read segments from multiple audio files to one buffer with extaudiofile - ios

Question

I need to be able to assemble audio from several files into a single buffer (stereo). My code is working as expected if I load each file into its own buffer. Looping through several files and losing into one larger buffer only plays back the segment from the last file.
Its possible that the header info is getting copied each time, or that the same area of the buffer is just being over-written with each new file.
Any suggestions would be appreciated.
Some code is listed below. I'm reading from encrypted files, so I'm using NSData and AudioFileOpenWithCallbacks.
// Assign the frame count to the soundStructArray instance variable
UInt64 totalFrames = [[inputNotes.stopTimes lastObject] intValue];
self.soundStructArray[0]->frameCount = (UInt32)totalFrames;
self.soundStructArray[0]->audioDataLeft =
(AudioUnitSampleType *) calloc (totalFrames, sizeof (AudioUnitSampleType));
AudioStreamBasicDescription importFormat = {0};
// if (2 == channelCount) {
self.soundStructArray[0]->isStereo = YES;
self.soundStructArray[0]->audioDataRight =
(AudioUnitSampleType *) calloc (totalFrames, sizeof (AudioUnitSampleType));
// Allocate memory for the buffer list struct according to the number of
// channels it represents.
AudioBufferList *bufferList;
UInt32 channelCount = 2;
bufferList = (AudioBufferList *) malloc (
sizeof (AudioBufferList) + sizeof (AudioBuffer) * (channelCount - 1)
);
if (NULL == bufferList) {DLog (#"*** malloc failure for allocating bufferList memory"); return;}
// initialize the mNumberBuffers member
bufferList->mNumberBuffers = channelCount;
// initialize the mBuffers member to 0
AudioBuffer emptyBuffer = {0};
size_t arrayIndex;
for (arrayIndex = 0; arrayIndex < channelCount; arrayIndex++) {
bufferList->mBuffers[arrayIndex] = emptyBuffer;
}
// set up the AudioBuffer structs in the buffer list
bufferList->mBuffers[0].mNumberChannels = 1;
bufferList->mBuffers[0].mDataByteSize = (UInt32)totalFrames * sizeof (AudioUnitSampleType);
bufferList->mBuffers[0].mData = self.soundStructArray[0]->audioDataLeft;
if (2 == channelCount) {
bufferList->mBuffers[1].mNumberChannels = 1;
bufferList->mBuffers[1].mDataByteSize = (UInt32)totalFrames * sizeof (AudioUnitSampleType);
bufferList->mBuffers[1].mData = self.soundStructArray[0]->audioDataRight;
}
NSString *fileType = #"m4a";
for (int audioFile = 0; audioFile < inputVoicesCount; ++audioFile) {
#autoreleasepool {
NSData *encData;
NSData *audioData;
AudioFileID refAudioFileID;
DLog (#"readAudioFilesIntoMemory - file %i", audioFile);
NSString *source = [[NSBundle mainBundle] pathForResource:[inputNotes.notes objectAtIndex:audioFile] ofType:fileType];
// NSURL *url = [NSURL encryptedFileURLWithPath:source];
if ([[NSFileManager defaultManager] fileExistsAtPath:source])
{
//File exists
encData = [[NSData alloc] initWithContentsOfFile:source];
if (encData)
{
NSError *error;
audioData = [RNDecryptor decryptData:encData
withPassword:key
error:&error];
}
}
else
{
DLog(#"File does not exist");
}
OSStatus result = AudioFileOpenWithCallbacks((__bridge void *)(audioData), readProc, 0, getSizeProc, NULL, kAudioFileMPEG4Type, &refAudioFileID);
if(result != noErr){
DLog(#"problem in theAudioFileReaderWithData function: result code %i \n", result);
}
// Instantiate an extended audio file object.
ExtAudioFileRef audioFileObject = 0;
result = ExtAudioFileWrapAudioFileID(refAudioFileID, NO, &audioFileObject);
if (result != noErr){
DLog(#"problem in theAudioFileReaderWithData function Wraping the audio FileID: result code %i \n", result);
}
// Get the audio file's number of channels.
AudioStreamBasicDescription fileAudioFormat = {0};
UInt32 formatPropertySize = sizeof (fileAudioFormat);
result = ExtAudioFileGetProperty (
audioFileObject,
kExtAudioFileProperty_FileDataFormat,
&formatPropertySize,
&fileAudioFormat
);
if (noErr != result) {[self printErrorMessage: #"ExtAudioFileGetProperty (file audio format)" withStatus: result]; return;}
importFormat = stereoStreamFormat;
result = ExtAudioFileSetProperty (
audioFileObject,
kExtAudioFileProperty_ClientDataFormat,
sizeof (importFormat),
&importFormat
);
if (noErr != result) {[self printErrorMessage: #"ExtAudioFileSetProperty (client data format)" withStatus: result]; return;}
// Assign the frame count to the soundStructArray instance variable
UInt64 desiredFrames = (UInt64) ([[inputNotes.stopTimes objectAtIndex:audioFile] intValue] - [[inputNotes.startTimes objectAtIndex:audioFile] intValue]);
// Perform a synchronous, sequential read of the audio data out of the file and
// into the soundStructArray[audioFile].audioDataLeft and (if stereo) .audioDataRight members.
UInt32 numberOfPacketsToRead = (UInt32) desiredFrames;
result = ExtAudioFileRead (
audioFileObject,
&numberOfPacketsToRead,
bufferList
);
if (noErr != result) {
[self printErrorMessage: #"ExtAudioFileRead failure - " withStatus: result];
// If reading from the file failed, then free the memory for the sound buffer.
// free (soundStructArray[audioFile].audioDataLeft);
// soundStructArray[audioFile].audioDataLeft = 0;
free (self.soundStructArray[0]->audioDataLeft);
self.soundStructArray[0]->audioDataLeft = 0;
free (self.soundStructArray[0]->audioDataRight);
self.soundStructArray[0]->audioDataRight = 0;
ExtAudioFileDispose (audioFileObject);
return;
}
ExtAudioFileDispose (audioFileObject);
AudioFileClose(refAudioFileID);
}
}//end of #autoreleasepool
free (bufferList);
// Set the sample index to zero, so that playback starts at the
// beginning of the sound.
self.soundStructArray[0]->sampleNumber = 0;
DLog (#"Finished reading all files into memory");
readingFiles = NO;
}