AVAssetWritter does not work with audio

Question

I am trying to get audio to work with video for an iOS application. The video is fine. Sound is not recorded to the file (my iPhone speaker is working).

Here's the init setup:

session = [[AVCaptureSession alloc] init];
    menu->session = session;
    menu_open = NO;
    session.sessionPreset = AVCaptureSessionPresetMedium;
    camera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    microphone = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    menu->camera = camera;
    [session beginConfiguration];
    [camera lockForConfiguration:nil];
    if([camera isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure]){
        camera.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
    }
    if([camera isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus]){
        camera.focusMode = AVCaptureFocusModeContinuousAutoFocus;
    }
    if([camera isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance]){
        camera.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
    }
    if ([camera hasTorch]) {
        if([camera isTorchModeSupported:AVCaptureTorchModeOn]){
            [camera setTorchMode:AVCaptureTorchModeOn];
        }
    }
    [camera unlockForConfiguration];
    [session commitConfiguration];
    AVCaptureDeviceInput * camera_input = [AVCaptureDeviceInput deviceInputWithDevice:camera error:nil];
    [session addInput:camera_input];
    microphone_input = [[AVCaptureDeviceInput deviceInputWithDevice:microphone error:nil] retain];
    AVCaptureVideoDataOutput * output = [[[AVCaptureVideoDataOutput alloc] init] autorelease];
    output.videoSettings = [NSDictionary dictionaryWithObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
    [session addOutput:output];
    output.minFrameDuration = CMTimeMake(1,30);
    dispatch_queue_t queue = dispatch_queue_create("MY QUEUE", NULL);
    [output setSampleBufferDelegate:self queue:queue];
    dispatch_release(queue);
    audio_output = [[[AVCaptureAudioDataOutput alloc] init] retain];
    queue = dispatch_queue_create("MY QUEUE", NULL);
    AudioOutputBufferDelegate * special_delegate = [[[AudioOutputBufferDelegate alloc] init] autorelease];
    special_delegate->normal_delegate = self;
    [special_delegate retain];
    [audio_output setSampleBufferDelegate:special_delegate queue:queue];
    dispatch_release(queue);
    [session startRunning];

Here is the beginning and end of the recording:

if (recording) { //Hence stop recording
    [video_button setTitle:@"Video" forState: UIControlStateNormal];
    recording = NO;
    [writer_input markAsFinished];
    [audio_writer_input markAsFinished];
    [video_writer endSessionAtSourceTime: CMTimeMakeWithSeconds([[NSDate date] timeIntervalSinceDate: start_time],30)];
    [video_writer finishWriting];
    UISaveVideoAtPathToSavedPhotosAlbum(temp_url,self,@selector(video:didFinishSavingWithError:contextInfo:),nil);
    [start_time release];
    [temp_url release];
    [av_adaptor release];
    [microphone lockForConfiguration:nil];
    [session beginConfiguration];
    [session removeInput:microphone_input];
    [session removeOutput:audio_output];
    [session commitConfiguration];
    [microphone unlockForConfiguration];
    [menu restateConfigiration];
    [vid_off play];
}else{ //Start recording
    [vid_on play];
    [microphone lockForConfiguration:nil];
    [session beginConfiguration];
    [session addInput:microphone_input];
    [session addOutput:audio_output];
    [session commitConfiguration];
    [microphone unlockForConfiguration];
    [menu restateConfigiration];
    [video_button setTitle:@"Stop" forState: UIControlStateNormal];
    recording = YES;
    NSError *error = nil;
    NSFileManager * file_manager = [[NSFileManager alloc] init];
    temp_url = [[NSString alloc] initWithFormat:@"%@/%@", NSTemporaryDirectory(), @"temp.mp4"];
    [file_manager removeItemAtPath: temp_url error:NULL];
    [file_manager release];
    video_writer = [[AVAssetWriter alloc] initWithURL: [NSURL fileURLWithPath:temp_url] fileType: AVFileTypeMPEG4 error: &error];
    NSDictionary *video_settings = [NSDictionary dictionaryWithObjectsAndKeys: AVVideoCodecH264, AVVideoCodecKey,[NSNumber numberWithInt:360], AVVideoWidthKey,[NSNumber numberWithInt:480], AVVideoHeightKey,nil];
    writer_input = [[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:video_settings] retain];
    AudioChannelLayout acl;
    bzero( &acl, sizeof(acl));
    acl.mChannelLayoutTag = kAudioChannelLayoutTag_Mono;
    audio_writer_input = [[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings: [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt: kAudioFormatMPEG4AAC], AVFormatIDKey,[NSNumber numberWithInt: 1], AVNumberOfChannelsKey,[NSNumber numberWithFloat: 44100.0], AVSampleRateKey,[NSNumber numberWithInt: 64000], AVEncoderBitRateKey,[NSData dataWithBytes: &acl length: sizeof(acl) ], AVChannelLayoutKey,nil]] retain];
    audio_writer_input.expectsMediaDataInRealTime = YES;
    av_adaptor = [[AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput: writer_input sourcePixelBufferAttributes:NULL] retain];
    [video_writer addInput:writer_input];
    [video_writer addInput: audio_writer_input];
    [video_writer startWriting];
    [video_writer startSessionAtSourceTime: CMTimeMake(0,1)];
    start_time = [[NSDate alloc] init];
}

Here is the delegate for audio:

@implementation AudioOutputBufferDelegate
    -(void)captureOutput: (AVCaptureOutput *) captureOutput didOutputSampleBuffer: (CMSampleBufferRef) sampleBuffer fromConnection: (AVCaptureConnection *) conenction{
        if (normal_delegate->recording) {
            CMSampleBufferSetOutputPresentationTimeStamp(sampleBuffer,CMTimeMakeWithSeconds([[NSDate date] timeIntervalSinceDate: normal_delegate->start_time],30));
            [normal_delegate->audio_writer_input appendSampleBuffer: sampleBuffer];
        }
    }
@end

The video method does not matter because it works. "restateConfigiration" just sorts the configuration of the session, otherwise the torch is turned off, etc .:

[session beginConfiguration];
    switch (quality) {
        case Low:
            session.sessionPreset = AVCaptureSessionPresetLow;
            break;
        case Medium:
            session.sessionPreset = AVCaptureSessionPreset640x480;
            break;
    }
    [session commitConfiguration];
    [camera lockForConfiguration:nil];
    if([camera isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure]){
        camera.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
    }
    if([camera isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus]){
        camera.focusMode = AVCaptureFocusModeContinuousAutoFocus;
    }
    if([camera isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance]){
        camera.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
    }
    if ([camera hasTorch]) {
        if (torch) {
            if([camera isTorchModeSupported:AVCaptureTorchModeOn]){
                [camera setTorchMode:AVCaptureTorchModeOn];
            }
        }else{
            if([camera isTorchModeSupported:AVCaptureTorchModeOff]){
                [camera setTorchMode:AVCaptureTorchModeOff];
            }
        }
    }
    [camera unlockForConfiguration];

Give up on you for any help.

Answer 1

AVAssetWriter and Audio

This may be the same problem as in the related record. Try commenting on these lines.

[writer_input markAsFinished];
[audio_writer_input markAsFinished];
[video_writer endSessionAtSourceTime: CMTimeMakeWithSeconds([[NSDate date] timeIntervalSinceDate: start_time],30)];

Edit

, . , , - , ​​ 0. , , :

if (_startTime.value == 0) {
    _startTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
}

[bufferWriter->writer startWriting];
[bufferWriter->writer startSessionAtSourceTime:_startTime];

, . AVFoundation , . , , - CMSampleBufferRef 1 , PTS. , PTS .

, . ( ).

switch (bufferWriter->writer.status) {
    case AVAssetWriterStatusUnknown:

        if (_startTime.value == 0) {
            _startTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
        }

        [bufferWriter->writer startWriting];
        [bufferWriter->writer startSessionAtSourceTime:_startTime];

        //Break if not ready, otherwise fall through.
        if (bufferWriter->writer.status != AVAssetWriterStatusWriting) {
            break ;
        }

    case AVAssetWriterStatusWriting:
        if( captureOutput == self.captureManager.audioOutput) {
                if( !bufferWriter->audioIn.readyForMoreMediaData) { 
                    break;
                }

                @try {
                    if( ![bufferWriter->audioIn appendSampleBuffer:sampleBuffer] ) {
                        [self delegateMessage:@"Audio Writing Error" withType:ERROR];
                    }
                }
                @catch (NSException *e) {
                    NSLog(@"Audio Exception: %@", [e reason]);
                }
        }
        else if( captureOutput == self.captureManager.videoOutput ) {

            if( !bufferWriter->videoIn.readyForMoreMediaData) { 
                break;; 
            }

            @try {
                if (!frontCamera) {
                    if( ![bufferWriter->videoIn appendSampleBuffer:sampleBuffer] ) {
                        [self delegateMessage:@"Video Writing Error" withType:ERROR];
                    }
                }
                else {
                    CMTime pt = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);

                    flipBuffer(sampleBuffer, pixelBuffer);

                    if( ![bufferWriter->adaptor appendPixelBuffer:pixelBuffer withPresentationTime:pt] ) {
                        [self delegateMessage:@"Video Writing Error" withType:ERROR];
                    }
                }

            }
            @catch (NSException *e) {
                NSLog(@"Video Exception Exception: %@", [e reason]);
            }
        }

        break;
    case AVAssetWriterStatusCompleted:
        return;
    case AVAssetWriterStatusFailed: 
        [self delegateMessage:@"Critical Error Writing Queues" withType:ERROR];
        bufferWriter->writer_failed = YES ;
        _broadcastError = YES;
        [self stopCapture] ;
        return;
    case AVAssetWriterStatusCancelled:
        break;
    default:
        break;
}