mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-27 04:01:08 +00:00
audiobasesink: added custom clock slaving method
This new clock slaving method allows for installing a callback that is invoked during playback. Inside this callback, a custom slaving mechanism can be used (for example, a control loop adjusting a PLL or an asynchronous resampler). Upon request, it can skew the playout pointer just like the "skew" method. This is useful if the clocks drifted apart too much, and a quick reset is necessary. Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org> https://bugzilla.gnome.org/show_bug.cgi?id=708362
This commit is contained in:
Carlos Rafael Giani
Jan Schmidt
parent
1b80196aed
commit
c5b75394a9
2 changed files with 266 additions and 1 deletions
|
|
@ -69,6 +69,11 @@ struct _GstAudioBaseSinkPrivate
|
|||
|
||||
/* number of nanoseconds to wait until creating a discontinuity */
|
||||
GstClockTime discont_wait;
|
||||
|
||||
/* custom slaving algorithm callback */
|
||||
GstAudioBaseSinkCustomSlavingCallback custom_slaving_callback;
|
||||
gpointer custom_slaving_cb_data;
|
||||
GDestroyNotify custom_slaving_cb_notify;
|
||||
};
|
||||
|
||||
/* BaseAudioSink signals and args */
|
||||
|
|
@ -124,6 +129,8 @@ gst_audio_base_sink_slave_method_get_type (void)
|
|||
"resample"},
|
||||
{GST_AUDIO_BASE_SINK_SLAVE_SKEW, "GST_AUDIO_BASE_SINK_SLAVE_SKEW", "skew"},
|
||||
{GST_AUDIO_BASE_SINK_SLAVE_NONE, "GST_AUDIO_BASE_SINK_SLAVE_NONE", "none"},
|
||||
{GST_AUDIO_BASE_SINK_SLAVE_CUSTOM, "GST_AUDIO_BASE_SINK_SLAVE_CUSTOM",
|
||||
"custom"},
|
||||
{0, NULL, NULL},
|
||||
};
|
||||
|
||||
|
|
@ -304,6 +311,9 @@ gst_audio_base_sink_init (GstAudioBaseSink * audiobasesink)
|
|||
audiobasesink->priv->drift_tolerance = DEFAULT_DRIFT_TOLERANCE;
|
||||
audiobasesink->priv->alignment_threshold = DEFAULT_ALIGNMENT_THRESHOLD;
|
||||
audiobasesink->priv->discont_wait = DEFAULT_DISCONT_WAIT;
|
||||
audiobasesink->priv->custom_slaving_callback = NULL;
|
||||
audiobasesink->priv->custom_slaving_cb_data = NULL;
|
||||
audiobasesink->priv->custom_slaving_cb_notify = NULL;
|
||||
|
||||
audiobasesink->provided_clock = gst_audio_clock_new ("GstAudioSinkClock",
|
||||
(GstAudioClockGetTimeFunc) gst_audio_base_sink_get_time, audiobasesink,
|
||||
|
|
@ -327,6 +337,9 @@ gst_audio_base_sink_dispose (GObject * object)
|
|||
|
||||
sink = GST_AUDIO_BASE_SINK (object);
|
||||
|
||||
if (sink->priv->custom_slaving_cb_notify)
|
||||
sink->priv->custom_slaving_cb_notify (sink->priv->custom_slaving_cb_data);
|
||||
|
||||
if (sink->provided_clock) {
|
||||
gst_audio_clock_invalidate (sink->provided_clock);
|
||||
gst_object_unref (sink->provided_clock);
|
||||
|
|
@ -743,6 +756,73 @@ gst_audio_base_sink_set_discont_wait (GstAudioBaseSink * sink,
|
|||
GST_OBJECT_UNLOCK (sink);
|
||||
}
|
||||
|
||||
/**
|
||||
* gst_audio_base_sink_set_custom_slaving_callback:
|
||||
* @sink: a #GstAudioBaseSink
|
||||
* @callback: a #GstAudioBaseSinkCustomSlavingCallback
|
||||
* @user_data: user data passed to the callback
|
||||
* @notify : called when user_data becomes unused
|
||||
*
|
||||
* Sets the custom slaving callback. This callback will
|
||||
* be invoked if the slave-method property is set to
|
||||
* GST_AUDIO_BASE_SINK_SLAVE_CUSTOM and the audio sink
|
||||
* receives and plays samples.
|
||||
*
|
||||
* Setting the callback to NULL causes the sink to
|
||||
* behave as if the GST_AUDIO_BASE_SINK_SLAVE_NONE
|
||||
* method were used.
|
||||
*
|
||||
* Since: 1.6
|
||||
*/
|
||||
void
|
||||
gst_audio_base_sink_set_custom_slaving_callback (GstAudioBaseSink * sink,
|
||||
GstAudioBaseSinkCustomSlavingCallback callback,
|
||||
gpointer user_data, GDestroyNotify notify)
|
||||
{
|
||||
g_return_if_fail (GST_IS_AUDIO_BASE_SINK (sink));
|
||||
|
||||
GST_OBJECT_LOCK (sink);
|
||||
sink->priv->custom_slaving_callback = callback;
|
||||
sink->priv->custom_slaving_cb_data = user_data;
|
||||
sink->priv->custom_slaving_cb_notify = notify;
|
||||
GST_OBJECT_UNLOCK (sink);
|
||||
}
|
||||
|
||||
static void
|
||||
gst_audio_base_sink_custom_cb_report_discont (GstAudioBaseSink * sink,
|
||||
GstAudioBaseSinkDiscontReason discont_reason)
|
||||
{
|
||||
if ((sink->priv->custom_slaving_callback != NULL) &&
|
||||
(sink->priv->slave_method == GST_AUDIO_BASE_SINK_SLAVE_CUSTOM)) {
|
||||
sink->priv->custom_slaving_callback (sink, GST_CLOCK_TIME_NONE,
|
||||
GST_CLOCK_TIME_NONE, NULL, discont_reason,
|
||||
sink->priv->custom_slaving_cb_data);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* gst_audio_base_sink_report_device_failure:
|
||||
* @sink: a #GstAudioBaseSink
|
||||
*
|
||||
* Informs this base class that the audio output device has failed for
|
||||
* some reason, causing a discontinuity (for example, because the device
|
||||
* recovered from the error, but lost all contents of its ring buffer).
|
||||
* This function is typically called by derived classes, and is useful
|
||||
* for the custom slave method.
|
||||
*
|
||||
* Since: 1.6
|
||||
*/
|
||||
void
|
||||
gst_audio_base_sink_report_device_failure (GstAudioBaseSink * sink)
|
||||
{
|
||||
g_return_if_fail (GST_IS_AUDIO_BASE_SINK (sink));
|
||||
|
||||
GST_OBJECT_LOCK (sink);
|
||||
gst_audio_base_sink_custom_cb_report_discont (sink,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_DEVICE_FAILURE);
|
||||
GST_OBJECT_UNLOCK (sink);
|
||||
}
|
||||
|
||||
/**
|
||||
* gst_audio_base_sink_get_discont_wait:
|
||||
* @sink: a #GstAudioBaseSink
|
||||
|
|
@ -903,6 +983,9 @@ gst_audio_base_sink_setcaps (GstBaseSink * bsink, GstCaps * caps)
|
|||
/* We need to resync since the ringbuffer restarted */
|
||||
gst_audio_base_sink_reset_sync (sink);
|
||||
|
||||
gst_audio_base_sink_custom_cb_report_discont (sink,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_NEW_CAPS);
|
||||
|
||||
if (bsink->pad_mode == GST_PAD_MODE_PUSH) {
|
||||
GST_DEBUG_OBJECT (sink, "activate ringbuffer");
|
||||
gst_audio_ring_buffer_activate (sink->ringbuffer, TRUE);
|
||||
|
|
@ -1096,6 +1179,10 @@ gst_audio_base_sink_event (GstBaseSink * bsink, GstEvent * event)
|
|||
case GST_EVENT_FLUSH_STOP:
|
||||
/* always resync on sample after a flush */
|
||||
gst_audio_base_sink_reset_sync (sink);
|
||||
|
||||
gst_audio_base_sink_custom_cb_report_discont (sink,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_FLUSH);
|
||||
|
||||
if (sink->ringbuffer)
|
||||
gst_audio_ring_buffer_set_flushing (sink->ringbuffer, FALSE);
|
||||
break;
|
||||
|
|
@ -1179,6 +1266,104 @@ clock_convert_external (GstClockTime external, GstClockTime cinternal,
|
|||
return external;
|
||||
}
|
||||
|
||||
|
||||
/* apply the clock offset and invoke a custom callback
|
||||
* which might also request changes to the playout pointer
|
||||
*
|
||||
* this reuses code from the skewing algorithm, but leaves
|
||||
* decision on whether or not to skew (and how much to skew)
|
||||
* up to the callback */
|
||||
static void
|
||||
gst_audio_base_sink_custom_slaving (GstAudioBaseSink * sink,
|
||||
GstClockTime render_start, GstClockTime render_stop,
|
||||
GstClockTime * srender_start, GstClockTime * srender_stop)
|
||||
{
|
||||
GstClockTime cinternal, cexternal, crate_num, crate_denom;
|
||||
GstClockTime etime, itime;
|
||||
GstClockTimeDiff requested_skew;
|
||||
gint driftsamples;
|
||||
gint64 last_align;
|
||||
|
||||
/* get calibration parameters to compensate for offsets */
|
||||
gst_clock_get_calibration (sink->provided_clock, &cinternal, &cexternal,
|
||||
&crate_num, &crate_denom);
|
||||
|
||||
/* sample clocks and figure out clock skew */
|
||||
etime = gst_clock_get_time (GST_ELEMENT_CLOCK (sink));
|
||||
itime = gst_audio_clock_get_time (sink->provided_clock);
|
||||
itime = gst_audio_clock_adjust (sink->provided_clock, itime);
|
||||
|
||||
GST_DEBUG_OBJECT (sink,
|
||||
"internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT
|
||||
" cinternal %" GST_TIME_FORMAT " cexternal %" GST_TIME_FORMAT,
|
||||
GST_TIME_ARGS (itime), GST_TIME_ARGS (etime),
|
||||
GST_TIME_ARGS (cinternal), GST_TIME_ARGS (cexternal));
|
||||
|
||||
/* make sure we never go below 0 */
|
||||
etime = etime > cexternal ? etime - cexternal : 0;
|
||||
itime = itime > cinternal ? itime - cinternal : 0;
|
||||
|
||||
/* don't do any skewing unless the callback explicitely requests one */
|
||||
requested_skew = 0;
|
||||
|
||||
if (sink->priv->custom_slaving_callback != NULL) {
|
||||
sink->priv->custom_slaving_callback (sink, etime, itime, &requested_skew,
|
||||
FALSE, sink->priv->custom_slaving_cb_data);
|
||||
GST_DEBUG_OBJECT (sink, "custom slaving requested skew %" G_GINT64_FORMAT,
|
||||
requested_skew);
|
||||
} else {
|
||||
GST_DEBUG_OBJECT (sink,
|
||||
"no custom slaving callback set - clock drift will not be compensated");
|
||||
}
|
||||
|
||||
if (requested_skew > 0) {
|
||||
cexternal = (cexternal > requested_skew) ? (cexternal - requested_skew) : 0;
|
||||
|
||||
driftsamples =
|
||||
(sink->ringbuffer->spec.info.rate * requested_skew) / GST_SECOND;
|
||||
last_align = sink->priv->last_align;
|
||||
|
||||
/* if we were aligning in the wrong direction or we aligned more than what we
|
||||
* will correct, resync */
|
||||
if ((last_align < 0) || (last_align > driftsamples))
|
||||
sink->next_sample = -1;
|
||||
|
||||
GST_DEBUG_OBJECT (sink,
|
||||
"last_align %" G_GINT64_FORMAT " driftsamples %u, next %"
|
||||
G_GUINT64_FORMAT, last_align, driftsamples, sink->next_sample);
|
||||
|
||||
gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal,
|
||||
crate_num, crate_denom);
|
||||
} else if (requested_skew < 0) {
|
||||
cexternal += ABS (requested_skew);
|
||||
|
||||
driftsamples =
|
||||
(sink->ringbuffer->spec.info.rate * ABS (requested_skew)) / GST_SECOND;
|
||||
last_align = sink->priv->last_align;
|
||||
|
||||
/* if we were aligning in the wrong direction or we aligned more than what we
|
||||
* will correct, resync */
|
||||
if ((last_align > 0) || (-last_align > driftsamples))
|
||||
sink->next_sample = -1;
|
||||
|
||||
GST_DEBUG_OBJECT (sink,
|
||||
"last_align %" G_GINT64_FORMAT " driftsamples %u, next %"
|
||||
G_GUINT64_FORMAT, last_align, driftsamples, sink->next_sample);
|
||||
|
||||
gst_clock_set_calibration (sink->provided_clock, cinternal, cexternal,
|
||||
crate_num, crate_denom);
|
||||
}
|
||||
|
||||
/* convert, ignoring speed */
|
||||
render_start = clock_convert_external (render_start, cinternal, cexternal,
|
||||
crate_num, crate_denom);
|
||||
render_stop = clock_convert_external (render_stop, cinternal, cexternal,
|
||||
crate_num, crate_denom);
|
||||
|
||||
*srender_start = render_start;
|
||||
*srender_stop = render_stop;
|
||||
}
|
||||
|
||||
/* algorithm to calculate sample positions that will result in resampling to
|
||||
* match the clock rate of the master */
|
||||
static void
|
||||
|
|
@ -1395,6 +1580,10 @@ gst_audio_base_sink_handle_slaving (GstAudioBaseSink * sink,
|
|||
gst_audio_base_sink_none_slaving (sink, render_start, render_stop,
|
||||
srender_start, srender_stop);
|
||||
break;
|
||||
case GST_AUDIO_BASE_SINK_SLAVE_CUSTOM:
|
||||
gst_audio_base_sink_custom_slaving (sink, render_start, render_stop,
|
||||
srender_start, srender_stop);
|
||||
break;
|
||||
default:
|
||||
g_warning ("unknown slaving method %d", sink->priv->slave_method);
|
||||
break;
|
||||
|
|
@ -1511,12 +1700,16 @@ gst_audio_base_sink_sync_latency (GstBaseSink * bsink, GstMiniObject * obj)
|
|||
break;
|
||||
case GST_AUDIO_BASE_SINK_SLAVE_SKEW:
|
||||
case GST_AUDIO_BASE_SINK_SLAVE_NONE:
|
||||
case GST_AUDIO_BASE_SINK_SLAVE_CUSTOM:
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
gst_audio_base_sink_reset_sync (sink);
|
||||
|
||||
gst_audio_base_sink_custom_cb_report_discont (sink,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_SYNC_LATENCY);
|
||||
|
||||
return GST_FLOW_OK;
|
||||
|
||||
/* ERRORS */
|
||||
|
|
@ -1607,6 +1800,9 @@ gst_audio_base_sink_get_alignment (GstAudioBaseSink * sink,
|
|||
"%s%" GST_TIME_FORMAT ", resyncing",
|
||||
sample_offset > sink->next_sample ? "+" : "-", GST_TIME_ARGS (diff_s));
|
||||
align = 0;
|
||||
|
||||
gst_audio_base_sink_custom_cb_report_discont (sink,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_ALIGNMENT);
|
||||
}
|
||||
|
||||
return align;
|
||||
|
|
|
|||
|
|
@ -86,6 +86,7 @@ G_BEGIN_DECLS
|
|||
* @GST_AUDIO_BASE_SINK_SLAVE_SKEW: Adjust playout pointer when master clock
|
||||
* drifts too much.
|
||||
* @GST_AUDIO_BASE_SINK_SLAVE_NONE: No adjustment is done.
|
||||
* @GST_AUDIO_BASE_SINK_SLAVE_CUSTOM: Use custom clock slaving algorithm (Since: 1.6)
|
||||
*
|
||||
* Different possible clock slaving algorithms used when the internal audio
|
||||
* clock is not selected as the pipeline master clock.
|
||||
|
|
@ -94,7 +95,8 @@ typedef enum
|
|||
{
|
||||
GST_AUDIO_BASE_SINK_SLAVE_RESAMPLE,
|
||||
GST_AUDIO_BASE_SINK_SLAVE_SKEW,
|
||||
GST_AUDIO_BASE_SINK_SLAVE_NONE
|
||||
GST_AUDIO_BASE_SINK_SLAVE_NONE,
|
||||
GST_AUDIO_BASE_SINK_SLAVE_CUSTOM
|
||||
} GstAudioBaseSinkSlaveMethod;
|
||||
|
||||
#define GST_TYPE_AUDIO_BASE_SINK_SLAVE_METHOD (gst_audio_base_sink_slave_method_get_type ())
|
||||
|
|
@ -103,6 +105,65 @@ typedef struct _GstAudioBaseSink GstAudioBaseSink;
|
|||
typedef struct _GstAudioBaseSinkClass GstAudioBaseSinkClass;
|
||||
typedef struct _GstAudioBaseSinkPrivate GstAudioBaseSinkPrivate;
|
||||
|
||||
/**
|
||||
* GstAudioBaseSinkDiscontReason:
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_NO_DISCONT: No discontinuity occurred
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_NEW_CAPS: New caps are set, causing renegotiotion
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_FLUSH: Samples have been flushed
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_SYNC_LATENCY: Sink was synchronized to the estimated latency (occurs during initialization)
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_ALIGNMENT: Aligning buffers failed because the timestamps are too discontinuous
|
||||
* GST_AUDIO_BASE_SINK_DISCONT_REASON_DEVICE_FAILURE: Audio output device experienced and recovered from an error but introduced latency in the process (see also @gst_audio_base_sink_report_device_failure)
|
||||
*
|
||||
* Different possible reasons for discontinuities. This enum is useful for the custom
|
||||
* slave method.
|
||||
*
|
||||
* Since: 1.6
|
||||
*/
|
||||
typedef enum
|
||||
{
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_NO_DISCONT,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_NEW_CAPS,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_FLUSH,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_SYNC_LATENCY,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_ALIGNMENT,
|
||||
GST_AUDIO_BASE_SINK_DISCONT_REASON_DEVICE_FAILURE
|
||||
} GstAudioBaseSinkDiscontReason;
|
||||
|
||||
/**
|
||||
* GstAudioBaseSinkCustomSlavingCallback:
|
||||
* @sink: a #GstAudioBaseSink
|
||||
* @etime: external clock time
|
||||
* @itime: internal clock time
|
||||
* @requested_skew: skew amount requested by the callback
|
||||
* @discont: TRUE if there was a discontinuity in the average skew
|
||||
* @user_data: user data
|
||||
*
|
||||
* This function is set with gst_audio_base_sink_set_custom_slaving_callback()
|
||||
* and is called during playback. It receives the current time of external and
|
||||
* internal clocks, which the callback can then use to apply any custom
|
||||
* slaving/synchronization schemes. The external clock is the sink's element clock,
|
||||
* the internal one is the internal audio clock. The internal audio clock's
|
||||
* calibration is applied to the timestamps before they are passed to the
|
||||
* callback. The difference between etime and itime is the skew; how much
|
||||
* internal and external clock lie apart from each other. A skew of 0 means
|
||||
* both clocks are perfectly in sync. itime > etime means the external clock
|
||||
* is going slower, while itime < etime means it is going faster than the
|
||||
* internal clock. etime and itime are always valid timestamps, except for when
|
||||
* discont is set to TRUE.
|
||||
* requested_skew is an output value the callback can write to. It informs the sink
|
||||
* of whether or not it should move the playout pointer, and if so, by how much.
|
||||
* This pointer is only NULL if discont is true; otherwise, it is safe to write
|
||||
* to *requested_skew. The default skew is 0.
|
||||
*
|
||||
* The sink may experience discontinuities. If one happens, discont is TRUE,
|
||||
* itime, etime are set to GST_CLOCK_TIME_NONE, and requested_skew is NULL.
|
||||
* This makes it possible to reset custom clock slaving algorithms when a
|
||||
* discontinuity happens.
|
||||
*
|
||||
* Since: 1.6
|
||||
*/
|
||||
typedef void (*GstAudioBaseSinkCustomSlavingCallback) (GstAudioBaseSink *sink, GstClockTime etime, GstClockTime itime, GstClockTimeDiff *requested_skew, GstAudioBaseSinkDiscontReason discont_reason, gpointer user_data);
|
||||
|
||||
/**
|
||||
* GstAudioBaseSink:
|
||||
*
|
||||
|
|
@ -187,6 +248,14 @@ void gst_audio_base_sink_set_discont_wait (GstAudioBaseSink * sink,
|
|||
GstClockTime
|
||||
gst_audio_base_sink_get_discont_wait (GstAudioBaseSink * sink);
|
||||
|
||||
void
|
||||
gst_audio_base_sink_set_custom_slaving_callback (GstAudioBaseSink * sink,
|
||||
GstAudioBaseSinkCustomSlavingCallback callback,
|
||||
gpointer user_data,
|
||||
GDestroyNotify notify);
|
||||
|
||||
void gst_audio_base_sink_report_device_failure (GstAudioBaseSink * sink);
|
||||
|
||||
G_END_DECLS
|
||||
|
||||
#endif /* __GST_AUDIO_BASE_SINK_H__ */
|
||||
|
|
|
|||
Loading…
Reference in a new issue