/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2005 Wim Taymans * * gstbaseaudiosink.c: * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include "gstbaseaudiosink.h" GST_DEBUG_CATEGORY_STATIC (gst_base_audio_sink_debug); #define GST_CAT_DEFAULT gst_base_audio_sink_debug /* BaseAudioSink signals and args */ enum { /* FILL ME */ LAST_SIGNAL }; /* we tollerate a 10th of a second diff before we start resyncing. This * should be enough to compensate for various rounding errors in the timestamp * and sample offset position. */ #define DIFF_TOLERANCE 10 #define DEFAULT_BUFFER_TIME 200 * GST_USECOND #define DEFAULT_LATENCY_TIME 10 * GST_USECOND #define DEFAULT_PROVIDE_CLOCK TRUE enum { PROP_0, PROP_BUFFER_TIME, PROP_LATENCY_TIME, PROP_PROVIDE_CLOCK, }; #define _do_init(bla) \ GST_DEBUG_CATEGORY_INIT (gst_base_audio_sink_debug, "baseaudiosink", 0, "baseaudiosink element"); GST_BOILERPLATE_FULL (GstBaseAudioSink, gst_base_audio_sink, GstBaseSink, GST_TYPE_BASE_SINK, _do_init); static void gst_base_audio_sink_dispose (GObject * object); static void gst_base_audio_sink_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_base_audio_sink_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static GstStateChangeReturn gst_base_audio_sink_change_state (GstElement * element, GstStateChange transition); static GstClock *gst_base_audio_sink_provide_clock (GstElement * elem); static GstClockTime gst_base_audio_sink_get_time (GstClock * clock, GstBaseAudioSink * sink); static void gst_base_audio_sink_callback (GstRingBuffer * rbuf, guint8 * data, guint len, gpointer user_data); static GstFlowReturn gst_base_audio_sink_preroll (GstBaseSink * bsink, GstBuffer * buffer); static GstFlowReturn gst_base_audio_sink_render (GstBaseSink * bsink, GstBuffer * buffer); static gboolean gst_base_audio_sink_event (GstBaseSink * bsink, GstEvent * event); static void gst_base_audio_sink_get_times (GstBaseSink * bsink, GstBuffer * buffer, GstClockTime * start, GstClockTime * end); static gboolean gst_base_audio_sink_setcaps (GstBaseSink * bsink, GstCaps * caps); //static guint gst_base_audio_sink_signals[LAST_SIGNAL] = { 0 }; static void gst_base_audio_sink_base_init (gpointer g_class) { } static void gst_base_audio_sink_class_init (GstBaseAudioSinkClass * klass) { gchar *longdesc; GObjectClass *gobject_class; GstElementClass *gstelement_class; GstBaseSinkClass *gstbasesink_class; gobject_class = (GObjectClass *) klass; gstelement_class = (GstElementClass *) klass; gstbasesink_class = (GstBaseSinkClass *) klass; gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_base_audio_sink_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_base_audio_sink_get_property); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_base_audio_sink_dispose); longdesc = g_strdup_printf ("Size of audio buffer in microseconds (use -1 for default of %" G_GUINT64_FORMAT " us)", DEFAULT_BUFFER_TIME / GST_USECOND); g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_BUFFER_TIME, g_param_spec_int64 ("buffer-time", "Buffer Time", longdesc, -1, G_MAXINT64, DEFAULT_BUFFER_TIME, G_PARAM_READWRITE)); g_free (longdesc); longdesc = g_strdup_printf ("Audio latency in microseconds (use -1 for default of %" G_GUINT64_FORMAT " us)", DEFAULT_LATENCY_TIME / GST_USECOND); g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_LATENCY_TIME, g_param_spec_int64 ("latency-time", "Latency Time", longdesc, -1, G_MAXINT64, DEFAULT_LATENCY_TIME, G_PARAM_READWRITE)); g_free (longdesc); g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_PROVIDE_CLOCK, g_param_spec_boolean ("provide-clock", "Provide Clock", "Provide a clock to be used as the global pipeline clock", DEFAULT_PROVIDE_CLOCK, G_PARAM_READWRITE)); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_base_audio_sink_change_state); gstelement_class->provide_clock = GST_DEBUG_FUNCPTR (gst_base_audio_sink_provide_clock); gstbasesink_class->event = GST_DEBUG_FUNCPTR (gst_base_audio_sink_event); gstbasesink_class->preroll = GST_DEBUG_FUNCPTR (gst_base_audio_sink_preroll); gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_base_audio_sink_render); gstbasesink_class->get_times = GST_DEBUG_FUNCPTR (gst_base_audio_sink_get_times); gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_base_audio_sink_setcaps); } static void gst_base_audio_sink_init (GstBaseAudioSink * baseaudiosink, GstBaseAudioSinkClass * g_class) { baseaudiosink->buffer_time = DEFAULT_BUFFER_TIME; baseaudiosink->latency_time = DEFAULT_LATENCY_TIME; baseaudiosink->provide_clock = DEFAULT_PROVIDE_CLOCK; baseaudiosink->provided_clock = gst_audio_clock_new ("clock", (GstAudioClockGetTimeFunc) gst_base_audio_sink_get_time, baseaudiosink); } static void gst_base_audio_sink_dispose (GObject * object) { GstBaseAudioSink *sink; sink = GST_BASE_AUDIO_SINK (object); if (sink->provided_clock) gst_object_unref (sink->provided_clock); sink->provided_clock = NULL; if (sink->ringbuffer) gst_object_unref (sink->ringbuffer); sink->ringbuffer = NULL; G_OBJECT_CLASS (parent_class)->dispose (object); } static GstClock * gst_base_audio_sink_provide_clock (GstElement * elem) { GstBaseAudioSink *sink; GstClock *clock; sink = GST_BASE_AUDIO_SINK (elem); /* we have no ringbuffer (must be NULL state */ if (sink->ringbuffer == NULL) goto wrong_state; if (!gst_ring_buffer_is_acquired (sink->ringbuffer)) goto wrong_state; GST_OBJECT_LOCK (sink); if (!sink->provide_clock) goto clock_disabled; clock = GST_CLOCK_CAST (gst_object_ref (sink->provided_clock)); GST_OBJECT_UNLOCK (sink); return clock; wrong_state: { GST_DEBUG_OBJECT (sink, "ringbuffer not acquired"); return NULL; } clock_disabled: { GST_DEBUG_OBJECT (sink, "clock provide disabled"); GST_OBJECT_UNLOCK (sink); return NULL; } } static GstClockTime gst_base_audio_sink_get_time (GstClock * clock, GstBaseAudioSink * sink) { guint64 samples; GstClockTime result; if (sink->ringbuffer == NULL || sink->ringbuffer->spec.rate == 0) return GST_CLOCK_TIME_NONE; /* our processed samples are always increasing */ samples = gst_ring_buffer_samples_done (sink->ringbuffer); result = gst_util_uint64_scale_int (samples, GST_SECOND, sink->ringbuffer->spec.rate); return result; } static void gst_base_audio_sink_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstBaseAudioSink *sink; sink = GST_BASE_AUDIO_SINK (object); switch (prop_id) { case PROP_BUFFER_TIME: sink->buffer_time = g_value_get_int64 (value); break; case PROP_LATENCY_TIME: sink->latency_time = g_value_get_int64 (value); break; case PROP_PROVIDE_CLOCK: GST_OBJECT_LOCK (sink); sink->provide_clock = g_value_get_boolean (value); GST_OBJECT_UNLOCK (sink); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_base_audio_sink_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstBaseAudioSink *sink; sink = GST_BASE_AUDIO_SINK (object); switch (prop_id) { case PROP_BUFFER_TIME: g_value_set_int64 (value, sink->buffer_time); break; case PROP_LATENCY_TIME: g_value_set_int64 (value, sink->latency_time); break; case PROP_PROVIDE_CLOCK: GST_OBJECT_LOCK (sink); g_value_set_boolean (value, sink->provide_clock); GST_OBJECT_UNLOCK (sink); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static gboolean gst_base_audio_sink_setcaps (GstBaseSink * bsink, GstCaps * caps) { GstBaseAudioSink *sink = GST_BASE_AUDIO_SINK (bsink); GstRingBufferSpec *spec; spec = &sink->ringbuffer->spec; GST_DEBUG_OBJECT (sink, "release old ringbuffer"); /* release old ringbuffer */ gst_ring_buffer_release (sink->ringbuffer); GST_DEBUG_OBJECT (sink, "parse caps"); spec->buffer_time = sink->buffer_time; spec->latency_time = sink->latency_time; /* parse new caps */ if (!gst_ring_buffer_parse_caps (spec, caps)) goto parse_error; gst_ring_buffer_debug_spec_buff (spec); GST_DEBUG_OBJECT (sink, "acquire new ringbuffer"); if (!gst_ring_buffer_acquire (sink->ringbuffer, spec)) goto acquire_error; /* calculate actual latency and buffer times */ spec->latency_time = spec->segsize * GST_MSECOND / (spec->rate * spec->bytes_per_sample); spec->buffer_time = spec->segtotal * spec->segsize * GST_MSECOND / (spec->rate * spec->bytes_per_sample); gst_ring_buffer_debug_spec_buff (spec); return TRUE; /* ERRORS */ parse_error: { GST_DEBUG_OBJECT (sink, "could not parse caps"); GST_ELEMENT_ERROR (sink, STREAM, FORMAT, (NULL), ("cannot parse audio format.")); return FALSE; } acquire_error: { GST_DEBUG_OBJECT (sink, "could not acquire ringbuffer"); return FALSE; } } static void gst_base_audio_sink_get_times (GstBaseSink * bsink, GstBuffer * buffer, GstClockTime * start, GstClockTime * end) { /* our clock sync is a bit too much for the base class to handle so * we implement it ourselves. */ *start = GST_CLOCK_TIME_NONE; *end = GST_CLOCK_TIME_NONE; } /* FIXME, this waits for the drain to happen but it cannot be * canceled. */ static gboolean gst_base_audio_sink_drain (GstBaseAudioSink * sink) { if (!sink->ringbuffer) return TRUE; if (!sink->ringbuffer->spec.rate) return TRUE; if (sink->next_sample != -1) { GstClockTime time; GstClock *clock; time = gst_util_uint64_scale_int (sink->next_sample, GST_SECOND, sink->ringbuffer->spec.rate); GST_OBJECT_LOCK (sink); if ((clock = GST_ELEMENT_CLOCK (sink)) != NULL) { GstClockID id = gst_clock_new_single_shot_id (clock, time); GST_OBJECT_UNLOCK (sink); GST_DEBUG_OBJECT (sink, "waiting for last sample to play"); gst_clock_id_wait (id, NULL); gst_clock_id_unref (id); sink->next_sample = -1; } else { GST_OBJECT_UNLOCK (sink); } } return TRUE; } static gboolean gst_base_audio_sink_event (GstBaseSink * bsink, GstEvent * event) { GstBaseAudioSink *sink = GST_BASE_AUDIO_SINK (bsink); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_FLUSH_START: gst_ring_buffer_set_flushing (sink->ringbuffer, TRUE); break; case GST_EVENT_FLUSH_STOP: /* always resync on sample after a flush */ sink->next_sample = -1; gst_ring_buffer_set_flushing (sink->ringbuffer, FALSE); break; case GST_EVENT_EOS: /* need to start playback when we reach EOS */ gst_ring_buffer_start (sink->ringbuffer); /* now wait till we played everything */ gst_base_audio_sink_drain (sink); break; default: break; } return TRUE; } static GstFlowReturn gst_base_audio_sink_preroll (GstBaseSink * bsink, GstBuffer * buffer) { GstBaseAudioSink *sink = GST_BASE_AUDIO_SINK (bsink); if (!gst_ring_buffer_is_acquired (sink->ringbuffer)) goto wrong_state; /* we don't really do anything when prerolling. We could make a * property to play this buffer to have some sort of scrubbing * support. */ return GST_FLOW_OK; wrong_state: { GST_DEBUG_OBJECT (sink, "ringbuffer in wrong state"); GST_ELEMENT_ERROR (sink, STREAM, FORMAT, (NULL), ("sink not negotiated.")); return GST_FLOW_NOT_NEGOTIATED; } } static guint64 gst_base_audio_sink_get_offset (GstBaseAudioSink * sink) { guint64 sample; gint writeseg, segdone, sps; gint diff; /* assume we can append to the previous sample */ sample = sink->next_sample; /* no previous sample, try to insert at position 0 */ if (sample == -1) sample = 0; sps = sink->ringbuffer->samples_per_seg; /* figure out the segment and the offset inside the segment where * the sample should be written. */ writeseg = sample / sps; /* get the currently processed segment */ segdone = g_atomic_int_get (&sink->ringbuffer->segdone) - sink->ringbuffer->segbase; /* see how far away it is from the write segment */ diff = writeseg - segdone; if (diff < 0) { /* sample would be dropped, position to next playable position */ sample = (segdone + 1) * sps; } return sample; } static GstFlowReturn gst_base_audio_sink_render (GstBaseSink * bsink, GstBuffer * buf) { guint64 render_offset, in_offset; GstClockTime time, stop, render_time, duration; GstBaseAudioSink *sink; GstRingBuffer *ringbuf; gint64 diff, ctime, cstop; guint8 *data; guint size; guint samples, written; gint bps; gdouble crate = 1.0; GstClockTime crate_num; GstClockTime crate_denom; GstClockTime cinternal, cexternal; sink = GST_BASE_AUDIO_SINK (bsink); if (G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT))) { /* always resync after a discont */ sink->next_sample = -1; } ringbuf = sink->ringbuffer; /* can't do anything when we don't have the device */ if (G_UNLIKELY (!gst_ring_buffer_is_acquired (ringbuf))) goto wrong_state; bps = ringbuf->spec.bytes_per_sample; size = GST_BUFFER_SIZE (buf); if (G_UNLIKELY (size % bps) != 0) goto wrong_size; samples = size / bps; in_offset = GST_BUFFER_OFFSET (buf); time = GST_BUFFER_TIMESTAMP (buf); duration = GST_BUFFER_DURATION (buf); data = GST_BUFFER_DATA (buf); GST_DEBUG_OBJECT (sink, "time %" GST_TIME_FORMAT ", offset %llu, start %" GST_TIME_FORMAT, GST_TIME_ARGS (time), in_offset, GST_TIME_ARGS (bsink->segment.start)); /* if not valid timestamp or we don't need to sync, try to play * sample ASAP */ if (!GST_CLOCK_TIME_IS_VALID (time) || !bsink->sync) { render_offset = gst_base_audio_sink_get_offset (sink); stop = -1; GST_DEBUG_OBJECT (sink, "Buffer of size %u has no time. Using render_offset=%" G_GUINT64_FORMAT, GST_BUFFER_SIZE (buf), render_offset); goto no_sync; } /* samples should be rendered based on their timestamp. All samples * arriving before the segment.start or after segment.stop are to be * thrown away. All samples should also be clipped to the segment * boundaries */ /* let's calc stop based on the number of samples in the buffer instead * of trusting the DURATION */ stop = time + gst_util_uint64_scale_int (samples, GST_SECOND, ringbuf->spec.rate); if (!gst_segment_clip (&bsink->segment, GST_FORMAT_TIME, time, stop, &ctime, &cstop)) goto out_of_segment; /* see if some clipping happened */ diff = ctime - time; if (diff > 0) { /* bring clipped time to samples */ diff = gst_util_uint64_scale_int (diff, ringbuf->spec.rate, GST_SECOND); GST_DEBUG_OBJECT (sink, "clipping start to %" GST_TIME_FORMAT " %" G_GUINT64_FORMAT " samples", GST_TIME_ARGS (ctime), diff); samples -= diff; data += diff * bps; time = ctime; } diff = stop - cstop; if (diff > 0) { /* bring clipped time to samples */ diff = gst_util_uint64_scale_int (diff, ringbuf->spec.rate, GST_SECOND); GST_DEBUG_OBJECT (sink, "clipping stop to %" GST_TIME_FORMAT " %" G_GUINT64_FORMAT " samples", GST_TIME_ARGS (cstop), diff); samples -= diff; stop = cstop; } gst_clock_get_calibration (sink->provided_clock, &cinternal, &cexternal, &crate_num, &crate_denom); /* bring buffer timestamp to running time */ render_time = gst_segment_to_running_time (&bsink->segment, GST_FORMAT_TIME, time); /* add base time to get absolute clock time */ render_time += (gst_element_get_base_time (GST_ELEMENT_CAST (bsink)) - cexternal) + cinternal; /* and bring the time to the offset in the buffer */ render_offset = gst_util_uint64_scale_int (render_time, ringbuf->spec.rate, GST_SECOND); GST_DEBUG_OBJECT (sink, "render time %" GST_TIME_FORMAT ", render offset %llu, samples %lu", GST_TIME_ARGS (render_time), render_offset, samples); /* roundoff errors in timestamp conversion */ if (G_LIKELY (sink->next_sample != -1)) { diff = ABS ((gint64) render_offset - (gint64) sink->next_sample); /* we tollerate a 10th of a second diff before we start resyncing. This * should be enough to compensate for various rounding errors in the timestamp * and sample offset position. We always resync if we got a discont anyway. */ if (diff < ringbuf->spec.rate / DIFF_TOLERANCE) { GST_DEBUG_OBJECT (sink, "align with prev sample, %" G_GINT64_FORMAT " < %lu", diff, ringbuf->spec.rate / DIFF_TOLERANCE); /* just align with previous sample then */ render_offset = sink->next_sample; } else { GST_DEBUG_OBJECT (sink, "resync after discont with previous sample of diff: %lu", diff); } } else { GST_DEBUG_OBJECT (sink, "resync after discont"); } crate = gst_guint64_to_gdouble (crate_num) / gst_guint64_to_gdouble (crate_denom); GST_DEBUG_OBJECT (sink, "internal %" G_GUINT64_FORMAT ", %" G_GUINT64_FORMAT ", rate %g", cinternal, cexternal, crate); no_sync: /* clip length based on rate */ samples = MIN (samples, samples / (crate * bsink->segment.abs_rate)); /* the next sample should be current sample and its length */ sink->next_sample = render_offset + samples; do { written = gst_ring_buffer_commit (ringbuf, render_offset, data, samples); GST_DEBUG_OBJECT (sink, "wrote %u of %u", written, samples); /* if we wrote all, we're done */ if (written == samples) break; /* else something interrupted us */ GST_DEBUG_OBJECT (sink, "wait for preroll..."); bsink->have_preroll = TRUE; GST_PAD_PREROLL_WAIT (bsink->sinkpad); bsink->have_preroll = FALSE; GST_DEBUG_OBJECT (sink, "preroll done"); if (G_UNLIKELY (bsink->flushing)) goto stopping; GST_DEBUG_OBJECT (sink, "continue after preroll"); render_offset += written; samples -= written; data += written * bps; } while (TRUE); if (GST_CLOCK_TIME_IS_VALID (stop) && stop >= bsink->segment.stop) { GST_DEBUG_OBJECT (sink, "start playback because we are at the end of segment"); gst_ring_buffer_start (ringbuf); } return GST_FLOW_OK; /* SPECIAL cases */ out_of_segment: { GST_DEBUG_OBJECT (sink, "dropping sample out of segment time %" GST_TIME_FORMAT ", start %" GST_TIME_FORMAT, GST_TIME_ARGS (time), GST_TIME_ARGS (bsink->segment.start)); return GST_FLOW_OK; } /* ERRORS */ wrong_state: { GST_DEBUG_OBJECT (sink, "ringbuffer not negotiated"); GST_ELEMENT_ERROR (sink, STREAM, FORMAT, (NULL), ("sink not negotiated.")); return GST_FLOW_NOT_NEGOTIATED; } wrong_size: { GST_DEBUG_OBJECT (sink, "wrong size"); GST_ELEMENT_ERROR (sink, STREAM, WRONG_TYPE, (NULL), ("sink received buffer of wrong size.")); return GST_FLOW_ERROR; } stopping: { GST_DEBUG_OBJECT (sink, "ringbuffer is stopping"); return GST_FLOW_WRONG_STATE; } } GstRingBuffer * gst_base_audio_sink_create_ringbuffer (GstBaseAudioSink * sink) { GstBaseAudioSinkClass *bclass; GstRingBuffer *buffer = NULL; bclass = GST_BASE_AUDIO_SINK_GET_CLASS (sink); if (bclass->create_ringbuffer) buffer = bclass->create_ringbuffer (sink); if (buffer) gst_object_set_parent (GST_OBJECT (buffer), GST_OBJECT (sink)); return buffer; } static void gst_base_audio_sink_callback (GstRingBuffer * rbuf, guint8 * data, guint len, gpointer user_data) { //GstBaseAudioSink *sink = GST_BASE_AUDIO_SINK (data); } static GstStateChangeReturn gst_base_audio_sink_change_state (GstElement * element, GstStateChange transition) { GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; GstBaseAudioSink *sink = GST_BASE_AUDIO_SINK (element); switch (transition) { case GST_STATE_CHANGE_NULL_TO_READY: if (sink->ringbuffer == NULL) { sink->ringbuffer = gst_base_audio_sink_create_ringbuffer (sink); gst_ring_buffer_set_callback (sink->ringbuffer, gst_base_audio_sink_callback, sink); } if (!gst_ring_buffer_open_device (sink->ringbuffer)) goto open_failed; break; case GST_STATE_CHANGE_READY_TO_PAUSED: gst_ring_buffer_set_flushing (sink->ringbuffer, FALSE); sink->next_sample = -1; break; case GST_STATE_CHANGE_PAUSED_TO_PLAYING: { GstClock *clock; GstClockTime time, base; GST_OBJECT_LOCK (sink); clock = GST_ELEMENT_CLOCK (sink); if (clock == NULL) goto no_clock; /* FIXME, only start slaving when we really start the ringbuffer */ /* if we are slaved to a clock, we need to set the initial * calibration */ if (clock != sink->provided_clock) { GstClockTime rate_num, rate_denom; base = element->base_time; time = gst_clock_get_internal_time (sink->provided_clock); GST_DEBUG_OBJECT (sink, "time: %" GST_TIME_FORMAT " base: %" GST_TIME_FORMAT, GST_TIME_ARGS (time), GST_TIME_ARGS (base)); gst_clock_set_master (sink->provided_clock, clock); /* FIXME, this is not yet accurate enough for smooth playback */ gst_clock_get_calibration (sink->provided_clock, NULL, NULL, &rate_num, &rate_denom); /* Does not work yet. */ gst_clock_set_calibration (sink->provided_clock, time, element->base_time, rate_num, rate_denom); } no_clock: GST_OBJECT_UNLOCK (sink); break; } case GST_STATE_CHANGE_PLAYING_TO_PAUSED: gst_ring_buffer_pause (sink->ringbuffer); break; case GST_STATE_CHANGE_PAUSED_TO_READY: gst_ring_buffer_set_flushing (sink->ringbuffer, TRUE); break; default: break; } ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); switch (transition) { case GST_STATE_CHANGE_PLAYING_TO_PAUSED: /* slop slaving ourselves to the master, if any */ gst_clock_set_master (sink->provided_clock, NULL); break; case GST_STATE_CHANGE_PAUSED_TO_READY: gst_ring_buffer_release (sink->ringbuffer); gst_pad_set_caps (GST_BASE_SINK_PAD (sink), NULL); break; case GST_STATE_CHANGE_READY_TO_NULL: gst_ring_buffer_close_device (sink->ringbuffer); break; default: break; } return ret; open_failed: { GST_DEBUG_OBJECT (sink, "open failed"); return GST_STATE_CHANGE_FAILURE; } }