<AudioBuffer>* output_buffer) { |
| // Allocate a buffer for the output samples. |
| *output_buffer = AudioBuffer::CreateBuffer( |
| config_.sample_format(), |
| config_.channel_layout(), |
| ChannelLayoutToChannelCount(config_.channel_layout()), |
| config_.samples_per_second(), |
| kMaxOpusOutputPacketSizeSamples); |
| const int buffer_size = |
| output_buffer->get()->channel_count() * |
| output_buffer->get()->frame_count() * |
| SampleFormatToBytesPerChannel(config_.sample_format()); |
| |
| float* float_output_buffer = reinterpret_cast<float*>( |
| output_buffer->get()->channel_data()[0]); |
| const int frames_decoded = |
| opus_multistream_decode_float(opus_decoder_, |
| input->data(), |
| input->data_size(), |
| float_output_buffer, |
| buffer_size, |
| 0); |
| |
| if (frames_decoded < 0) { |
| DLOG(ERROR) << "opus_multistream_decode failed for" |
| << " timestamp: " << input->timestamp().InMicroseconds() |
| << " us, duration: " << input->duration().InMicroseconds() |
| << " us, packet size: " << input->data_size() << " bytes with" |
| << " status: " << opus_strerror(frames_decoded); |
| return false; |
| } |
| |
| // Trim off any extraneous allocation. |
| DCHECK_LE(frames_decoded, output_buffer->get()->frame_count()); |
| const int trim_frames = output_buffer->get()->frame_count() - frames_decoded; |
| if (trim_frames > 0) |
| output_buffer->get()->TrimEnd(trim_frames); |
| |
| // Handles discards and timestamping. Discard the buffer if more data needed. |
| if (!discard_helper_->ProcessBuffers(input, *output_buffer)) |
| *output_buffer = NULL; |
| |
| return true; |
| } |
| |
| } // namespace media |