audio/coreaudio.c - qemu - Git at Google

 /*
  * QEMU OS X CoreAudio audio driver
  *
  * Copyright (c) 2005 Mike Kronenberg
  *
  * 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.
  */

 #include <CoreAudio/CoreAudio.h>
 #include <string.h>             /* strerror */
 #include <pthread.h>            /* pthread_X */

 #include "vl.h"

 #define AUDIO_CAP "coreaudio"
 #include "audio_int.h"

 struct {
     int buffer_frames;
     int nbuffers;
     int isAtexit;
 } conf = {
     .buffer_frames = 512,
     .nbuffers = 4,
     .isAtexit = 0
 };

 typedef struct coreaudioVoiceOut {
     HWVoiceOut hw;
     pthread_mutex_t mutex;
     int isAtexit;
     AudioDeviceID outputDeviceID;
     UInt32 audioDevicePropertyBufferFrameSize;
     AudioStreamBasicDescription outputStreamBasicDescription;
     int live;
     int decr;
     int rpos;
 } coreaudioVoiceOut;

 static void coreaudio_logstatus (OSStatus status)
 {
     char *str = "BUG";

     switch(status) {
     case kAudioHardwareNoError:
         str = "kAudioHardwareNoError";
         break;

     case kAudioHardwareNotRunningError:
         str = "kAudioHardwareNotRunningError";
         break;

     case kAudioHardwareUnspecifiedError:
         str = "kAudioHardwareUnspecifiedError";
         break;

     case kAudioHardwareUnknownPropertyError:
         str = "kAudioHardwareUnknownPropertyError";
         break;

     case kAudioHardwareBadPropertySizeError:
         str = "kAudioHardwareBadPropertySizeError";
         break;

     case kAudioHardwareIllegalOperationError:
         str = "kAudioHardwareIllegalOperationError";
         break;

     case kAudioHardwareBadDeviceError:
         str = "kAudioHardwareBadDeviceError";
         break;

     case kAudioHardwareBadStreamError:
         str = "kAudioHardwareBadStreamError";
         break;

     case kAudioHardwareUnsupportedOperationError:
         str = "kAudioHardwareUnsupportedOperationError";
         break;

     case kAudioDeviceUnsupportedFormatError:
         str = "kAudioDeviceUnsupportedFormatError";
         break;

     case kAudioDevicePermissionsError:
         str = "kAudioDevicePermissionsError";
         break;

     default:
         AUD_log (AUDIO_CAP, "Reason: status code %ld\n", status);
         return;
     }

     AUD_log (AUDIO_CAP, "Reason: %s\n", str);
 }

 static void GCC_FMT_ATTR (2, 3) coreaudio_logerr (
     OSStatus status,
     const char *fmt,
     ...
     )
 {
     va_list ap;

     va_start (ap, fmt);
     AUD_log (AUDIO_CAP, fmt, ap);
     va_end (ap);

     coreaudio_logstatus (status);
 }

 static void GCC_FMT_ATTR (3, 4) coreaudio_logerr2 (
     OSStatus status,
     const char *typ,
     const char *fmt,
     ...
     )
 {
     va_list ap;

     AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);

     va_start (ap, fmt);
     AUD_vlog (AUDIO_CAP, fmt, ap);
     va_end (ap);

     coreaudio_logstatus (status);
 }

 static inline UInt32 isPlaying (AudioDeviceID outputDeviceID)
 {
     OSStatus status;
     UInt32 result = 0;
     UInt32 propertySize = sizeof(outputDeviceID);
     status = AudioDeviceGetProperty(
         outputDeviceID, 0, 0,
         kAudioDevicePropertyDeviceIsRunning, &propertySize, &result);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr(status,
                          "Could not determine whether Device is playing\n");
     }
     return result;
 }

 static void coreaudio_atexit (void)
 {
     conf.isAtexit = 1;
 }

 static int coreaudio_lock (coreaudioVoiceOut *core, const char *fn_name)
 {
     int err;

     err = pthread_mutex_lock (&core->mutex);
     if (err) {
         dolog ("Could not lock voice for %s\nReason: %s\n",
                fn_name, strerror (err));
         return -1;
     }
     return 0;
 }

 static int coreaudio_unlock (coreaudioVoiceOut *core, const char *fn_name)
 {
     int err;

     err = pthread_mutex_unlock (&core->mutex);
     if (err) {
         dolog ("Could not unlock voice for %s\nReason: %s\n",
                fn_name, strerror (err));
         return -1;
     }
     return 0;
 }

 static int coreaudio_run_out (HWVoiceOut *hw)
 {
     int live, decr;
     coreaudioVoiceOut *core = (coreaudioVoiceOut *) hw;

     if (coreaudio_lock (core, "coreaudio_run_out")) {
         return 0;
     }

     live = audio_pcm_hw_get_live_out (hw);

     if (core->decr > live) {
         ldebug ("core->decr %d live %d core->live %d\n",
                 core->decr,
                 live,
                 core->live);
     }

     decr = audio_MIN (core->decr, live);
     core->decr -= decr;

     core->live = live - decr;
     hw->rpos = core->rpos;

     coreaudio_unlock (core, "coreaudio_run_out");
     return decr;
 }

 /* callback to feed audiooutput buffer */
 static OSStatus audioDeviceIOProc(
     AudioDeviceID inDevice,
     const AudioTimeStamp* inNow,
     const AudioBufferList* inInputData,
     const AudioTimeStamp* inInputTime,
     AudioBufferList* outOutputData,
     const AudioTimeStamp* inOutputTime,
     void* hwptr)
 {
     UInt32 frame, frameCount;
     float *out = outOutputData->mBuffers[0].mData;
     HWVoiceOut *hw = hwptr;
     coreaudioVoiceOut *core = (coreaudioVoiceOut *) hwptr;
     int rpos, live;
     st_sample_t *src;
 #ifndef FLOAT_MIXENG
 #ifdef RECIPROCAL
     const float scale = 1.f / UINT_MAX;
 #else
     const float scale = UINT_MAX;
 #endif
 #endif

     if (coreaudio_lock (core, "audioDeviceIOProc")) {
         inInputTime = 0;
         return 0;
     }

     frameCount = core->audioDevicePropertyBufferFrameSize;
     live = core->live;

     /* if there are not enough samples, set signal and return */
     if (live < frameCount) {
         inInputTime = 0;
         coreaudio_unlock (core, "audioDeviceIOProc(empty)");
         return 0;
     }

     rpos = core->rpos;
     src = hw->mix_buf + rpos;

     /* fill buffer */
     for (frame = 0; frame < frameCount; frame++) {
 #ifdef FLOAT_MIXENG
         *out++ = src[frame].l; /* left channel */
         *out++ = src[frame].r; /* right channel */
 #else
 #ifdef RECIPROCAL
         *out++ = src[frame].l * scale; /* left channel */
         *out++ = src[frame].r * scale; /* right channel */
 #else
         *out++ = src[frame].l / scale; /* left channel */
         *out++ = src[frame].r / scale; /* right channel */
 #endif
 #endif
     }

     rpos = (rpos + frameCount) % hw->samples;
     core->decr += frameCount;
     core->rpos = rpos;

     coreaudio_unlock (core, "audioDeviceIOProc");
     return 0;
 }

 static int coreaudio_write (SWVoiceOut *sw, void *buf, int len)
 {
     return audio_pcm_sw_write (sw, buf, len);
 }

 static int coreaudio_init_out (HWVoiceOut *hw, audsettings_t *as)
 {
     OSStatus status;
     coreaudioVoiceOut *core = (coreaudioVoiceOut *) hw;
     UInt32 propertySize;
     int err;
     const char *typ = "playback";
     AudioValueRange frameRange;

     /* create mutex */
     err = pthread_mutex_init(&core->mutex, NULL);
     if (err) {
         dolog("Could not create mutex\nReason: %s\n", strerror (err));
         return -1;
     }

     audio_pcm_init_info (&hw->info, as);

     /* open default output device */
     propertySize = sizeof(core->outputDeviceID);
     status = AudioHardwareGetProperty(
         kAudioHardwarePropertyDefaultOutputDevice,
         &propertySize,
         &core->outputDeviceID);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ,
                            "Could not get default output Device\n");
         return -1;
     }
     if (core->outputDeviceID == kAudioDeviceUnknown) {
         dolog ("Could not initialize %s - Unknown Audiodevice\n", typ);
         return -1;
     }

     /* get minimum and maximum buffer frame sizes */
     propertySize = sizeof(frameRange);
     status = AudioDeviceGetProperty(
         core->outputDeviceID,
         0,
         0,
         kAudioDevicePropertyBufferFrameSizeRange,
         &propertySize,
         &frameRange);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ,
                            "Could not get device buffer frame range\n");
         return -1;
     }

     if (frameRange.mMinimum > conf.buffer_frames) {
         core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMinimum;
         dolog ("warning: Upsizing Buffer Frames to %f\n", frameRange.mMinimum);
     }
     else if (frameRange.mMaximum < conf.buffer_frames) {
         core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMaximum;
         dolog ("warning: Downsizing Buffer Frames to %f\n", frameRange.mMaximum);
     }
     else {
         core->audioDevicePropertyBufferFrameSize = conf.buffer_frames;
     }

     /* set Buffer Frame Size */
     propertySize = sizeof(core->audioDevicePropertyBufferFrameSize);
     status = AudioDeviceSetProperty(
         core->outputDeviceID,
         NULL,
         0,
         false,
         kAudioDevicePropertyBufferFrameSize,
         propertySize,
         &core->audioDevicePropertyBufferFrameSize);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ,
                            "Could not set device buffer frame size %ld\n",
                            core->audioDevicePropertyBufferFrameSize);
         return -1;
     }

     /* get Buffer Frame Size */
     propertySize = sizeof(core->audioDevicePropertyBufferFrameSize);
     status = AudioDeviceGetProperty(
         core->outputDeviceID,
         0,
         false,
         kAudioDevicePropertyBufferFrameSize,
         &propertySize,
         &core->audioDevicePropertyBufferFrameSize);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ,
                            "Could not get device buffer frame size\n");
         return -1;
     }
     hw->samples = conf.nbuffers * core->audioDevicePropertyBufferFrameSize;

     /* get StreamFormat */
     propertySize = sizeof(core->outputStreamBasicDescription);
     status = AudioDeviceGetProperty(
         core->outputDeviceID,
         0,
         false,
         kAudioDevicePropertyStreamFormat,
         &propertySize,
         &core->outputStreamBasicDescription);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ,
                            "Could not get Device Stream properties\n");
         core->outputDeviceID = kAudioDeviceUnknown;
         return -1;
     }

     /* set Samplerate */
     core->outputStreamBasicDescription.mSampleRate = (Float64) as->freq;
     propertySize = sizeof(core->outputStreamBasicDescription);
     status = AudioDeviceSetProperty(
         core->outputDeviceID,
         0,
         0,
         0,
         kAudioDevicePropertyStreamFormat,
         propertySize,
         &core->outputStreamBasicDescription);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ, "Could not set samplerate %d\n",
                            as->freq);
         core->outputDeviceID = kAudioDeviceUnknown;
         return -1;
     }

     /* set Callback */
     status = AudioDeviceAddIOProc(core->outputDeviceID, audioDeviceIOProc, hw);
     if (status != kAudioHardwareNoError) {
         coreaudio_logerr2 (status, typ, "Could not set IOProc\n");
         core->outputDeviceID = kAudioDeviceUnknown;
         return -1;
     }

     /* start Playback */
     if (!isPlaying(core->outputDeviceID)) {
         status = AudioDeviceStart(core->outputDeviceID, audioDeviceIOProc);
         if (status != kAudioHardwareNoError) {
             coreaudio_logerr2 (status, typ, "Could not start playback\n");
             AudioDeviceRemoveIOProc(core->outputDeviceID, audioDeviceIOProc);
             core->outputDeviceID = kAudioDeviceUnknown;
             return -1;
         }
     }

     return 0;
 }

 static void coreaudio_fini_out (HWVoiceOut *hw)
 {
     OSStatus status;
     int err;
     coreaudioVoiceOut *core = (coreaudioVoiceOut *) hw;

     if (!conf.isAtexit) {
         /* stop playback */
         if (isPlaying(core->outputDeviceID)) {
             status = AudioDeviceStop(core->outputDeviceID, audioDeviceIOProc);
             if (status != kAudioHardwareNoError) {
                 coreaudio_logerr (status, "Could not stop playback\n");
             }
         }

         /* remove callback */
         status = AudioDeviceRemoveIOProc(core->outputDeviceID,
                                          audioDeviceIOProc);
         if (status != kAudioHardwareNoError) {
             coreaudio_logerr (status, "Could not remove IOProc\n");
         }
     }
     core->outputDeviceID = kAudioDeviceUnknown;

     /* destroy mutex */
     err = pthread_mutex_destroy(&core->mutex);
     if (err) {
         dolog("Could not destroy mutex\nReason: %s\n", strerror (err));
     }
 }

 static int coreaudio_ctl_out (HWVoiceOut *hw, int cmd, ...)
 {
     OSStatus status;
     coreaudioVoiceOut *core = (coreaudioVoiceOut *) hw;

     switch (cmd) {
     case VOICE_ENABLE:
         /* start playback */
         if (!isPlaying(core->outputDeviceID)) {
             status = AudioDeviceStart(core->outputDeviceID, audioDeviceIOProc);
             if (status != kAudioHardwareNoError) {
                 coreaudio_logerr (status, "Could not resume playback\n");
             }
         }
         break;

     case VOICE_DISABLE:
         /* stop playback */
         if (!conf.isAtexit) {
             if (isPlaying(core->outputDeviceID)) {
                 status = AudioDeviceStop(core->outputDeviceID, audioDeviceIOProc);
                 if (status != kAudioHardwareNoError) {
                     coreaudio_logerr (status, "Could not pause playback\n");
                 }
             }
         }
         break;
     }
     return 0;
 }

 static void *coreaudio_audio_init (void)
 {
     atexit(coreaudio_atexit);
     return &coreaudio_audio_init;
 }

 static void coreaudio_audio_fini (void *opaque)
 {
     (void) opaque;
 }

 static struct audio_option coreaudio_options[] = {
     {"BUFFER_SIZE", AUD_OPT_INT, &conf.buffer_frames,
      "Size of the buffer in frames", NULL, 0},
     {"BUFFER_COUNT", AUD_OPT_INT, &conf.nbuffers,
      "Number of buffers", NULL, 0},
     {NULL, 0, NULL, NULL, NULL, 0}
 };

 static struct audio_pcm_ops coreaudio_pcm_ops = {
     coreaudio_init_out,
     coreaudio_fini_out,
     coreaudio_run_out,
     coreaudio_write,
     coreaudio_ctl_out,

     NULL,
     NULL,
     NULL,
     NULL,
     NULL
 };

 struct audio_driver coreaudio_audio_driver = {
     INIT_FIELD (name           = ) "coreaudio",
     INIT_FIELD (descr          = )
     "CoreAudio http://developer.apple.com/audio/coreaudio.html",
     INIT_FIELD (options        = ) coreaudio_options,
     INIT_FIELD (init           = ) coreaudio_audio_init,
     INIT_FIELD (fini           = ) coreaudio_audio_fini,
     INIT_FIELD (pcm_ops        = ) &coreaudio_pcm_ops,
     INIT_FIELD (can_be_default = ) 1,
     INIT_FIELD (max_voices_out = ) 1,
     INIT_FIELD (max_voices_in  = ) 0,
     INIT_FIELD (voice_size_out = ) sizeof (coreaudioVoiceOut),
     INIT_FIELD (voice_size_in  = ) 0
 };
	/*
	* QEMU OS X CoreAudio audio driver
	*
	* Copyright (c) 2005 Mike Kronenberg
	*
	* 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.
	*/

	#include <CoreAudio/CoreAudio.h>
	#include <string.h> /* strerror */
	#include <pthread.h> /* pthread_X */

	#include "vl.h"

	#define AUDIO_CAP "coreaudio"
	#include "audio_int.h"

	struct {
	int buffer_frames;
	int nbuffers;
	int isAtexit;
	} conf = {
	.buffer_frames = 512,
	.nbuffers = 4,
	.isAtexit = 0
	};

	typedef struct coreaudioVoiceOut {
	HWVoiceOut hw;
	pthread_mutex_t mutex;
	int isAtexit;
	AudioDeviceID outputDeviceID;
	UInt32 audioDevicePropertyBufferFrameSize;
	AudioStreamBasicDescription outputStreamBasicDescription;
	int live;
	int decr;
	int rpos;
	} coreaudioVoiceOut;

	static void coreaudio_logstatus (OSStatus status)
	{
	char *str = "BUG";

	switch(status) {
	case kAudioHardwareNoError:
	str = "kAudioHardwareNoError";
	break;

	case kAudioHardwareNotRunningError:
	str = "kAudioHardwareNotRunningError";
	break;

	case kAudioHardwareUnspecifiedError:
	str = "kAudioHardwareUnspecifiedError";
	break;

	case kAudioHardwareUnknownPropertyError:
	str = "kAudioHardwareUnknownPropertyError";
	break;

	case kAudioHardwareBadPropertySizeError:
	str = "kAudioHardwareBadPropertySizeError";
	break;

	case kAudioHardwareIllegalOperationError:
	str = "kAudioHardwareIllegalOperationError";
	break;

	case kAudioHardwareBadDeviceError:
	str = "kAudioHardwareBadDeviceError";
	break;

	case kAudioHardwareBadStreamError:
	str = "kAudioHardwareBadStreamError";
	break;

	case kAudioHardwareUnsupportedOperationError:
	str = "kAudioHardwareUnsupportedOperationError";
	break;

	case kAudioDeviceUnsupportedFormatError:
	str = "kAudioDeviceUnsupportedFormatError";
	break;

	case kAudioDevicePermissionsError:
	str = "kAudioDevicePermissionsError";
	break;

	default:
	AUD_log (AUDIO_CAP, "Reason: status code %ld\n", status);
	return;
	}

	AUD_log (AUDIO_CAP, "Reason: %s\n", str);
	}

	static void GCC_FMT_ATTR (2, 3) coreaudio_logerr (
	OSStatus status,
	const char *fmt,
	...
	)
	{
	va_list ap;

	va_start (ap, fmt);
	AUD_log (AUDIO_CAP, fmt, ap);
	va_end (ap);

	coreaudio_logstatus (status);
	}

	static void GCC_FMT_ATTR (3, 4) coreaudio_logerr2 (
	OSStatus status,
	const char *typ,
	const char *fmt,
	...
	)
	{
	va_list ap;

	AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);

	va_start (ap, fmt);
	AUD_vlog (AUDIO_CAP, fmt, ap);
	va_end (ap);

	coreaudio_logstatus (status);
	}

	static inline UInt32 isPlaying (AudioDeviceID outputDeviceID)
	{
	OSStatus status;
	UInt32 result = 0;
	UInt32 propertySize = sizeof(outputDeviceID);
	status = AudioDeviceGetProperty(
	outputDeviceID, 0, 0,
	kAudioDevicePropertyDeviceIsRunning, &propertySize, &result);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr(status,
	"Could not determine whether Device is playing\n");
	}
	return result;
	}

	static void coreaudio_atexit (void)
	{
	conf.isAtexit = 1;
	}

	static int coreaudio_lock (coreaudioVoiceOut core, const char fn_name)
	{
	int err;

	err = pthread_mutex_lock (&core->mutex);
	if (err) {
	dolog ("Could not lock voice for %s\nReason: %s\n",
	fn_name, strerror (err));
	return -1;
	}
	return 0;
	}

	static int coreaudio_unlock (coreaudioVoiceOut core, const char fn_name)
	{
	int err;

	err = pthread_mutex_unlock (&core->mutex);
	if (err) {
	dolog ("Could not unlock voice for %s\nReason: %s\n",
	fn_name, strerror (err));
	return -1;
	}
	return 0;
	}

	static int coreaudio_run_out (HWVoiceOut *hw)
	{
	int live, decr;
	coreaudioVoiceOut core = (coreaudioVoiceOut ) hw;

	if (coreaudio_lock (core, "coreaudio_run_out")) {
	return 0;
	}

	live = audio_pcm_hw_get_live_out (hw);

	if (core->decr > live) {
	ldebug ("core->decr %d live %d core->live %d\n",
	core->decr,
	live,
	core->live);
	}

	decr = audio_MIN (core->decr, live);
	core->decr -= decr;

	core->live = live - decr;
	hw->rpos = core->rpos;

	coreaudio_unlock (core, "coreaudio_run_out");
	return decr;
	}

	/* callback to feed audiooutput buffer */
	static OSStatus audioDeviceIOProc(
	AudioDeviceID inDevice,
	const AudioTimeStamp* inNow,
	const AudioBufferList* inInputData,
	const AudioTimeStamp* inInputTime,
	AudioBufferList* outOutputData,
	const AudioTimeStamp* inOutputTime,
	void* hwptr)
	{
	UInt32 frame, frameCount;
	float *out = outOutputData->mBuffers[0].mData;
	HWVoiceOut *hw = hwptr;
	coreaudioVoiceOut core = (coreaudioVoiceOut ) hwptr;
	int rpos, live;
	st_sample_t *src;
	#ifndef FLOAT_MIXENG
	#ifdef RECIPROCAL
	const float scale = 1.f / UINT_MAX;
	#else
	const float scale = UINT_MAX;
	#endif
	#endif

	if (coreaudio_lock (core, "audioDeviceIOProc")) {
	inInputTime = 0;
	return 0;
	}

	frameCount = core->audioDevicePropertyBufferFrameSize;
	live = core->live;

	/* if there are not enough samples, set signal and return */
	if (live < frameCount) {
	inInputTime = 0;
	coreaudio_unlock (core, "audioDeviceIOProc(empty)");
	return 0;
	}

	rpos = core->rpos;
	src = hw->mix_buf + rpos;

	/* fill buffer */
	for (frame = 0; frame < frameCount; frame++) {
	#ifdef FLOAT_MIXENG
	out++ = src[frame].l; / left channel */
	out++ = src[frame].r; / right channel */
	#else
	#ifdef RECIPROCAL
	out++ = src[frame].l scale; /* left channel */
	out++ = src[frame].r scale; /* right channel */
	#else
	out++ = src[frame].l / scale; / left channel */
	out++ = src[frame].r / scale; / right channel */
	#endif
	#endif
	}

	rpos = (rpos + frameCount) % hw->samples;
	core->decr += frameCount;
	core->rpos = rpos;

	coreaudio_unlock (core, "audioDeviceIOProc");
	return 0;
	}

	static int coreaudio_write (SWVoiceOut sw, void buf, int len)
	{
	return audio_pcm_sw_write (sw, buf, len);
	}

	static int coreaudio_init_out (HWVoiceOut hw, audsettings_t as)
	{
	OSStatus status;
	coreaudioVoiceOut core = (coreaudioVoiceOut ) hw;
	UInt32 propertySize;
	int err;
	const char *typ = "playback";
	AudioValueRange frameRange;

	/* create mutex */
	err = pthread_mutex_init(&core->mutex, NULL);
	if (err) {
	dolog("Could not create mutex\nReason: %s\n", strerror (err));
	return -1;
	}

	audio_pcm_init_info (&hw->info, as);

	/* open default output device */
	propertySize = sizeof(core->outputDeviceID);
	status = AudioHardwareGetProperty(
	kAudioHardwarePropertyDefaultOutputDevice,
	&propertySize,
	&core->outputDeviceID);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ,
	"Could not get default output Device\n");
	return -1;
	}
	if (core->outputDeviceID == kAudioDeviceUnknown) {
	dolog ("Could not initialize %s - Unknown Audiodevice\n", typ);
	return -1;
	}

	/* get minimum and maximum buffer frame sizes */
	propertySize = sizeof(frameRange);
	status = AudioDeviceGetProperty(
	core->outputDeviceID,
	0,
	0,
	kAudioDevicePropertyBufferFrameSizeRange,
	&propertySize,
	&frameRange);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ,
	"Could not get device buffer frame range\n");
	return -1;
	}

	if (frameRange.mMinimum > conf.buffer_frames) {
	core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMinimum;
	dolog ("warning: Upsizing Buffer Frames to %f\n", frameRange.mMinimum);
	}
	else if (frameRange.mMaximum < conf.buffer_frames) {
	core->audioDevicePropertyBufferFrameSize = (UInt32) frameRange.mMaximum;
	dolog ("warning: Downsizing Buffer Frames to %f\n", frameRange.mMaximum);
	}
	else {
	core->audioDevicePropertyBufferFrameSize = conf.buffer_frames;
	}

	/* set Buffer Frame Size */
	propertySize = sizeof(core->audioDevicePropertyBufferFrameSize);
	status = AudioDeviceSetProperty(
	core->outputDeviceID,
	NULL,
	0,
	false,
	kAudioDevicePropertyBufferFrameSize,
	propertySize,
	&core->audioDevicePropertyBufferFrameSize);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ,
	"Could not set device buffer frame size %ld\n",
	core->audioDevicePropertyBufferFrameSize);
	return -1;
	}

	/* get Buffer Frame Size */
	propertySize = sizeof(core->audioDevicePropertyBufferFrameSize);
	status = AudioDeviceGetProperty(
	core->outputDeviceID,
	0,
	false,
	kAudioDevicePropertyBufferFrameSize,
	&propertySize,
	&core->audioDevicePropertyBufferFrameSize);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ,
	"Could not get device buffer frame size\n");
	return -1;
	}
	hw->samples = conf.nbuffers * core->audioDevicePropertyBufferFrameSize;

	/* get StreamFormat */
	propertySize = sizeof(core->outputStreamBasicDescription);
	status = AudioDeviceGetProperty(
	core->outputDeviceID,
	0,
	false,
	kAudioDevicePropertyStreamFormat,
	&propertySize,
	&core->outputStreamBasicDescription);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ,
	"Could not get Device Stream properties\n");
	core->outputDeviceID = kAudioDeviceUnknown;
	return -1;
	}

	/* set Samplerate */
	core->outputStreamBasicDescription.mSampleRate = (Float64) as->freq;
	propertySize = sizeof(core->outputStreamBasicDescription);
	status = AudioDeviceSetProperty(
	core->outputDeviceID,
	0,
	0,
	0,
	kAudioDevicePropertyStreamFormat,
	propertySize,
	&core->outputStreamBasicDescription);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ, "Could not set samplerate %d\n",
	as->freq);
	core->outputDeviceID = kAudioDeviceUnknown;
	return -1;
	}

	/* set Callback */
	status = AudioDeviceAddIOProc(core->outputDeviceID, audioDeviceIOProc, hw);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ, "Could not set IOProc\n");
	core->outputDeviceID = kAudioDeviceUnknown;
	return -1;
	}

	/* start Playback */
	if (!isPlaying(core->outputDeviceID)) {
	status = AudioDeviceStart(core->outputDeviceID, audioDeviceIOProc);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr2 (status, typ, "Could not start playback\n");
	AudioDeviceRemoveIOProc(core->outputDeviceID, audioDeviceIOProc);
	core->outputDeviceID = kAudioDeviceUnknown;
	return -1;
	}
	}

	return 0;
	}

	static void coreaudio_fini_out (HWVoiceOut *hw)
	{
	OSStatus status;
	int err;
	coreaudioVoiceOut core = (coreaudioVoiceOut ) hw;

	if (!conf.isAtexit) {
	/* stop playback */
	if (isPlaying(core->outputDeviceID)) {
	status = AudioDeviceStop(core->outputDeviceID, audioDeviceIOProc);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr (status, "Could not stop playback\n");
	}
	}

	/* remove callback */
	status = AudioDeviceRemoveIOProc(core->outputDeviceID,
	audioDeviceIOProc);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr (status, "Could not remove IOProc\n");
	}
	}
	core->outputDeviceID = kAudioDeviceUnknown;

	/* destroy mutex */
	err = pthread_mutex_destroy(&core->mutex);
	if (err) {
	dolog("Could not destroy mutex\nReason: %s\n", strerror (err));
	}
	}

	static int coreaudio_ctl_out (HWVoiceOut *hw, int cmd, ...)
	{
	OSStatus status;
	coreaudioVoiceOut core = (coreaudioVoiceOut ) hw;

	switch (cmd) {
	case VOICE_ENABLE:
	/* start playback */
	if (!isPlaying(core->outputDeviceID)) {
	status = AudioDeviceStart(core->outputDeviceID, audioDeviceIOProc);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr (status, "Could not resume playback\n");
	}
	}
	break;

	case VOICE_DISABLE:
	/* stop playback */
	if (!conf.isAtexit) {
	if (isPlaying(core->outputDeviceID)) {
	status = AudioDeviceStop(core->outputDeviceID, audioDeviceIOProc);
	if (status != kAudioHardwareNoError) {
	coreaudio_logerr (status, "Could not pause playback\n");
	}
	}
	}
	break;
	}
	return 0;
	}

	static void *coreaudio_audio_init (void)
	{
	atexit(coreaudio_atexit);
	return &coreaudio_audio_init;
	}

	static void coreaudio_audio_fini (void *opaque)
	{
	(void) opaque;
	}

	static struct audio_option coreaudio_options[] = {
	{"BUFFER_SIZE", AUD_OPT_INT, &conf.buffer_frames,
	"Size of the buffer in frames", NULL, 0},
	{"BUFFER_COUNT", AUD_OPT_INT, &conf.nbuffers,
	"Number of buffers", NULL, 0},
	{NULL, 0, NULL, NULL, NULL, 0}
	};

	static struct audio_pcm_ops coreaudio_pcm_ops = {
	coreaudio_init_out,
	coreaudio_fini_out,
	coreaudio_run_out,
	coreaudio_write,
	coreaudio_ctl_out,

	NULL,
	NULL,
	NULL,
	NULL,
	NULL
	};

	struct audio_driver coreaudio_audio_driver = {
	INIT_FIELD (name = ) "coreaudio",
	INIT_FIELD (descr = )
	"CoreAudio http://developer.apple.com/audio/coreaudio.html",
	INIT_FIELD (options = ) coreaudio_options,
	INIT_FIELD (init = ) coreaudio_audio_init,
	INIT_FIELD (fini = ) coreaudio_audio_fini,
	INIT_FIELD (pcm_ops = ) &coreaudio_pcm_ops,
	INIT_FIELD (can_be_default = ) 1,
	INIT_FIELD (max_voices_out = ) 1,
	INIT_FIELD (max_voices_in = ) 0,
	INIT_FIELD (voice_size_out = ) sizeof (coreaudioVoiceOut),
	INIT_FIELD (voice_size_in = ) 0
	};