static int
laudio_alsa_start(uint64_t cur_pos, uint64_t next_pkt)
{
int ret;
ret = snd_pcm_prepare(hdl);
if (ret < 0)
{
DPRINTF(E_LOG, L_LAUDIO, "Could not prepare PCM device: %s\n", snd_strerror(ret));
return -1;
}
DPRINTF(E_DBG, L_LAUDIO, "Start local audio curpos %" PRIu64 ", next_pkt %" PRIu64 "\n", cur_pos, next_pkt);
DPRINTF(E_DBG, L_LAUDIO, "PCM will start after %d samples (%d packets)\n", pcm_buf_threshold, pcm_buf_threshold / AIRTUNES_V2_PACKET_SAMPLES);
/* Make pcm_pos the rtptime of the packet containing cur_pos */
pcm_pos = next_pkt;
while (pcm_pos > cur_pos)
pcm_pos -= AIRTUNES_V2_PACKET_SAMPLES;
pcm_start_pos = next_pkt + pcm_buf_threshold;
/* Compensate threshold, as it's taken into account by snd_pcm_delay() */
//pcm_pos += pcm_buf_threshold;
DPRINTF(E_DBG, L_LAUDIO, "PCM pos %" PRIu64 ", start pos %" PRIu64 "\n", pcm_pos, pcm_start_pos);
pcm_pkt_head = NULL;
pcm_pkt_tail = NULL;
pcm_last_error = 0;
pcm_recovery = 0;
ret = laudio_alsa_set_start_threshold(pcm_buf_threshold);
if (ret < 0)
{
DPRINTF(E_LOG, L_LAUDIO, "Could not set PCM start threshold for local audio start\n");
return -1;
}
update_status(LAUDIO_STARTED);
return 0;
}
static void
laudio_alsa_write(uint8_t *buf, uint64_t rtptime)
{
struct pcm_packet *pkt;
snd_pcm_sframes_t nsamp;
int ret;
pkt = (struct pcm_packet *)malloc(sizeof(struct pcm_packet));
if (!pkt)
{
DPRINTF(E_LOG, L_LAUDIO, "Out of memory for PCM pkt\n");
update_status(LAUDIO_FAILED);
return;
}
memcpy(pkt->samples, buf, sizeof(pkt->samples));
pkt->rtptime = rtptime;
pkt->offset = 0;
pkt->next = NULL;
if (pcm_pkt_tail)
{
pcm_pkt_tail->next = pkt;
pcm_pkt_tail = pkt;
}
else
{
pcm_pkt_head = pkt;
pcm_pkt_tail = pkt;
}
if (pcm_pos < pcm_pkt_head->rtptime)
{
pcm_pos += AIRTUNES_V2_PACKET_SAMPLES;
return;
}
else if ((pcm_status != LAUDIO_RUNNING) && (pcm_pos + pcm_buf_threshold >= pcm_start_pos))
{
/* Kill threshold */
ret = laudio_alsa_set_start_threshold(0);
if (ret < 0)
DPRINTF(E_WARN, L_LAUDIO, "Couldn't set PCM start threshold to 0 for output start\n");
update_status(LAUDIO_RUNNING);
}
pkt = pcm_pkt_head;
while (pkt)
{
if (pcm_recovery)
{
ret = laudio_alsa_xrun_recover(0);
if ((ret == 2) && (pcm_recovery < 10))
return;
else
{
if (ret == 2)
DPRINTF(E_LOG, L_LAUDIO, "Couldn't recover PCM device after 10 tries, aborting\n");
update_status(LAUDIO_FAILED);
return;
}
}
nsamp = snd_pcm_writei(hdl, pkt->samples + pkt->offset, BTOS(sizeof(pkt->samples) - pkt->offset));
if ((nsamp == -EPIPE) || (nsamp == -ESTRPIPE))
{
ret = laudio_alsa_xrun_recover(nsamp);
if ((ret < 0) || (ret == 1))
{
if (ret < 0)
DPRINTF(E_LOG, L_LAUDIO, "PCM write error: %s\n", snd_strerror(ret));
update_status(LAUDIO_FAILED);
return;
}
else if (ret != 0)
return;
continue;
}
else if (nsamp < 0)
{
DPRINTF(E_LOG, L_LAUDIO, "PCM write error: %s\n", snd_strerror(nsamp));
update_status(LAUDIO_FAILED);
return;
}
pcm_pos += nsamp;
pkt->offset += STOB(nsamp);
if (pkt->offset == sizeof(pkt->samples))
{
pcm_pkt_head = pkt->next;
if (pkt == pcm_pkt_tail)
pcm_pkt_tail = NULL;
free(pkt);
pkt = pcm_pkt_head;
}
/* Don't let ALSA fill up the buffer too much */
// Disabled - seems to cause buffer underruns
// if (nsamp == AIRTUNES_V2_PACKET_SAMPLES)
// return;
}
}
static int
laudio_alsa_start(uint64_t cur_pos, uint64_t next_pkt)
{
snd_output_t *output;
char *debug_pcm_cfg;
int ret;
ret = snd_pcm_prepare(hdl);
if (ret < 0)
{
DPRINTF(E_LOG, L_LAUDIO, "Could not prepare PCM device: %s\n", snd_strerror(ret));
return -1;
}
DPRINTF(E_DBG, L_LAUDIO, "Start local audio curpos %" PRIu64 ", next_pkt %" PRIu64 "\n", cur_pos, next_pkt);
/* Make pcm_pos the rtptime of the packet containing cur_pos */
pcm_pos = next_pkt;
while (pcm_pos > cur_pos)
pcm_pos -= AIRTUNES_V2_PACKET_SAMPLES;
pcm_start_pos = next_pkt + pcm_period_size;
/* Compensate period size, otherwise get_pos won't be correct */
pcm_pos += pcm_period_size;
DPRINTF(E_DBG, L_LAUDIO, "PCM pos %" PRIu64 ", start pos %" PRIu64 "\n", pcm_pos, pcm_start_pos);
pcm_pkt_head = NULL;
pcm_pkt_tail = NULL;
pcm_last_error = 0;
pcm_recovery = 0;
// alsa doesn't actually seem to wait for this threshold?
ret = laudio_alsa_set_start_threshold(pcm_buf_threshold);
if (ret < 0)
{
DPRINTF(E_LOG, L_LAUDIO, "Could not set PCM start threshold for local audio start\n");
return -1;
}
// Dump PCM config data for E_DBG logging
ret = snd_output_buffer_open(&output);
if (ret == 0)
{
if (snd_pcm_dump_setup(hdl, output) == 0)
{
snd_output_buffer_string(output, &debug_pcm_cfg);
DPRINTF(E_DBG, L_LAUDIO, "Dump of sound device config:\n%s\n", debug_pcm_cfg);
}
snd_output_close(output);
}
update_status(LAUDIO_STARTED);
return 0;
}
