int audio_get_formats(struct audio_info_struct *ai)
{
snd_pcm_hw_params_t *hw;
unsigned int rate;
int supported_formats, i;
snd_pcm_hw_params_alloca(&hw);
if (snd_pcm_hw_params_any(ai->handle, hw) < 0) {
fprintf(stderr, "audio_get_formats(): no configuration available\n");
return -1;
}
if (snd_pcm_hw_params_set_access(ai->handle, hw, SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
return -1;
if (snd_pcm_hw_params_set_channels(ai->handle, hw, ai->channels) < 0)
return 0;
rate = ai->rate;
if (snd_pcm_hw_params_set_rate_near(ai->handle, hw, &rate, NULL) < 0)
return -1;
if (!rates_match(ai->rate, rate))
return 0;
supported_formats = 0;
for (i = 0; i < NUM_FORMATS; ++i) {
if (snd_pcm_hw_params_test_format(ai->handle, hw, format_map[i].alsa) == 0)
supported_formats |= format_map[i].mpg123;
}
return supported_formats;
}
static int get_formats_alsa(audio_output_t *ao)
{
snd_pcm_t *pcm=(snd_pcm_t*)ao->userptr;
snd_pcm_hw_params_t *hw;
unsigned int rate;
int supported_formats, i;
snd_pcm_hw_params_alloca(&hw);
if (snd_pcm_hw_params_any(pcm, hw) < 0) {
if(!0) printf("get_formats_alsa(): no configuration available");
return -1;
}
if (snd_pcm_hw_params_set_access(pcm, hw, SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
return -1;
if (snd_pcm_hw_params_set_channels(pcm, hw, ao->channels) < 0)
return 0;
rate = ao->rate;
if (snd_pcm_hw_params_set_rate_near(pcm, hw, &rate, NULL) < 0)
return -1;
if (!rates_match(ao->rate, rate))
return 0;
supported_formats = 0;
for (i = 0; i < NUM_FORMATS; ++i) {
if (snd_pcm_hw_params_test_format(pcm, hw, format_map[i].alsa) == 0)
supported_formats |= format_map[i].mpg123;
}
return supported_formats;
}
static int initialize_device(struct audio_info_struct *ai)
{
snd_pcm_hw_params_t *hw;
int i;
snd_pcm_format_t format;
unsigned int rate;
snd_pcm_uframes_t buffer_size;
snd_pcm_uframes_t period_size;
snd_pcm_sw_params_t *sw;
snd_pcm_uframes_t boundary;
snd_pcm_hw_params_alloca(&hw);
if (snd_pcm_hw_params_any(ai->handle, hw) < 0) {
fprintf(stderr, "initialize_device(): no configuration available\n");
return -1;
}
if (snd_pcm_hw_params_set_access(ai->handle, hw, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
fprintf(stderr, "initialize_device(): device does not support interleaved access\n");
return -1;
}
format = SND_PCM_FORMAT_UNKNOWN;
for (i = 0; i < NUM_FORMATS; ++i) {
if (ai->format == format_map[i].mpg123) {
format = format_map[i].alsa;
break;
}
}
if (format == SND_PCM_FORMAT_UNKNOWN) {
fprintf(stderr, "initialize_device(): invalid sample format %d\n", ai->format);
errno = EINVAL;
return -1;
}
if (snd_pcm_hw_params_set_format(ai->handle, hw, format) < 0) {
fprintf(stderr, "initialize_device(): cannot set format %s\n", snd_pcm_format_name(format));
return -1;
}
if (snd_pcm_hw_params_set_channels(ai->handle, hw, ai->channels) < 0) {
fprintf(stderr, "initialize_device(): cannot set %d channels\n", ai->channels);
return -1;
}
rate = ai->rate;
if (snd_pcm_hw_params_set_rate_near(ai->handle, hw, &rate, NULL) < 0) {
fprintf(stderr, "initialize_device(): cannot set rate %u\n", rate);
return -1;
}
if (!rates_match(ai->rate, rate)) {
fprintf(stderr, "initialize_device(): rate %ld not available, using %u\n", ai->rate, rate);
/* return -1; */
}
buffer_size = rate * BUFFER_LENGTH;
if (snd_pcm_hw_params_set_buffer_size_near(ai->handle, hw, &buffer_size) < 0) {
fprintf(stderr, "initialize_device(): cannot set buffer size\n");
return -1;
}
period_size = buffer_size / 4;
if (snd_pcm_hw_params_set_period_size_near(ai->handle, hw, &period_size, NULL) < 0) {
fprintf(stderr, "initialize_device(): cannot set period size\n");
return -1;
}
if (snd_pcm_hw_params(ai->handle, hw) < 0) {
fprintf(stderr, "initialize_device(): cannot set hw params\n");
return -1;
}
snd_pcm_sw_params_alloca(&sw);
if (snd_pcm_sw_params_current(ai->handle, sw) < 0) {
fprintf(stderr, "initialize_device(): cannot get sw params\n");
return -1;
}
/* start playing after the first write */
if (snd_pcm_sw_params_set_start_threshold(ai->handle, sw, 1) < 0) {
fprintf(stderr, "initialize_device(): cannot set start threshold\n");
return -1;
}
if (snd_pcm_sw_params_get_boundary(sw, &boundary) < 0) {
fprintf(stderr, "initialize_device(): cannot get boundary\n");
return -1;
}
/* never stop on underruns */
if (snd_pcm_sw_params_set_stop_threshold(ai->handle, sw, boundary) < 0) {
fprintf(stderr, "initialize_device(): cannot set stop threshold\n");
return -1;
}
/* wake up on every interrupt */
if (snd_pcm_sw_params_set_avail_min(ai->handle, sw, 1) < 0) {
fprintf(stderr, "initialize_device(): cannot set min avail\n");
return -1;
}
#if 0
/* always write as many frames as possible */
if (snd_pcm_sw_params_set_xfer_align(ai->handle, sw, 1) < 0) {
fprintf(stderr, "initialize_device(): cannot set transfer alignment\n");
return -1;
}
#endif
/* play silence when there is an underrun */
if (snd_pcm_sw_params_set_silence_size(ai->handle, sw, boundary) < 0) {
fprintf(stderr, "initialize_device(): cannot set silence size\n");
return -1;
}
if (snd_pcm_sw_params(ai->handle, sw) < 0) {
fprintf(stderr, "initialize_device(): cannot set sw params\n");
return -1;
}
return 0;
}
static int initialize_device(audio_output_t *ao)
{
snd_pcm_hw_params_t *hw=NULL;
snd_pcm_sw_params_t *sw=NULL;
snd_pcm_uframes_t buffer_size;
snd_pcm_uframes_t period_size;
snd_pcm_format_t format;
snd_pcm_t *pcm=(snd_pcm_t*)ao->userptr;
unsigned int rate;
int i;
snd_pcm_hw_params_alloca(&hw); /* Ignore GCC warning here... alsa-lib>=1.0.16 doesn't trigger that anymore, too. */
if (snd_pcm_hw_params_any(pcm, hw) < 0) {
if(!0) printf("initialize_device(): no configuration available");
return -1;
}
if (snd_pcm_hw_params_set_access(pcm, hw, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
if(!0) printf("initialize_device(): device does not support interleaved access");
return -1;
}
#if 0
format = SND_PCM_FORMAT_UNKNOWN;
for (i = 0; i < NUM_FORMATS; ++i) {
if (ao->format == format_map[i].mpg123) {
format = format_map[i].alsa;
break;
}
}
if (format == SND_PCM_FORMAT_UNKNOWN) {
if(!0) printf("initialize_device(): invalid sample format %d", ao->format);
errno = EINVAL;
return -1;
}
#endif
format = SND_PCM_FORMAT_S16_LE;
if (snd_pcm_hw_params_set_format(pcm, hw, format) < 0) {
if(!0) printf("initialize_device(): cannot set format %s", snd_pcm_format_name(format));
return -1;
}
if (snd_pcm_hw_params_set_channels(pcm, hw, ao->channels) < 0) {
if(!0) printf("initialize_device(): cannot set %d channels", ao->channels);
return -1;
}
rate = ao->rate;
if (snd_pcm_hw_params_set_rate_near(pcm, hw, &rate, NULL) < 0) {
if(!0) printf("initialize_device(): cannot set rate %u", rate);
return -1;
}
if (!rates_match(ao->rate, rate)) {
if(!0) error2("initialize_device(): rate %ld not available, using %u", ao->rate, rate);
/* return -1; */
}
buffer_size = rate * BUFFER_LENGTH;
if (snd_pcm_hw_params_set_buffer_size_near(pcm, hw, &buffer_size) < 0) {
if(!0) printf("initialize_device(): cannot set buffer size");
return -1;
}
printf("buffer_size=%lu", (unsigned long)buffer_size);
period_size = buffer_size / 4;
if (snd_pcm_hw_params_set_period_size_near(pcm, hw, &period_size, NULL) < 0) {
if(!0) printf("initialize_device(): cannot set period size");
return -1;
}
if (snd_pcm_hw_params(pcm, hw) < 0) {
if(!0) printf("initialize_device(): cannot set hw params");
return -1;
}
snd_pcm_sw_params_alloca(&sw);
if (snd_pcm_sw_params_current(pcm, sw) < 0) {
if(!0) printf("initialize_device(): cannot get sw params");
return -1;
}
/* start playing right away */
if (snd_pcm_sw_params_set_start_threshold(pcm, sw, 1) < 0) {
if(!0) printf("initialize_device(): cannot set start threshold");
return -1;
}
/* wake up on every interrupt */
if (snd_pcm_sw_params_set_avail_min(pcm, sw, 1) < 0) {
if(!0) printf("initialize_device(): cannot set min available");
return -1;
}
#if SND_LIB_VERSION < ((1<<16)|16)
/* Always write as many frames as possible (deprecated since alsa-lib 1.0.16) */
if (snd_pcm_sw_params_set_xfer_align(pcm, sw, 1) < 0) {
if(!0) printf("initialize_device(): cannot set transfer alignment");
return -1;
}
#endif
if (snd_pcm_sw_params(pcm, sw) < 0) {
if(!0) printf("initialize_device(): cannot set sw params");
return -1;
}
return 0;
}
