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ao_alsa: make pause state more robust, reduce minor code duplication

With the previous commit, ao_alsa.c now has 3 possible ways to pause
playback. Actually all 3 of them need get_delay() to fake its return
value, so don't duplicate that code.

Also much of the code looks a bit questionable when considering
inconsistent pause/resume calls from outside, so ignore redundant calls.
This commit is contained in:
wm4 2016-08-09 16:52:33 +02:00
parent 2ded41d2be
commit 367e9fb7f1

View File

@ -53,7 +53,7 @@ struct priv {
bool device_lost;
snd_pcm_format_t alsa_fmt;
bool can_pause;
bool pretend_pause;
bool paused;
snd_pcm_sframes_t prepause_frames;
double delay_before_pause;
snd_pcm_uframes_t buffersize;
@ -883,7 +883,7 @@ static double get_delay(struct ao *ao)
struct priv *p = ao->priv;
snd_pcm_sframes_t delay;
if (snd_pcm_state(p->alsa) == SND_PCM_STATE_PAUSED || p->pretend_pause)
if (p->paused)
return p->delay_before_pause;
if (snd_pcm_delay(p->alsa, &delay) < 0)
@ -917,29 +917,27 @@ static void audio_pause(struct ao *ao)
struct priv *p = ao->priv;
int err;
if (p->paused)
return;
p->delay_before_pause = get_delay(ao);
p->prepause_frames = p->delay_before_pause * ao->samplerate;
if (ao->stream_silence) {
if (snd_pcm_state(p->alsa) == SND_PCM_STATE_RUNNING) {
p->delay_before_pause = get_delay(ao);
p->prepause_frames = p->delay_before_pause * ao->samplerate;
soft_reset(ao);
p->pretend_pause = true;
}
soft_reset(ao);
} else if (p->can_pause) {
if (snd_pcm_state(p->alsa) == SND_PCM_STATE_RUNNING) {
p->delay_before_pause = get_delay(ao);
err = snd_pcm_pause(p->alsa, 1);
CHECK_ALSA_ERROR("pcm pause error");
p->prepause_frames = 0;
}
} else {
if (snd_pcm_delay(p->alsa, &p->prepause_frames) < 0
|| p->prepause_frames < 0)
p->prepause_frames = 0;
p->delay_before_pause = p->prepause_frames / (double)ao->samplerate;
err = snd_pcm_drop(p->alsa);
CHECK_ALSA_ERROR("pcm drop error");
}
p->paused = true;
alsa_error: ;
}
@ -961,13 +959,14 @@ static void audio_resume(struct ao *ao)
struct priv *p = ao->priv;
int err;
if (!p->paused)
return;
resume_device(ao);
if (ao->stream_silence) {
p->pretend_pause = false;
p->paused = false;
get_delay(ao); // recovers from underrun (as a side-effect)
if (p->prepause_frames)
ao_play_silence(ao, p->prepause_frames);
} else if (p->can_pause) {
if (snd_pcm_state(p->alsa) == SND_PCM_STATE_PAUSED) {
err = snd_pcm_pause(p->alsa, 0);
@ -977,11 +976,13 @@ static void audio_resume(struct ao *ao)
MP_VERBOSE(ao, "resume not supported by hardware\n");
err = snd_pcm_prepare(p->alsa);
CHECK_ALSA_ERROR("pcm prepare error");
if (p->prepause_frames)
ao_play_silence(ao, p->prepause_frames);
}
if (p->prepause_frames)
ao_play_silence(ao, p->prepause_frames);
alsa_error: ;
p->paused = false;
}
static void reset(struct ao *ao)
@ -989,13 +990,13 @@ static void reset(struct ao *ao)
struct priv *p = ao->priv;
int err;
p->pretend_pause = false;
p->paused = false;
p->prepause_frames = 0;
p->delay_before_pause = 0;
if (ao->stream_silence) {
soft_reset(ao);
} else {
p->prepause_frames = 0;
p->delay_before_pause = 0;
err = snd_pcm_drop(p->alsa);
CHECK_ALSA_ERROR("pcm prepare error");
err = snd_pcm_prepare(p->alsa);
@ -1039,6 +1040,8 @@ static int play(struct ao *ao, void **data, int samples, int flags)
}
} while (res == 0);
p->paused = false;
return res < 0 ? -1 : res;
alsa_error: