audio_converter.cc revision effb81e5f8246d0db0270817048dc992db66e9fb
12a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 22a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 32a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// found in the LICENSE file. 4c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// 5c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// AudioConverter implementation. Uses MultiChannelSincResampler for resampling 6c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// audio, ChannelMixer for channel mixing, and AudioPullFifo for buffering. 7c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// 8c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// Delay estimates are provided to InputCallbacks based on the frame delay 9c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)// information reported via the resampler and FIFO units. 102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/audio_converter.h" 122a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 132a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include <algorithm> 142a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "base/bind.h" 162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "base/bind_helpers.h" 1790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include "media/base/audio_bus.h" 182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/audio_pull_fifo.h" 192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/channel_mixer.h" 202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/multi_channel_resampler.h" 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/vector_math.h" 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace media { 242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)AudioConverter::AudioConverter(const AudioParameters& input_params, 262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) const AudioParameters& output_params, 272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool disable_fifo) 28effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch : chunk_size_(input_params.frames_per_buffer()), 2923730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) downmix_early_(false), 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_(0), 312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_channel_count_(input_params.channels()) { 322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) CHECK(input_params.IsValid()); 332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) CHECK(output_params.IsValid()); 342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Handle different input and output channel layouts. 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (input_params.channel_layout() != output_params.channel_layout()) { 372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Remixing channel layout from " << input_params.channel_layout() 382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << " to " << output_params.channel_layout() << "; from " 392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << input_params.channels() << " channels to " 402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << output_params.channels() << " channels."; 412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_.reset(new ChannelMixer(input_params, output_params)); 422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Pare off data as early as we can for efficiency. 442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) downmix_early_ = input_params.channels() > output_params.channels(); 452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Only resample if necessary since it's expensive. 482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (input_params.sample_rate() != output_params.sample_rate()) { 492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Resampling from " << input_params.sample_rate() << " to " 502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << output_params.sample_rate(); 51b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) const int request_size = disable_fifo ? SincResampler::kDefaultRequestSize : 52b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) input_params.frames_per_buffer(); 53effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch const double io_sample_rate_ratio = 54effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch input_params.sample_rate() / 55effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch static_cast<double>(output_params.sample_rate()); 562a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_.reset(new MultiChannelResampler( 57effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch downmix_early_ ? output_params.channels() : input_params.channels(), 58effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch io_sample_rate_ratio, 59effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch request_size, 60effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch base::Bind(&AudioConverter::ProvideInput, base::Unretained(this)))); 612a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 622a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 632a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_frame_duration_ = base::TimeDelta::FromMicroseconds( 642a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) base::Time::kMicrosecondsPerSecond / 652a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) static_cast<double>(input_params.sample_rate())); 662a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) output_frame_duration_ = base::TimeDelta::FromMicroseconds( 672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) base::Time::kMicrosecondsPerSecond / 682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) static_cast<double>(output_params.sample_rate())); 692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 70b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) // The resampler can be configured to work with a specific request size, so a 71b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) // FIFO is not necessary when resampling. 72b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) if (disable_fifo || resampler_) 732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return; 742a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 75b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) // Since the output device may want a different buffer size than the caller 76b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) // asked for, we need to use a FIFO to ensure that both sides read in chunk 77b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) // sizes they're configured for. 78b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) if (input_params.frames_per_buffer() != output_params.frames_per_buffer()) { 792a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Rebuffering from " << input_params.frames_per_buffer() 802a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << " to " << output_params.frames_per_buffer(); 8123730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) chunk_size_ = input_params.frames_per_buffer(); 822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_.reset(new AudioPullFifo( 8323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) downmix_early_ ? output_params.channels() : input_params.channels(), 8423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) chunk_size_, 8523730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) base::Bind(&AudioConverter::SourceCallback, base::Unretained(this)))); 862a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 882a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)AudioConverter::~AudioConverter() {} 902a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 912a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::AddInput(InputCallback* input) { 92a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) DCHECK(std::find(transform_inputs_.begin(), transform_inputs_.end(), input) == 93a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) transform_inputs_.end()); 942a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.push_back(input); 952a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 962a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 972a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::RemoveInput(InputCallback* input) { 982a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK(std::find(transform_inputs_.begin(), transform_inputs_.end(), input) != 992a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.end()); 1002a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.remove(input); 1012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1022a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (transform_inputs_.empty()) 1032a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Reset(); 1042a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1062a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::Reset() { 1072a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) 1082a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_->Clear(); 1092a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) 1102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_->Flush(); 1112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1122a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 11323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)int AudioConverter::ChunkSize() const { 11423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) if (!resampler_) 11523730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) return chunk_size_; 11623730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) return resampler_->ChunkSize(); 11723730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)} 11823730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 119c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)void AudioConverter::ConvertWithDelay(const base::TimeDelta& initial_delay, 120c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) AudioBus* dest) { 121c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) initial_delay_ = initial_delay; 122c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) 1232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (transform_inputs_.empty()) { 1242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) dest->Zero(); 1252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return; 1262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 128c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Determine if channel mixing should be done and if it should be done before 129c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // or after resampling. If it's possible to reduce the channel count prior to 130c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // resampling we can save a lot of processing time. Vice versa, we don't want 131c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // to increase the channel count prior to resampling for the same reason. 1322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool needs_mixing = channel_mixer_ && !downmix_early_; 13323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 13423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) if (needs_mixing) 13523730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) CreateUnmixedAudioIfNecessary(dest->frames()); 13623730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 1372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AudioBus* temp_dest = needs_mixing ? unmixed_audio_.get() : dest; 1382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK(temp_dest); 1392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 140c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Figure out which method to call based on whether we're resampling and 141c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // rebuffering, just resampling, or just mixing. We want to avoid any extra 142c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // steps when possible since we may be converting audio data in real time. 1432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!resampler_ && !audio_fifo_) { 1442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) SourceCallback(0, temp_dest); 1452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } else { 1462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) 147b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) resampler_->Resample(temp_dest->frames(), temp_dest); 1482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) else 1492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) ProvideInput(0, temp_dest); 1502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 152c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Finally upmix the channels if we didn't do so earlier. 1532a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (needs_mixing) { 1542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), dest->frames()); 1552a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_->Transform(temp_dest, dest); 1562a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1572a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1582a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 159c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)void AudioConverter::Convert(AudioBus* dest) { 160c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) ConvertWithDelay(base::TimeDelta::FromMilliseconds(0), dest); 161c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)} 162c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) 1632a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::SourceCallback(int fifo_frame_delay, AudioBus* dest) { 164effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch const bool needs_downmix = channel_mixer_ && downmix_early_; 1652a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1662a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!mixer_input_audio_bus_ || 1672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->frames() != dest->frames()) { 1682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_ = 1692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AudioBus::Create(input_channel_count_, dest->frames()); 1702a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1712a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 17223730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) // If we're downmixing early we need a temporary AudioBus which matches 17323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) // the the input channel count and input frame size since we're passing 17423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) // |unmixed_audio_| directly to the |source_callback_|. 17523730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) if (needs_downmix) 17623730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) CreateUnmixedAudioIfNecessary(dest->frames()); 1772a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 178effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch AudioBus* const temp_dest = needs_downmix ? unmixed_audio_.get() : dest; 1792a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1802a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Sanity check our inputs. 1812a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), mixer_input_audio_bus_->frames()); 1822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->channels(), mixer_input_audio_bus_->channels()); 1832a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1842a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Calculate the buffer delay for this callback. 185c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) base::TimeDelta buffer_delay = initial_delay_; 1862a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) { 1872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) buffer_delay += base::TimeDelta::FromMicroseconds( 1882a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_ * output_frame_duration_.InMicroseconds()); 1892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1902a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) { 1912a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) buffer_delay += base::TimeDelta::FromMicroseconds( 1922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) fifo_frame_delay * input_frame_duration_.InMicroseconds()); 1932a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1942a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 195effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // If we only have a single input, avoid an extra copy. 196effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch AudioBus* const provide_input_dest = 197effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch transform_inputs_.size() == 1 ? temp_dest : mixer_input_audio_bus_.get(); 198effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch 1992a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Have each mixer render its data into an output buffer then mix the result. 2002a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) for (InputCallbackSet::iterator it = transform_inputs_.begin(); 2012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) it != transform_inputs_.end(); ++it) { 2022a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) InputCallback* input = *it; 2032a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 204effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch const float volume = input->ProvideInput(provide_input_dest, buffer_delay); 2052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2062a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Optimize the most common single input, full volume case. 2072a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (it == transform_inputs_.begin()) { 2082a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (volume == 1.0f) { 209effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch if (temp_dest != provide_input_dest) 210effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch provide_input_dest->CopyTo(temp_dest); 211c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } else if (volume > 0) { 212effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch for (int i = 0; i < provide_input_dest->channels(); ++i) { 213c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) vector_math::FMUL( 214effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch provide_input_dest->channel(i), volume, 215effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch provide_input_dest->frames(), temp_dest->channel(i)); 216c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } 217c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } else { 218c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Zero |temp_dest| otherwise, so we're mixing into a clean buffer. 219c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) temp_dest->Zero(); 2202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 222c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) continue; 2232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Volume adjust and mix each mixer input into |temp_dest| after rendering. 2262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (volume > 0) { 2272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) for (int i = 0; i < mixer_input_audio_bus_->channels(); ++i) { 2282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) vector_math::FMAC( 2292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->channel(i), volume, 2302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->frames(), temp_dest->channel(i)); 2312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (needs_downmix) { 2362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), dest->frames()); 2372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_->Transform(temp_dest, dest); 2382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 2402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::ProvideInput(int resampler_frame_delay, AudioBus* dest) { 2422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_ = resampler_frame_delay; 2432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) 2442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_->Consume(dest, dest->frames()); 2452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) else 2462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) SourceCallback(0, dest); 2472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 2482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 24923730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)void AudioConverter::CreateUnmixedAudioIfNecessary(int frames) { 25023730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) if (!unmixed_audio_ || unmixed_audio_->frames() != frames) 25123730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) unmixed_audio_ = AudioBus::Create(input_channel_count_, frames); 25223730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)} 25323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 2542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} // namespace media 255