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#include <ao/ao.h>
struct AudioAO : Audio {
AudioAO() { initialize(); }
~AudioAO() { terminate(); }
auto availableDevices() -> string_vector {
return {"Default"};
}
auto availableFrequencies() -> vector<double> {
return {44100.0, 48000.0, 96000.0};
}
auto availableLatencies() -> vector<uint> {
return {100};
}
auto availableChannels() -> vector<uint> {
return {2};
}
auto ready() -> bool { return _ready; }
auto blocking() -> bool { return true; }
auto channels() -> uint { return 2; }
auto frequency() -> double { return _frequency; }
auto latency() -> uint { return 100; }
auto setFrequency(double frequency) -> bool {
if(_frequency == frequency) return true;
_frequency = frequency;
return initialize();
}
auto output(const double samples[]) -> void {
uint32_t sample = 0;
sample |= (uint16_t)sclamp<16>(samples[0] * 32767.0) << 0;
sample |= (uint16_t)sclamp<16>(samples[1] * 32767.0) << 16;
ao_play(_interface, (char*)&sample, 4);
}
auto initialize() -> bool {
terminate();
ao_initialize();
int driverID = ao_default_driver_id();
if(driverID < 0) return false;
ao_sample_format format;
format.bits = 16;
format.channels = 2;
format.rate = (uint)_frequency;
format.byte_format = AO_FMT_LITTLE;
format.matrix = nullptr;
ao_info* information = ao_driver_info(driverID);
if(!information) return false;
_device = information->short_name;
ao_option* options = nullptr;
if(_device == "alsa") {
ao_append_option(&options, "buffer_time", "100000"); //100ms latency (default was 500ms)
}
_interface = ao_open_live(driverID, &format, options);
if(!_interface) return false;
return _ready = true;
}
auto terminate() -> void {
_ready = false;
if(_interface) {
ao_close(_interface);
_interface = nullptr;
}
ao_shutdown();
}
bool _ready = false;
string _device = "Default";
double _frequency = 48000.0;
ao_device* _interface = nullptr;
};
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