112 lines
3.6 KiB
Objective-C
112 lines
3.6 KiB
Objective-C
#import <Foundation/Foundation.h>
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#import <AudioToolbox/AudioToolbox.h>
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#import "GBAudioClient.h"
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static OSStatus render(
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GBAudioClient *self,
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AudioUnitRenderActionFlags *ioActionFlags,
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const AudioTimeStamp *inTimeStamp,
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UInt32 inBusNumber,
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UInt32 inNumberFrames,
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AudioBufferList *ioData)
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{
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GB_sample_t *buffer = (GB_sample_t *)ioData->mBuffers[0].mData;
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self.renderBlock(self.rate, inNumberFrames, buffer);
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return noErr;
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}
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@implementation GBAudioClient
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{
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AudioComponentInstance audioUnit;
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}
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-(id) initWithRendererBlock:(void (^)(UInt32 sampleRate, UInt32 nFrames, GB_sample_t *buffer)) block
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andSampleRate:(UInt32) rate
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{
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if (!(self = [super init])) {
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return nil;
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}
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// Configure the search parameters to find the default playback output unit
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// (called the kAudioUnitSubType_RemoteIO on iOS but
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// kAudioUnitSubType_DefaultOutput on Mac OS X)
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AudioComponentDescription defaultOutputDescription;
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defaultOutputDescription.componentType = kAudioUnitType_Output;
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defaultOutputDescription.componentSubType = kAudioUnitSubType_DefaultOutput;
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defaultOutputDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
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defaultOutputDescription.componentFlags = 0;
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defaultOutputDescription.componentFlagsMask = 0;
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// Get the default playback output unit
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AudioComponent defaultOutput = AudioComponentFindNext(NULL, &defaultOutputDescription);
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NSAssert(defaultOutput, @"Can't find default output");
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// Create a new unit based on this that we'll use for output
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OSErr err = AudioComponentInstanceNew(defaultOutput, &audioUnit);
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NSAssert1(audioUnit, @"Error creating unit: %hd", err);
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// Set our tone rendering function on the unit
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AURenderCallbackStruct input;
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input.inputProc = (void*)render;
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input.inputProcRefCon = (__bridge void * _Nullable)(self);
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err = AudioUnitSetProperty(audioUnit,
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kAudioUnitProperty_SetRenderCallback,
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kAudioUnitScope_Input,
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0,
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&input,
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sizeof(input));
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NSAssert1(err == noErr, @"Error setting callback: %hd", err);
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AudioStreamBasicDescription streamFormat;
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streamFormat.mSampleRate = rate;
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streamFormat.mFormatID = kAudioFormatLinearPCM;
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streamFormat.mFormatFlags =
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kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked | kAudioFormatFlagsNativeEndian;
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streamFormat.mBytesPerPacket = 4;
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streamFormat.mFramesPerPacket = 1;
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streamFormat.mBytesPerFrame = 4;
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streamFormat.mChannelsPerFrame = 2;
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streamFormat.mBitsPerChannel = 2 * 8;
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err = AudioUnitSetProperty (audioUnit,
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kAudioUnitProperty_StreamFormat,
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kAudioUnitScope_Input,
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0,
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&streamFormat,
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sizeof(AudioStreamBasicDescription));
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NSAssert1(err == noErr, @"Error setting stream format: %hd", err);
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err = AudioUnitInitialize(audioUnit);
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NSAssert1(err == noErr, @"Error initializing unit: %hd", err);
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self.renderBlock = block;
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_rate = rate;
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return self;
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}
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-(void) start
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{
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OSErr err = AudioOutputUnitStart(audioUnit);
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NSAssert1(err == noErr, @"Error starting unit: %hd", err);
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_playing = true;
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}
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-(void) stop
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{
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AudioOutputUnitStop(audioUnit);
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_playing = false;
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}
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-(void) dealloc
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{
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[self stop];
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AudioUnitUninitialize(audioUnit);
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AudioComponentInstanceDispose(audioUnit);
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}
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@end
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