[vlc-commits] PulseAudio: sync at start
Rémi Denis-Courmont
git at videolan.org
Tue Jul 19 18:26:49 CEST 2011
vlc/vlc-1.1 | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Mon Jul 18 18:32:31 2011 +0300| [a9acf5f96f43b8f783dbc053ed805c90d89ce0d2] | committer: Rémi Denis-Courmont
PulseAudio: sync at start
(cherry picked from commit 2aea47cfbe916a57b8775f8463f5ffaa32df1eef)
Conflicts:
modules/audio_output/pulse.c
> http://git.videolan.org/gitweb.cgi/vlc/vlc-1.1.git/?a=commit;h=a9acf5f96f43b8f783dbc053ed805c90d89ce0d2
---
modules/audio_output/pulse.c | 113 ++++++++++++++++++++++--------------------
1 files changed, 60 insertions(+), 53 deletions(-)
diff --git a/modules/audio_output/pulse.c b/modules/audio_output/pulse.c
index 2dae2bb..08311ec 100644
--- a/modules/audio_output/pulse.c
+++ b/modules/audio_output/pulse.c
@@ -144,9 +144,12 @@ static void stream_suspended_cb(pa_stream *s, void *userdata)
static void stream_underflow_cb(pa_stream *s, void *userdata)
{
aout_instance_t *aout = userdata;
+ pa_operation *op;
- msg_Dbg(aout, "underflow");
- (void) s;
+ msg_Warn(aout, "underflow");
+ op = pa_stream_cork(s, 1, NULL, NULL);
+ if (op != NULL)
+ pa_operation_unref(op);
}
static int stream_wait(pa_threaded_mainloop *mainloop, pa_stream *stream)
@@ -193,6 +196,17 @@ static void Play(aout_instance_t *aout)
aout_sys_t *sys = aout->output.p_sys;
pa_stream *s = sys->stream;
+ /* This function is called exactly once per block in the output FIFO. */
+ block_t *block = aout_FifoPop(aout, &aout->output.fifo);
+ assert (block != NULL);
+
+ const void *ptr = data_convert(&block);
+ if (unlikely(ptr == NULL))
+ return;
+
+ size_t len = block->i_buffer;
+ //mtime_t pts = block->i_pts + block->i_length;
+
/* Note: The core already holds the output FIFO lock at this point.
* Therefore we must not under any circumstances (try to) acquire the
* output FIFO lock while the PulseAudio threaded main loop lock is held
@@ -200,36 +214,47 @@ static void Play(aout_instance_t *aout)
* will take place, and sooner or later a deadlock. */
pa_threaded_mainloop_lock(sys->mainloop);
- if (pa_stream_is_corked(sys->stream) > 0) {
- pa_operation *op = pa_stream_cork(s, 0, NULL, NULL);
+ if (pa_stream_is_corked(s) > 0) {
+ /* Start or resume the stream. Zeroes are prepended to sync.
+ * This does not really work because PulseAudio latency measurement is
+ * garbage at start. */
+ pa_operation *op;
+ pa_usec_t latency;
+ int negative;
+
+ if (pa_stream_get_latency(s, &latency, &negative) == 0)
+ msg_Dbg(aout, "starting with %c%"PRIu64" us latency",
+ negative ? '-' : '+', latency);
+ else
+ latency = negative = 0;
+
+ mtime_t advance = block->i_pts - mdate();
+ if (negative)
+ advance += latency;
+ else
+ advance -= latency;
+
+ if (advance > 0) {
+ size_t nb = (advance * aout->output.output.i_rate) / CLOCK_FREQ;
+ size_t size = aout->output.output.i_bytes_per_frame;
+ float *zeroes = calloc (nb, size);
+
+ msg_Dbg(aout, "prepending %zu zeroes", nb);
+ if (likely(zeroes != NULL))
+ if (pa_stream_write(s, zeroes, nb * size, free, 0,
+ PA_SEEK_RELATIVE) < 0)
+ free(zeroes);
+ }
+
+ op = pa_stream_cork(s, 0, NULL, NULL);
+ if (op != NULL)
+ pa_operation_unref(op);
+ op = pa_stream_trigger(s, NULL, NULL);
if (op != NULL)
pa_operation_unref(op);
msg_Dbg(aout, "uncorking");
}
-#if 0
- /* This function should be called by the LibVLC core a header of time,
- * but not more than AOUT_MAX_PREPARE. The PulseAudio latency should be
- * shorter than that (though it might not be the case with some evil piece
- * of audio output hardware). So we may need to trigger playback early,
- * (that is to say, short cut the PulseAudio prebuffering). Otherwise,
- * audio and video may be out of synchronization. */
- pa_usec_t latency;
- int negative;
- if (pa_stream_get_latency(s, &latency, &negative) < 0) {
- /* Especially at start of stream, latency may not be known (yet). */
- if (pa_context_errno(sys->context) != PA_ERR_NODATA)
- error(aout, "cannot determine latency", sys->context);
- } else {
- mtime_t gap = aout_FifoFirstDate(aout, &aout->output.fifo) - mdate()
- - latency;
-
- if (gap > AOUT_PTS_TOLERANCE)
- msg_Dbg(aout, "buffer too early (%"PRId64" us)", gap);
- else if (gap < -AOUT_PTS_TOLERANCE)
- msg_Err(aout, "buffer too late (%"PRId64" us)", -gap);
- }
-#endif
#if 0 /* Fault injector to test underrun recovery */
static unsigned u = 0;
if ((++u % 500) == 0) {
@@ -238,33 +263,14 @@ static void Play(aout_instance_t *aout)
}
#endif
- /* This function is called exactly once per block in the output FIFO, so
- * this for-loop is not necessary.
- * If this function is changed to not always dequeue blocks, be sure to
- * limit the queue size to a reasonable limit to avoid huge leaks. */
- for (;;) {
- block_t *block = aout_FifoPop(aout, &aout->output.fifo);
- if (block == NULL)
- break;
-
- const void *ptr = data_convert(&block);
- if (unlikely(ptr == NULL))
- break;
-
- size_t len = block->i_buffer;
- //mtime_t pts = block->i_pts, duration = block->i_length;
-
- if (pa_stream_write(s, ptr, len, data_free, 0, PA_SEEK_RELATIVE) < 0)
- {
- error(aout, "cannot write", sys->context);
- block_Release(block);
- }
+ if (pa_stream_write(s, ptr, len, data_free, 0, PA_SEEK_RELATIVE) < 0) {
+ error(aout, "cannot write", sys->context);
+ block_Release(block);
}
pa_threaded_mainloop_unlock(sys->mainloop);
}
-
/*****************************************************************************
* Open: open the audio device
*****************************************************************************/
@@ -381,15 +387,16 @@ static int Open(vlc_object_t *obj)
msg_Dbg(aout, "using %s channel map", (name != NULL) ? name : "?");
}
- const pa_stream_flags_t flags = PA_STREAM_INTERPOLATE_TIMING
- | PA_STREAM_AUTO_TIMING_UPDATE
- | PA_STREAM_START_CORKED;
+ /* Stream parameters */
+ const pa_stream_flags_t flags = PA_STREAM_START_CORKED
+ //| PA_STREAM_INTERPOLATE_TIMING
+ | PA_STREAM_AUTO_TIMING_UPDATE;
const uint32_t byterate = pa_bytes_per_second(&ss);
struct pa_buffer_attr attr;
attr.maxlength = -1;
attr.tlength = byterate * AOUT_MAX_PREPARE_TIME / CLOCK_FREQ;
- attr.prebuf = -1;
+ attr.prebuf = 0; /* trigger manually */
attr.minreq = -1;
attr.fragsize = 0; /* not used for output */
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