audio_converter.cc revision c2e0dbddbe15c98d52c4786dac06cb8952a8ae6d
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" 172a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/audio_pull_fifo.h" 182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/channel_mixer.h" 192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/multi_channel_resampler.h" 202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "media/base/vector_math.h" 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace media { 232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)AudioConverter::AudioConverter(const AudioParameters& input_params, 252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) const AudioParameters& output_params, 262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool disable_fifo) 272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) : downmix_early_(false), 282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_(0), 292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_channel_count_(input_params.channels()) { 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) CHECK(input_params.IsValid()); 312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) CHECK(output_params.IsValid()); 322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Handle different input and output channel layouts. 342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (input_params.channel_layout() != output_params.channel_layout()) { 352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Remixing channel layout from " << input_params.channel_layout() 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << " to " << output_params.channel_layout() << "; from " 372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << input_params.channels() << " channels to " 382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << output_params.channels() << " channels."; 392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_.reset(new ChannelMixer(input_params, output_params)); 402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Pare off data as early as we can for efficiency. 422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) downmix_early_ = input_params.channels() > output_params.channels(); 432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (downmix_early_) { 442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Remixing channel layout prior to resampling."; 452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // |unmixed_audio_| will be allocated on the fly. 462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } else { 472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Instead, if we're not downmixing early we need a temporary AudioBus 482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // which matches the input channel count but uses the output frame size 492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // since we'll mix into the AudioBus from the output stream. 502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) unmixed_audio_ = AudioBus::Create( 512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_params.channels(), output_params.frames_per_buffer()); 522a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 532a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 552a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Only resample if necessary since it's expensive. 562a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (input_params.sample_rate() != output_params.sample_rate()) { 572a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Resampling from " << input_params.sample_rate() << " to " 582a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << output_params.sample_rate(); 592a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) double io_sample_rate_ratio = input_params.sample_rate() / 602a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) static_cast<double>(output_params.sample_rate()); 612a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_.reset(new MultiChannelResampler( 622a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) downmix_early_ ? output_params.channels() : 632a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_params.channels(), 642a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) io_sample_rate_ratio, base::Bind( 652a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) &AudioConverter::ProvideInput, base::Unretained(this)))); 662a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_frame_duration_ = base::TimeDelta::FromMicroseconds( 692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) base::Time::kMicrosecondsPerSecond / 702a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) static_cast<double>(input_params.sample_rate())); 712a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) output_frame_duration_ = base::TimeDelta::FromMicroseconds( 722a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) base::Time::kMicrosecondsPerSecond / 732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) static_cast<double>(output_params.sample_rate())); 742a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 752a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (disable_fifo) 762a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return; 772a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 782a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Since the resampler / output device may want a different buffer size than 792a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // the caller asked for, we need to use a FIFO to ensure that both sides 802a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // read in chunk sizes they're configured for. 812a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_.get() || 822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_params.frames_per_buffer() != output_params.frames_per_buffer()) { 832a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DVLOG(1) << "Rebuffering from " << input_params.frames_per_buffer() 842a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) << " to " << output_params.frames_per_buffer(); 852a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_.reset(new AudioPullFifo( 862a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) downmix_early_ ? output_params.channels() : 872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_params.channels(), 882a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) input_params.frames_per_buffer(), base::Bind( 892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) &AudioConverter::SourceCallback, 902a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) base::Unretained(this)))); 912a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 932a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 942a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)AudioConverter::~AudioConverter() {} 952a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 962a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::AddInput(InputCallback* input) { 97c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // TODO(dalecurtis): Speculative CHECK for http://crbug.com/233026, should be 98c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // converted to a DCHECK once resolved. 99c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) CHECK(std::find(transform_inputs_.begin(), transform_inputs_.end(), input) == 100c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) transform_inputs_.end()); 1012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.push_back(input); 1022a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1032a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1042a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::RemoveInput(InputCallback* input) { 1052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK(std::find(transform_inputs_.begin(), transform_inputs_.end(), input) != 1062a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.end()); 1072a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) transform_inputs_.remove(input); 1082a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1092a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (transform_inputs_.empty()) 1102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Reset(); 1112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1122a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1132a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::Reset() { 1142a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) 1152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_->Clear(); 1162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) 1172a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_->Flush(); 1182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 120c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)void AudioConverter::ConvertWithDelay(const base::TimeDelta& initial_delay, 121c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) AudioBus* dest) { 122c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) initial_delay_ = initial_delay; 123c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) 1242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (transform_inputs_.empty()) { 1252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) dest->Zero(); 1262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return; 1272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 129c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Determine if channel mixing should be done and if it should be done before 130c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // or after resampling. If it's possible to reduce the channel count prior to 131c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // resampling we can save a lot of processing time. Vice versa, we don't want 132c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // to increase the channel count prior to resampling for the same reason. 1332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool needs_mixing = channel_mixer_ && !downmix_early_; 1342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AudioBus* temp_dest = needs_mixing ? unmixed_audio_.get() : dest; 1352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK(temp_dest); 1362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 137c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Figure out which method to call based on whether we're resampling and 138c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // rebuffering, just resampling, or just mixing. We want to avoid any extra 139c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // steps when possible since we may be converting audio data in real time. 1402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!resampler_ && !audio_fifo_) { 1412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) SourceCallback(0, temp_dest); 1422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } else { 1432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) 1442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_->Resample(temp_dest, temp_dest->frames()); 1452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) else 1462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) ProvideInput(0, temp_dest); 1472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 149c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Finally upmix the channels if we didn't do so earlier. 1502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (needs_mixing) { 1512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), dest->frames()); 1522a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_->Transform(temp_dest, dest); 1532a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1552a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 156c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)void AudioConverter::Convert(AudioBus* dest) { 157c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) ConvertWithDelay(base::TimeDelta::FromMilliseconds(0), dest); 158c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)} 159c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) 1602a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::SourceCallback(int fifo_frame_delay, AudioBus* dest) { 1612a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool needs_downmix = channel_mixer_ && downmix_early_; 1622a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1632a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!mixer_input_audio_bus_ || 1642a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->frames() != dest->frames()) { 1652a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_ = 1662a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AudioBus::Create(input_channel_count_, dest->frames()); 1672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (needs_downmix && 1702a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) (!unmixed_audio_ || unmixed_audio_->frames() != dest->frames())) { 1712a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // If we're downmixing early we need a temporary AudioBus which matches 1722a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // the the input channel count and input frame size since we're passing 1732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // |unmixed_audio_| directly to the |source_callback_|. 1742a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) unmixed_audio_ = AudioBus::Create(input_channel_count_, dest->frames()); 1752a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1762a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1772a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AudioBus* temp_dest = needs_downmix ? unmixed_audio_.get() : dest; 1782a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1792a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Sanity check our inputs. 1802a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), mixer_input_audio_bus_->frames()); 1812a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->channels(), mixer_input_audio_bus_->channels()); 1822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1832a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Calculate the buffer delay for this callback. 184c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) base::TimeDelta buffer_delay = initial_delay_; 1852a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (resampler_) { 1862a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) buffer_delay += base::TimeDelta::FromMicroseconds( 1872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_ * output_frame_duration_.InMicroseconds()); 1882a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) { 1902a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) buffer_delay += base::TimeDelta::FromMicroseconds( 1912a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) fifo_frame_delay * input_frame_duration_.InMicroseconds()); 1922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1932a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1942a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Have each mixer render its data into an output buffer then mix the result. 1952a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) for (InputCallbackSet::iterator it = transform_inputs_.begin(); 1962a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) it != transform_inputs_.end(); ++it) { 1972a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) InputCallback* input = *it; 1982a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1992a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) float volume = input->ProvideInput( 2002a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_.get(), buffer_delay); 2012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2022a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Optimize the most common single input, full volume case. 2032a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (it == transform_inputs_.begin()) { 2042a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (volume == 1.0f) { 2052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->CopyTo(temp_dest); 206c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } else if (volume > 0) { 207c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) for (int i = 0; i < mixer_input_audio_bus_->channels(); ++i) { 208c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) vector_math::FMUL( 209c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) mixer_input_audio_bus_->channel(i), volume, 210c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) mixer_input_audio_bus_->frames(), temp_dest->channel(i)); 211c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } 212c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) } else { 213c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // Zero |temp_dest| otherwise, so we're mixing into a clean buffer. 214c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) temp_dest->Zero(); 2152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 217c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) continue; 2182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Volume adjust and mix each mixer input into |temp_dest| after rendering. 2212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (volume > 0) { 2222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) for (int i = 0; i < mixer_input_audio_bus_->channels(); ++i) { 2232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) vector_math::FMAC( 2242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->channel(i), volume, 2252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) mixer_input_audio_bus_->frames(), temp_dest->channel(i)); 2262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (needs_downmix) { 2312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) DCHECK_EQ(temp_dest->frames(), dest->frames()); 2322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) channel_mixer_->Transform(temp_dest, dest); 2332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 2352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void AudioConverter::ProvideInput(int resampler_frame_delay, AudioBus* dest) { 2372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) resampler_frame_delay_ = resampler_frame_delay; 2382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (audio_fifo_) 2392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) audio_fifo_->Consume(dest, dest->frames()); 2402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) else 2412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) SourceCallback(0, dest); 2422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 2432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} // namespace media 245