/*

SDL - Simple DirectMedia Layer

This library is free software; you can redistribute it and/or

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

You should have received a copy of the GNU Lesser 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

Sam Lantinga

slouken@libsdl.org

*/

#include <AudioUnit/AudioUnit.h>

#include "SDL_audio.h"

#include "../SDL_audio_c.h"

#include "../SDL_sysaudio.h"

#include "SDL_coreaudio.h"

typedef struct COREAUDIO_DeviceList

{

AudioDeviceID id;

const char *name;

} COREAUDIO_DeviceList;

static COREAUDIO_DeviceList *inputDevices = NULL;

static int inputDeviceCount = 0;

static COREAUDIO_DeviceList *outputDevices = NULL;

static int outputDeviceCount = 0;

if (*devices) {

int i = *devCount;

while (i--)

SDL_free((void *) (*devices)[i].name);

SDL_free(*devices);

*devices = NULL;

}

*devCount = 0;

}

build_device_list(int iscapture, COREAUDIO_DeviceList ** devices,

int *devCount)

Boolean outWritable = 0;

OSStatus result = noErr;

UInt32 size = 0;

AudioDeviceID *devs = NULL;

UInt32 i = 0;

UInt32 max = 0;

free_device_list(devices, devCount);

result = AudioHardwareGetPropertyInfo(kAudioHardwarePropertyDevices,

if (result != kAudioHardwareNoError)

return;

devs = (AudioDeviceID *) alloca(size);

if (devs == NULL)

return;

max = size / sizeof(AudioDeviceID);

*devices = (COREAUDIO_DeviceList *) SDL_malloc(max * sizeof(**devices));

if (*devices == NULL)

return;

result = AudioHardwareGetProperty(kAudioHardwarePropertyDevices,

if (result != kAudioHardwareNoError)

return;

for (i = 0; i < max; i++) {

CFStringRef cfstr = NULL;

char *ptr = NULL;

AudioDeviceID dev = devs[i];

AudioBufferList *buflist = NULL;

int usable = 0;

CFIndex len = 0;

result = AudioDeviceGetPropertyInfo(dev, 0, iscapture,

kAudioDevicePropertyStreamConfiguration,

&size, &outWritable);

if (result != noErr)

continue;

buflist = (AudioBufferList *) SDL_malloc(size);

if (buflist == NULL)

continue;

result = AudioDeviceGetProperty(dev, 0, iscapture,

kAudioDevicePropertyStreamConfiguration,

&size, buflist);

if (result == noErr) {

UInt32 j;

for (j = 0; j < buflist->mNumberBuffers; j++) {

if (buflist->mBuffers[j].mNumberChannels > 0) {

usable = 1;

break;

}

}

}

SDL_free(buflist);

if (!usable)

continue;

&size, &cfstr);

if (result != kAudioHardwareNoError)

continue;

len = CFStringGetMaximumSizeForEncoding(CFStringGetLength(cfstr),

kCFStringEncodingUTF8);

ptr = (char *) SDL_malloc(len + 1);

usable = ((ptr != NULL) &&

(CFStringGetCString

(cfstr, ptr, len + 1, kCFStringEncodingUTF8)));

CFRelease(cfstr);

if (usable) {

len = strlen(ptr);

/* Some devices have whitespace at the end...trim it. */

len--;

}

usable = (len > 0);

}

if (!usable) {

SDL_free(ptr);

} else {

ptr[len] = '\0';

((iscapture) ? "capture" : "output"),

(int) *devCount, ptr, (int) dev);

#endif

(*devices)[*devCount].id = dev;

(*devices)[*devCount].name = ptr;

(*devCount)++;

}

}

}

static inline void

build_device_lists(void)

build_device_list(0, &outputDevices, &outputDeviceCount);

build_device_list(1, &inputDevices, &inputDeviceCount);

}

static inline void

free_device_lists(void)

{

free_device_list(&outputDevices, &outputDeviceCount);

free_device_list(&inputDevices, &inputDeviceCount);

}

static int

{

int i = ((iscapture) ? inputDeviceCount : outputDeviceCount);

COREAUDIO_DeviceList *devs = ((iscapture) ? inputDevices : outputDevices);

while (i--) {

if (SDL_strcmp(devname, devs->name) == 0) {

*id = devs->id;

return 1;

}

return 0;

}

static int

COREAUDIO_DetectDevices(int iscapture)

{

if (iscapture) {

build_device_list(1, &inputDevices, &inputDeviceCount);

return inputDeviceCount;

} else {

build_device_list(0, &outputDevices, &outputDeviceCount);

return outputDeviceCount;

}

static const char *

COREAUDIO_GetDeviceName(int index, int iscapture)

{

if ((iscapture) && (index < inputDeviceCount)) {

return inputDevices[index].name;

} else if ((!iscapture) && (index < outputDeviceCount)) {

return outputDevices[index].name;

}

SDL_SetError("No such device");

return NULL;

}

static void

COREAUDIO_Deinitialize(void)

{

free_device_lists();

}

/* The CoreAudio callback */

AudioUnitRenderActionFlags * ioActionFlags,

const AudioTimeStamp * inTimeStamp,

UInt32 inBusNumber, UInt32 inNumberFrames,

AudioBufferList * ioDataList)

UInt32 remaining, len;

void *ptr;

/* Is there ever more than one buffer, and what do you do with it? */

if (ioDataList->mNumberBuffers != 1) {

return noErr;

}

return 0;

}

/* No SDL conversion should be needed here, ever, since we accept

any input format in OpenAudio, and leave the conversion to CoreAudio.

*/

assert(!this->convert.needed);

assert(this->spec.channels == ioData->mNumberChannels);

remaining = ioData->mDataByteSize;

ptr = ioData->mData;

while (remaining > 0) {

SDL_memset(this->hidden->buffer, this->spec.silence,

this->hidden->bufferSize);

(*this->spec.callback) (this->spec.userdata, this->hidden->buffer,

this->hidden->bufferSize);

if (len > remaining)

len = remaining;

(char *) this->hidden->buffer + this->hidden->bufferOffset,

len);

return 0;

}

static OSStatus

inputCallback(void *inRefCon,

const AudioTimeStamp * inTimeStamp,

UInt32 inBusNumber, UInt32 inNumberFrames,

//err = AudioUnitRender(afr->fAudioUnit, ioActionFlags, inTimeStamp, inBusNumber, inNumberFrames, afr->fAudioBuffer);

// !!! FIXME: write me!

return noErr;

}

static void

COREAUDIO_CloseDevice(_THIS)

if (this->hidden->audioUnitOpened) {

OSStatus result = noErr;

AURenderCallbackStruct callback;

const AudioUnitElement output_bus = 0;

const AudioUnitElement input_bus = 1;

const int iscapture = this->iscapture;

const AudioUnitElement bus =

((iscapture) ? input_bus : output_bus);

const AudioUnitScope scope =

((iscapture) ? kAudioUnitScope_Output :

kAudioUnitScope_Input);

/* stop processing the audio unit */

result = AudioOutputUnitStop(this->hidden->audioUnit);

/* Remove the input callback */

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioUnitProperty_SetRenderCallback,

scope, bus, &callback,

CloseComponent(this->hidden->audioUnit);

this->hidden->audioUnitOpened = 0;

}

SDL_free(this->hidden->buffer);

SDL_free(this->hidden);

this->hidden = NULL;

}

}

#define CHECK_RESULT(msg) \

if (result != noErr) { \

COREAUDIO_CloseDevice(this); \

SDL_SetError("CoreAudio error (%s): %d", msg, (int) result); \

return 0; \

}

static int

find_device_by_name(_THIS, const char *devname, int iscapture)

{

AudioDeviceID devid = 0;

OSStatus result = noErr;

UInt32 size = 0;

UInt32 alive = 0;

pid_t pid = 0;

if (devname == NULL) {

((iscapture) ? kAudioHardwarePropertyDefaultInputDevice :

kAudioHardwarePropertyDefaultOutputDevice);

result = AudioHardwareGetProperty(propid, &size, &devid);

CHECK_RESULT("AudioHardwareGetProperty (default device)");

} else {

if (!find_device_id(devname, iscapture, &devid)) {

SDL_SetError("CoreAudio: No such audio device.");

return 0;

}

}

result = AudioDeviceGetProperty(devid, 0, iscapture,

kAudioDevicePropertyDeviceIsAlive,

&size, &alive);

CHECK_RESULT

("AudioDeviceGetProperty (kAudioDevicePropertyDeviceIsAlive)");

if (!alive) {

SDL_SetError("CoreAudio: requested device exists, but isn't alive.");

return 0;

result = AudioDeviceGetProperty(devid, 0, iscapture,

kAudioDevicePropertyHogMode, &size, &pid);

/* some devices don't support this property, so errors are fine here. */

if ((result == noErr) && (pid != -1)) {

SDL_SetError("CoreAudio: requested device is being hogged.");

return 0;

}

this->hidden->deviceID = devid;

return 1;

}

static int

prepare_audiounit(_THIS, const char *devname, int iscapture,

{

OSStatus result = noErr;

Component comp = NULL;

int use_system_device = 0;

UInt32 enableIO = 0;

const AudioUnitElement output_bus = 0;

const AudioUnitElement input_bus = 1;

const AudioUnitElement bus = ((iscapture) ? input_bus : output_bus);

const AudioUnitScope scope = ((iscapture) ? kAudioUnitScope_Output :

if (!find_device_by_name(this, devname, iscapture)) {

SDL_SetError("Couldn't find requested CoreAudio device");

return 0;

}

SDL_memset(&desc, '\0', sizeof(ComponentDescription));

desc.componentType = kAudioUnitType_Output;

desc.componentSubType = kAudioUnitSubType_HALOutput;

desc.componentManufacturer = kAudioUnitManufacturer_Apple;

comp = FindNextComponent(NULL, &desc);

if (comp == NULL) {

SDL_SetError("Couldn't find requested CoreAudio component");

return 0;

}

/* Open & initialize the audio unit */

result = OpenAComponent(comp, &this->hidden->audioUnit);

CHECK_RESULT("OpenAComponent");

this->hidden->audioUnitOpened = 1;

// !!! FIXME: this is wrong?

enableIO = ((iscapture) ? 1 : 0);

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioOutputUnitProperty_EnableIO,

kAudioUnitScope_Input, input_bus,

CHECK_RESULT("AudioUnitSetProperty (kAudioUnitProperty_EnableIO input)");

// !!! FIXME: this is wrong?

enableIO = ((iscapture) ? 0 : 1);

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioOutputUnitProperty_EnableIO,

kAudioUnitScope_Output, output_bus,

CHECK_RESULT("AudioUnitSetProperty (kAudioUnitProperty_EnableIO output)");

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioOutputUnitProperty_CurrentDevice,

kAudioUnitScope_Global, 0,

&this->hidden->deviceID,

sizeof(AudioDeviceID));

CHECK_RESULT

("AudioUnitSetProperty (kAudioOutputUnitProperty_CurrentDevice)");

/* Set the data format of the audio unit. */

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioUnitProperty_StreamFormat,

CHECK_RESULT("AudioUnitSetProperty (kAudioUnitProperty_StreamFormat)");

/* Set the audio callback */

callback.inputProc = ((iscapture) ? inputCallback : outputCallback);

callback.inputProcRefCon = this;

result = AudioUnitSetProperty(this->hidden->audioUnit,

kAudioUnitProperty_SetRenderCallback,

scope, bus, &callback, sizeof(callback));

CHECK_RESULT

("AudioUnitSetProperty (kAudioUnitProperty_SetInputCallback)");

/* Calculate the final parameters for this audio specification */

SDL_CalculateAudioSpec(&this->spec);

/* Allocate a sample buffer */

this->hidden->bufferOffset = this->hidden->bufferSize = this->spec.size;

this->hidden->buffer = SDL_malloc(this->hidden->bufferSize);

result = AudioUnitInitialize(this->hidden->audioUnit);

CHECK_RESULT("AudioUnitInitialize");

/* Finally, start processing of the audio unit */

result = AudioOutputUnitStart(this->hidden->audioUnit);

CHECK_RESULT("AudioOutputUnitStart");

/* We're running! */

return 1;

}

static int

COREAUDIO_OpenDevice(_THIS, const char *devname, int iscapture)

{

/* Initialize all variables that we clean on shutdown */

this->hidden = (struct SDL_PrivateAudioData *)

if (this->hidden == NULL) {

SDL_OutOfMemory();

return (0);

}

SDL_memset(this->hidden, 0, (sizeof *this->hidden));

strdesc.mFormatID = kAudioFormatLinearPCM;

strdesc.mFormatFlags = kLinearPCMFormatFlagIsPacked;

strdesc.mChannelsPerFrame = this->spec.channels;

strdesc.mSampleRate = this->spec.freq;

while ((!valid_datatype) && (test_format)) {

/* Just a list of valid SDL formats, so people don't pass junk here. */

switch (test_format) {

case AUDIO_U8:

case AUDIO_S8:

case AUDIO_U16LSB:

case AUDIO_S16LSB:

case AUDIO_U16MSB:

case AUDIO_S16MSB:

case AUDIO_S32LSB:

case AUDIO_S32MSB:

case AUDIO_F32LSB:

case AUDIO_F32MSB:

valid_datatype = 1;

strdesc.mBitsPerChannel = SDL_AUDIO_BITSIZE(this->spec.format);

if (SDL_AUDIO_ISBIGENDIAN(this->spec.format))

strdesc.mFormatFlags |= kLinearPCMFormatFlagIsBigEndian;

strdesc.mFormatFlags |= kLinearPCMFormatFlagIsSignedInteger;

break;

}

}

strdesc.mBytesPerFrame =

strdesc.mBitsPerChannel * strdesc.mChannelsPerFrame / 8;

strdesc.mBytesPerPacket =

strdesc.mBytesPerFrame * strdesc.mFramesPerPacket;

{

/* Set the function pointers */

impl->DetectDevices = COREAUDIO_DetectDevices;

impl->GetDeviceName = COREAUDIO_GetDeviceName;

impl->OpenDevice = COREAUDIO_OpenDevice;

impl->CloseDevice = COREAUDIO_CloseDevice;

impl->Deinitialize = COREAUDIO_Deinitialize;

impl->ProvidesOwnCallbackThread = 1;

return 1;

AudioBootStrap COREAUDIO_bootstrap = {

"coreaudio", "Mac OS X CoreAudio", COREAUDIO_Init, 0

};