aurioTouch2 录音问题。我需要将数据从一个 AudioBufferList 添加到另一个

Posted 2023-02-25

【中文标题】aurioTouch2 录音问题。我需要将数据从一个 AudioBufferList 添加到另一个

【英文标题】：aurioTouch2 recording issue. I need to add data from one AudioBufferList to another

【发布时间】：2012-07-13 13:03:53

【问题描述】：

我调查aurioTouch2 示例代码。但我想将所有内容记录在文件中。 aurioTouch 不提供这种可能性。我尝试在FFTBufferManager.cpp 中使用此代码在void FFTBufferManager::GrabAudioData(AudioBufferList *inBL) 中记录数据

ExtAudioFileRef cafFile;
AudiostreamBasicDescription cafDesc;

cafDesc.mBitsPerChannel = 16;
cafDesc.mBytesPerFrame = 4;
cafDesc.mBytesPerPacket = 4;
cafDesc.mChannelsPerFrame = 2;
cafDesc.mFormatFlags = 0;
cafDesc.mFormatID = 'ima4';
cafDesc.mFramesPerPacket = 1;
cafDesc.mReserved = 0;
cafDesc.mSampleRate = 44100;


CFStringRef refH;
refH = CFStringCreateWithCString(kCFAllocatorDefault, "/var/mobile/Applications/BD596ECF-A6F2-41EB-B4CE-3A9644B1C26A/Documents/voice2.caff", kCFStringEncodingUTF8);
CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, 
                                                        refH, 
                                                        kCFURLPOSIXPathStyle, 
                                                        false);
OSType status = ExtAudioFileCreateWithURL(
                                          destinationURL,                    // inURL
                                          'caff',                     // inFileType
                                          &cafDesc,                   // inStreamDesc
                                          NULL,                       // inChannelLayout
                                          kAudioFileFlags_EraseFile,  // inFlags
                                          &cafFile                    // outExtAudioFile
                                          );    // returns 0xFFFFFFCE
ExtAudioFileWrite(cafFile, mNumberFrames, inBL);

这很好用，但我使用AudioBufferList *inBL，这只是所有音频数据的一小部分（大约 1 秒）。此函数每 1 秒调用一次，以分析来自麦克风的新音频数据。因此，如果我可以将数据从一个 AudioBufferList 添加到另一个 AudioBufferList，那就太好了。

或者可能有人知道其他方法。

【问题讨论】：

为什么要硬编码整个路径？ /Applications/ 之后的哈希值在其他设备上不会相同。

因为.cpp文件中的代码，我无法使用常规方式获取文件夹路径！

如果您投反对票，请对此发表评论

我高度对此表示怀疑。您的应用永远不会在生产环境中运行，因为每个设备上的路径都不同。查看 iOS 开发者文档。

【参考方案1】：

您应该设置新的 AudioUnit 来录制音频（带有自己的回调函数）。

    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, &mAudioUnit);

    // Enable IO for recording
    UInt32 flag = 1;
    status = AudioUnitSetProperty(mAudioUnit,
                                  kAudioOutputUnitProperty_EnableIO,
                                  kAudioUnitScope_Input,
                                  kInputBus,
                                  &flag,
                                  sizeof(flag));

    // Enable IO for playback
    status = AudioUnitSetProperty(mAudioUnit,
                                  kAudioOutputUnitProperty_EnableIO,
                                  kAudioUnitScope_Output,
                                  kOutputBus,
                                  &flag,
                                  sizeof(flag));

    // Describe format
    AudioStreamBasicDescription audioFormat=0;
    audioFormat.mSampleRate         = kSampleRate;
    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(mAudioUnit,
                                  kAudioUnitProperty_StreamFormat,
                                  kAudioUnitScope_Output,
                                  kInputBus,
                                  &audioFormat,
                                  sizeof(audioFormat));
    status = AudioUnitSetProperty(mAudioUnit,
                                  kAudioUnitProperty_StreamFormat,
                                  kAudioUnitScope_Input,
                                  kOutputBus,
                                  &audioFormat,
                                  sizeof(audioFormat));


    // Set input callback
    AURenderCallbackStruct callbackStruct;
    callbackStruct.inputProc = recordingCallback;
    callbackStruct.inputProcRefCon = (__bridge void *)self;

    status = AudioUnitSetProperty(mAudioUnit,
                                  kAudioOutputUnitProperty_SetInputCallback,
                                  kAudioUnitScope_Global,
                                  kInputBus,
                                  &callbackStruct,
                                  sizeof(callbackStruct));

    // Disable buffer allocation for the recorder (optional - do this if we want to pass in our own)
    flag = 0;
    status = AudioUnitSetProperty(mAudioUnit,
                                  kAudioUnitProperty_ShouldAllocateBuffer,
                                  kAudioUnitScope_Output,
                                  kInputBus,
                                  &flag,
                                  sizeof(flag));

    // On initialise le fichier audio
    NSArray  *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *destinationFilePath = [[NSString alloc] initWithFormat: @"%@/output.caf", documentsDirectory];
    NSLog(@">>> %@\n", destinationFilePath);

    CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (__bridge CFStringRef)destinationFilePath, kCFURLPOSIXPathStyle, false);

    OSStatus setupErr = ExtAudioFileCreateWithURL(destinationURL, kAudioFileCAFType, &audioFormat, NULL, kAudioFileFlags_EraseFile, &mAudioFileRef);  
    CFRelease(destinationURL);
    NSAssert(setupErr == noErr, @"Couldn't create file for writing");

    setupErr = ExtAudioFileSetProperty(mAudioFileRef, kExtAudioFileProperty_ClientDataFormat, sizeof(AudioStreamBasicDescription), &audioFormat);
    NSAssert(setupErr == noErr, @"Couldn't create file for format");

    setupErr =  ExtAudioFileWriteAsync(mAudioFileRef, 0, NULL);
    NSAssert(setupErr == noErr, @"Couldn't initialize write buffers for audio file");

    CheckError(AudioUnitInitialize(mAudioUnit), "AudioUnitInitialize");
    CheckError(AudioOutputUnitStart(mAudioUnit), "AudioOutputUnitStart");