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#include <ao/ao.h>
struct AudioAO : Audio {
~AudioAO() { term(); }
int driver_id;
ao_sample_format driver_format;
ao_device* audio_device = nullptr;
struct {
unsigned frequency = 22050;
} settings;
auto cap(const string& name) -> bool {
if(name == Audio::Frequency) return true;
return false;
}
auto get(const string& name) -> any {
if(name == Audio::Frequency) return settings.frequency;
return {};
}
auto set(const string& name, const any& value) -> bool {
if(name == Audio::Frequency && value.is<unsigned>()) {
settings.frequency = value.get<unsigned>();
if(audio_device) init();
return true;
}
return false;
}
auto sample(uint16_t l_sample, uint16_t r_sample) -> void {
uint32_t samp = (l_sample << 0) + (r_sample << 16);
ao_play(audio_device, (char*)&samp, 4); //This may need to be byte swapped for Big Endian
}
auto clear() -> void {
}
auto init() -> bool {
ao_initialize();
driver_id = ao_default_driver_id(); //ao_driver_id((const char*)driver)
if(driver_id < 0) return false;
driver_format.bits = 16;
driver_format.channels = 2;
driver_format.rate = settings.frequency;
driver_format.byte_format = AO_FMT_LITTLE;
ao_option* options = nullptr;
ao_info *di = ao_driver_info(driver_id);
if(!di) return false;
if(!strcmp(di->short_name, "alsa")) {
ao_append_option(&options, "buffer_time", "100000"); //100ms latency (default was 500ms)
}
audio_device = ao_open_live(driver_id, &driver_format, options);
if(!audio_device) return false;
return true;
}
auto term() -> void {
if(audio_device) {
ao_close(audio_device);
audio_device = nullptr;
}
ao_shutdown();
}
};
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