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#include <ao/ao.h>
struct AudioAO : AudioDriver {
AudioAO& self = *this;
AudioAO(Audio& super) : AudioDriver(super) {}
~AudioAO() { terminate(); }
auto create() -> bool override {
super.setChannels(2);
super.setFrequency(48000);
return initialize();
}
auto driver() -> string override { return "libao"; }
auto ready() -> bool override { return _ready; }
auto hasChannels() -> vector<u32> override {
return {2};
}
auto hasFrequencies() -> vector<u32> override {
return {44100, 48000, 96000};
}
auto setFrequency(u32 frequency) -> bool override { return initialize(); }
auto output(const f64 samples[]) -> void override {
u32 sample = 0;
sample |= (u16)sclamp<16>(samples[0] * 32767.0) << 0;
sample |= (u16)sclamp<16>(samples[1] * 32767.0) << 16;
ao_play(_interface, (char*)&sample, 4);
}
private:
auto initialize() -> bool {
terminate();
ao_initialize();
s32 driverID = ao_default_driver_id();
if(driverID < 0) return false;
ao_sample_format format;
format.bits = 16;
format.channels = 2;
format.rate = self.frequency;
format.byte_format = AO_FMT_LITTLE;
format.matrix = nullptr;
ao_info* information = ao_driver_info(driverID);
if(!information) return false;
string 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;
ao_device* _interface = nullptr;
};
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