moonlight-qt/app/streaming/audio/renderers/soundioaudiorenderer.cpp

462 lines
16 KiB
C++

#include "soundioaudiorenderer.h"
#include <SDL.h>
#include <QtGlobal>
// GFE sends us packets in 5 ms chunks
const double SoundIoAudioRenderer::k_RawSampleLengthSec = 0.005;
#ifdef Q_OS_LINUX
// PulseAudio and ALSA require more than just 5 ms samples
// for some reason, so write a minimum of 20 ms each time to
// prevent underruns on Bluetooth.
const double SoundIoAudioRenderer::k_MinSampleLengthSec = 0.020;
#else
// This determines the size of the buffers we'll
// get from CoreAudio. It is also the minimum
// size that we will write when called to fill a buffer.
const double SoundIoAudioRenderer::k_MinSampleLengthSec = k_RawSampleLengthSec;
#endif
SoundIoAudioRenderer::SoundIoAudioRenderer()
: m_OpusChannelCount(0),
m_SoundIo(nullptr),
m_Device(nullptr),
m_OutputStream(nullptr),
m_RingBuffer(nullptr),
m_Latency(0),
m_Errored(false)
{
}
SoundIoAudioRenderer::~SoundIoAudioRenderer()
{
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Audio latency: %f",
m_Latency);
if (m_OutputStream != nullptr) {
soundio_outstream_destroy(m_OutputStream);
}
// Must be destroyed after the stream is stopped
// or we could still get sioWriteCallback() calls.
if (m_RingBuffer != nullptr) {
soundio_ring_buffer_destroy(m_RingBuffer);
}
if (m_Device != nullptr) {
soundio_device_unref(m_Device);
}
if (m_SoundIo != nullptr) {
soundio_destroy(m_SoundIo);
}
}
int SoundIoAudioRenderer::scoreChannelLayout(const struct SoundIoChannelLayout* layout, const OPUS_MULTISTREAM_CONFIGURATION* opusConfig)
{
int score = 50;
// Compute a score for this layout based on how many matching channels
// we find (or acceptable alternatives).
for (int i = 0; i < layout->channel_count; i++) {
if (opusConfig->channelCount >= 2) {
switch (layout->channels[i]) {
case SoundIoChannelIdFrontLeft:
case SoundIoChannelIdFrontRight:
score += 2;
break;
default:
break;
}
}
if (opusConfig->channelCount >= 6) {
switch (layout->channels[i]) {
case SoundIoChannelIdFrontCenter:
case SoundIoChannelIdLfe:
score += 2;
break;
case SoundIoChannelIdSideLeft:
case SoundIoChannelIdSideRight:
score++;
break;
// Score layouts using the back L/R as higher
// value than those using side L/R.
case SoundIoChannelIdBackLeft:
case SoundIoChannelIdBackRight:
score += 2;
break;
default:
break;
}
}
}
// Now subtract the difference between the desired and actual channel count
// to punish layouts that have extra unused speakers.
if (opusConfig->channelCount < layout->channel_count) {
score -= layout->channel_count - opusConfig->channelCount;
}
return score;
}
bool SoundIoAudioRenderer::prepareForPlayback(const OPUS_MULTISTREAM_CONFIGURATION* opusConfig)
{
m_SoundIo = soundio_create();
if (m_SoundIo == nullptr) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_create() failed");
return false;
}
m_SoundIo->app_name = "Moonlight";
m_SoundIo->userdata = this;
m_SoundIo->on_backend_disconnect = sioBackendDisconnect;
m_SoundIo->on_devices_change = sioDevicesChanged;
int err = soundio_connect(m_SoundIo);
if (err != SoundIoErrorNone) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_connect() failed: %s",
soundio_strerror(err));
return false;
}
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Audio backend: %s",
soundio_backend_name(m_SoundIo->current_backend));
// Don't continue if we could only open the dummy backend
if (m_SoundIo->current_backend == SoundIoBackendDummy) {
return false;
}
// Flush events to update with new device arrivals
soundio_flush_events(m_SoundIo);
// Remember the actual channel count for later
m_OpusChannelCount = opusConfig->channelCount;
int outputDeviceIndex = soundio_default_output_device_index(m_SoundIo);
if (outputDeviceIndex < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"No output device found");
return false;
}
m_Device = soundio_get_output_device(m_SoundIo, outputDeviceIndex);
if (m_Device == nullptr) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_get_output_device() failed");
return false;
}
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Selected audio device: %s",
m_Device->name);
m_OutputStream = soundio_outstream_create(m_Device);
if (m_OutputStream == nullptr) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_outstream_create() failed");
return false;
}
m_OutputStream->format = SoundIoFormatS16NE;
m_OutputStream->sample_rate = opusConfig->sampleRate;
m_OutputStream->software_latency = k_MinSampleLengthSec;
m_OutputStream->name = "Moonlight";
m_OutputStream->userdata = this;
m_OutputStream->error_callback = sioErrorCallback;
m_OutputStream->write_callback = sioWriteCallback;
SoundIoChannelLayout bestLayout = m_Device->current_layout;
for (int i = 0; i < m_Device->layout_count; i++) {
if (scoreChannelLayout(&bestLayout, opusConfig) <
scoreChannelLayout(&m_Device->layouts[i], opusConfig)) {
bestLayout = m_Device->layouts[i];
}
}
if (bestLayout.channel_count < opusConfig->channelCount) {
SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
"No compatible channel layouts found. Some channels may not be played!");
}
m_OutputStream->layout = bestLayout;
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Native layout: %s (%d channels)",
m_OutputStream->layout.name ?
m_OutputStream->layout.name : "<UNKNOWN>",
m_OutputStream->layout.channel_count);
err = soundio_outstream_open(m_OutputStream);
if (err != SoundIoErrorNone) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_outstream_open() failed: %s",
soundio_strerror(err));
return false;
}
if (m_OutputStream->layout_error) {
SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
"Channel layout failed: %s",
soundio_strerror(m_OutputStream->layout_error));
// ALSA through PulseAudio appears to fail snd_pcm_set_chmap()
// even after claiming the layout is supported (and even on totally
// standard layouts like Stereo). We'll just ignore this for ALSA
// and only bail if we get an actual failure out of one of these APIs.
if (m_SoundIo->current_backend != SoundIoBackendAlsa) {
return false;
}
}
m_EffectiveLayout = m_OutputStream->layout;
for (int i = 0; i < m_EffectiveLayout.channel_count; i++) {
// Fixup the layout to use back L/R so our channel position
// logic in sioWriteCallback() works.
if (m_EffectiveLayout.channels[i] == SoundIoChannelIdSideLeft) {
m_EffectiveLayout.channels[i] = SoundIoChannelIdBackLeft;
}
if (m_EffectiveLayout.channels[i] == SoundIoChannelIdSideRight) {
m_EffectiveLayout.channels[i] = SoundIoChannelIdBackRight;
}
}
int packetsToBuffer;
#ifdef Q_OS_LINUX
// PulseAudio and ALSA need the large buffer (see comment on k_MinSampleLengthSec),
// so we need a buffer at least double that size to allow packets to arrive
// while we're writing to the sink.
packetsToBuffer = (int)(k_MinSampleLengthSec / k_RawSampleLengthSec) * 2;
#else
if (m_SoundIo->current_backend == SoundIoBackendWasapi) {
// 15 ms buffer seems to be fine for WASAPI
packetsToBuffer = 3;
}
else {
// 30 ms buffer on CoreAudio to avoid glitching on macOS
packetsToBuffer = 6;
}
#endif
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Audio buffer size: %d packets",
packetsToBuffer);
m_RingBuffer = soundio_ring_buffer_create(m_SoundIo,
m_OutputStream->bytes_per_sample *
m_OpusChannelCount *
SAMPLES_PER_FRAME *
packetsToBuffer);
if (m_RingBuffer == nullptr) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_ring_buffer_create() failed");
return false;
}
err = soundio_outstream_start(m_OutputStream);
if (err != SoundIoErrorNone) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_outstream_start() failed: %s",
soundio_strerror(err));
return false;
}
// HACK: For some reason, a constant latency hangs around in the audio pipeline
// unless we wait for the audio stream to drain before actually submitting any samples.
// This is a gross hack, but it works remarkably well.
SDL_Delay(500);
return true;
}
bool SoundIoAudioRenderer::submitAudio(short* audioBuffer, int audioSize)
{
if (m_Errored) {
return false;
}
// Flush events to update with new device arrivals
soundio_flush_events(m_SoundIo);
// We must always write a full frame of audio. If we don't,
// the reader will get out of sync with the writer and our
// channels will get all mixed up. To ensure this is always
// the case, round our bytes free down to the next multiple
// of our frame size.
int bytesFree = soundio_ring_buffer_free_count(m_RingBuffer);
int bytesPerFrame = m_OpusChannelCount * m_OutputStream->bytes_per_sample;
int bytesToWrite = qMin(audioSize, (bytesFree / bytesPerFrame) * bytesPerFrame);
memcpy(soundio_ring_buffer_write_ptr(m_RingBuffer), audioBuffer, bytesToWrite);
soundio_ring_buffer_advance_write_ptr(m_RingBuffer, bytesToWrite);
return true;
}
void SoundIoAudioRenderer::sioErrorCallback(SoundIoOutStream* stream, int err)
{
auto me = reinterpret_cast<SoundIoAudioRenderer*>(stream->userdata);
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"Audio rendering error: %s",
soundio_strerror(err));
// Trigger reinitialization
me->m_Errored = true;
}
void SoundIoAudioRenderer::sioBackendDisconnect(SoundIo* soundio, int err)
{
auto me = reinterpret_cast<SoundIoAudioRenderer*>(soundio->userdata);
SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
"Audio backend disconnected: %s",
soundio_strerror(err));
// Trigger reinitialization
me->m_Errored = true;
}
void SoundIoAudioRenderer::sioDevicesChanged(SoundIo* soundio)
{
auto me = reinterpret_cast<SoundIoAudioRenderer*>(soundio->userdata);
if (me->m_Device == nullptr) {
// Ignore calls that take place during initialization
return;
}
int outputDeviceIndex = soundio_default_output_device_index(soundio);
if (outputDeviceIndex >= 0) {
struct SoundIoDevice* outputDevice = soundio_get_output_device(soundio, outputDeviceIndex);
if (outputDevice == nullptr) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_get_output_device() failed");
return;
}
if (!soundio_device_equal(outputDevice, me->m_Device)) {
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Default audio output device changed");
// Trigger reinitialization
me->m_Errored = true;
}
soundio_device_unref(outputDevice);
}
}
// bytes_per_frame should never be used on the ring buffer! It's not always
// the same number of bytes per frames as the output stream!
void SoundIoAudioRenderer::sioWriteCallback(SoundIoOutStream* stream, int frameCountMin, int frameCountMax)
{
auto me = reinterpret_cast<SoundIoAudioRenderer*>(stream->userdata);
char* readPtr = soundio_ring_buffer_read_ptr(me->m_RingBuffer);
int framesLeft = soundio_ring_buffer_fill_count(me->m_RingBuffer) /
(me->m_OpusChannelCount * stream->bytes_per_sample);
int bytesRead = 0;
// Ensure we always write at least a buffer, even if it's silence, to avoid
// busy looping when no audio data is available while libsoundio tries to keep
// us from starving the output device.
frameCountMin = qMax(frameCountMin, (int)(stream->sample_rate * k_MinSampleLengthSec));
frameCountMin = qMin(frameCountMin, frameCountMax);
// Clamp framesLeft to frameCountMin to ensure that we never write more than one sample.
// This makes sure that we never increase our latency beyond what the sink is consuming.
framesLeft = qMin(framesLeft, frameCountMin);
// Track latency on queueing-based backends
if (me->m_SoundIo->current_backend != SoundIoBackendCoreAudio && me->m_SoundIo->current_backend != SoundIoBackendJack) {
soundio_outstream_get_latency(stream, &me->m_Latency);
}
for (;;) {
int frameCount;
int err;
struct SoundIoChannelArea* areas;
// Always meet the minimum but don't write more than that
// if we'll have to insert silence
frameCount = qMax(framesLeft, frameCountMin);
if (frameCount == 0) {
// Nothing more to write
break;
}
err = soundio_outstream_begin_write(stream, &areas, &frameCount);
if (err != SoundIoErrorNone) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_outstream_begin_write() failed: %s",
soundio_strerror(err));
break;
}
for (int frame = 0; frame < frameCount; frame++) {
for (int ch = 0; ch < me->m_EffectiveLayout.channel_count; ch++) {
// SoundIoChannelId - 1 happens to match Moonlight's channel layout.
// For side L/R, this logic depends on us fixing those up
// in m_EffectiveLayout to back L/R.
int readPtrChannel = me->m_EffectiveLayout.channels[ch] - 1;
if (frame >= framesLeft || readPtrChannel >= me->m_OpusChannelCount) {
// Write silence if we have no buffered frames left or
// nothing in the audio stream for this channel
memset(areas[ch].ptr, 0, stream->bytes_per_sample);
}
else {
// Write audio data from our ring buffer
memcpy(areas[ch].ptr,
&readPtr[readPtrChannel * stream->bytes_per_sample],
stream->bytes_per_sample);
}
areas[ch].ptr += areas[ch].step;
}
// Move on to the next frame if we aren't inserting silence
if (frame < framesLeft) {
readPtr += stream->bytes_per_sample * me->m_OpusChannelCount;
bytesRead += stream->bytes_per_sample * me->m_OpusChannelCount;
}
}
err = soundio_outstream_end_write(stream);
if (err != SoundIoErrorNone && err != SoundIoErrorUnderflow) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"soundio_outstream_end_write() failed: %s",
soundio_strerror(err));
break;
}
if (framesLeft >= frameCount) {
framesLeft -= frameCount;
}
else {
framesLeft = 0;
}
if (frameCountMin >= frameCount) {
frameCountMin -= frameCount;
}
else {
frameCountMin = 0;
}
}
soundio_ring_buffer_advance_read_ptr(me->m_RingBuffer, bytesRead);
}