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baseaudiosink: make drift tolerance configurable

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Add drift-tolerance property (defaulting to 20ms) to handle resync after clock
drift or timestamp drift instead of relying on the latency-time value for clock
drift and 500ms for timestamp drift.
Remove warning about discont timestamp and simply resync. The warning is in some
cases not correct and is triggered more frequently now that we lower the
tolerance value.
This commit is contained in:
Wim Taymans 2009-11-04 16:16:31 +01:00
parent 0672457604
commit d8942e2850
1 changed files with 64 additions and 42 deletions
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106
gst-libs/gst/audio/gstbaseaudiosink.c
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@ -58,6 +58,9 @@ struct _GstBaseAudioSinkPrivate
GstClockTime eos_time; GstClockTime eos_time;
gboolean do_time_offset; gboolean do_time_offset;
/* number of microseconds we alow timestamps or clock slaving to drift
* before resyncing */
guint64 drift_tolerance;
}; };
/* BaseAudioSink signals and args */ /* BaseAudioSink signals and args */
@ -85,14 +88,22 @@ enum
/* FIXME, enable pull mode when clock slaving and trick modes are figured out */ /* FIXME, enable pull mode when clock slaving and trick modes are figured out */
#define DEFAULT_CAN_ACTIVATE_PULL FALSE #define DEFAULT_CAN_ACTIVATE_PULL FALSE
/* when timestamps or clock slaving drift for more than 10ms we resync. This is
* a reasonable default */
#define DEFAULT_DRIFT_TOLERANCE ((20 * GST_MSECOND) / GST_USECOND)
enum enum
{ {
PROP_0, PROP_0,
PROP_BUFFER_TIME, PROP_BUFFER_TIME,
PROP_LATENCY_TIME, PROP_LATENCY_TIME,
PROP_PROVIDE_CLOCK, PROP_PROVIDE_CLOCK,
PROP_SLAVE_METHOD, PROP_SLAVE_METHOD,
PROP_CAN_ACTIVATE_PULL PROP_CAN_ACTIVATE_PULL,
PROP_DRIFT_TOLERANCE,
PROP_LAST
}; };
GType GType
@ -208,6 +219,19 @@ gst_base_audio_sink_class_init (GstBaseAudioSinkClass * klass)
g_param_spec_boolean ("can-activate-pull", "Allow Pull Scheduling", g_param_spec_boolean ("can-activate-pull", "Allow Pull Scheduling",
"Allow pull-based scheduling", DEFAULT_CAN_ACTIVATE_PULL, "Allow pull-based scheduling", DEFAULT_CAN_ACTIVATE_PULL,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstBaseAudioSink:drift-tolerance
*
* Controls the amount of time in milliseconds that timestamps or clocks are allowed
* to drift before resynchronisation happens.
*
* Since: 0.10.26
*/
g_object_class_install_property (gobject_class, PROP_DRIFT_TOLERANCE,
g_param_spec_int64 ("drift-tolerance", "Drift Tolerance",
"Tolerance for timestamp and clock drift in microseconds", 1,
G_MAXINT64, DEFAULT_DRIFT_TOLERANCE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gstelement_class->change_state = gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_base_audio_sink_change_state); GST_DEBUG_FUNCPTR (gst_base_audio_sink_change_state);
@ -252,6 +276,7 @@ gst_base_audio_sink_init (GstBaseAudioSink * baseaudiosink,
GST_BASE_SINK (baseaudiosink)->can_activate_push = TRUE; GST_BASE_SINK (baseaudiosink)->can_activate_push = TRUE;
GST_BASE_SINK (baseaudiosink)->can_activate_pull = DEFAULT_CAN_ACTIVATE_PULL; GST_BASE_SINK (baseaudiosink)->can_activate_pull = DEFAULT_CAN_ACTIVATE_PULL;
baseaudiosink->priv->drift_tolerance = DEFAULT_DRIFT_TOLERANCE;
/* install some custom pad_query functions */ /* install some custom pad_query functions */
gst_pad_set_query_function (GST_BASE_SINK_PAD (baseaudiosink), gst_pad_set_query_function (GST_BASE_SINK_PAD (baseaudiosink),
@ -605,6 +630,9 @@ gst_base_audio_sink_set_property (GObject * object, guint prop_id,
case PROP_CAN_ACTIVATE_PULL: case PROP_CAN_ACTIVATE_PULL:
GST_BASE_SINK (sink)->can_activate_pull = g_value_get_boolean (value); GST_BASE_SINK (sink)->can_activate_pull = g_value_get_boolean (value);
break; break;
case PROP_DRIFT_TOLERANCE:
sink->priv->drift_tolerance = g_value_get_int64 (value);
break;
default: default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break; break;
@ -635,6 +663,9 @@ gst_base_audio_sink_get_property (GObject * object, guint prop_id,
case PROP_CAN_ACTIVATE_PULL: case PROP_CAN_ACTIVATE_PULL:
g_value_set_boolean (value, GST_BASE_SINK (sink)->can_activate_pull); g_value_set_boolean (value, GST_BASE_SINK (sink)->can_activate_pull);
break; break;
case PROP_DRIFT_TOLERANCE:
g_value_set_int64 (value, sink->priv->drift_tolerance);
break;
default: default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break; break;
@ -952,8 +983,8 @@ gst_base_audio_sink_skew_slaving (GstBaseAudioSink * sink,
{ {
GstClockTime cinternal, cexternal, crate_num, crate_denom; GstClockTime cinternal, cexternal, crate_num, crate_denom;
GstClockTime etime, itime; GstClockTime etime, itime;
GstClockTimeDiff skew, segtime, segtime2; GstClockTimeDiff skew, mdrift, mdrift2;
gint segsamples; gint driftsamples;
gint64 last_align; gint64 last_align;
/* get calibration parameters to compensate for offsets */ /* get calibration parameters to compensate for offsets */
@ -990,56 +1021,52 @@ gst_base_audio_sink_skew_slaving (GstBaseAudioSink * sink,
GST_TIME_FORMAT " skew %" G_GINT64_FORMAT " avg %" G_GINT64_FORMAT, GST_TIME_FORMAT " skew %" G_GINT64_FORMAT " avg %" G_GINT64_FORMAT,
GST_TIME_ARGS (itime), GST_TIME_ARGS (etime), skew, sink->priv->avg_skew); GST_TIME_ARGS (itime), GST_TIME_ARGS (etime), skew, sink->priv->avg_skew);
/* the max drift we allow is the length of a segment */ /* the max drift we allow */
segtime = sink->ringbuffer->spec.latency_time * 1000; mdrift = sink->priv->drift_tolerance * 1000;
segtime2 = segtime / 2; mdrift2 = mdrift / 2;
/* adjust playout pointer based on skew */ /* adjust playout pointer based on skew */
if (sink->priv->avg_skew > segtime2) { if (sink->priv->avg_skew > mdrift2) {
/* master is running slower, move internal time forward */ /* master is running slower, move internal time forward */
GST_WARNING_OBJECT (sink, GST_WARNING_OBJECT (sink,
"correct clock skew %" G_GINT64_FORMAT " > %" G_GINT64_FORMAT, "correct clock skew %" G_GINT64_FORMAT " > %" G_GINT64_FORMAT,
sink->priv->avg_skew, segtime2); sink->priv->avg_skew, mdrift2);
cexternal = cexternal > segtime ? cexternal - segtime : 0; cexternal = cexternal > mdrift ? cexternal - mdrift : 0;
sink->priv->avg_skew -= segtime; sink->priv->avg_skew -= mdrift;
segsamples = driftsamples = (sink->ringbuffer->spec.rate * mdrift) / GST_SECOND;
sink->ringbuffer->spec.segsize /
sink->ringbuffer->spec.bytes_per_sample;
last_align = sink->priv->last_align; last_align = sink->priv->last_align;
/* if we were aligning in the wrong direction or we aligned more than what we /* if we were aligning in the wrong direction or we aligned more than what we
* will correct, resync */ * will correct, resync */
if (last_align < 0 || last_align > segsamples) if (last_align < 0 || last_align > driftsamples)
sink->next_sample = -1; sink->next_sample = -1;
GST_DEBUG_OBJECT (sink, GST_DEBUG_OBJECT (sink,
"last_align %" G_GINT64_FORMAT " segsamples %u, next %" "last_align %" G_GINT64_FORMAT " driftsamples %u, next %"
G_GUINT64_FORMAT, last_align, segsamples, sink->next_sample); G_GUINT64_FORMAT, last_align, driftsamples, sink->next_sample);
gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal, gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal,
crate_num, crate_denom); crate_num, crate_denom);
} else if (sink->priv->avg_skew < -segtime2) { } else if (sink->priv->avg_skew < -mdrift2) {
/* master is running faster, move external time forwards */ /* master is running faster, move external time forwards */
GST_WARNING_OBJECT (sink, GST_WARNING_OBJECT (sink,
"correct clock skew %" G_GINT64_FORMAT " < %" G_GINT64_FORMAT, "correct clock skew %" G_GINT64_FORMAT " < %" G_GINT64_FORMAT,
sink->priv->avg_skew, -segtime2); sink->priv->avg_skew, -mdrift2);
cexternal += segtime; cexternal += mdrift;
sink->priv->avg_skew += segtime; sink->priv->avg_skew += mdrift;
segsamples = driftsamples = (sink->ringbuffer->spec.rate * mdrift) / GST_SECOND;
sink->ringbuffer->spec.segsize /
sink->ringbuffer->spec.bytes_per_sample;
last_align = sink->priv->last_align; last_align = sink->priv->last_align;
/* if we were aligning in the wrong direction or we aligned more than what we /* if we were aligning in the wrong direction or we aligned more than what we
* will correct, resync */ * will correct, resync */
if (last_align > 0 || -last_align > segsamples) if (last_align > 0 || -last_align > driftsamples)
sink->next_sample = -1; sink->next_sample = -1;
GST_DEBUG_OBJECT (sink, GST_DEBUG_OBJECT (sink,
"last_align %" G_GINT64_FORMAT " segsamples %u, next %" "last_align %" G_GINT64_FORMAT " driftsamples %u, next %"
G_GUINT64_FORMAT, last_align, segsamples, sink->next_sample); G_GUINT64_FORMAT, last_align, driftsamples, sink->next_sample);
gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal, gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal,
crate_num, crate_denom); crate_num, crate_denom);
@ -1248,6 +1275,7 @@ gst_base_audio_sink_render (GstBaseSink * bsink, GstBuffer * buf)
GstFlowReturn ret; GstFlowReturn ret;
GstSegment clip_seg; GstSegment clip_seg;
gint64 time_offset; gint64 time_offset;
gint64 maxdrift;
sink = GST_BASE_AUDIO_SINK (bsink); sink = GST_BASE_AUDIO_SINK (bsink);
@ -1482,26 +1510,20 @@ gst_base_audio_sink_render (GstBaseSink * bsink, GstBuffer * buf)
else else
diff = sink->next_sample - sample_offset; diff = sink->next_sample - sample_offset;
/* we tollerate half a second diff before we start resyncing. This /* calculate the max allowed drift in units of samples. By default this is
* should be enough to compensate for various rounding errors in the timestamp * 20ms and should be anough to compensate for timestamp rounding errors. */
* and sample offset position. We always resync if we got a discont anyway and maxdrift = (ringbuf->spec.rate * sink->priv->drift_tolerance) / GST_MSECOND;
* non-discont should be aligned by definition. */
if (G_LIKELY (diff < ringbuf->spec.rate / DIFF_TOLERANCE)) { if (G_LIKELY (diff < maxdrift)) {
/* calc align with previous sample */ /* calc align with previous sample */
align = sink->next_sample - sample_offset; align = sink->next_sample - sample_offset;
GST_DEBUG_OBJECT (sink, GST_DEBUG_OBJECT (sink,
"align with prev sample, ABS (%" G_GINT64_FORMAT ") < %d", align, "align with prev sample, ABS (%" G_GINT64_FORMAT ") < %"
ringbuf->spec.rate / DIFF_TOLERANCE); G_GINT64_FORMAT, align, maxdrift);
} else { } else {
/* bring sample diff to seconds for error message */ GST_DEBUG_OBJECT (sink,
diff = gst_util_uint64_scale_int (diff, GST_SECOND, ringbuf->spec.rate); "discont timestamp (%" G_GINT64_FORMAT ") >= %" G_GINT64_FORMAT, diff,
/* timestamps drifted apart from previous samples too much, we need to maxdrift);
* resync. We log this as an element warning. */
GST_ELEMENT_WARNING (sink, CORE, CLOCK,
("Compensating for audio synchronisation problems"),
("Unexpected discontinuity in audio timestamps of more "
"than half a second (%" GST_TIME_FORMAT "), resyncing",
GST_TIME_ARGS (diff)));
align = 0; align = 0;
} }
sink->priv->last_align = align; sink->priv->last_align = align;