RealtimeOutgoingAudioSourceCocoa.cpp [plain text]
#include "config.h"
#include "RealtimeOutgoingAudioSourceCocoa.h"
#if USE(LIBWEBRTC)
#include "CAAudioStreamDescription.h"
#include "LibWebRTCAudioFormat.h"
#include "LibWebRTCProvider.h"
namespace WebCore {
static inline AudioStreamBasicDescription libwebrtcAudioFormat(Float64 sampleRate, size_t channelCount)
{
size_t libWebRTCChannelCount = channelCount >= 2 ? 2 : channelCount;
AudioStreamBasicDescription streamFormat;
FillOutASBDForLPCM(streamFormat, sampleRate, libWebRTCChannelCount, LibWebRTCAudioFormat::sampleSize, LibWebRTCAudioFormat::sampleSize, LibWebRTCAudioFormat::isFloat, LibWebRTCAudioFormat::isBigEndian, LibWebRTCAudioFormat::isNonInterleaved);
return streamFormat;
}
RealtimeOutgoingAudioSourceCocoa::RealtimeOutgoingAudioSourceCocoa(Ref<MediaStreamTrackPrivate>&& audioSource)
: RealtimeOutgoingAudioSource(WTFMove(audioSource))
, m_sampleConverter(AudioSampleDataSource::create(LibWebRTCAudioFormat::sampleRate * 2))
{
}
Ref<RealtimeOutgoingAudioSource> RealtimeOutgoingAudioSource::create(Ref<MediaStreamTrackPrivate>&& audioSource)
{
return RealtimeOutgoingAudioSourceCocoa::create(WTFMove(audioSource));
}
bool RealtimeOutgoingAudioSourceCocoa::isReachingBufferedAudioDataHighLimit()
{
auto writtenAudioDuration = m_writeCount / m_inputStreamDescription.sampleRate();
auto readAudioDuration = m_readCount / m_outputStreamDescription.sampleRate();
ASSERT(writtenAudioDuration >= readAudioDuration);
return writtenAudioDuration > readAudioDuration + 0.5;
}
bool RealtimeOutgoingAudioSourceCocoa::isReachingBufferedAudioDataLowLimit()
{
auto writtenAudioDuration = m_writeCount / m_inputStreamDescription.sampleRate();
auto readAudioDuration = m_readCount / m_outputStreamDescription.sampleRate();
ASSERT(writtenAudioDuration >= readAudioDuration);
return writtenAudioDuration < readAudioDuration + 0.1;
}
bool RealtimeOutgoingAudioSourceCocoa::hasBufferedEnoughData()
{
auto writtenAudioDuration = m_writeCount / m_inputStreamDescription.sampleRate();
auto readAudioDuration = m_readCount / m_outputStreamDescription.sampleRate();
ASSERT(writtenAudioDuration >= readAudioDuration);
return writtenAudioDuration >= readAudioDuration + 0.01;
}
void RealtimeOutgoingAudioSourceCocoa::audioSamplesAvailable(const MediaTime&, const PlatformAudioData& audioData, const AudioStreamDescription& streamDescription, size_t sampleCount)
{
if (m_inputStreamDescription != streamDescription) {
m_inputStreamDescription = toCAAudioStreamDescription(streamDescription);
auto status = m_sampleConverter->setInputFormat(m_inputStreamDescription);
ASSERT_UNUSED(status, !status);
m_outputStreamDescription = libwebrtcAudioFormat(LibWebRTCAudioFormat::sampleRate, streamDescription.numberOfChannels());
status = m_sampleConverter->setOutputFormat(m_outputStreamDescription.streamDescription());
ASSERT(!status);
}
if (m_skippingAudioData) {
if (!isReachingBufferedAudioDataLowLimit())
return;
m_skippingAudioData = false;
} else if (isReachingBufferedAudioDataHighLimit()) {
m_skippingAudioData = true;
return;
}
m_sampleConverter->pushSamples(MediaTime(m_writeCount, static_cast<uint32_t>(m_inputStreamDescription.sampleRate())), audioData, sampleCount);
m_writeCount += sampleCount;
if (!hasBufferedEnoughData())
return;
LibWebRTCProvider::callOnWebRTCSignalingThread([protectedThis = makeRef(*this)] {
protectedThis->pullAudioData();
});
}
void RealtimeOutgoingAudioSourceCocoa::pullAudioData()
{
size_t chunkSampleCount = m_outputStreamDescription.sampleRate() / 100;
size_t bufferSize = chunkSampleCount * LibWebRTCAudioFormat::sampleByteSize * m_outputStreamDescription.numberOfChannels();
m_audioBuffer.grow(bufferSize);
AudioBufferList bufferList;
bufferList.mNumberBuffers = 1;
bufferList.mBuffers[0].mNumberChannels = m_outputStreamDescription.numberOfChannels();
bufferList.mBuffers[0].mDataByteSize = bufferSize;
bufferList.mBuffers[0].mData = m_audioBuffer.data();
if (isSilenced() != m_sampleConverter->muted())
m_sampleConverter->setMuted(isSilenced());
m_sampleConverter->pullAvalaibleSamplesAsChunks(bufferList, chunkSampleCount, m_readCount, [this, chunkSampleCount] {
m_readCount += chunkSampleCount;
for (auto sink : m_sinks)
sink->OnData(m_audioBuffer.data(), LibWebRTCAudioFormat::sampleSize, m_outputStreamDescription.sampleRate(), m_outputStreamDescription.numberOfChannels(), chunkSampleCount);
});
}
}
#endif // USE(LIBWEBRTC)