cocoa_s.cpp

00001 /* $Id: cocoa_s.cpp 11694 2007-12-25 13:28:09Z rubidium $ */
00002 
00003 /*****************************************************************************
00004  *                             Cocoa sound driver                            *
00005  * Known things left to do:                                                  *
00006  * - Might need to do endian checking for it to work on both ppc and x86     *
00007  *****************************************************************************/
00008 
00009 #ifdef WITH_COCOA
00010 
00011 #define MAC_OS_X_VERSION_MIN_REQUIRED    MAC_OS_X_VERSION_10_3
00012 #include <AvailabilityMacros.h>
00013 
00014 #include <AudioUnit/AudioUnit.h>
00015 
00016 /* Name conflict */
00017 #define Rect        OTTDRect
00018 #define Point       OTTDPoint
00019 #define WindowClass OTTDWindowClass
00020 
00021 #include "../stdafx.h"
00022 #include "../debug.h"
00023 #include "../driver.h"
00024 #include "../mixer.h"
00025 #include "../core/endian_func.hpp"
00026 
00027 #include "cocoa_s.h"
00028 
00029 #undef WindowClass
00030 #undef Point
00031 #undef Rect
00032 
00033 static FSoundDriver_Cocoa iFSoundDriver_Cocoa;
00034 
00035 static AudioUnit _outputAudioUnit;
00036 
00037 /* The CoreAudio callback */
00038 static OSStatus audioCallback(void *inRefCon, AudioUnitRenderActionFlags *inActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32 inNumberFrames, AudioBufferList * ioData)
00039 {
00040   MxMixSamples(ioData->mBuffers[0].mData, ioData->mBuffers[0].mDataByteSize / 4);
00041 
00042   return noErr;
00043 }
00044 
00045 
00046 const char *SoundDriver_Cocoa::Start(const char * const *parm)
00047 {
00048   Component comp;
00049   ComponentDescription desc;
00050   struct AURenderCallbackStruct callback;
00051   AudioStreamBasicDescription requestedDesc;
00052 
00053   /* Setup a AudioStreamBasicDescription with the requested format */
00054   requestedDesc.mFormatID = kAudioFormatLinearPCM;
00055   requestedDesc.mFormatFlags = kLinearPCMFormatFlagIsPacked;
00056   requestedDesc.mChannelsPerFrame = 2;
00057   requestedDesc.mSampleRate = GetDriverParamInt(parm, "hz", 11025);
00058 
00059   requestedDesc.mBitsPerChannel = 16;
00060   requestedDesc.mFormatFlags |= kLinearPCMFormatFlagIsSignedInteger;
00061 
00062 #ifdef TTD_BIG_ENDIAN
00063   requestedDesc.mFormatFlags |= kLinearPCMFormatFlagIsBigEndian;
00064 #endif
00065 
00066   requestedDesc.mFramesPerPacket = 1;
00067   requestedDesc.mBytesPerFrame = requestedDesc.mBitsPerChannel * requestedDesc.mChannelsPerFrame / 8;
00068   requestedDesc.mBytesPerPacket = requestedDesc.mBytesPerFrame * requestedDesc.mFramesPerPacket;
00069 
00070 
00071   /* Locate the default output audio unit */
00072   desc.componentType = kAudioUnitType_Output;
00073   desc.componentSubType = kAudioUnitSubType_HALOutput;
00074   desc.componentManufacturer = kAudioUnitManufacturer_Apple;
00075   desc.componentFlags = 0;
00076   desc.componentFlagsMask = 0;
00077 
00078   comp = FindNextComponent (NULL, &desc);
00079   if (comp == NULL) {
00080     return "cocoa_s: Failed to start CoreAudio: FindNextComponent returned NULL";
00081   }
00082 
00083   /* Open & initialize the default output audio unit */
00084   if (OpenAComponent(comp, &_outputAudioUnit) != noErr) {
00085     return "cocoa_s: Failed to start CoreAudio: OpenAComponent";
00086   }
00087 
00088   if (AudioUnitInitialize(_outputAudioUnit) != noErr) {
00089     return "cocoa_s: Failed to start CoreAudio: AudioUnitInitialize";
00090   }
00091 
00092   /* Set the input format of the audio unit. */
00093   if (AudioUnitSetProperty(_outputAudioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &requestedDesc, sizeof(requestedDesc)) != noErr) {
00094     return "cocoa_s: Failed to start CoreAudio: AudioUnitSetProperty (kAudioUnitProperty_StreamFormat)";
00095   }
00096 
00097   /* Set the audio callback */
00098   callback.inputProc = audioCallback;
00099   callback.inputProcRefCon = NULL;
00100   if (AudioUnitSetProperty(_outputAudioUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Input, 0, &callback, sizeof(callback)) != noErr) {
00101     return "cocoa_s: Failed to start CoreAudio: AudioUnitSetProperty (kAudioUnitProperty_SetRenderCallback)";
00102   }
00103 
00104   /* Finally, start processing of the audio unit */
00105   if (AudioOutputUnitStart(_outputAudioUnit) != noErr) {
00106     return "cocoa_s: Failed to start CoreAudio: AudioOutputUnitStart";
00107   }
00108 
00109   /* We're running! */
00110   return NULL;
00111 }
00112 
00113 
00114 void SoundDriver_Cocoa::Stop()
00115 {
00116   struct AURenderCallbackStruct callback;
00117 
00118   /* stop processing the audio unit */
00119   if (AudioOutputUnitStop(_outputAudioUnit) != noErr) {
00120     DEBUG(driver, 0, "cocoa_s: Core_CloseAudio: AudioOutputUnitStop failed");
00121     return;
00122   }
00123 
00124   /* Remove the input callback */
00125   callback.inputProc = 0;
00126   callback.inputProcRefCon = 0;
00127   if (AudioUnitSetProperty(_outputAudioUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Input, 0, &callback, sizeof(callback)) != noErr) {
00128     DEBUG(driver, 0, "cocoa_s: Core_CloseAudio: AudioUnitSetProperty (kAudioUnitProperty_SetRenderCallback) failed");
00129     return;
00130   }
00131 
00132   if (CloseComponent(_outputAudioUnit) != noErr) {
00133     DEBUG(driver, 0, "cocoa_s: Core_CloseAudio: CloseComponent failed");
00134     return;
00135   }
00136 }
00137 
00138 #endif /* WITH_COCOA */

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