嗨,我正在尝试使用AudioConverterFillComplexBuffer将AAC缓冲区转换为PCM。这是我的代码
-(void)initDecoder{
AudioStreamBasicDescription outAudioStreamBasicDescription;
outAudioStreamBasicDescription.mSampleRate = 44100.0;
outAudioStreamBasicDescription.mFormatID = kAudioFormatLinearPCM;
outAudioStreamBasicDescription.mFormatFlags = 0xc;
outAudioStreamBasicDescription.mBytesPerPacket = 2;
outAudioStreamBasicDescription.mFramesPerPacket = 1;
outAudioStreamBasicDescription.mBytesPerFrame = 2;
outAudioStreamBasicDescription.mChannelsPerFrame = 1;
outAudioStreamBasicDescription.mBitsPerChannel = 16;
AudioStreamBasicDescription inAudioStreamBasicDescription;
inAudioStreamBasicDescription.mSampleRate = 44100;
inAudioStreamBasicDescription.mFormatID = kAudioFormatMPEG4AAC;
inAudioStreamBasicDescription.mFormatFlags = kMPEG4Object_AAC_SSR;
inAudioStreamBasicDescription.mBytesPerPacket = 0;
inAudioStreamBasicDescription.mFramesPerPacket = 1024;
inAudioStreamBasicDescription.mBytesPerFrame = 0;
inAudioStreamBasicDescription.mChannelsPerFrame = 1;
inAudioStreamBasicDescription.mBitsPerChannel = 0;
inAudioStreamBasicDescription.mReserved = 0;
AudioClassDescription audioClassDescription;
memset(&audioClassDescription, 0, sizeof(audioClassDescription));
audioClassDescription.mManufacturer = kAppleSoftwareAudioCodecManufacturer;
audioClassDescription.mSubType = outAudioStreamBasicDescription.mFormatID;
audioClassDescription.mType = kAudioFormatLinearPCM;
NSAssert(audioClassDescription.mSubType == outAudioStreamBasicDescription.mFormatID && audioClassDescription.mManufacturer == kAppleSoftwareAudioCodecManufacturer, nil);
NSAssert(AudioConverterNewSpecific(&inAudioStreamBasicDescription, &outAudioStreamBasicDescription, 1, &audioClassDescription, &audioConverterDecode) == 0, nil);
}
OSStatus inInputDataProc(AudioConverterRef inAudioConverter, UInt32 *ioNumberDataPackets, AudioBufferList *ioData, AudioStreamPacketDescription **outDataPacketDescription, void *inUserData)
{
AudioBufferList audioBufferList = *(AudioBufferList *)inUserData;
ioData->mBuffers[0].mData = audioBufferList.mBuffers[0].mData;
ioData->mBuffers[0].mDataByteSize = audioBufferList.mBuffers[0].mDataByteSize;
return noErr;
}
-(void)decodeSample:(AudioBufferList)inAaudioBufferList{
//inAaudioBufferList is the AAC buffer
if (!audioConverterDecode) {
[self initDecoder];
}
NSAssert(inAaudioBufferList.mNumberBuffers == 1, nil);
uint32_t bufferSize = 1024*2;//inAaudioBufferList.mBuffers[0].mDataByteSize;
uint8_t *buffer = (uint8_t *)malloc(1024*2);
memset(buffer, 0, bufferSize);
AudioBufferList outAudioBufferList;
outAudioBufferList.mNumberBuffers = 1;
outAudioBufferList.mBuffers[0].mNumberChannels = 1;
outAudioBufferList.mBuffers[0].mDataByteSize = bufferSize;
outAudioBufferList.mBuffers[0].mData = buffer;
UInt32 ioOutputDataPacketSize = bufferSize;
OSStatus ret = AudioConverterFillComplexBuffer(audioConverterDecode, inInputDataProc, &inAaudioBufferList, &ioOutputDataPacketSize, &outAudioBufferList, NULL) ;//== 0, nil);
NSData *data = [NSData dataWithBytes:outAudioBufferList.mBuffers[0].mData length:outAudioBufferList.mBuffers[0].mDataByteSize];
DLog(@"Rev Size = %d",(unsigned int)outAudioBufferList.mBuffers[0].mDataByteSize);
free(buffer);
}
解码后的输出长度为零,AudioConverterFillComplexBuffer的OSStatus代码为561015652
那怎么可能是错误的..?
最佳答案
这是在黑暗中拍摄的照片,您可能已经找到了解决方法,但是我相信您需要更改此方法
UInt32 ioOutputDataPacketSize = bufferSize;
对此
UInt32 ioOutputDataPacketSize = bufferSize/2;
就我个人而言,我在inInputDataProc方法中执行此操作并始终发送
UInt32 ioOutputDataPacketSize = 1;
放入AudioConverterFillComplexBuffer方法,然后像这样在inInputDataProc中进行设置。
UInt32 maxPackets = audioBufferList.mBuffers[0].mDataByteSize / 2;
*ioNumberDataPackets = maxPackets;
希望这可以帮助。