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Multiple fixes in VCHI audio driver:

Browse Source 
- Pre-buffer audio data to VideoCore so there are no audible glitches when
    driver is too late to provide samples
- Start actual playback when there is some prebuffered audio,
    it fixes audible noisy click in the beginning of playback
- Use #defines instead of hardcoded values where appropriate
- Fix copy-pasted comment

PR:		208678
This commit is contained in:
gonzo 2016-04-13 05:28:27 +00:00
parent 5976479952
commit eb5df9db73
1 changed files with 28 additions and 19 deletions
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47
sys/arm/broadcom/bcm2835/bcm2835_audio.c
View File

@ -46,6 +46,7 @@ SND_DECLARE_FILE("$FreeBSD$");
#define VCHIQ_AUDIO_PACKET_SIZE 4000
#define VCHIQ_AUDIO_BUFFER_SIZE 128000
#define VCHIQ_AUDIO_PREBUFFER 10 /* Number of pre-buffered audio messages */
#define VCHIQ_AUDIO_MAX_VOLUME
/* volume in terms of 0.01dB */
@ -91,6 +92,7 @@ struct bcm2835_audio_chinfo {
uint32_t free_buffer;
uint32_t buffered_ptr;
int playback_state;
int prebuffered;
};
struct bcm2835_audio_info {
@ -170,11 +172,10 @@ bcm2835_audio_callback(void *param, const VCHI_CALLBACK_REASON_T reason, void *m
ch->complete_pos = (ch->complete_pos + count) % sndbuf_getsize(ch->buffer);
ch->free_buffer += count;
chn_intr(sc->pch.channel);
if (perr || ch->free_buffer >= VCHIQ_AUDIO_PACKET_SIZE) {
chn_intr(ch->channel);
if (perr || ch->free_buffer >= VCHIQ_AUDIO_PACKET_SIZE)
cv_signal(&sc->data_cv);
}
} else
printf("%s: unknown m.type: %d\n", __func__, m.type);
}
@ -244,6 +245,7 @@ bcm2835_audio_reset_channel(struct bcm2835_audio_chinfo *ch)
ch->playback_state = 0;
ch->buffered_ptr = 0;
ch->complete_pos = 0;
ch->prebuffered = 0;
sndbuf_reset(ch->buffer);
}
@ -478,21 +480,29 @@ bcm2835_audio_worker(void *data)
if (sc->unloading)
break;
if ((ch->playback_state == PLAYBACK_PLAYING) &&
(vchiq_unbuffered_bytes(ch) >= VCHIQ_AUDIO_PACKET_SIZE)
&& (ch->free_buffer >= VCHIQ_AUDIO_PACKET_SIZE)) {
bcm2835_audio_write_samples(ch);
} else {
if (ch->playback_state == PLAYBACK_STOPPING) {
bcm2835_audio_reset_channel(&sc->pch);
ch->playback_state = PLAYBACK_IDLE;
}
if (ch->playback_state == PLAYBACK_IDLE) {
cv_wait_sig(&sc->data_cv, &sc->data_lock);
continue;
}
if (ch->playback_state == PLAYBACK_STARTING) {
/* Give it initial kick */
chn_intr(sc->pch.channel);
if (ch->playback_state == PLAYBACK_STOPPING) {
bcm2835_audio_reset_channel(&sc->pch);
ch->playback_state = PLAYBACK_IDLE;
continue;
}
if (ch->free_buffer < vchiq_unbuffered_bytes(ch)) {
cv_timedwait_sig(&sc->data_cv, &sc->data_lock, 10);
continue;
}
bcm2835_audio_write_samples(ch);
if (ch->playback_state == PLAYBACK_STARTING) {
ch->prebuffered++;
if (ch->prebuffered == VCHIQ_AUDIO_PREBUFFER) {
bcm2835_audio_start(ch);
ch->playback_state = PLAYBACK_PLAYING;
}
}
@ -514,7 +524,7 @@ bcm2835_audio_create_worker(struct bcm2835_audio_info *sc)
}
/* -------------------------------------------------------------------- */
/* channel interface for ESS18xx */
/* channel interface for VCHI audio */
static void *
bcmchan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, struct pcm_channel *c, int dir)
{
@ -612,7 +622,6 @@ bcmchan_trigger(kobj_t obj, void *data, int go)
switch (go) {
case PCMTRIG_START:
bcm2835_audio_start(ch);
ch->playback_state = PLAYBACK_STARTING;
/* wakeup worker thread */
cv_signal(&sc->data_cv);
@ -620,7 +629,7 @@ bcmchan_trigger(kobj_t obj, void *data, int go)
case PCMTRIG_STOP:
case PCMTRIG_ABORT:
ch->playback_state = 1;
ch->playback_state = PLAYBACK_STOPPING;
bcm2835_audio_stop(ch);
break;