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#include <pulse/pulseaudio.h>
struct AudioPulseAudio : Audio {
AudioPulseAudio() { initialize(); }
~AudioPulseAudio() { terminate(); }
auto availableDevices() -> string_vector {
return {"Default"};
}
auto availableFrequencies() -> vector<double> {
return {44100.0, 48000.0, 96000.0};
}
auto availableLatencies() -> vector<uint> {
return {20, 40, 60, 80, 100};
}
auto availableChannels() -> vector<uint> {
return {2};
}
auto ready() -> bool { return _ready; }
auto blocking() -> bool { return _blocking; }
auto channels() -> uint { return 2; }
auto frequency() -> double { return _frequency; }
auto latency() -> uint { return _latency; }
auto setBlocking(bool blocking) -> bool {
if(_blocking == blocking) return true;
_blocking = blocking;
return true;
}
auto setFrequency(double frequency) -> bool {
if(_frequency == frequency) return true;
_frequency = frequency;
return initialize();
}
auto setLatency(uint latency) -> bool {
if(_latency == latency) return true;
_latency = latency;
return initialize();
}
auto output(const double samples[]) -> void {
pa_stream_begin_write(_stream, (void**)&_buffer, &_period);
_buffer[_offset] = (uint16_t)sclamp<16>(samples[0] * 32767.0) << 0;
_buffer[_offset] |= (uint16_t)sclamp<16>(samples[1] * 32767.0) << 16;
if((++_offset + 1) * pa_frame_size(&_specification) <= _period) return;
while(true) {
if(_first) {
_first = false;
pa_mainloop_iterate(_mainLoop, 0, nullptr);
} else {
pa_mainloop_iterate(_mainLoop, 1, nullptr);
}
uint length = pa_stream_writable_size(_stream);
if(length >= _offset * pa_frame_size(&_specification)) break;
if(!_blocking) {
_offset = 0;
return;
}
}
pa_stream_write(_stream, (const void*)_buffer, _offset * pa_frame_size(&_specification), nullptr, 0LL, PA_SEEK_RELATIVE);
_buffer = nullptr;
_offset = 0;
}
private:
auto initialize() -> bool {
terminate();
_mainLoop = pa_mainloop_new();
_context = pa_context_new(pa_mainloop_get_api(_mainLoop), "ruby::pulseAudio");
pa_context_connect(_context, nullptr, PA_CONTEXT_NOFLAGS, nullptr);
pa_context_state_t contextState;
do {
pa_mainloop_iterate(_mainLoop, 1, nullptr);
contextState = pa_context_get_state(_context);
if(!PA_CONTEXT_IS_GOOD(contextState)) return false;
} while(contextState != PA_CONTEXT_READY);
_specification.format = PA_SAMPLE_S16LE;
_specification.channels = 2;
_specification.rate = (uint)_frequency;
_stream = pa_stream_new(_context, "audio", &_specification, nullptr);
pa_buffer_attr bufferAttributes;
bufferAttributes.maxlength = -1;
bufferAttributes.tlength = pa_usec_to_bytes(_latency * PA_USEC_PER_MSEC, &_specification);
bufferAttributes.prebuf = -1;
bufferAttributes.minreq = -1;
bufferAttributes.fragsize = -1;
pa_stream_flags_t flags = (pa_stream_flags_t)(PA_STREAM_ADJUST_LATENCY | PA_STREAM_VARIABLE_RATE);
pa_stream_connect_playback(_stream, nullptr, &bufferAttributes, flags, nullptr, nullptr);
pa_stream_state_t streamState;
do {
pa_mainloop_iterate(_mainLoop, 1, nullptr);
streamState = pa_stream_get_state(_stream);
if(!PA_STREAM_IS_GOOD(streamState)) return false;
} while(streamState != PA_STREAM_READY);
_period = 960;
_offset = 0;
_first = true;
return _ready = true;
}
auto terminate() -> void {
_ready = false;
if(_buffer) {
pa_stream_cancel_write(_stream);
_buffer = nullptr;
}
if(_stream) {
pa_stream_disconnect(_stream);
pa_stream_unref(_stream);
_stream = nullptr;
}
if(_context) {
pa_context_disconnect(_context);
pa_context_unref(_context);
_context = nullptr;
}
if(_mainLoop) {
pa_mainloop_free(_mainLoop);
_mainLoop = nullptr;
}
}
bool _ready = false;
bool _blocking = true;
double _frequency = 48000.0;
uint _latency = 40;
uint32_t* _buffer = nullptr;
size_t _period = 0;
uint _offset = 0;
pa_mainloop* _mainLoop = nullptr;
pa_context* _context = nullptr;
pa_stream* _stream = nullptr;
pa_sample_spec _specification;
bool _first = true;
};
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