AVCaptureVideoDataOutput ve AVCaptureAudioDataOutput kullanırken performans sorunları

Question

AVCaptureVideoDataOutput ve AVCaptureAudioDataOutput kullanarak ses + video kaydederken gecikme sorunları yaşıyorum. Bazen video, birkaç milisaniyeye kadar, bazen ses, videoyla senkronize edilmez.

Bazı günlükler ekledim ve önce captureOutput geri çağrısında çok fazla video arabelleği aldığımı ve bir süre sonra ses arabelleklerini aldığımı gözlemledim (bazen ses arabelleklerini almıyorum ve sonuçta ortaya çıkan video ses olmadan). Video arabelleklerini işleyen kodu yorumlarsam, ses arabelleklerini sorunsuz alırım. Geri arama burada

-(BOOL) setupWriter:(NSURL *)videoURL session:(AVCaptureSession *)captureSessionLocal 
{ 
    NSError *error = nil; 
    self._videoWriter = [[AVAssetWriter alloc] initWithURL:videoURL fileType:AVFileTypeQuickTimeMovie 
                 error:&error]; 
    NSParameterAssert(self._videoWriter); 


    // Add video input 
    NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys: 
            AVVideoCodecH264, AVVideoCodecKey, 
            [NSNumber numberWithInt:640], AVVideoWidthKey, 
            [NSNumber numberWithInt:480], AVVideoHeightKey, 
            nil]; 

    self._videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo 
                     outputSettings:videoSettings]; 


    NSParameterAssert(self._videoWriterInput); 
    self._videoWriterInput.expectsMediaDataInRealTime = YES; 
    self._videoWriterInput.transform = [self returnOrientation]; 

    // Add the audio input 
    AudioChannelLayout acl; 
    bzero(&acl, sizeof(acl)); 
    acl.mChannelLayoutTag = kAudioChannelLayoutTag_Mono; 


    NSDictionary* audioOutputSettings = nil;   
    // Both type of audio inputs causes output video file to be corrupted. 

     // should work on any device requires more space 
     audioOutputSettings = [ NSDictionary dictionaryWithObjectsAndKeys:      
           [ NSNumber numberWithInt: kAudioFormatAppleLossless ], AVFormatIDKey, 
           [ NSNumber numberWithInt: 16 ], AVEncoderBitDepthHintKey, 
           [ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey, 
           [ NSNumber numberWithInt: 1 ], AVNumberOfChannelsKey,          
           [ NSData dataWithBytes: &acl length: sizeof(acl) ], AVChannelLayoutKey, 
           nil ]; 

    self._audioWriterInput = [AVAssetWriterInput 
             assetWriterInputWithMediaType: AVMediaTypeAudio 
             outputSettings: audioOutputSettings ]; 

    self._audioWriterInput.expectsMediaDataInRealTime = YES;  

    // add input 
    [self._videoWriter addInput:_videoWriterInput]; 
    [self._videoWriter addInput:_audioWriterInput]; 

    return YES; 
} 

Ve edilir: bir şey

- (void)captureOutput:(AVCaptureOutput *)captureOutput 
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer 
     fromConnection:(AVCaptureConnection *)connection 
{ 

    if(!CMSampleBufferDataIsReady(sampleBuffer)) 
    { 
     NSLog(@"sample buffer is not ready. Skipping sample"); 
     return; 
    } 
    if(_videoWriter.status != AVAssetWriterStatusCompleted) 
    { 
     if(_videoWriter.status != AVAssetWriterStatusWriting ) 
     {    
      CMTime lastSampleTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer); 
      [_videoWriter startWriting]; 
      [_videoWriter startSessionAtSourceTime:lastSampleTime]; 
     } 

     if(captureOutput == _videoOutput) 
     { 
      if([self._videoWriterInput isReadyForMoreMediaData]) 
      { 

      [self newVideoSample:sampleBuffer]; 

      } 
     } 
     else if(captureOutput == _audioOutput) 
     { 
      if([self._audioWriterInput isReadyForMoreMediaData]) 
      { 

       [self newAudioSample:sampleBuffer]; 


      } 
     } 
    } 

} 

-(void) newAudioSample:(CMSampleBufferRef)sampleBuffer 
{ 

     if(_videoWriter.status > AVAssetWriterStatusWriting) 
     { 

      [self NSLogPrint:[NSString stringWithFormat:@"Audio:Warning: writer status is %d", _videoWriter.status]]; 
      if(_videoWriter.status == AVAssetWriterStatusFailed) 
       [self NSLogPrint:[NSString stringWithFormat:@"Audio:Error: %@", _videoWriter.error]]; 
      return; 
     } 

     if(![_audioWriterInput appendSampleBuffer:sampleBuffer]) 
      [self NSLogPrint:[NSString stringWithFormat:@"Unable to write to audio input"]]; 

} 

-(void) newVideoSample:(CMSampleBufferRef)sampleBuffer 
{ 
    if(_videoWriter.status > AVAssetWriterStatusWriting) 
    { 
     [self NSLogPrint:[NSString stringWithFormat:@"Video:Warning: writer status is %d", _videoWriter.status]]; 
     if(_videoWriter.status == AVAssetWriterStatusFailed) 
      [self NSLogPrint:[NSString stringWithFormat:@"Video:Error: %@", _videoWriter.error]]; 
     return; 
    } 


    if(![_videoWriterInput appendSampleBuffer:sampleBuffer]) 
     [self NSLogPrint:[NSString stringWithFormat:@"Unable to write to video input"]]; 
} 

var mı

-(void)initMovieOutput:(AVCaptureSession *)captureSessionLocal 
{ 
    AVCaptureVideoDataOutput *dataOutput = [[AVCaptureVideoDataOutput alloc] init]; 
    self._videoOutput = dataOutput; 
    [dataOutput release]; 

    self._videoOutput.alwaysDiscardsLateVideoFrames = NO; 
    self._videoOutput.videoSettings = [NSDictionary dictionaryWithObject: [NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange] 
                  forKey:(id)kCVPixelBufferPixelFormatTypeKey 
            ];  
    AVCaptureAudioDataOutput *audioOutput = [[AVCaptureAudioDataOutput alloc] init]; 
    self._audioOutput = audioOutput; 
    [audioOutput release]; 

    [captureSessionLocal addOutput:self._videoOutput]; 
    [captureSessionLocal addOutput:self._audioOutput]; 


    // Setup the queue 
    dispatch_queue_t queue = dispatch_queue_create("MyQueue", NULL); 
    [self._videoOutput setSampleBufferDelegate:self queue:queue]; 
    [self._audioOutput setSampleBufferDelegate:self queue:queue]; 
    dispatch_release(queue); 
} 

İşte

Yazara kurmak:

Bu

kullanıyorum kodudur Benim kodumda yanlış, neden video geciktiriyor? (Bunu bir Iphone 4 ios 4.2.1 üzerinde test ediyorum)

Answer 1

Seri kuyrukları kullanıyorsunuz gibi görünüyor. Ses Çıktısı kuyruğu, video çıkış kuyruğundan hemen sonradır. Eşzamanlı kuyrukları kullanmayı düşünün.