2008/6/12 Takashi Iwai <tiwai@xxxxxxx>:
> It's unlikely a driver issue but an incompatibility of dmix, I guess.
> But still I don't figure out why this happens. The hwsync is done at
> each snd_pcm_dmix_delay() call (as long as slowptr is set, and it's so
> as default). So, there shouldn't be any difference...
>
> What happens if you use "hw" or "plughw"?
With both plughw and hw works fine.
If helps, I have simplified the problematic bsnes code into this:
#include <alsa/asoundlib.h>
#include <stdint.h>
int main(){
snd_pcm_t *handle;
unsigned length;
unsigned frequency;
snd_pcm_uframes_t buffer_size;
snd_pcm_uframes_t period_size;
if(snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0) < 0) {
exit(1);
}
if(snd_pcm_set_params(handle, SND_PCM_FORMAT_S16_LE,
SND_PCM_ACCESS_RW_INTERLEAVED,
2, 44100, 1, 100000) < 0) {
exit(2);
}
if(snd_pcm_get_params(handle, &buffer_size, &period_size) < 0) {
exit(3);
}
snd_output_t *setup;
if (snd_output_stdio_attach(&setup, stdout, 0) < 0) {
exit(4);
}
snd_pcm_dump_setup(handle, setup);
uint32_t data[period_size];
while(1){
length = period_size;
printf("State: %d\n", snd_pcm_state(handle));
snd_pcm_sframes_t delay;
//snd_pcm_avail_update(handle);
snd_pcm_delay(handle, &delay);
printf("Delay: %d\n", delay);
if(delay < 0){
snd_pcm_prepare(handle);
}else if(delay > buffer_size - period_size) {
printf("Delay/Goal: %d/%u\n", delay, buffer_size - period_size);
length = 0;
continue;
}
printf("Passed\n");
uint32_t *buffer_ptr = data;
do {
snd_pcm_sframes_t written = snd_pcm_writei(handle, buffer_ptr, length);
if(written < 0) {
snd_pcm_recover(handle, written, 1);
} else if(written < length) {
//only some samples written
length -= written;
buffer_ptr += written;
} else {
//all samples written
length = 0;
}
} while(length != 0);
}
}
The listened effect is that when fails you listen the noise for just
buffer_time, and when works the noise never ends.
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