OSStatus DoConvertFile(CFURLRef sourceURL, CFURLRef destinationURL, OSType outputFormat, Float64 outputSampleRate)
{
ExtAudioFileRef sourceFile = 0;
ExtAudioFileRef destinationFile = 0;
Boolean canResumeFromInterruption = true; // we can continue unless told otherwise
OSStatus error = noErr;
// in this sample we should never be on the main thread here
assert(![NSThread isMainThread]);
// transition thread state to kStateRunning before continuing
ThreadStateSetRunning();
printf("DoConvertFile\n");
try {
CAStreamBasicDescription srcFormat, dstFormat;
// open the source file
XThrowIfError(ExtAudioFileOpenURL(sourceURL, &sourceFile), "ExtAudioFileOpenURL failed");
// get the source data format
UInt32 size = sizeof(srcFormat);
XThrowIfError(ExtAudioFileGetProperty(sourceFile, kExtAudioFileProperty_FileDataFormat, &size, &srcFormat), "couldn't get source data format");
printf("\nSource file format: "); srcFormat.Print();
// setup the output file format
dstFormat.mSampleRate = (outputSampleRate == 0 ? srcFormat.mSampleRate : outputSampleRate); // set sample rate
if (outputFormat == kAudioFormatLinearPCM) {
// if PCM was selected as the destination format, create a 16-bit int PCM file format description
dstFormat.mFormatID = outputFormat;
dstFormat.mChannelsPerFrame = srcFormat.NumberChannels();
dstFormat.mBitsPerChannel = 16;
dstFormat.mBytesPerPacket = dstFormat.mBytesPerFrame = 2 * dstFormat.mChannelsPerFrame;
dstFormat.mFramesPerPacket = 1;
dstFormat.mFormatFlags = kLinearPCMFormatFlagIsPacked | kLinearPCMFormatFlagIsSignedInteger; // little-endian
} else {
// compressed format - need to set at least format, sample rate and channel fields for kAudioFormatProperty_FormatInfo
dstFormat.mFormatID = outputFormat;
dstFormat.mChannelsPerFrame = (outputFormat == kAudioFormatiLBC ? 1 : srcFormat.NumberChannels()); // for iLBC num channels must be 1
// use AudioFormat API to fill out the rest of the description
size = sizeof(dstFormat);
XThrowIfError(AudioFormatGetProperty(kAudioFormatProperty_FormatInfo, 0, NULL, &size, &dstFormat), "couldn't create destination data format");
}
printf("\nDestination file format: "); dstFormat.Print();
// create the destination file
XThrowIfError(ExtAudioFileCreateWithURL(destinationURL, kAudioFileCAFType, &dstFormat, NULL, kAudioFileFlags_EraseFile, &destinationFile), "ExtAudioFileCreateWithURL failed!");
// set the client format - The format must be linear PCM (kAudioFormatLinearPCM)
// You must set this in order to encode or decode a non-PCM file data format
// You may set this on PCM files to specify the data format used in your calls to read/write
CAStreamBasicDescription clientFormat;
if (outputFormat == kAudioFormatLinearPCM) {
clientFormat = dstFormat;
} else {
clientFormat.SetCanonical(srcFormat.NumberChannels(), true);
clientFormat.mSampleRate = srcFormat.mSampleRate;
}
printf("\nClient data format: "); clientFormat.Print();
printf("\n");
size = sizeof(clientFormat);
XThrowIfError(ExtAudioFileSetProperty(sourceFile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat), "couldn't set source client format");
size = sizeof(clientFormat);
XThrowIfError(ExtAudioFileSetProperty(destinationFile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat), "couldn't set destination client format");
// can the audio converter (which in this case is owned by an ExtAudioFile object) resume conversion after an interruption?
AudioConverterRef audioConverter;
size = sizeof(audioConverter);
XThrowIfError(ExtAudioFileGetProperty(destinationFile, kExtAudioFileProperty_AudioConverter, &size, &audioConverter), "Couldn't get Audio Converter!");
// this property may be queried at any time after construction of the audio converter (which in this case is owned by an ExtAudioFile object)
// after setting the output format -- there's no clear reason to prefer construction time, interruption time, or potential resumption time but we prefer
// construction time since it means less code to execute during or after interruption time
UInt32 canResume = 0;
size = sizeof(canResume);
error = AudioConverterGetProperty(audioConverter, kAudioConverterPropertyCanResumeFromInterruption, &size, &canResume);
if (noErr == error) {
// we recieved a valid return value from the GetProperty call
// if the property's value is 1, then the codec CAN resume work following an interruption
// if the property's value is 0, then interruptions destroy the codec's state and we're done
if (0 == canResume) canResumeFromInterruption = false;
printf("Audio Converter %s continue after interruption!\n", (canResumeFromInterruption == 0 ? "CANNOT" : "CAN"));
} else {
// if the property is unimplemented (kAudioConverterErr_PropertyNotSupported, or paramErr returned in the case of PCM),
// then the codec being used is not a hardware codec so we're not concerned about codec state
// we are always going to be able to resume conversion after an interruption
if (kAudioConverterErr_PropertyNotSupported == error) {
printf("kAudioConverterPropertyCanResumeFromInterruption property not supported!\n");
} else {
printf("AudioConverterGetProperty kAudioConverterPropertyCanResumeFromInterruption result %ld\n", error);
}
error = noErr;
}
// set up buffers
UInt32 bufferByteSize = 32768;
char srcBuffer[bufferByteSize];
// keep track of the source file offset so we know where to reset the source for
// reading if interrupted and input was not consumed by the audio converter
SInt64 sourceFrameOffset = 0;
//***** do the read and write - the conversion is done on and by the write call *****//
printf("Converting...\n");
while (1) {
AudioBufferList fillBufList;
fillBufList.mNumberBuffers = 1;
fillBufList.mBuffers[0].mNumberChannels = clientFormat.NumberChannels();
fillBufList.mBuffers[0].mDataByteSize = bufferByteSize;
fillBufList.mBuffers[0].mData = srcBuffer;
// client format is always linear PCM - so here we determine how many frames of lpcm
// we can read/write given our buffer size
UInt32 numFrames;
if (clientFormat.mBytesPerFrame > 0) // rids bogus analyzer div by zero warning mBytesPerFrame can't be 0 and is protected by an Assert
numFrames = clientFormat.BytesToFrames(bufferByteSize); // (bufferByteSize / clientFormat.mBytesPerFrame);
XThrowIfError(ExtAudioFileRead(sourceFile, &numFrames, &fillBufList), "ExtAudioFileRead failed!");
if (!numFrames) {
// this is our termination condition
error = noErr;
break;
}
sourceFrameOffset += numFrames;
// this will block if we're interrupted
Boolean wasInterrupted = ThreadStatePausedCheck();
if ((error || wasInterrupted) && (false == canResumeFromInterruption)) {
// this is our interruption termination condition
// an interruption has occured but the audio converter cannot continue
error = kMyAudioConverterErr_CannotResumeFromInterruptionError;
break;
}
error = ExtAudioFileWrite(destinationFile, numFrames, &fillBufList);
// if interrupted in the process of the write call, we must handle the errors appropriately
if (error) {
if (kExtAudioFileError_CodecUnavailableInputConsumed == error) {
printf("ExtAudioFileWrite kExtAudioFileError_CodecUnavailableInputConsumed error %ld\n", error);
/*
Returned when ExtAudioFileWrite was interrupted. You must stop calling
ExtAudioFileWrite. If the underlying audio converter can resume after an
interruption (see kAudioConverterPropertyCanResumeFromInterruption), you must
wait for an EndInterruption notification from AudioSession, then activate the session
before resuming. In this situation, the buffer you provided to ExtAudioFileWrite was successfully
consumed and you may proceed to the next buffer
*/
} else if (kExtAudioFileError_CodecUnavailableInputNotConsumed == error) {
printf("ExtAudioFileWrite kExtAudioFileError_CodecUnavailableInputNotConsumed error %ld\n", error);
/*
Returned when ExtAudioFileWrite was interrupted. You must stop calling
ExtAudioFileWrite. If the underlying audio converter can resume after an
interruption (see kAudioConverterPropertyCanResumeFromInterruption), you must
wait for an EndInterruption notification from AudioSession, then activate the session
before resuming. In this situation, the buffer you provided to ExtAudioFileWrite was not
successfully consumed and you must try to write it again
*/
// seek back to last offset before last read so we can try again after the interruption
sourceFrameOffset -= numFrames;
XThrowIfError(ExtAudioFileSeek(sourceFile, sourceFrameOffset), "ExtAudioFileSeek failed!");
} else {
XThrowIfError(error, "ExtAudioFileWrite error!");
}
} // if
} // while
}
catch (CAXException e) {
char buf[256];
fprintf(stderr, "Error: %s (%s)\n", e.mOperation, e.FormatError(buf));
error = e.mError;
}
// close
if (destinationFile) ExtAudioFileDispose(destinationFile);
if (sourceFile) ExtAudioFileDispose(sourceFile);
// transition thread state to kStateDone before continuing
ThreadStateSetDone();
return error;
}
void WriteOutputFile (const char* outputFilePath,
OSType dataFormat,
Float64 srate,
MusicTimeStamp sequenceLength,
bool shouldPrint,
AUGraph inGraph,
UInt32 numFrames,
MusicPlayer player)
{
OSStatus result = 0;
UInt32 size;
CAStreamBasicDescription outputFormat;
outputFormat.mChannelsPerFrame = 2;
outputFormat.mSampleRate = srate;
outputFormat.mFormatID = dataFormat;
AudioFileTypeID destFileType;
CAAudioFileFormats::Instance()->InferFileFormatFromFilename (outputFilePath, destFileType);
if (dataFormat == kAudioFormatLinearPCM) {
outputFormat.mBytesPerPacket = outputFormat.mChannelsPerFrame * 2;
outputFormat.mFramesPerPacket = 1;
outputFormat.mBytesPerFrame = outputFormat.mBytesPerPacket;
outputFormat.mBitsPerChannel = 16;
if (destFileType == kAudioFileWAVEType)
outputFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger
| kLinearPCMFormatFlagIsPacked;
else
outputFormat.mFormatFlags = kLinearPCMFormatFlagIsBigEndian
| kLinearPCMFormatFlagIsSignedInteger
| kLinearPCMFormatFlagIsPacked;
} else {
// use AudioFormat API to fill out the rest.
size = sizeof(outputFormat);
FailIf ((result = AudioFormatGetProperty(kAudioFormatProperty_FormatInfo, 0, NULL, &size, &outputFormat)), fail, "");
}
if (shouldPrint) {
printf ("Writing to file: %s with format:\n* ", outputFilePath);
outputFormat.Print();
}
CFURLRef url; url = CFURLCreateFromFileSystemRepresentation(NULL, (const UInt8*)outputFilePath, strlen(outputFilePath), false);
// create output file, delete existing file
ExtAudioFileRef outfile;
result = ExtAudioFileCreateWithURL(url, destFileType, &outputFormat, NULL, kAudioFileFlags_EraseFile, &outfile);
if (url) CFRelease (url);
FailIf (result, fail, "ExtAudioFileCreateWithURL");
AudioUnit outputUnit; outputUnit = NULL;
UInt32 nodeCount;
FailIf ((result = AUGraphGetNodeCount (inGraph, &nodeCount)), fail, "AUGraphGetNodeCount");
for (UInt32 i = 0; i < nodeCount; ++i)
{
AUNode node;
FailIf ((result = AUGraphGetIndNode(inGraph, i, &node)), fail, "AUGraphGetIndNode");
AudioComponentDescription desc;
FailIf ((result = AUGraphNodeInfo(inGraph, node, &desc, NULL)), fail, "AUGraphNodeInfo");
if (desc.componentType == kAudioUnitType_Output)
{
FailIf ((result = AUGraphNodeInfo(inGraph, node, 0, &outputUnit)), fail, "AUGraphNodeInfo");
break;
}
}
FailIf ((result = (outputUnit == NULL)), fail, "outputUnit == NULL");
{
CAStreamBasicDescription clientFormat = CAStreamBasicDescription();
size = sizeof(clientFormat);
FailIf ((result = AudioUnitGetProperty (outputUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output, 0,
&clientFormat, &size)), fail, "AudioUnitGetProperty: kAudioUnitProperty_StreamFormat");
size = sizeof(clientFormat);
FailIf ((result = ExtAudioFileSetProperty(outfile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat)), fail, "ExtAudioFileSetProperty: kExtAudioFileProperty_ClientDataFormat");
{
MusicTimeStamp currentTime;
AUOutputBL outputBuffer (clientFormat, numFrames);
AudioTimeStamp tStamp;
memset (&tStamp, 0, sizeof(AudioTimeStamp));
tStamp.mFlags = kAudioTimeStampSampleTimeValid;
int i = 0;
int numTimesFor10Secs = (int)(10. / (numFrames / srate));
do {
outputBuffer.Prepare();
AudioUnitRenderActionFlags actionFlags = 0;
FailIf ((result = AudioUnitRender (outputUnit, &actionFlags, &tStamp, 0, numFrames, outputBuffer.ABL())), fail, "AudioUnitRender");
tStamp.mSampleTime += numFrames;
FailIf ((result = ExtAudioFileWrite(outfile, numFrames, outputBuffer.ABL())), fail, "ExtAudioFileWrite");
FailIf ((result = MusicPlayerGetTime (player, ¤tTime)), fail, "MusicPlayerGetTime");
if (shouldPrint && (++i % numTimesFor10Secs == 0))
printf ("current time: %6.2f beats\n", currentTime);
} while (currentTime < sequenceLength);
}
}
// close
ExtAudioFileDispose(outfile);
return;
fail:
printf ("Problem: %ld\n", (long)result);
exit(1);
}
void DoAQOfflineRender(CFURLRef sourceURL, CFURLRef destinationURL)
{
// main audio queue code
try {
AQTestInfo myInfo;
myInfo.mDone = false;
myInfo.mFlushed = false;
myInfo.mCurrentPacket = 0;
// get the source file
XThrowIfError(AudioFileOpenURL(sourceURL, 0x01/*fsRdPerm*/, 0/*inFileTypeHint*/, &myInfo.mAudioFile), "AudioFileOpen failed");
UInt32 size = sizeof(myInfo.mDataFormat);
XThrowIfError(AudioFileGetProperty(myInfo.mAudioFile, kAudioFilePropertyDataFormat, &size, &myInfo.mDataFormat), "couldn't get file's data format");
printf ("File format: "); myInfo.mDataFormat.Print();
// create a new audio queue output
XThrowIfError(AudioQueueNewOutput(&myInfo.mDataFormat, // The data format of the audio to play. For linear PCM, only interleaved formats are supported.
AQTestBufferCallback, // A callback function to use with the playback audio queue.
&myInfo, // A custom data structure for use with the callback function.
CFRunLoopGetCurrent(), // The event loop on which the callback function pointed to by the inCallbackProc parameter is to be called.
// If you specify NULL, the callback is invoked on one of the audio queue’s internal threads.
kCFRunLoopCommonModes, // The run loop mode in which to invoke the callback function specified in the inCallbackProc parameter.
0, // Reserved for future use. Must be 0.
&myInfo.mQueue), // On output, the newly created playback audio queue object.
"AudioQueueNew failed");
UInt32 bufferByteSize;
// we need to calculate how many packets we read at a time and how big a buffer we need
// we base this on the size of the packets in the file and an approximate duration for each buffer
{
bool isFormatVBR = (myInfo.mDataFormat.mBytesPerPacket == 0 || myInfo.mDataFormat.mFramesPerPacket == 0);
// first check to see what the max size of a packet is - if it is bigger
// than our allocation default size, that needs to become larger
UInt32 maxPacketSize;
size = sizeof(maxPacketSize);
XThrowIfError(AudioFileGetProperty(myInfo.mAudioFile, kAudioFilePropertyPacketSizeUpperBound, &size, &maxPacketSize), "couldn't get file's max packet size");
// adjust buffer size to represent about a second of audio based on this format
CalculateBytesForTime(myInfo.mDataFormat, maxPacketSize, 1.0/*seconds*/, &bufferByteSize, &myInfo.mNumPacketsToRead);
if (isFormatVBR) {
myInfo.mPacketDescs = new AudioStreamPacketDescription [myInfo.mNumPacketsToRead];
} else {
myInfo.mPacketDescs = NULL; // we don't provide packet descriptions for constant bit rate formats (like linear PCM)
}
printf ("Buffer Byte Size: %d, Num Packets to Read: %d\n", (int)bufferByteSize, (int)myInfo.mNumPacketsToRead);
}
// if the file has a magic cookie, we should get it and set it on the AQ
size = sizeof(UInt32);
OSStatus result = AudioFileGetPropertyInfo (myInfo.mAudioFile, kAudioFilePropertyMagicCookieData, &size, NULL);
if (!result && size) {
char* cookie = new char [size];
XThrowIfError (AudioFileGetProperty (myInfo.mAudioFile, kAudioFilePropertyMagicCookieData, &size, cookie), "get cookie from file");
XThrowIfError (AudioQueueSetProperty(myInfo.mQueue, kAudioQueueProperty_MagicCookie, cookie, size), "set cookie on queue");
delete [] cookie;
}
// channel layout?
OSStatus err = AudioFileGetPropertyInfo(myInfo.mAudioFile, kAudioFilePropertyChannelLayout, &size, NULL);
AudioChannelLayout *acl = NULL;
if (err == noErr && size > 0) {
acl = (AudioChannelLayout *)malloc(size);
XThrowIfError(AudioFileGetProperty(myInfo.mAudioFile, kAudioFilePropertyChannelLayout, &size, acl), "get audio file's channel layout");
XThrowIfError(AudioQueueSetProperty(myInfo.mQueue, kAudioQueueProperty_ChannelLayout, acl, size), "set channel layout on queue");
}
//allocate the input read buffer
XThrowIfError(AudioQueueAllocateBuffer(myInfo.mQueue, bufferByteSize, &myInfo.mBuffer), "AudioQueueAllocateBuffer");
// prepare a canonical interleaved capture format
CAStreamBasicDescription captureFormat;
captureFormat.mSampleRate = myInfo.mDataFormat.mSampleRate;
captureFormat.SetAUCanonical(myInfo.mDataFormat.mChannelsPerFrame, true); // interleaved
XThrowIfError(AudioQueueSetOfflineRenderFormat(myInfo.mQueue, &captureFormat, acl), "set offline render format");
ExtAudioFileRef captureFile;
// prepare a 16-bit int file format, sample channel count and sample rate
CAStreamBasicDescription dstFormat;
dstFormat.mSampleRate = myInfo.mDataFormat.mSampleRate;
dstFormat.mChannelsPerFrame = myInfo.mDataFormat.mChannelsPerFrame;
dstFormat.mFormatID = kAudioFormatLinearPCM;
dstFormat.mFormatFlags = kLinearPCMFormatFlagIsPacked | kLinearPCMFormatFlagIsSignedInteger; // little-endian
dstFormat.mBitsPerChannel = 16;
dstFormat.mBytesPerPacket = dstFormat.mBytesPerFrame = 2 * dstFormat.mChannelsPerFrame;
dstFormat.mFramesPerPacket = 1;
// create the capture file
XThrowIfError(ExtAudioFileCreateWithURL(destinationURL, kAudioFileCAFType, &dstFormat, acl, kAudioFileFlags_EraseFile, &captureFile), "ExtAudioFileCreateWithURL");
// set the capture file's client format to be the canonical format from the queue
XThrowIfError(ExtAudioFileSetProperty(captureFile, kExtAudioFileProperty_ClientDataFormat, sizeof(AudioStreamBasicDescription), &captureFormat), "set ExtAudioFile client format");
// allocate the capture buffer, just keep it at half the size of the enqueue buffer
// we don't ever want to pull any faster than we can push data in for render
// this 2:1 ratio keeps the AQ Offline Render happy
const UInt32 captureBufferByteSize = bufferByteSize / 2;
AudioQueueBufferRef captureBuffer;
AudioBufferList captureABL;
XThrowIfError(AudioQueueAllocateBuffer(myInfo.mQueue, captureBufferByteSize, &captureBuffer), "AudioQueueAllocateBuffer");
captureABL.mNumberBuffers = 1;
captureABL.mBuffers[0].mData = captureBuffer->mAudioData;
captureABL.mBuffers[0].mNumberChannels = captureFormat.mChannelsPerFrame;
// lets start playing now - stop is called in the AQTestBufferCallback when there's
// no more to read from the file
XThrowIfError(AudioQueueStart(myInfo.mQueue, NULL), "AudioQueueStart failed");
AudioTimeStamp ts;
ts.mFlags = kAudioTimeStampSampleTimeValid;
ts.mSampleTime = 0;
// we need to call this once asking for 0 frames
XThrowIfError(AudioQueueOfflineRender(myInfo.mQueue, &ts, captureBuffer, 0), "AudioQueueOfflineRender");
// we need to enqueue a buffer after the queue has started
AQTestBufferCallback(&myInfo, myInfo.mQueue, myInfo.mBuffer);
while (true) {
UInt32 reqFrames = captureBufferByteSize / captureFormat.mBytesPerFrame;
XThrowIfError(AudioQueueOfflineRender(myInfo.mQueue, &ts, captureBuffer, reqFrames), "AudioQueueOfflineRender");
captureABL.mBuffers[0].mData = captureBuffer->mAudioData;
captureABL.mBuffers[0].mDataByteSize = captureBuffer->mAudioDataByteSize;
UInt32 writeFrames = captureABL.mBuffers[0].mDataByteSize / captureFormat.mBytesPerFrame;
printf("t = %.f: AudioQueueOfflineRender: req %d fr/%d bytes, got %ld fr/%d bytes\n", ts.mSampleTime, (int)reqFrames, (int)captureBufferByteSize, writeFrames, (int)captureABL.mBuffers[0].mDataByteSize);
XThrowIfError(ExtAudioFileWrite(captureFile, writeFrames, &captureABL), "ExtAudioFileWrite");
if (myInfo.mFlushed) break;
ts.mSampleTime += writeFrames;
}
CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1, false);
XThrowIfError(AudioQueueDispose(myInfo.mQueue, true), "AudioQueueDispose(true) failed");
XThrowIfError(AudioFileClose(myInfo.mAudioFile), "AudioQueueDispose(false) failed");
XThrowIfError(ExtAudioFileDispose(captureFile), "ExtAudioFileDispose failed");
if (myInfo.mPacketDescs) delete [] myInfo.mPacketDescs;
if (acl) free(acl);
}
catch (CAXException e) {
char buf[256];
fprintf(stderr, "Error: %s (%s)\n", e.mOperation, e.FormatError(buf));
}
return;
}
int ConvertFile (CFURLRef inputFileURL,
CAStreamBasicDescription &inputFormat,
CFURLRef outputFileURL,
AudioFileTypeID outputFileType,
CAStreamBasicDescription &outputFormat,
UInt32 outputBitRate)
{
ExtAudioFileRef infile, outfile;
// first open the input file
OSStatus err = ExtAudioFileOpenURL (inputFileURL, &infile);
XThrowIfError (err, "ExtAudioFileOpen");
// if outputBitRate is specified, this can change the sample rate of the output file
// so we let this "take care of itself"
if (outputBitRate)
outputFormat.mSampleRate = 0.;
// create the output file (this will erase an exsiting file)
err = ExtAudioFileCreateWithURL (outputFileURL, outputFileType, &outputFormat, NULL, kAudioFileFlags_EraseFile, &outfile);
XThrowIfError (err, "ExtAudioFileCreateNew");
// get and set the client format - it should be lpcm
CAStreamBasicDescription clientFormat = (inputFormat.mFormatID == kAudioFormatLinearPCM ? inputFormat : outputFormat);
UInt32 size = sizeof(clientFormat);
err = ExtAudioFileSetProperty(infile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat);
XThrowIfError (err, "ExtAudioFileSetProperty inFile, kExtAudioFileProperty_ClientDataFormat");
size = sizeof(clientFormat);
err = ExtAudioFileSetProperty(outfile, kExtAudioFileProperty_ClientDataFormat, size, &clientFormat);
XThrowIfError (err, "ExtAudioFileSetProperty outFile, kExtAudioFileProperty_ClientDataFormat");
if( outputBitRate > 0 ) {
printf ("Dest bit rate: %d\n", (int)outputBitRate);
AudioConverterRef outConverter;
size = sizeof(outConverter);
err = ExtAudioFileGetProperty(outfile, kExtAudioFileProperty_AudioConverter, &size, &outConverter);
XThrowIfError (err, "ExtAudioFileGetProperty outFile, kExtAudioFileProperty_AudioConverter");
err = AudioConverterSetProperty(outConverter, kAudioConverterEncodeBitRate,
sizeof(outputBitRate), &outputBitRate);
XThrowIfError (err, "AudioConverterSetProperty, kAudioConverterEncodeBitRate");
// we have changed the converter, so we should do this in case
// setting a converter property changes the converter used by ExtAF in some manner
CFArrayRef config = NULL;
err = ExtAudioFileSetProperty(outfile, kExtAudioFileProperty_ConverterConfig, sizeof(config), &config);
XThrowIfError (err, "ExtAudioFileSetProperty outFile, kExtAudioFileProperty_ConverterConfig");
}
// set up buffers
char srcBuffer[kSrcBufSize];
// do the read and write - the conversion is done on and by the write call
while (1)
{
AudioBufferList fillBufList;
fillBufList.mNumberBuffers = 1;
fillBufList.mBuffers[0].mNumberChannels = inputFormat.mChannelsPerFrame;
fillBufList.mBuffers[0].mDataByteSize = kSrcBufSize;
fillBufList.mBuffers[0].mData = srcBuffer;
// client format is always linear PCM - so here we determine how many frames of lpcm
// we can read/write given our buffer size
UInt32 numFrames = (kSrcBufSize / clientFormat.mBytesPerFrame);
// printf("test %d\n", numFrames);
err = ExtAudioFileRead (infile, &numFrames, &fillBufList);
XThrowIfError (err, "ExtAudioFileRead");
if (!numFrames) {
// this is our termination condition
break;
}
err = ExtAudioFileWrite(outfile, numFrames, &fillBufList);
XThrowIfError (err, "ExtAudioFileWrite");
}
// close
ExtAudioFileDispose(outfile);
ExtAudioFileDispose(infile);
return 0;
}
