sys/osxaudio/gstosxaudioringbuffer.c - imx-gst-plugins-good - Git at Google

 /*
  * GStreamer
  * Copyright (C) 2006 Zaheer Abbas Merali <zaheerabbas at merali dot org>
  * Copyright (C) 2008 Pioneers of the Inevitable <songbird@songbirdnest.com>
  * Copyright (C) 2012 Fluendo S.A. <support@fluendo.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
  * Alternatively, the contents of this file may be used under the
  * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
  * which case the following provisions apply instead of the ones
  * mentioned above:
  *
  * 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., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 #ifdef HAVE_CONFIG_H
 #  include <config.h>
 #endif

 #include <gst/gst.h>
 #include <gst/gst-i18n-plugin.h>
 #include <gst/audio/audio-channels.h>
 #include "gstosxaudioringbuffer.h"
 #include "gstosxaudiosink.h"
 #include "gstosxaudiosrc.h"

 #include <unistd.h>             /* for getpid() */

 GST_DEBUG_CATEGORY_STATIC (osx_audio_debug);
 #define GST_CAT_DEFAULT osx_audio_debug

 #include "gstosxcoreaudio.h"

 static void gst_osx_audio_ring_buffer_dispose (GObject * object);
 static gboolean gst_osx_audio_ring_buffer_open_device (GstAudioRingBuffer *
     buf);
 static gboolean gst_osx_audio_ring_buffer_close_device (GstAudioRingBuffer *
     buf);

 static gboolean gst_osx_audio_ring_buffer_acquire (GstAudioRingBuffer * buf,
     GstAudioRingBufferSpec * spec);
 static gboolean gst_osx_audio_ring_buffer_release (GstAudioRingBuffer * buf);

 static gboolean gst_osx_audio_ring_buffer_start (GstAudioRingBuffer * buf);
 static gboolean gst_osx_audio_ring_buffer_pause (GstAudioRingBuffer * buf);
 static gboolean gst_osx_audio_ring_buffer_stop (GstAudioRingBuffer * buf);
 static guint gst_osx_audio_ring_buffer_delay (GstAudioRingBuffer * buf);
 static GstAudioRingBufferClass *ring_parent_class = NULL;

 #define gst_osx_audio_ring_buffer_do_init \
   GST_DEBUG_CATEGORY_INIT (osx_audio_debug, "osxaudio", 0, "OSX Audio Elements");

 G_DEFINE_TYPE_WITH_CODE (GstOsxAudioRingBuffer, gst_osx_audio_ring_buffer,
     GST_TYPE_AUDIO_RING_BUFFER, gst_osx_audio_ring_buffer_do_init);

 static void
 gst_osx_audio_ring_buffer_class_init (GstOsxAudioRingBufferClass * klass)
 {
   GObjectClass *gobject_class;
   GstAudioRingBufferClass *gstringbuffer_class;

   gobject_class = (GObjectClass *) klass;
   gstringbuffer_class = (GstAudioRingBufferClass *) klass;

   ring_parent_class = g_type_class_peek_parent (klass);

   gobject_class->dispose = gst_osx_audio_ring_buffer_dispose;

   gstringbuffer_class->open_device =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_open_device);
   gstringbuffer_class->close_device =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_close_device);
   gstringbuffer_class->acquire =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_acquire);
   gstringbuffer_class->release =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_release);
   gstringbuffer_class->start =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_start);
   gstringbuffer_class->pause =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_pause);
   gstringbuffer_class->resume =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_start);
   gstringbuffer_class->stop =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_stop);
   gstringbuffer_class->delay =
       GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_delay);

   GST_DEBUG ("osx audio ring buffer class init");
 }

 static void
 gst_osx_audio_ring_buffer_init (GstOsxAudioRingBuffer * ringbuffer)
 {
   ringbuffer->core_audio = gst_core_audio_new (GST_OBJECT (ringbuffer));
 }

 static void
 gst_osx_audio_ring_buffer_dispose (GObject * object)
 {
   GstOsxAudioRingBuffer *osxbuf;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (object);

   if (osxbuf->core_audio) {
     g_object_unref (osxbuf->core_audio);
     osxbuf->core_audio = NULL;
   }
   G_OBJECT_CLASS (ring_parent_class)->dispose (object);
 }

 static gboolean
 gst_osx_audio_ring_buffer_open_device (GstAudioRingBuffer * buf)
 {
   GstObject *osxel = GST_OBJECT_PARENT (buf);
   GstOsxAudioRingBuffer *osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   if (!gst_core_audio_select_device (osxbuf->core_audio)) {
     GST_ELEMENT_ERROR (osxel, RESOURCE, NOT_FOUND,
         (_("CoreAudio device not found")), (NULL));
     return FALSE;
   }

   if (!gst_core_audio_open (osxbuf->core_audio)) {
     GST_ELEMENT_ERROR (osxel, RESOURCE, OPEN_READ,
         (_("CoreAudio device could not be opened")), (NULL));
     return FALSE;
   }

   return TRUE;
 }

 static gboolean
 gst_osx_audio_ring_buffer_close_device (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf;
   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   return gst_core_audio_close (osxbuf->core_audio);
 }

 static gboolean
 gst_osx_audio_ring_buffer_acquire (GstAudioRingBuffer * buf,
     GstAudioRingBufferSpec * spec)
 {
   gboolean ret = FALSE, is_passthrough = FALSE;
   GstOsxAudioRingBuffer *osxbuf;
   AudioStreamBasicDescription format;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   if (RINGBUFFER_IS_SPDIF (spec->type)) {
     format.mFormatID = kAudioFormat60958AC3;
     format.mSampleRate = (double) GST_AUDIO_INFO_RATE (&spec->info);
     format.mChannelsPerFrame = 2;
     format.mFormatFlags = kAudioFormatFlagIsSignedInteger |
         kAudioFormatFlagIsPacked | kAudioFormatFlagIsNonMixable;
     format.mBytesPerFrame = 0;
     format.mBitsPerChannel = 16;
     format.mBytesPerPacket = 6144;
     format.mFramesPerPacket = 1536;
     format.mReserved = 0;
     spec->segsize = 6144;
     spec->segtotal = 10;
     is_passthrough = TRUE;
   } else {
     int width, depth;
     /* Fill out the audio description we're going to be using */
     format.mFormatID = kAudioFormatLinearPCM;
     format.mSampleRate = (double) GST_AUDIO_INFO_RATE (&spec->info);
     format.mChannelsPerFrame = GST_AUDIO_INFO_CHANNELS (&spec->info);
     if (GST_AUDIO_INFO_IS_FLOAT (&spec->info)) {
       format.mFormatFlags = kAudioFormatFlagsNativeFloatPacked;
       width = depth = GST_AUDIO_INFO_WIDTH (&spec->info);
     } else {
       format.mFormatFlags = kAudioFormatFlagIsSignedInteger;
       width = GST_AUDIO_INFO_WIDTH (&spec->info);
       depth = GST_AUDIO_INFO_DEPTH (&spec->info);
       if (width == depth) {
         format.mFormatFlags |= kAudioFormatFlagIsPacked;
       } else {
         format.mFormatFlags |= kAudioFormatFlagIsAlignedHigh;
       }
     }

     if (GST_AUDIO_INFO_IS_BIG_ENDIAN (&spec->info)) {
       format.mFormatFlags |= kAudioFormatFlagIsBigEndian;
     }

     format.mBytesPerFrame = GST_AUDIO_INFO_BPF (&spec->info);
     format.mBitsPerChannel = depth;
     format.mBytesPerPacket = GST_AUDIO_INFO_BPF (&spec->info);
     format.mFramesPerPacket = 1;
     format.mReserved = 0;
     spec->segsize =
         (spec->latency_time * GST_AUDIO_INFO_RATE (&spec->info) /
         G_USEC_PER_SEC) * GST_AUDIO_INFO_BPF (&spec->info);
     spec->segtotal = spec->buffer_time / spec->latency_time;
     is_passthrough = FALSE;
   }

   GST_DEBUG_OBJECT (osxbuf, "Format: " CORE_AUDIO_FORMAT,
       CORE_AUDIO_FORMAT_ARGS (format));

   /* gst_audio_ring_buffer_set_channel_positions is not called
    * since the AUs perform channel reordering themselves.
    * (see gst_core_audio_set_channel_layout) */

   buf->size = spec->segtotal * spec->segsize;
   buf->memory = g_malloc0 (buf->size);

   ret = gst_core_audio_initialize (osxbuf->core_audio, format, spec->caps,
       is_passthrough);

   if (!ret) {
     g_free (buf->memory);
     buf->memory = NULL;
     buf->size = 0;
   }

   osxbuf->segoffset = 0;

   return ret;
 }

 static gboolean
 gst_osx_audio_ring_buffer_release (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   gst_core_audio_uninitialize (osxbuf->core_audio);

   g_free (buf->memory);
   buf->memory = NULL;
   buf->size = 0;

   return TRUE;
 }

 static gboolean
 gst_osx_audio_ring_buffer_start (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   return gst_core_audio_start_processing (osxbuf->core_audio);
 }

 static gboolean
 gst_osx_audio_ring_buffer_pause (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   return gst_core_audio_pause_processing (osxbuf->core_audio);
 }


 static gboolean
 gst_osx_audio_ring_buffer_stop (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   gst_core_audio_stop_processing (osxbuf->core_audio);

   return TRUE;
 }

 static guint
 gst_osx_audio_ring_buffer_delay (GstAudioRingBuffer * buf)
 {
   GstOsxAudioRingBuffer *osxbuf;
   double latency;
   guint samples;

   osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

   if (!gst_core_audio_get_samples_and_latency (osxbuf->core_audio,
           GST_AUDIO_INFO_RATE (&buf->spec.info), &samples, &latency)) {
     return 0;
   }
   GST_DEBUG_OBJECT (buf, "Got latency: %f seconds -> %d samples",
       latency, samples);
   return samples;
 }
	/*
	* GStreamer
	* Copyright (C) 2006 Zaheer Abbas Merali <zaheerabbas at merali dot org>
	* Copyright (C) 2008 Pioneers of the Inevitable <songbird@songbirdnest.com>
	* Copyright (C) 2012 Fluendo S.A. <support@fluendo.com>
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	* DEALINGS IN THE SOFTWARE.
	*
	* Alternatively, the contents of this file may be used under the
	* GNU Lesser General Public License Version 2.1 (the "LGPL"), in
	* which case the following provisions apply instead of the ones
	* mentioned above:
	*
	* 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., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	#ifdef HAVE_CONFIG_H
	# include <config.h>
	#endif

	#include <gst/gst.h>
	#include <gst/gst-i18n-plugin.h>
	#include <gst/audio/audio-channels.h>
	#include "gstosxaudioringbuffer.h"
	#include "gstosxaudiosink.h"
	#include "gstosxaudiosrc.h"

	#include <unistd.h> /* for getpid() */

	GST_DEBUG_CATEGORY_STATIC (osx_audio_debug);
	#define GST_CAT_DEFAULT osx_audio_debug

	#include "gstosxcoreaudio.h"

	static void gst_osx_audio_ring_buffer_dispose (GObject * object);
	static gboolean gst_osx_audio_ring_buffer_open_device (GstAudioRingBuffer *
	buf);
	static gboolean gst_osx_audio_ring_buffer_close_device (GstAudioRingBuffer *
	buf);

	static gboolean gst_osx_audio_ring_buffer_acquire (GstAudioRingBuffer * buf,
	GstAudioRingBufferSpec * spec);
	static gboolean gst_osx_audio_ring_buffer_release (GstAudioRingBuffer * buf);

	static gboolean gst_osx_audio_ring_buffer_start (GstAudioRingBuffer * buf);
	static gboolean gst_osx_audio_ring_buffer_pause (GstAudioRingBuffer * buf);
	static gboolean gst_osx_audio_ring_buffer_stop (GstAudioRingBuffer * buf);
	static guint gst_osx_audio_ring_buffer_delay (GstAudioRingBuffer * buf);
	static GstAudioRingBufferClass *ring_parent_class = NULL;

	#define gst_osx_audio_ring_buffer_do_init \
	GST_DEBUG_CATEGORY_INIT (osx_audio_debug, "osxaudio", 0, "OSX Audio Elements");

	G_DEFINE_TYPE_WITH_CODE (GstOsxAudioRingBuffer, gst_osx_audio_ring_buffer,
	GST_TYPE_AUDIO_RING_BUFFER, gst_osx_audio_ring_buffer_do_init);

	static void
	gst_osx_audio_ring_buffer_class_init (GstOsxAudioRingBufferClass * klass)
	{
	GObjectClass *gobject_class;
	GstAudioRingBufferClass *gstringbuffer_class;

	gobject_class = (GObjectClass *) klass;
	gstringbuffer_class = (GstAudioRingBufferClass *) klass;

	ring_parent_class = g_type_class_peek_parent (klass);

	gobject_class->dispose = gst_osx_audio_ring_buffer_dispose;

	gstringbuffer_class->open_device =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_open_device);
	gstringbuffer_class->close_device =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_close_device);
	gstringbuffer_class->acquire =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_acquire);
	gstringbuffer_class->release =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_release);
	gstringbuffer_class->start =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_start);
	gstringbuffer_class->pause =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_pause);
	gstringbuffer_class->resume =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_start);
	gstringbuffer_class->stop =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_stop);
	gstringbuffer_class->delay =
	GST_DEBUG_FUNCPTR (gst_osx_audio_ring_buffer_delay);

	GST_DEBUG ("osx audio ring buffer class init");
	}

	static void
	gst_osx_audio_ring_buffer_init (GstOsxAudioRingBuffer * ringbuffer)
	{
	ringbuffer->core_audio = gst_core_audio_new (GST_OBJECT (ringbuffer));
	}

	static void
	gst_osx_audio_ring_buffer_dispose (GObject * object)
	{
	GstOsxAudioRingBuffer *osxbuf;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (object);

	if (osxbuf->core_audio) {
	g_object_unref (osxbuf->core_audio);
	osxbuf->core_audio = NULL;
	}
	G_OBJECT_CLASS (ring_parent_class)->dispose (object);
	}

	static gboolean
	gst_osx_audio_ring_buffer_open_device (GstAudioRingBuffer * buf)
	{
	GstObject *osxel = GST_OBJECT_PARENT (buf);
	GstOsxAudioRingBuffer *osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	if (!gst_core_audio_select_device (osxbuf->core_audio)) {
	GST_ELEMENT_ERROR (osxel, RESOURCE, NOT_FOUND,
	(_("CoreAudio device not found")), (NULL));
	return FALSE;
	}

	if (!gst_core_audio_open (osxbuf->core_audio)) {
	GST_ELEMENT_ERROR (osxel, RESOURCE, OPEN_READ,
	(_("CoreAudio device could not be opened")), (NULL));
	return FALSE;
	}

	return TRUE;
	}

	static gboolean
	gst_osx_audio_ring_buffer_close_device (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf;
	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	return gst_core_audio_close (osxbuf->core_audio);
	}

	static gboolean
	gst_osx_audio_ring_buffer_acquire (GstAudioRingBuffer * buf,
	GstAudioRingBufferSpec * spec)
	{
	gboolean ret = FALSE, is_passthrough = FALSE;
	GstOsxAudioRingBuffer *osxbuf;
	AudioStreamBasicDescription format;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	if (RINGBUFFER_IS_SPDIF (spec->type)) {
	format.mFormatID = kAudioFormat60958AC3;
	format.mSampleRate = (double) GST_AUDIO_INFO_RATE (&spec->info);
	format.mChannelsPerFrame = 2;
	format.mFormatFlags = kAudioFormatFlagIsSignedInteger \|
	kAudioFormatFlagIsPacked \| kAudioFormatFlagIsNonMixable;
	format.mBytesPerFrame = 0;
	format.mBitsPerChannel = 16;
	format.mBytesPerPacket = 6144;
	format.mFramesPerPacket = 1536;
	format.mReserved = 0;
	spec->segsize = 6144;
	spec->segtotal = 10;
	is_passthrough = TRUE;
	} else {
	int width, depth;
	/* Fill out the audio description we're going to be using */
	format.mFormatID = kAudioFormatLinearPCM;
	format.mSampleRate = (double) GST_AUDIO_INFO_RATE (&spec->info);
	format.mChannelsPerFrame = GST_AUDIO_INFO_CHANNELS (&spec->info);
	if (GST_AUDIO_INFO_IS_FLOAT (&spec->info)) {
	format.mFormatFlags = kAudioFormatFlagsNativeFloatPacked;
	width = depth = GST_AUDIO_INFO_WIDTH (&spec->info);
	} else {
	format.mFormatFlags = kAudioFormatFlagIsSignedInteger;
	width = GST_AUDIO_INFO_WIDTH (&spec->info);
	depth = GST_AUDIO_INFO_DEPTH (&spec->info);
	if (width == depth) {
	format.mFormatFlags \|= kAudioFormatFlagIsPacked;
	} else {
	format.mFormatFlags \|= kAudioFormatFlagIsAlignedHigh;
	}
	}

	if (GST_AUDIO_INFO_IS_BIG_ENDIAN (&spec->info)) {
	format.mFormatFlags \|= kAudioFormatFlagIsBigEndian;
	}

	format.mBytesPerFrame = GST_AUDIO_INFO_BPF (&spec->info);
	format.mBitsPerChannel = depth;
	format.mBytesPerPacket = GST_AUDIO_INFO_BPF (&spec->info);
	format.mFramesPerPacket = 1;
	format.mReserved = 0;
	spec->segsize =
	(spec->latency_time * GST_AUDIO_INFO_RATE (&spec->info) /
	G_USEC_PER_SEC) * GST_AUDIO_INFO_BPF (&spec->info);
	spec->segtotal = spec->buffer_time / spec->latency_time;
	is_passthrough = FALSE;
	}

	GST_DEBUG_OBJECT (osxbuf, "Format: " CORE_AUDIO_FORMAT,
	CORE_AUDIO_FORMAT_ARGS (format));

	/* gst_audio_ring_buffer_set_channel_positions is not called
	* since the AUs perform channel reordering themselves.
	* (see gst_core_audio_set_channel_layout) */

	buf->size = spec->segtotal * spec->segsize;
	buf->memory = g_malloc0 (buf->size);

	ret = gst_core_audio_initialize (osxbuf->core_audio, format, spec->caps,
	is_passthrough);

	if (!ret) {
	g_free (buf->memory);
	buf->memory = NULL;
	buf->size = 0;
	}

	osxbuf->segoffset = 0;

	return ret;
	}

	static gboolean
	gst_osx_audio_ring_buffer_release (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	gst_core_audio_uninitialize (osxbuf->core_audio);

	g_free (buf->memory);
	buf->memory = NULL;
	buf->size = 0;

	return TRUE;
	}

	static gboolean
	gst_osx_audio_ring_buffer_start (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	return gst_core_audio_start_processing (osxbuf->core_audio);
	}

	static gboolean
	gst_osx_audio_ring_buffer_pause (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	return gst_core_audio_pause_processing (osxbuf->core_audio);
	}


	static gboolean
	gst_osx_audio_ring_buffer_stop (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	gst_core_audio_stop_processing (osxbuf->core_audio);

	return TRUE;
	}

	static guint
	gst_osx_audio_ring_buffer_delay (GstAudioRingBuffer * buf)
	{
	GstOsxAudioRingBuffer *osxbuf;
	double latency;
	guint samples;

	osxbuf = GST_OSX_AUDIO_RING_BUFFER (buf);

	if (!gst_core_audio_get_samples_and_latency (osxbuf->core_audio,
	GST_AUDIO_INFO_RATE (&buf->spec.info), &samples, &latency)) {
	return 0;
	}
	GST_DEBUG_OBJECT (buf, "Got latency: %f seconds -> %d samples",
	latency, samples);
	return samples;
	}