任何人都可以帮我通过音频单元录制iPhone输出声音 [英] Can anybody help me in recording iPhone output sound through Audio Unit
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问题描述
这是我的代码：
i使用此代码通过使用Audio Unit
记录iPhone输出音频，然后将输出保存在output.caf中，但output.caf文件为空
any身体知道我该怎么办？
输出音频文件为空
this is my code : i use this code to record the iPhone output audio by using Audio Unit then saving the output in output.caf but the output.caf file is empty any body have idea about what shall i do ? the output audio file is empty
这是音频单元的初始化
-(void) initializaeOutputUnit
{
OSStatus status;
// Describe audio component
AudioComponentDescription desc;
desc.componentType = kAudioUnitType_Output;
desc.componentSubType = kAudioUnitSubType_RemoteIO;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
desc.componentManufacturer = kAudioUnitManufacturer_Apple;
// Get component
AudioComponent inputComponent = AudioComponentFindNext(NULL, &desc);
// Get audio units
status = AudioComponentInstanceNew(inputComponent, &audioUnit);
// Enable IO for recording
UInt32 flag = 1;
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Input,
kInputBus,
&flag,
sizeof(flag));
// Enable IO for playback
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Output,
kOutputBus,
&flag,
sizeof(flag));
// Describe format
AudioStreamBasicDescription audioFormat={0};
audioFormat.mSampleRate = 44100.00;
audioFormat.mFormatID = kAudioFormatLinearPCM;
audioFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
audioFormat.mFramesPerPacket = 1;
audioFormat.mChannelsPerFrame = 1;
audioFormat.mBitsPerChannel = 16;
audioFormat.mBytesPerPacket = 2;
audioFormat.mBytesPerFrame = 2;
// Apply format
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output,
kInputBus,
&audioFormat,
sizeof(audioFormat));
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Input,
kOutputBus,
&audioFormat,
sizeof(audioFormat));
// Set input callback
AURenderCallbackStruct callbackStruct;
callbackStruct.inputProc = recordingCallback;
callbackStruct.inputProcRefCon = self;
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Global,
kInputBus,
&callbackStruct,
sizeof(callbackStruct));
// Set output callback
callbackStruct.inputProc = playbackCallback;
callbackStruct.inputProcRefCon = self;
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Global,
kOutputBus,
&callbackStruct,
sizeof(callbackStruct));
// Disable buffer allocation for the recorder (optional - do this if we want to pass in our own)
flag = 0;
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_ShouldAllocateBuffer,
kAudioUnitScope_Output,
kInputBus,
&flag,
sizeof(flag));
AudioUnitInitialize(audioUnit);
AudioOutputUnitStart(audioUnit);
// On initialise le fichier audio
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *destinationFilePath = [[[NSString alloc] initWithFormat: @"%@/output.caf", documentsDirectory] autorelease];
NSLog(@">>> %@", destinationFilePath);
CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)destinationFilePath, kCFURLPOSIXPathStyle, false);
OSStatus setupErr = ExtAudioFileCreateWithURL(destinationURL, kAudioFileWAVEType, &audioFormat, NULL, kAudioFileFlags_EraseFile, &effectState.audioFileRef);
CFRelease(destinationURL);
NSAssert(setupErr == noErr, @"Couldn't create file for writing");
setupErr = ExtAudioFileSetProperty(effectState.audioFileRef, kExtAudioFileProperty_ClientDataFormat, sizeof(AudioStreamBasicDescription), &audioFormat);
NSAssert(setupErr == noErr, @"Couldn't create file for format");
setupErr = ExtAudioFileWriteAsync(effectState.audioFileRef, 0, NULL);
NSAssert(setupErr == noErr, @"Couldn't initialize write buffers for audio file");
}
录音回拨
static OSStatus recordingCallback (void * inRefCon,
AudioUnitRenderActionFlags * ioActionFlags,
const AudioTimeStamp * inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList * ioData) {
NSLog(@"callback");
if (*ioActionFlags == kAudioUnitRenderAction_PostRender&&inBusNumber==0)
{
AudioBufferList *bufferList; // <- Fill this up with buffers (you will want to malloc it, as it's a dynamic-length list)
EffectState *effectState = (EffectState *)inRefCon;
AudioUnit rioUnit =[(MixerHostAudio*)inRefCon getAudioUnit];
OSStatus status;
NSLog(@"de5eal el call back ");
// BELOW I GET THE ERROR
status = AudioUnitRender( rioUnit,
ioActionFlags,
inTimeStamp,
inBusNumber,
inNumberFrames,
bufferList);
if (noErr != status) { NSLog(@"AudioUnitRender error"); return noErr;}
// Now, we have the samples we just read sitting in buffers in bufferList
ExtAudioFileWriteAsync(effectState->audioFileRef, inNumberFrames, bufferList);
}
return noErr;
}
// then stop Recording
- (void) stopRecord
{
AudioOutputUnitStop(audioUnit);
AudioUnitUninitialize(audioUnit);
}
推荐答案
在 initializaeOutputUnit 您只创建了音频文件：
In initializaeOutputUnit you only created your audio file:
OSStatus setupErr = ExtAudioFileCreateWithURL(destinationURL, kAudioFileWAVEType, &audioFormat, NULL, kAudioFileFlags_EraseFile, &effectState.audioFileRef);
传递 0 （帧）和 NULL （audiobuffer）仅适用于init内部缓冲区：
by passing 0 (frames) and NULL (audiobuffer) is just for init internal buffers:
setupErr = ExtAudioFileWriteAsync(effectState.audioFileRef, 0, NULL);
这是 recordingCallback 中出现的问题：
1）ioActionFlags始终为0且inBusNumber始终为1，因为这就是你如何设置回调（kInputBus = 1）：
1) ioActionFlags are always 0 and inBusNumber are always 1, because thats how you setup your callback (kInputBus = 1):
if (*ioActionFlags == kAudioUnitRenderAction_PostRender&&inBusNumber==0)
所以只需删除if语句。
so just remove the if statement.
2）从 AudioUnitRender ，您将收到 -50错误，这是在CoreAudioTypes.h中定义为 kAudio_ParamError 错误。这是因为bufferList没有定义而且是NULL！
2) From AudioUnitRender you will receive -50 error, which is defined in CoreAudioTypes.h as an kAudio_ParamError error. This happens by bufferList is not defined and NULL!
OSStatus status;
status = AudioUnitRender(THIS->mAudioUnit,
ioActionFlags,
inTimeStamp,
kInputBus,
inNumberFrames,
&bufferList);
if (noErr != status) {
printf("AudioUnitRender error: %ld", status);
return noErr;
}
您只需要定义一个有效的AudioBuffer并传递给AudioUnitRender，这是我的工作RenderCallback：
You just need to define an valid AudioBuffer and pass it to AudioUnitRender, this is my working RenderCallback:
static OSStatus recordingCallback (void * inRefCon,
AudioUnitRenderActionFlags * ioActionFlags,
const AudioTimeStamp * inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList * ioData) {
double timeInSeconds = inTimeStamp->mSampleTime / kSampleRate;
printf("\n%fs inBusNumber: %lu inNumberFrames: %lu ", timeInSeconds, inBusNumber, inNumberFrames);
//printAudioUnitRenderActionFlags(ioActionFlags);
AudioBufferList bufferList;
SInt16 samples[inNumberFrames]; // A large enough size to not have to worry about buffer overrun
memset (&samples, 0, sizeof (samples));
bufferList.mNumberBuffers = 1;
bufferList.mBuffers[0].mData = samples;
bufferList.mBuffers[0].mNumberChannels = 1;
bufferList.mBuffers[0].mDataByteSize = inNumberFrames*sizeof(SInt16);
ViewController* THIS = THIS = (__bridge ViewController *)inRefCon;
OSStatus status;
status = AudioUnitRender(THIS->mAudioUnit,
ioActionFlags,
inTimeStamp,
kInputBus,
inNumberFrames,
&bufferList);
if (noErr != status) {
printf("AudioUnitRender error: %ld", status);
return noErr;
}
// Now, we have the samples we just read sitting in buffers in bufferList
ExtAudioFileWriteAsync(THIS->mAudioFileRef, inNumberFrames, &bufferList);
return noErr;
}
在 stopRecord 你应该用 ExtAudioFileDispose 关闭音频文件：
In stopRecord you should close the audio file with ExtAudioFileDispose:
- (void)stopRecording:(NSTimer*)theTimer {
printf("\nstopRecording\n");
AudioOutputUnitStop(mAudioUnit);
AudioUnitUninitialize(mAudioUnit);
OSStatus status = ExtAudioFileDispose(mAudioFileRef);
printf("OSStatus(ExtAudioFileDispose): %ld\n", status);
}
完整源代码：http://pastebin.com/92Fyjaye
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