I have reduced this question quite a bit and am hoping for some help.
Basically this class has two methods, one to start recording audio (-recordMode) and the other to play audio (playMode). I currently have this class in a project with a single view controller with two buttons that call the corresponding methods (rec, play). There are no other variables, the class is self-contained.
However it will not play/rec anything and I cannot figure out why. When I try to play the file I get a file size of 0 and an error because you cant init the AVAudioPlayer with a nil reference of course. But I dont understand why the file is empty or why self.outputPath is nil.
.h file
#import <AVFoundation/AVFoundation.h>
@interface MicCommunicator : NSObject<AVCaptureAudioDataOutputSampleBufferDelegate>
@property(nonatomic,retain) NSURL *outputPath;
@property(nonatomic,retain) AVCaptureSession * captureSession;
@property(nonatomic,retain) AVCaptureAudioDataOutput * output;
-(void)beginStreaming;
-(void)playMode;
-(void)recordMode;
@end
.m file:
@implementation MicCommunicator {
AVAssetWriter *assetWriter;
AVAssetWriterInput *assetWriterInput;
}
@synthesize captureSession = _captureSession;
@synthesize output = _output;
@synthesize outputPath = _outputPath;
-(id)init {
if ((self = [super init])) {
NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
self.outputPath = [NSURL fileURLWithPath:[[searchPaths objectAtIndex:0] stringByAppendingPathComponent:@"micOutput.output"]];
AudioChannelLayout acl;
bzero(&acl, sizeof(acl));
acl.mChannelLayoutTag = kAudioChannelLayoutTag_Mono; //kAudioChannelLayoutTag_Stereo;
NSDictionary *audioOutputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt: kAudioFormatULaw],AVFormatIDKey,
[NSNumber numberWithFloat:8000.0],AVSampleRateKey,//was 44100.0
[NSData dataWithBytes: &acl length: sizeof( AudioChannelLayout ) ], AVChannelLayoutKey,
[NSNumber numberWithInt:1],AVNumberOfChannelsKey,
[NSNumber numberWithInt:8000.0],AVEncoderBitRateKey,
nil];
assetWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings:audioOutputSettings];
[assetWriterInput setExpectsMediaDataInRealTime:YES];
assetWriter = [[AVAssetWriter assetWriterWithURL:_outputPath fileType:AVFileTypeWAVE error:nil] retain];
[assetWriter addInput:assetWriterInput];
}
return self;
}
-(void)dealloc {
[assetWriter release];
[super dealloc];
}
//conveniance methods
-(void)playMode
{
[self stopRecording];
NSError *error;
AVAudioPlayer * audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:self.outputPath error:&error];
audioPlayer.numberOfLoops = -1;
if (audioPlayer == nil){
NSLog(@"error: %@",[error description]);
}else{
NSLog(@"playing");
[audioPlayer play];
}
}
-(void)recordMode
{
[self beginStreaming];
}
-(void)stopRecording
{
[self.captureSession stopRunning];
[assetWriterInput markAsFinished];
[assetWriter finishWriting];
NSDictionary *outputFileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:[NSString stringWithFormat:@"%@",self.outputPath] error:nil];
NSLog (@"done. file size is %llu", [outputFileAttributes fileSize]);
}
//starts audio recording
-(void)beginStreaming {
self.captureSession = [[AVCaptureSession alloc] init];
AVCaptureDevice *audioCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error = nil;
AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error];
if (audioInput)
[self.captureSession addInput:audioInput];
else {
NSLog(@"No audio input found.");
return;
}
AVCaptureAudioDataOutput *output = [[AVCaptureAudioDataOutput alloc] init];
dispatch_queue_t outputQueue = dispatch_queue_create("micOutputDispatchQueue", NULL);
[output setSampleBufferDelegate:self queue:outputQueue];
dispatch_release(outputQueue);
[self.captureSession addOutput:output];
[assetWriter startWriting];
[self.captureSession startRunning];
}
//callback
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
AudioBufferList audioBufferList;
NSMutableData *data= [[NSMutableData alloc] init];
CMBlockBufferRef blockBuffer;
CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, NULL, &audioBufferList, sizeof(audioBufferList), NULL, NULL, 0, &blockBuffer);
//for (int y = 0; y < audioBufferList.mNumberBuffers; y++) {
// AudioBuffer audioBuffer = audioBufferList.mBuffers[y];
// Float32 *frame = (Float32*)audioBuffer.mData;
//
// [data appendBytes:frame length:audioBuffer.mDataByteSize];
//}
// append [data bytes] to your NSOutputStream
// These two lines write to disk, you may not need this, just providing an example
[assetWriter startSessionAtSourceTime:CMSampleBufferGetPresentationTimeStamp(sampleBuffer)];
[assetWriterInput appendSampleBuffer:sampleBuffer];
CFRelease(blockBuffer);
blockBuffer=NULL;
[data release];
}
@end
