static void *
alsa_thread(void *arg)
{
gint16 *ptr;
int err, cptr;
guint8 *buf;
sfx_pcm_device_t *self = (sfx_pcm_device_t *) arg;
buf = (guint8 *) malloc(period_size * frame_size);
while (run_thread) {
ptr = (gint16 *) buf;
cptr = period_size;
sci_gettime(&last_callback_secs, &last_callback_usecs);
self->timer->block();
if (alsa_sfx_timer_callback)
alsa_sfx_timer_callback(alsa_sfx_timer_data);
self->timer->unblock();
sfx_audbuf_read(&audio_buffer, buf, period_size);
while (cptr > 0) {
err = snd_pcm_writei(handle, ptr, cptr);
if (err == -EAGAIN)
continue;
if (err < 0) {
if (xrun_recovery(handle, err) < 0) {
fprintf(stderr, "[SND:ALSA] Write error: %s\n", snd_strerror(err));
run_thread = 0;
}
break; /* skip one period */
}
ptr += err * channels;
cptr -= err;
}
}
free(buf);
return NULL;
}
static void
timer_sdl_internal_callback(void *userdata, byte *dest, int len)
{
sci_gettime(&last_callback_secs, &last_callback_usecs);
last_callback_len = len;
if (sdl_sfx_timer_callback)
sdl_sfx_timer_callback(sdl_sfx_timer_data);
#if 0
if (!sfx_audbuf_read_timestamp(&audio_buffer, &ts)) {
int delta = (buf_size - len) / frame_size;
sfx_timestamp_t real_ts;
long deltatime;
long sec2, usec2;
sci_gettime(&sec2, &usec2);
real_ts = sfx_timestamp_add(sfx_new_timestamp(sec, usec, rate), delta);
deltatime = sfx_timestamp_usecs_diff(ts, real_ts);
fprintf(stderr, "[SDL] Frames requested: %d Playing %ld too late. Needed %ldus for computations.\n",
len / frame_size, deltatime,
(usec2-usec) + (sec2-sec)*1000000);
if (abs(deltatime) > DELTA_TIME_LIMIT)
sciprintf("[SND:SDL] Very high delta time for PCM playback: %ld too late (%d frames in the future)\n",
deltatime, sfx_timestamp_frame_diff(sfx_new_timestamp(sec, usec, rate), ts));
#if 0
if (deltatime < 0) {
/* Read and discard frames, explicitly underrunning */
int max_read = len / frame_size;
int frames_to_kill = sfx_timestamp_frame_diff(real_ts, ts);
while (frames_to_kill) {
int d = frames_to_kill > max_read? max_read : frames_to_kill;
sfx_audbuf_read(&audio_buffer, dest, d);
frames_to_kill -= d;
}
}
#endif
}
#endif
sfx_audbuf_read(&audio_buffer, dest, len / frame_size);
#if 0
if (!fil) {
fil = fopen("/tmp/sdl.log", "w");
}
{
int i;
int end = len / frame_size;
gint16 *d = dest;
fprintf(fil, "Writing %d/%d\n", len, frame_size);
for (i = 0; i < end; i++) {
fprintf(fil, "\t%d\t%d\n", d[0], d[1]);
d += 2;
}
}
#endif
}
