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ext/alsa/: Add clock to alsasrc. Take new capture timestamp when restarting after an overrun. Split up some functions...

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Original commit message from CVS:
* ext/alsa/gstalsa.c: (gst_alsa_change_state), (gst_alsa_start),
(gst_alsa_xrun_recovery):
* ext/alsa/gstalsa.h:
* ext/alsa/gstalsasink.c: (gst_alsa_sink_check_event),
(gst_alsa_sink_loop), (gst_alsa_sink_get_time):
* ext/alsa/gstalsasrc.c: (gst_alsa_src_init),
(gst_alsa_src_get_time), (gst_alsa_src_update_avail),
(gst_alsa_src_loop):
Add clock to alsasrc. Take new capture timestamp when
restarting after an overrun. Split up some functions between
alsasrc ans alsasink.
This commit is contained in:
Wim Taymans 2004-06-23 18:08:26 +00:00
parent 96c2a15318
commit e56c174f8d
5 changed files with 101 additions and 31 deletions
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14
ChangeLog
View file

@ -1,3 +1,17 @@
2004-06-23 Wim Taymans <wim@fluendo.com>
* ext/alsa/gstalsa.c: (gst_alsa_change_state), (gst_alsa_start),
(gst_alsa_xrun_recovery):
* ext/alsa/gstalsa.h:
* ext/alsa/gstalsasink.c: (gst_alsa_sink_check_event),
(gst_alsa_sink_loop), (gst_alsa_sink_get_time):
* ext/alsa/gstalsasrc.c: (gst_alsa_src_init),
(gst_alsa_src_get_time), (gst_alsa_src_update_avail),
(gst_alsa_src_loop):
Add clock to alsasrc. Take new capture timestamp when
restarting after an overrun. Split up some functions between
alsasrc ans alsasink.
2004-06-23 Thomas Vander Stichele <thomas at apestaart dot org>
* ext/alsa/gstalsa.c: (gst_alsa_init), (gst_alsa_dispose),

42
ext/alsa/gstalsa.c
View file

@ -1085,7 +1085,8 @@ gst_alsa_change_state (GstElement * element)
if (!(GST_FLAG_IS_SET (element, GST_ALSA_RUNNING) ||
gst_alsa_start_audio (this)))
return GST_STATE_FAILURE;
this->transmitted = 0;
this->played = 0;
this->captured = 0;
break;
case GST_STATE_PAUSED_TO_PLAYING:
if (snd_pcm_state (this->handle) == SND_PCM_STATE_PAUSED) {
@ -1202,6 +1203,8 @@ gst_alsa_pcm_wait (GstAlsa * this)
inline gboolean
gst_alsa_start (GstAlsa * this)
{
GstClockTime elemnow;
GST_DEBUG ("Setting state to RUNNING");
switch (snd_pcm_state (this->handle)) {
@ -1212,6 +1215,13 @@ gst_alsa_start (GstAlsa * this)
ERROR_CHECK (snd_pcm_prepare (this->handle), "error preparing: %s");
case SND_PCM_STATE_SUSPENDED:
case SND_PCM_STATE_PREPARED:
/* The strategy to recover the timestamps from the xrun is to take the
* current element time and pretend we just sent all the samples up to
* that time. This will result in an offset discontinuity in the next
* buffer along with the correct timestamp on that buffer, we only
* update the capture timestamps */
elemnow = gst_element_get_time (GST_ELEMENT (this));
this->captured = gst_alsa_timestamp_to_samples (this, elemnow);
ERROR_CHECK (snd_pcm_start (this->handle), "error starting playback: %s");
break;
case SND_PCM_STATE_PAUSED:
@ -1244,13 +1254,6 @@ gst_alsa_xrun_recovery (GstAlsa * this)
GST_ERROR_OBJECT (this, "status error: %s", snd_strerror (err));
if (snd_pcm_status_get_state (status) == SND_PCM_STATE_XRUN) {
struct timeval now, diff, tstamp;
gettimeofday (&now, 0);
snd_pcm_status_get_trigger_tstamp (status, &tstamp);
timersub (&now, &tstamp, &diff);
GST_INFO_OBJECT (this, "alsa: xrun of at least %.3f msecs",
diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
/* if we're allowed to recover, ... */
if (this->autorecover) {
@ -1264,12 +1267,25 @@ gst_alsa_xrun_recovery (GstAlsa * this)
this->period_count *= 2;
}
}
}
if (!(gst_alsa_stop_audio (this) && gst_alsa_start_audio (this))) {
GST_ELEMENT_ERROR (this, RESOURCE, FAILED, (NULL),
("Error restarting audio after xrun"));
return FALSE;
/* prepare the device again */
if ((err = snd_pcm_prepare (this->handle)) < 0) {
GST_ERROR_OBJECT (this, "prepare error: %s", snd_strerror (err));
return FALSE;
}
if (!gst_alsa_start (this)) {
GST_ELEMENT_ERROR (this, RESOURCE, FAILED, (NULL),
("Error starting audio after xrun"));
return FALSE;
}
GST_DEBUG_OBJECT (this, "XRun!!!! pretending we captured %lld samples",
this->captured);
} else {
if (!(gst_alsa_stop_audio (this) && gst_alsa_start_audio (this))) {
GST_ELEMENT_ERROR (this, RESOURCE, FAILED, (NULL),
("Error restarting audio after xrun"));
return FALSE;
}
}
return TRUE;

4
ext/alsa/gstalsa.h
View file

@ -156,11 +156,13 @@ struct _GstAlsa {
/* clocking */
GstAlsaClock * clock; /* our provided clock */
snd_pcm_uframes_t transmitted; /* samples transmitted since last sync
GstClockTime clock_base;
snd_pcm_uframes_t played; /* samples transmitted since last sync
This thing actually is our master clock.
We will event insert silent samples or
drop some to sync to incoming timestamps.
*/
snd_pcm_uframes_t captured;
GstClockTime max_discont; /* max difference between current
playback timestamp and buffers timestamps
*/

14
ext/alsa/gstalsasink.c
View file

@ -217,7 +217,7 @@ gst_alsa_sink_check_event (GstAlsaSink * sink, gint pad_nr)
break;
}
delay = (this->format == NULL) ? 0 :
GST_SECOND * this->transmitted / this->format->rate -
GST_SECOND * this->played / this->format->rate -
gst_alsa_sink_get_time (this);
if (gst_event_discont_get_value (event, GST_FORMAT_TIME, &value)) {
gst_element_set_time_delay (GST_ELEMENT (this), MIN (value, delay),
@ -386,11 +386,11 @@ sink_restart:
* better way to get this info */
if (element->base_time > this->clock->start_time) {
expected =
this->transmitted - gst_alsa_timestamp_to_samples (this,
this->played - gst_alsa_timestamp_to_samples (this,
element->base_time - this->clock->start_time);
} else {
expected =
this->transmitted + gst_alsa_timestamp_to_samples (this,
this->played + gst_alsa_timestamp_to_samples (this,
this->clock->start_time - element->base_time);
}
} else {
@ -485,7 +485,7 @@ sink_restart:
if ((copied = this->transmit (this, &avail)) < 0)
return;
/* update our clock */
this->transmitted += copied;
this->played += copied;
/* flush the data */
bytes = gst_alsa_samples_to_bytes (this, copied);
for (i = 0; i < element->numpads; i++) {
@ -543,11 +543,11 @@ gst_alsa_sink_get_time (GstAlsa * this)
if (!this->format)
return 0;
if (snd_pcm_delay (this->handle, &delay) != 0) {
return this->transmitted / this->format->rate;
return this->played / this->format->rate;
}
if (this->transmitted <= delay) {
if (this->played <= delay) {
return 0;
}
return GST_SECOND * (this->transmitted - delay) / this->format->rate;
return GST_SECOND * (this->played - delay) / this->format->rate;
}

58
ext/alsa/gstalsasrc.c
View file

@ -43,6 +43,7 @@ static int gst_alsa_src_read (GstAlsa * this, snd_pcm_sframes_t * avail);
static void gst_alsa_src_loop (GstElement * element);
static void gst_alsa_src_flush (GstAlsaSrc * src);
static GstElementStateReturn gst_alsa_src_change_state (GstElement * element);
static GstClockTime gst_alsa_src_get_time (GstAlsa * this);
static GstAlsa *src_parent_class = NULL;
@ -127,9 +128,25 @@ gst_alsa_src_init (GstAlsaSrc * src)
gst_pad_set_getcaps_function (this->pad[0], gst_alsa_get_caps);
gst_element_add_pad (GST_ELEMENT (this), this->pad[0]);
this->clock =
gst_alsa_clock_new ("alsasrcclock", gst_alsa_src_get_time, this);
/* we hold a ref to our clock until we're disposed */
gst_object_ref (GST_OBJECT (this->clock));
gst_object_sink (GST_OBJECT (this->clock));
gst_element_set_loop_function (GST_ELEMENT (this), gst_alsa_src_loop);
}
static GstClockTime
gst_alsa_src_get_time (GstAlsa * this)
{
GTimeVal now;
g_get_current_time (&now);
return GST_TIMEVAL_TO_TIME (now);
}
static int
gst_alsa_src_mmap (GstAlsa * this, snd_pcm_sframes_t * avail)
{
@ -305,6 +322,30 @@ gst_alsa_src_set_caps (GstAlsaSrc * src, gboolean aggressive)
return FALSE;
}
inline snd_pcm_sframes_t
gst_alsa_src_update_avail (GstAlsa * this)
{
snd_pcm_sframes_t avail = -1;
while (avail < 0) {
avail = snd_pcm_avail_update (this->handle);
if (avail < 0) {
if (avail == -EPIPE) {
gst_alsa_xrun_recovery (this);
} else {
GST_WARNING_OBJECT (this, "unknown ALSA avail_update return value (%d)",
(int) avail);
}
}
if (snd_pcm_state (this->handle) != SND_PCM_STATE_RUNNING) {
if (!gst_alsa_start (this)) {
return 0;
}
}
}
return avail;
}
/* we transmit buffers of period_size frames */
static void
gst_alsa_src_loop (GstElement * element)
@ -326,14 +367,13 @@ gst_alsa_src_loop (GstElement * element)
GstClockTime now;
now = gst_element_get_time (element);
this->clock_base = gst_alsa_get_time (this);
this->transmitted = gst_alsa_timestamp_to_samples (this, now);
this->clock_base = gst_alsa_src_get_time (this);
this->captured = gst_alsa_timestamp_to_samples (this, now);
}
/* the cast to long is explicitly needed;
* with avail = -32 and period_size = 100, avail < period_size is false */
while ((long) (avail =
gst_alsa_update_avail (this)) < (long) this->period_size) {
while ((avail = gst_alsa_src_update_avail (this)) < this->period_size) {
/* wait */
if (gst_alsa_pcm_wait (this) == FALSE)
return;
@ -363,7 +403,7 @@ gst_alsa_src_loop (GstElement * element)
* what is now in the buffer */
outreal = gst_element_get_time (GST_ELEMENT (this)) - outdur;
/* ideal time is counting samples */
outideal = gst_alsa_samples_to_timestamp (this, this->transmitted);
outideal = gst_alsa_samples_to_timestamp (this, this->captured);
outsize = gst_alsa_samples_to_bytes (this, copied);
outtime = GST_CLOCK_TIME_NONE;
@ -371,11 +411,9 @@ gst_alsa_src_loop (GstElement * element)
if (GST_ELEMENT_CLOCK (this)) {
if (GST_CLOCK (GST_ALSA (this)->clock) == GST_ELEMENT_CLOCK (this)) {
outtime = outideal;
diff = outideal - outreal;
GST_DEBUG_OBJECT (this, "ideal %lld, real %lld, diff %lld\n", outideal,
outreal, diff);
gst_alsa_clock_update (this, outideal);
} else {
outtime = outreal;
}
@ -392,14 +430,14 @@ gst_alsa_src_loop (GstElement * element)
GST_BUFFER_TIMESTAMP (src->buf[i]) = outtime;
GST_BUFFER_DURATION (src->buf[i]) = outdur;
GST_BUFFER_OFFSET (src->buf[i]) = this->transmitted;
GST_BUFFER_OFFSET_END (src->buf[i]) = this->transmitted + copied;
GST_BUFFER_OFFSET (src->buf[i]) = this->captured;
GST_BUFFER_OFFSET_END (src->buf[i]) = this->captured + copied;
buf = src->buf[i];
src->buf[i] = NULL;
gst_pad_push (this->pad[i], GST_DATA (buf));
}
this->transmitted += copied;
this->captured += copied;
}
}