use SDL2's preferred/non-legacy means of opening, and working with, an audio device

This commit is contained in:
David Ludwig 2017-08-27 18:05:13 -04:00
parent 145ca0c210
commit d5e68ceebf

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@ -45,6 +45,8 @@ static int audio_sample_size_index = 0;
static int audio_channel_count_index = 0;
// Global variables
static SDL_AudioDeviceID audio_device = 0;
static SDL_AudioSpec audio_spec_obtained;
static SDL_sem *audio_irq_done_sem = NULL; // Signal from interrupt to streaming thread: data block read
static uint8 silence_byte; // Byte value to use to fill sound buffers with silence
static uint8 *audio_mix_buf = NULL;
@ -86,40 +88,36 @@ static bool open_sdl_audio(void)
audio_channel_count_index = audio_channel_counts.size() - 1;
}
SDL_AudioSpec audio_spec;
SDL_zero(audio_spec);
audio_spec.freq = audio_sample_rates[audio_sample_rate_index] >> 16;
audio_spec.format = (audio_sample_sizes[audio_sample_size_index] == 8) ? AUDIO_U8 : AUDIO_S16MSB;
audio_spec.channels = audio_channel_counts[audio_channel_count_index];
audio_spec.samples = 4096;
audio_spec.callback = stream_func;
audio_spec.userdata = NULL;
SDL_AudioSpec audio_spec_desired;
SDL_zero(audio_spec_desired);
audio_spec_desired.freq = audio_sample_rates[audio_sample_rate_index] >> 16;
audio_spec_desired.format = (audio_sample_sizes[audio_sample_size_index] == 8) ? AUDIO_U8 : AUDIO_S16MSB;
audio_spec_desired.channels = audio_channel_counts[audio_channel_count_index];
audio_spec_desired.samples = 4096;
audio_spec_desired.callback = stream_func;
audio_spec_desired.userdata = NULL;
// Open the audio device, forcing the desired format
if (SDL_OpenAudio(&audio_spec, NULL) < 0) {
SDL_zero(audio_spec_obtained);
audio_device = SDL_OpenAudioDevice(NULL, 0, &audio_spec_desired, &audio_spec_obtained, 0);
if (!audio_device) {
fprintf(stderr, "WARNING: Cannot open audio: %s\n", SDL_GetError());
return false;
}
// HACK: workaround a possible bug in SDL 2.0.5 (reported via https://bugzilla.libsdl.org/show_bug.cgi?id=3710 )
// whereby SDL does not update audio_spec.size
if (audio_spec.size == 0) {
audio_spec.size = (SDL_AUDIO_BITSIZE(audio_spec.format) / 8) * audio_spec.channels * audio_spec.samples;
}
#if defined(BINCUE)
OpenAudio_bincue(audio_spec.freq, audio_spec.format, audio_spec.channels,
audio_spec.silence);
OpenAudio_bincue(audio_spec_obtained.freq, audio_spec_obtained.format, audio_spec_obtained.channels,
audio_spec_obtained.silence);
#endif
const char * driver_name = SDL_GetCurrentAudioDriver();
printf("Using SDL/%s audio output\n", driver_name ? driver_name : "");
silence_byte = audio_spec.silence;
SDL_PauseAudio(0);
silence_byte = audio_spec_obtained.silence;
SDL_PauseAudioDevice(audio_device, 0);
// Sound buffer size = 4096 frames
audio_frames_per_block = audio_spec.samples;
audio_mix_buf = (uint8*)malloc(audio_spec.size);
audio_frames_per_block = audio_spec_obtained.samples;
audio_mix_buf = (uint8*)malloc(audio_spec_obtained.size);
return true;
}
@ -168,7 +166,10 @@ void AudioInit(void)
static void close_audio(void)
{
// Close audio device
SDL_CloseAudio();
if (audio_device) {
SDL_CloseAudioDevice(audio_device);
audio_device = 0;
}
free(audio_mix_buf);
audio_mix_buf = NULL;
audio_open = false;
@ -231,7 +232,7 @@ static void stream_func(void *arg, uint8 *stream, int stream_len)
// Send data to audio device
Mac2Host_memcpy(audio_mix_buf, ReadMacInt32(apple_stream_info + scd_buffer), work_size);
memset((uint8 *)stream, silence_byte, stream_len);
SDL_MixAudio(stream, audio_mix_buf, work_size, audio_volume);
SDL_MixAudioFormat(stream, audio_mix_buf, audio_spec_obtained.format, work_size, audio_volume);
D(bug("stream: data written\n"));