Audio is not being recorded using AVAssetWrite - ios

Question

I am trying to record audio in a file for 14 days. I am getting audio data in PCM format through screen mirroring in which audio is received and from this I am converting it to CMSampleBuffer using this code
-(void)createAudioSampleBufferFromData:(uint8_t*)buf withSize:(uint32_t)buflen timeStamp:(double)timeStamp{
OSStatus status;
AudioStreamBasicDescription monoStreamFormat;
memset(&monoStreamFormat, 0, sizeof(monoStreamFormat));
monoStreamFormat.mFormatID = kAudioFormatLinearPCM;
monoStreamFormat.mSampleRate = 44100;
monoStreamFormat.mChannelsPerFrame = 2;
monoStreamFormat.mBitsPerChannel = 16;
monoStreamFormat.mFramesPerPacket = 1; // uncompressed audio
monoStreamFormat.mBytesPerFrame =monoStreamFormat.mChannelsPerFrame * monoStreamFormat.mBitsPerChannel/8;
monoStreamFormat.mBytesPerPacket = monoStreamFormat.mBytesPerFrame * monoStreamFormat.mFramesPerPacket;
monoStreamFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
CMFormatDescriptionRef format = NULL;
status = CMAudioFormatDescriptionCreate(kCFAllocatorDefault, &monoStreamFormat, 0, NULL, 0, NULL, NULL, &format);
if (status != noErr) {
// really shouldn't happen
return;
}
long blockLength = buflen;
CMSampleBufferRef sampleBuffer = NULL;
CMBlockBufferRef blockBuffer = NULL;
status = CMBlockBufferCreateWithMemoryBlock(kCFAllocatorDefault, buf, // memoryBlock to hold buffered data
blockLength, // block length of the mem block in bytes.
kCFAllocatorDefault, NULL,
0, // offsetToData
blockLength, // dataLength of relevant bytes, starting at offsetToData
0, &blockBuffer);
if(status == noErr)
{
CMSampleTimingInfo timings = {CMTimeMake(1, 44100.0), CMClockGetTime(CMClockGetHostTimeClock()), kCMTimeInvalid };
const size_t sampleSize = blockLength;
status = CMSampleBufferCreate(kCFAllocatorDefault,
NULL, true, NULL, NULL,
format, 1, 0, &timings, 1,
&sampleSize, &sampleBuffer);
CMItemCount itemCount = CMSampleBufferGetNumSamples(sampleBuffer);
[self notifyAudioBufferReceived:sampleBuffer];
// if(blockBuffer)
// CFRelease(blockBuffer);
}
}
And in following method this CMSampleBuffers are receiving:
- (void)airPlayServer:(id)server audioBufferReceived:(CMSampleBufferRef)buffer {
if(recordingStarted){
[decoderAndRecorder.recorder newAudioSample:buffer];
}
// CFRelease(buffer);
}
from here these buffers go to AVAssetWriter class where I am appending these buffer to record audio into file. AVAssetWriter class is following:
- (instancetype)init
{
self = [super init];
if (self) {
// Create asset writer
dateString = [self dateInString];
NSString *documents = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex: 0];
filePath = [documents stringByAppendingPathComponent:[NSString stringWithFormat:#"screen recording - %#.caf",dateString]];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
[[NSFileManager defaultManager] removeItemAtPath:filePath
error:nil];
}
NSLog(#"%#", filePath);
NSError *error = nil;
_assetWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:filePath]
fileType:AVFileTypeCoreAudioFormat
error:&error];
AudioChannelLayout acl;
memset(&acl,0, sizeof(acl));
acl.mChannelLayoutTag = kAudioChannelLayoutTag_Mono;
NSDictionary* audioOutputSettings = nil;
audioOutputSettings = [ NSDictionary dictionaryWithObjectsAndKeys:
[ NSNumber numberWithInt: kAudioFormatLinearPCM ], AVFormatIDKey,
[ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey,
[ NSNumber numberWithInt: 1 ], AVNumberOfChannelsKey,
[ NSData dataWithBytes: &acl length: sizeof( acl ) ], AVChannelLayoutKey,
[ NSNumber numberWithInt: 16 ], AVLinearPCMBitDepthKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
[NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
nil ];
_audioWriterInput = [[AVAssetWriterInput alloc]
initWithMediaType: AVMediaTypeAudio
outputSettings: audioOutputSettings ];
_audioWriterInput.expectsMediaDataInRealTime = YES;
NSParameterAssert(_audioWriterInput);
NSParameterAssert([_assetWriter canAddInput:_audioWriterInput]);
[_assetWriter addInput:_audioWriterInput];
}
}
return self;
}
-(void)startSession{
//This is vedio recorder code
_isStarted =[_assetWriter startWriting];
if(_isStarted)
{
NSLog(#"======== Session started");
[_assetWriter startSessionAtSourceTime:_startingTime];
}
else {
NSLog(#"======== Session failed : %#", _assetWriter.error);
}
}
-(void)endSession
{
_isStarted = NO;
[_audioWriterInput markAsFinished];
[_assetWriter finishWritingWithCompletionHandler:^{
NSLog(#"====== File Save Successfully =======");
}];
}
- (void)newAudioSample:(CMSampleBufferRef)sampleBuffer
{
if (_isStarted) {
if (_videoWriter.status == AVAssetWriterStatusWriting) {
// if(_audioWriterInput.readyForMoreMediaData){
//NSLog(#"Warning: writer status is %d", _videoWriter.status)
if(sampleBuffer){
if (![_audioWriterInput appendSampleBuffer:sampleBuffer]) {
NSLog(#"Unable to write to audio input");
}else{
NSLog(#"====Audio is being recorded===");
}
}
// }
}else if(_videoWriter.status == AVAssetWriterStatusFailed){
NSLog(#"<----- Appending failed ----->");
NSLog(#"Error: %#", _videoWriter.error);
}
}
}
That's all. File is created but with zero bytes. No data is written in it. Please help with with this problem.