I converted CAF to AAC format using TPAACAudioConverter but converted file duration is 0

问题:

I'm using AVAudioRecorder. I record the sound in caf format. After that i convert the file caf to aac format using TPAACAudioConverter. It works fine but converted file duration is 00:00. Is there any way to get duration of aac audio file.

回答1:

The AAC format doesn't support for some simulator.You can check it on your device. It will works fine and you may get AAC audio file duration.

回答2:

Can you playback the caf file ?

If you only want to record a sound from microphone to an aac file, you can use Audio Queue Services (I can post some code)

Edit : it's an implementation from Apple dev tutorial, there might be some errors since I modified it to fit your question

//AudioQ.mm @implementation AudioQ static const int nBuffer = 3;  struct AQRecorderState{     AudioStreamBasicDescription mDataFormat;     AudioQueueRef               mQueue;     AudioQueueBufferRef         mBuffers[nBuffer];     AudioFileID                 mAudioFile;     UInt32                      bufferByteSize;     SInt64                      mCurrentPacket;     bool                        mIsRunning; };  AQRecorderState aqData; CFURLRef url; static OSStatus BufferFilledHandler(                                     void *                               inUserData,                                     SInt64                               inPosition,                                     UInt32                               requestCount,                                     const void *                         buffer,                                     UInt32 *                             actualCount                                      ){     // callback when you write to the file     // you can handle audio packet and send them for broadcasting     return 0; }  static void HandleInputBuffer(                               void                              *aqData,                               AudioQueueRef                     inAq,                               AudioQueueBufferRef                   inBuffer,                               const AudioTimeStamp              *inStartTime,                               UInt32                                inNumPackets,                               const AudioStreamPacketDescription    *inPacketDesc                               ) {     AQRecorderState *pAqData = (AQRecorderState*) aqData;     if (AudioFileWritePackets (                                pAqData->mAudioFile,                                false,                                inBuffer->mAudioDataByteSize,                                inPacketDesc,                                pAqData->mCurrentPacket,                                &inNumPackets,                                inBuffer->mAudioData                                ) == noErr) {         pAqData->mCurrentPacket += inNumPackets;     } else {         NSLog(@"err writing packet");     }     if (pAqData->mIsRunning == 0)         return;     AudioQueueEnqueueBuffer(pAqData->mQueue,inBuffer,0,NULL); }  -(OSStatus) initializeAQ{      //--- set the output format ---//     aqData.mDataFormat.mSampleRate = 22050;     aqData.mDataFormat.mFormatID = kAudioFormatMPEG4AAC;     aqData.mDataFormat.mFormatFlags = kMPEG4Object_AAC_Main;     aqData.mDataFormat.mBytesPerPacket = 0;     aqData.mDataFormat.mFramesPerPacket = 1024;     aqData.mDataFormat.mBytesPerFrame = 0;     aqData.mDataFormat.mChannelsPerFrame = 1;     aqData.mDataFormat.mBitsPerChannel = 0;     AudioFileTypeID fileType = kAudioFileAAC_ADTSType;      aqData.bufferByteSize = 0x5000; // ??      AudioQueueNewInput(&aqData.mDataFormat, HandleInputBuffer, &aqData, CFRunLoopGetMain(), kCFRunLoopCommonModes, 0, &aqData.mQueue);     aqData.mCurrentPacket = 0;     aqData.mIsRunning = true;       //--- record in a file get the callback when writing ---//     AQRecorderState *pAqData = &aqData;     AudioFileInitializeWithCallbacks((void*)&pAqData,                                      nil,                                      BufferFilledHandler,                                      nil,                                      nil,                                      fileType,                                      &aqData.mDataFormat,                                      kAudioFileFlags_EraseFile,                                      &aqData.mAudioFile);      //--- prepare set of audio queue buffers ---//     for(int i = 0 ; i < nBuffer ; i++){         AudioQueueAllocateBuffer(aqData.mQueue, aqData.bufferByteSize, &aqData.mBuffers[i]);         AudioQueueEnqueueBuffer(aqData.mQueue, aqData.mBuffers[i], 0, NULL);     }     return 0;    }  -(void) start{     AudioQueueStart(aqData.mQueue, NULL);        }  -(void) stop{     NSLog(@"stoping");     AudioQueueStop(aqData.mQueue, true);     aqData.mIsRunning = false;     AudioQueueDispose (aqData.mQueue,true);     AudioFileClose (aqData.mAudioFile); } @end 

AudioQ.h

static void HandleInputBuffer(                               void                                  *aqData,                               AudioQueueRef                         inAq,                               AudioQueueBufferRef                   inBuffer,                               const AudioTimeStamp                  *inStartTime,                               UInt32                                inNumPackets,                               const AudioStreamPacketDescription    *inPacketDesc                               );  static OSStatus BufferFilledHandler(                                     void *                               inUserData,                                     SInt64                               inPosition,                                     UInt32                               requestCount,                                     const void *                         buffer,                                     UInt32 *                             actualCount                                     ); -(OSStatus)initializeAQ; -(void)stop; -(void)start; 

文章来源: I converted CAF to AAC format using TPAACAudioConverter but converted file duration is 0