nkeynes@964: /**
nkeynes@964:  * $Id$
nkeynes@964:  * 
nkeynes@964:  * The darwin core-audio audio driver
nkeynes@964:  *
nkeynes@964:  * Copyright (c) 2008 Nathan Keynes.
nkeynes@964:  *
nkeynes@964:  * This program is free software; you can redistribute it and/or modify
nkeynes@964:  * it under the terms of the GNU General Public License as published by
nkeynes@964:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@964:  * (at your option) any later version.
nkeynes@964:  *
nkeynes@964:  * This program is distributed in the hope that it will be useful,
nkeynes@964:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@964:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@964:  * GNU General Public License for more details.
nkeynes@964:  */
nkeynes@964: #include <stdio.h>
nkeynes@964: #include <unistd.h>
nkeynes@964: #include <CoreAudio/CoreAudio.h>
nkeynes@964: #include "aica/audio.h"
nkeynes@964: #include "lxdream.h"
nkeynes@964: 
nkeynes@964: #define BUFFER_SIZE (sizeof(float)*2*2205)
nkeynes@964: 
nkeynes@964: static AudioDeviceID output_device;
nkeynes@964: static volatile audio_buffer_t output_buffer = NULL;
nkeynes@964: static uint32_t buffer_size;
nkeynes@964: 
nkeynes@1024: static OSStatus audio_osx_callback( AudioDeviceID inDevice,
nkeynes@964:                              const AudioTimeStamp *inNow,
nkeynes@964:                              const AudioBufferList *inInputData,
nkeynes@964:                              const AudioTimeStamp *inInputTime,
nkeynes@964:                              AudioBufferList *outOutputData,
nkeynes@964:                              const AudioTimeStamp *inOutputTime,
nkeynes@964:                              void *inClientData)
nkeynes@964: {
nkeynes@964:     char *output = outOutputData->mBuffers[0].mData;
nkeynes@964:     int data_requested = buffer_size;
nkeynes@964: 
nkeynes@964:     while( output_buffer != NULL && data_requested > 0 ) {
nkeynes@964:         int copysize = output_buffer->length - output_buffer->posn;
nkeynes@964:         if( copysize > data_requested ) {
nkeynes@964:             copysize = data_requested;
nkeynes@964:         }
nkeynes@964:         memcpy( output, &output_buffer->data[output_buffer->posn], copysize );
nkeynes@964:         output += copysize;
nkeynes@964:         data_requested -= copysize;
nkeynes@964:         output_buffer->posn += copysize;
nkeynes@964:         if( output_buffer->posn >= output_buffer->length ) {
nkeynes@964:             output_buffer = audio_next_read_buffer();
nkeynes@964:         }
nkeynes@964:     }
nkeynes@964:     if( data_requested > 0 ) {
nkeynes@964:         memset( output, 0, data_requested );
nkeynes@964:     }
nkeynes@964:     return noErr;
nkeynes@964: }
nkeynes@964: 
nkeynes@964: static gboolean audio_osx_shutdown()
nkeynes@964: {
nkeynes@964:     AudioDeviceStop( output_device, audio_osx_callback );
nkeynes@964:     AudioDeviceRemoveIOProc( output_device, audio_osx_callback );
nkeynes@964:     return TRUE;
nkeynes@964: }
nkeynes@964: 
nkeynes@964: static gboolean audio_osx_init()
nkeynes@964: {
nkeynes@964:     UInt32 size = sizeof(output_device);
nkeynes@964:     AudioStreamBasicDescription outputDesc;
nkeynes@964:     UInt32 outputDescSize = sizeof(outputDesc);
nkeynes@964: 
nkeynes@964:     if( AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice,
nkeynes@964:             &size, &output_device) != noErr ||
nkeynes@964:             output_device == kAudioDeviceUnknown ) {
nkeynes@964:         return FALSE;
nkeynes@964:     }
nkeynes@964: 
nkeynes@964:     if( AudioDeviceGetProperty( output_device, 1, 0, kAudioDevicePropertyStreamFormat,
nkeynes@964:             &outputDescSize, &outputDesc ) != noErr ) {
nkeynes@964:         return FALSE;
nkeynes@964:     }
nkeynes@964: 
nkeynes@964:     buffer_size = BUFFER_SIZE;
nkeynes@964: 
nkeynes@964:     if( AudioDeviceSetProperty( output_device, 0, 0, 0, kAudioDevicePropertyBufferSize,
nkeynes@964:             sizeof(buffer_size), &buffer_size ) != noErr ) {
nkeynes@964:         return FALSE;
nkeynes@964:     }
nkeynes@964: 
nkeynes@964:     AudioDeviceAddIOProc( output_device, audio_osx_callback, NULL );    
nkeynes@964:     return TRUE;
nkeynes@964: }
nkeynes@964: static gboolean audio_osx_process_buffer( audio_buffer_t buffer )
nkeynes@964: {
nkeynes@964:     if( output_buffer == NULL ) {
nkeynes@964:         output_buffer = buffer;
nkeynes@964:         output_buffer->posn = 0;
nkeynes@964:         AudioDeviceStart(output_device, audio_osx_callback);
nkeynes@964:     }
nkeynes@964:     return FALSE;
nkeynes@964: }
nkeynes@964: 
nkeynes@1024: static void audio_osx_start()
nkeynes@964: {
nkeynes@964:     if( output_buffer != NULL ) {
nkeynes@964:         AudioDeviceStart(output_device, audio_osx_callback);
nkeynes@964:     }
nkeynes@964: }
nkeynes@964: 
nkeynes@1024: static void audio_osx_stop()
nkeynes@964: {
nkeynes@964:     AudioDeviceStop( output_device, audio_osx_callback );
nkeynes@964: }
nkeynes@964: 
nkeynes@964: 
nkeynes@1024: static struct audio_driver audio_osx_driver = { 
nkeynes@964:         "osx",
nkeynes@964:         N_("OS X CoreAudio system driver"), 
nkeynes@1024:         1, // Preferred on OS X
nkeynes@964:         DEFAULT_SAMPLE_RATE,
nkeynes@964:         AUDIO_FMT_FLOATST,
nkeynes@964:         audio_osx_init,
nkeynes@964:         audio_osx_start, 
nkeynes@964:         audio_osx_process_buffer,
nkeynes@964:         audio_osx_stop,
nkeynes@964:         audio_osx_shutdown};
nkeynes@964: 
nkeynes@1024: AUDIO_DRIVER( "osx", audio_osx_driver );