278 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			278 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* GStreamer
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|  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
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|  *                    2005 Wim Taymans <wim@fluendo.com>
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|  *
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|  * gstaudiobasesink.h:
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|  *
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|  * This library is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Library General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2 of the License, or (at your option) any later version.
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|  *
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|  * This library is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Library General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Library General Public
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|  * License along with this library; if not, write to the
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|  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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|  * Boston, MA 02110-1301, USA.
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|  */
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| 
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| /* a base class for audio sinks.
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|  *
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|  * It uses a ringbuffer to schedule playback of samples. This makes
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|  * it very easy to drop or insert samples to align incoming
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|  * buffers to the exact playback timestamp.
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|  *
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|  * Subclasses must provide a ringbuffer pointing to either DMA
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|  * memory or regular memory. A subclass should also call a callback
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|  * function when it has played N segments in the buffer. The subclass
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|  * is free to use a thread to signal this callback, use EIO or any
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|  * other mechanism.
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|  *
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|  * The base class is able to operate in push or pull mode. The chain
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|  * mode will queue the samples in the ringbuffer as much as possible.
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|  * The available space is calculated in the callback function.
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|  *
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|  * The pull mode will pull_range() a new buffer of N samples with a
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|  * configurable latency. This allows for high-end real time
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|  * audio processing pipelines driven by the audiosink. The callback
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|  * function will be used to perform a pull_range() on the sinkpad.
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|  * The thread scheduling the callback can be a real-time thread.
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|  *
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|  * Subclasses must implement a GstAudioRingBuffer in addition to overriding
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|  * the methods in GstBaseSink and this class.
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|  */
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| 
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| #ifndef __GST_AUDIO_AUDIO_H__
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| #include <gst/audio/audio.h>
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| #endif
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| 
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| #ifndef __GST_AUDIO_BASE_SINK_H__
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| #define __GST_AUDIO_BASE_SINK_H__
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| 
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| #include <gst/base/gstbasesink.h>
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| 
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| G_BEGIN_DECLS
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| 
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| #define GST_TYPE_AUDIO_BASE_SINK                (gst_audio_base_sink_get_type())
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| #define GST_AUDIO_BASE_SINK(obj)                (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AUDIO_BASE_SINK,GstAudioBaseSink))
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| #define GST_AUDIO_BASE_SINK_CAST(obj)           ((GstAudioBaseSink*)obj)
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| #define GST_AUDIO_BASE_SINK_CLASS(klass)        (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AUDIO_BASE_SINK,GstAudioBaseSinkClass))
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| #define GST_AUDIO_BASE_SINK_GET_CLASS(obj)      (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_AUDIO_BASE_SINK, GstAudioBaseSinkClass))
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| #define GST_IS_AUDIO_BASE_SINK(obj)             (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_BASE_SINK))
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| #define GST_IS_AUDIO_BASE_SINK_CLASS(klass)     (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AUDIO_BASE_SINK))
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| 
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| /**
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|  * GST_AUDIO_BASE_SINK_CLOCK:
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|  * @obj: a #GstAudioBaseSink
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|  *
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|  * Get the #GstClock of @obj.
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|  */
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| #define GST_AUDIO_BASE_SINK_CLOCK(obj)   (GST_AUDIO_BASE_SINK (obj)->clock)
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| /**
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|  * GST_AUDIO_BASE_SINK_PAD:
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|  * @obj: a #GstAudioBaseSink
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|  *
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|  * Get the sink #GstPad of @obj.
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|  */
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| #define GST_AUDIO_BASE_SINK_PAD(obj)     (GST_BASE_SINK (obj)->sinkpad)
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| 
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| /**
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|  * GstAudioBaseSinkSlaveMethod:
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|  * @GST_AUDIO_BASE_SINK_SLAVE_RESAMPLE: Resample to match the master clock
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|  * @GST_AUDIO_BASE_SINK_SLAVE_SKEW: Adjust playout pointer when master clock
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|  * drifts too much.
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|  * @GST_AUDIO_BASE_SINK_SLAVE_NONE: No adjustment is done.
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|  * @GST_AUDIO_BASE_SINK_SLAVE_CUSTOM: Use custom clock slaving algorithm (Since: 1.6)
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|  *
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|  * Different possible clock slaving algorithms used when the internal audio
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|  * clock is not selected as the pipeline master clock.
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|  */
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| typedef enum
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| {
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|   GST_AUDIO_BASE_SINK_SLAVE_RESAMPLE,
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|   GST_AUDIO_BASE_SINK_SLAVE_SKEW,
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|   GST_AUDIO_BASE_SINK_SLAVE_NONE,
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|   GST_AUDIO_BASE_SINK_SLAVE_CUSTOM
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| } GstAudioBaseSinkSlaveMethod;
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| 
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| typedef struct _GstAudioBaseSink GstAudioBaseSink;
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| typedef struct _GstAudioBaseSinkClass GstAudioBaseSinkClass;
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| typedef struct _GstAudioBaseSinkPrivate GstAudioBaseSinkPrivate;
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| 
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| /**
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|  * GstAudioBaseSinkDiscontReason:
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|  * @GST_AUDIO_BASE_SINK_DISCONT_REASON_NO_DISCONT: No discontinuity occurred
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|  * @GST_AUDIO_BASE_SINK_DISCONT_REASON_NEW_CAPS: New caps are set, causing renegotiotion
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|  * @GST_AUDIO_BASE_SINK_DISCONT_REASON_FLUSH: Samples have been flushed
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|  * @GST_AUDIO_BASE_SINK_DISCONT_REASON_SYNC_LATENCY: Sink was synchronized to the estimated latency (occurs during initialization)
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|  * @GST_AUDIO_BASE_SINK_DISCONT_REASON_ALIGNMENT: Aligning buffers failed because the timestamps are too discontinuous
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|  * @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())
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|  *
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|  * Different possible reasons for discontinuities. This enum is useful for the custom
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|  * slave method.
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|  *
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|  * Since: 1.6
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|  */
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| typedef enum
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| {
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_NO_DISCONT,
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_NEW_CAPS,
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_FLUSH,
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_SYNC_LATENCY,
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_ALIGNMENT,
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|   GST_AUDIO_BASE_SINK_DISCONT_REASON_DEVICE_FAILURE
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| } GstAudioBaseSinkDiscontReason;
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| 
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| /**
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|  * GstAudioBaseSinkCustomSlavingCallback:
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|  * @sink: a #GstAudioBaseSink
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|  * @etime: external clock time
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|  * @itime: internal clock time
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|  * @requested_skew: skew amount requested by the callback
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|  * @discont_reason: reason for discontinuity (if any)
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|  * @user_data: user data
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|  *
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|  * This function is set with gst_audio_base_sink_set_custom_slaving_callback()
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|  * and is called during playback. It receives the current time of external and
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|  * internal clocks, which the callback can then use to apply any custom
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|  * slaving/synchronization schemes.
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|  *
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|  * The external clock is the sink's element clock, the internal one is the
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|  * internal audio clock. The internal audio clock's calibration is applied to
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|  * the timestamps before they are passed to the callback. The difference between
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|  * etime and itime is the skew; how much internal and external clock lie apart
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|  * from each other. A skew of 0 means both clocks are perfectly in sync.
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|  * itime > etime means the external clock is going slower, while itime < etime
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|  * means it is going faster than the internal clock. etime and itime are always
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|  * valid timestamps, except for when a discontinuity happens.
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|  *
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|  * requested_skew is an output value the callback can write to. It informs the
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|  * sink of whether or not it should move the playout pointer, and if so, by how
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|  * much. This pointer is only NULL if a discontinuity occurs; otherwise, it is
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|  * safe to write to *requested_skew. The default skew is 0.
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|  *
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|  * The sink may experience discontinuities. If one happens, discont is TRUE,
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|  * itime, etime are set to GST_CLOCK_TIME_NONE, and requested_skew is NULL.
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|  * This makes it possible to reset custom clock slaving algorithms when a
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|  * discontinuity happens.
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|  *
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|  * Since: 1.6
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|  */
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| typedef void (*GstAudioBaseSinkCustomSlavingCallback) (GstAudioBaseSink *sink, GstClockTime etime, GstClockTime itime, GstClockTimeDiff *requested_skew, GstAudioBaseSinkDiscontReason discont_reason, gpointer user_data);
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| 
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| /**
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|  * GstAudioBaseSink:
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|  *
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|  * Opaque #GstAudioBaseSink.
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|  */
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| struct _GstAudioBaseSink {
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|   GstBaseSink         element;
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| 
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|   /*< protected >*/ /* with LOCK */
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|   /* our ringbuffer */
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|   GstAudioRingBuffer *ringbuffer;
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| 
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|   /* required buffer and latency in microseconds */
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|   guint64             buffer_time;
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|   guint64             latency_time;
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| 
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|   /* the next sample to write */
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|   guint64             next_sample;
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| 
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|   /* clock */
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|   GstClock           *provided_clock;
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| 
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|   /* with g_atomic_; currently rendering eos */
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|   gboolean            eos_rendering;
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| 
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|   /*< private >*/
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|   GstAudioBaseSinkPrivate *priv;
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| 
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|   gpointer _gst_reserved[GST_PADDING];
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| };
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| 
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| /**
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|  * GstAudioBaseSinkClass:
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|  * @parent_class: the parent class.
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|  * @create_ringbuffer: create and return a #GstAudioRingBuffer to write to.
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|  * @payload: payload data in a format suitable to write to the sink. If no
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|  *           payloading is required, returns a reffed copy of the original
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|  *           buffer, else returns the payloaded buffer with all other metadata
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|  *           copied.
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|  *
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|  * #GstAudioBaseSink class. Override the vmethod to implement
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|  * functionality.
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|  */
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| struct _GstAudioBaseSinkClass {
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|   GstBaseSinkClass     parent_class;
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| 
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|   /* subclass ringbuffer allocation */
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|   GstAudioRingBuffer* (*create_ringbuffer)  (GstAudioBaseSink *sink);
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| 
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|   /* subclass payloader */
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|   GstBuffer*          (*payload)            (GstAudioBaseSink *sink,
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|                                              GstBuffer        *buffer);
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|   /*< private >*/
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|   gpointer _gst_reserved[GST_PADDING];
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| };
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| 
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| GST_AUDIO_API
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| GType gst_audio_base_sink_get_type(void);
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| 
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| GST_AUDIO_API
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| GstAudioRingBuffer *
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|            gst_audio_base_sink_create_ringbuffer       (GstAudioBaseSink *sink);
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| 
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| GST_AUDIO_API
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| void       gst_audio_base_sink_set_provide_clock       (GstAudioBaseSink *sink, gboolean provide);
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| 
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| GST_AUDIO_API
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| gboolean   gst_audio_base_sink_get_provide_clock       (GstAudioBaseSink *sink);
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| 
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| GST_AUDIO_API
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| void       gst_audio_base_sink_set_slave_method        (GstAudioBaseSink *sink,
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|                                                         GstAudioBaseSinkSlaveMethod method);
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| GST_AUDIO_API
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| GstAudioBaseSinkSlaveMethod
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|            gst_audio_base_sink_get_slave_method        (GstAudioBaseSink *sink);
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| 
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| GST_AUDIO_API
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| void       gst_audio_base_sink_set_drift_tolerance     (GstAudioBaseSink *sink,
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|                                                         gint64 drift_tolerance);
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| GST_AUDIO_API
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| gint64     gst_audio_base_sink_get_drift_tolerance     (GstAudioBaseSink *sink);
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| 
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| GST_AUDIO_API
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| void       gst_audio_base_sink_set_alignment_threshold (GstAudioBaseSink * sink,
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|                                                         GstClockTime alignment_threshold);
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| GST_AUDIO_API
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| GstClockTime
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|            gst_audio_base_sink_get_alignment_threshold (GstAudioBaseSink * sink);
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| 
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| GST_AUDIO_API
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| void       gst_audio_base_sink_set_discont_wait        (GstAudioBaseSink * sink,
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|                                                         GstClockTime discont_wait);
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| GST_AUDIO_API
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| GstClockTime
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|            gst_audio_base_sink_get_discont_wait        (GstAudioBaseSink * sink);
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| 
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| GST_AUDIO_API
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| void
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| gst_audio_base_sink_set_custom_slaving_callback        (GstAudioBaseSink * sink,
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|                                                         GstAudioBaseSinkCustomSlavingCallback callback,
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|                                                         gpointer user_data,
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|                                                         GDestroyNotify notify);
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| 
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| GST_AUDIO_API
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| void gst_audio_base_sink_report_device_failure         (GstAudioBaseSink * sink);
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| 
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| G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstAudioBaseSink, gst_object_unref)
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| 
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| G_END_DECLS
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| 
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| #endif /* __GST_AUDIO_BASE_SINK_H__ */
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