static int playback(struct device_t *dv)
{
int r;
struct alsa_t *alsa = (struct alsa_t*)dv->local;
if (dv->player) {
player_collect(dv->player, alsa->playback.buf,
alsa->playback.period, alsa->playback.rate);
} else {
memset(alsa->playback.buf, 0,
alsa->playback.period * DEVICE_CHANNELS * sizeof(short));
}
r = snd_pcm_writei(alsa->playback.pcm, alsa->playback.buf,
alsa->playback.period);
if (r < 0)
return r;
if (r < alsa->playback.period) {
fprintf(stderr, "alsa: playback underrun %d/%ld.\n", r,
alsa->playback.period);
}
return 0;
}
static void process_deck(struct device_t *dv, jack_nframes_t nframes)
{
int n;
jack_default_audio_sample_t *in[DEVICE_CHANNELS], *out[DEVICE_CHANNELS];
jack_nframes_t remain;
struct jack_t *jack = (struct jack_t*)dv->local;
for (n = 0; n < DEVICE_CHANNELS; n++) {
in[n] = jack_port_get_buffer(jack->input_port[n], nframes);
assert(in[n] != NULL);
out[n] = jack_port_get_buffer(jack->output_port[n], nframes);
assert(out[n] != NULL);
}
/* For large values of nframes, communicate with the timecoder and
* player in smaller blocks */
remain = nframes;
while (remain > 0) {
signed short buf[MAX_BLOCK * DEVICE_CHANNELS];
jack_nframes_t block;
if (remain < MAX_BLOCK)
block = remain;
else
block = MAX_BLOCK;
/* Timecode input */
interleave(buf, in, block);
if (dv->timecoder)
timecoder_submit(dv->timecoder, buf, block);
/* Audio output -- handle in the same loop for finer granularity */
player_collect(dv->player, buf, block, rate);
uninterleave(out, buf, block);
remain -= block;
}
}
void device_collect(struct device *dv, signed short *pcm, size_t n)
{
assert(dv->player != NULL);
player_collect(dv->player, pcm, n);
}