Make movie file with picture Array and song file, using AVAsset

I'm trying to make movie file using a picture array and an audio file. To make movie with a picture array i used the big post by zoul here. All is perfect, I have my movie with my picture. However when I try to add some audio tracks I have lot of problems. To understand I put my code :

When I call this method, picture array and song file are ready :

-(void) writeImagesToMovieAtPath:(NSString *) path withSize:(CGSize) size
{
    NSString *documentsDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSArray *dirContents = [[NSFileManager defaultManager] directoryContentsAtPath:documentsDirectoryPath];
    for (NSString *tString in dirContents) {
        if ([tString isEqualToString:@"essai.mp4"]) 
        {
            [[NSFileManager defaultManager]removeItemAtPath:[NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,tString] error:nil];

        }
    }

    NSLog(@"Write Started");

    NSError *error = nil;

    AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
                                  [NSURL fileURLWithPath:path] fileType:AVFileTypeMPEG4
                                                              error:&error];    
    NSParameterAssert(videoWriter);

    NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                   [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                                   nil];

    AudioChannelLayout channelLayout;
    memset(&channelLayout, 0, sizeof(AudioChannelLayout));
    channelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;

    NSDictionary *audioSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   [NSNumber numberWithInt:kAudioFormatMPEG4AAC], AVFormatIDKey,
                                   [NSNumber numberWithFloat:44100.0] ,AVSampleRateKey, 
                                   [NSNumber numberWithInt: 1] ,AVNumberOfChannelsKey,
                                   [NSNumber numberWithInt:192000],AVEncoderBitRateKey,
                                   [NSData dataWithBytes:&channelLayout length:sizeof(AudioChannelLayout)],AVChannelLayoutKey,
                                   nil];

    AVAssetWriterInput* videoWriterInput = [[AVAssetWriterInput
                                             assetWriterInputWithMediaType:AVMediaTypeVideo
                                             outputSettings:videoSettings] retain];

    AVAssetWriterInput* audioWriterInput = [[AVAssetWriterInput
                                             assetWriterInputWithMediaType:AVMediaTypeAudio
                                             outputSettings:audioSettings] retain];

    NSURL* fileURL = [[NSBundle mainBundle] URLForResource:@"Big_Voice_1" withExtension:@"caf"];

    NSLog(@"%@",fileURL);
    AVAsset *asset = [[AVURLAsset URLAssetWithURL:fileURL 
                                            options:nil] retain];


    AVAssetReader *audioReader = [[AVAssetReader assetReaderWithAsset:asset error:&error] retain];


    AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
                                                     assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput
                                                     sourcePixelBufferAttributes:nil];


    AVAssetTrack* audioTrack = [asset.tracks objectAtIndex:0]; 

    AVAssetReaderOutput *readerOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:audioTrack outputSettings:nil];

    [audioReader addOutput:readerOutput];                                             


    NSParameterAssert(videoWriterInput);
    NSParameterAssert(audioWriterInput);
    NSParameterAssert([videoWriter canAddInput:audioWriterInput]);
    NSParameterAssert([videoWriter canAddInput:videoWriterInput]);
    audioWriterInput.expectsMediaDataInRealTime = NO;
    videoWriterInput.expectsMediaDataInRealTime = YES;
    [videoWriter addInput:audioWriterInput];
    [videoWriter addInput:videoWriterInput];
    //Start a session:
    [videoWriter startWriting];
    [videoWriter startSessionAtSourceTime:kCMTimeZero];


    //Video encoding

    CVPixelBufferRef buffer = NULL;

    //convert uiimage to CGImage.

    int frameCount = 0;

    for(int i = 0; i<20; i++)
    {
        buffer = [self pixelBufferFromCGImage:[[m_PictArray objectAtIndex:i] CGImage] andSize:size];


        BOOL append_ok = NO;
        int j = 0;
        while (!append_ok && j < 30) 
        {
            if (adaptor.assetWriterInput.readyForMoreMediaData) 
            {
                printf("appending %d attemp %d\n", frameCount, j);

                CMTime frameTime = CMTimeMake(frameCount,(int32_t) 10);

                //CVPixelBufferPoolCreatePixelBuffer (kCFAllocatorDefault, adaptor.pixelBufferPool, &buffer);
                append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
                CVPixelBufferPoolRef bufferPool = adaptor.pixelBufferPool;
                NSParameterAssert(bufferPool != NULL);

                [NSThread sleepForTimeInterval:0.05];
            } 
            else 
            {
                printf("adaptor not ready %d, %d\n", frameCount, j);
                [NSThread sleepForTimeInterval:0.1];
            }
            j++;
        }
        if (!append_ok) {
            printf("error appending image %d times %d\n", frameCount, j);
        }
        frameCount++;
    }

    //Finish the session:
    [videoWriterInput markAsFinished];





//Start a session:
        [videoWriter startWriting];
        [videoWriter startSessionAtSourceTime:kCMTimeZero];

        CVPixelBufferRef buffer = NULL;

        //Write all picture array in movie file.

        int frameCount = 0;

        for(int i = 0; i<[m_PictArray count]; i++)
        {
            buffer = [self pixelBufferFromCGImage:[[m_PictArray objectAtIndex:i] CGImage] andSize:size];


            BOOL append_ok = NO;
            int j = 0;
            while (!append_ok && j < 30) 
            {
                if (adaptor.assetWriterInput.readyForMoreMediaData) 
                {
                    printf("appending %d attemp %d\n", frameCount, j);

                    CMTime frameTime = CMTimeMake(frameCount,(int32_t) 10);


                    append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
                    CVPixelBufferPoolRef bufferPool = adaptor.pixelBufferPool;
                    NSParameterAssert(bufferPool != NULL);

                    [NSThread sleepForTimeInterval:0.05];
                } 
                else 
                {
                    printf("adaptor not ready %d, %d\n", frameCount, j);
                    [NSThread sleepForTimeInterval:0.1];
                }
                j++;
            }
            if (!append_ok) {
                printf("error appending image %d times %d\n", frameCount, j);
            }
            frameCount++;
        }

        //Finish writing picture:
        [videoWriterInput markAsFinished];

I finish write picture in movie file and I want copy audio in the file and I do this :

[audioReader startReading];

    [videoWriter startSessionAtSourceTime:kCMTimeZero];
    dispatch_queue_t mediaInputQueue = dispatch_queue_create("mediaInputQueue", NULL);
    [audioWriterInput requestMediaDataWhenReadyOnQueue:mediaInputQueue usingBlock:^
     {
         NSLog(@"Request");
         NSLog(@"Asset Writer ready :%d",audioWriterInput.readyForMoreMediaData);
         while (audioWriterInput.readyForMoreMediaData) {
             NSLog(@"Ready");
             CMSampleBufferRef nextBuffer = [readerOutput copyNextSampleBuffer];
             if (nextBuffer) {
                 NSLog(@"NextBuffer");
                 [audioWriterInput appendSampleBuffer:nextBuffer];
             }
         }
     }
     ];

    [audioWriterInput markAsFinished];
    [videoWriter finishWriting];

However the status of AssetWriterInput of audio file is always "NO".

My question : How to add audio to a video file using AVFoundation?

So please can someone help me by telling me if I forget something or if something is wrong.

Thank you very much


I finally found how make movie with a picture array and an audio file. So if you want do the same thing I put my code here (be careful to memory):

  • First make a movie file with your picture array use zoul's post here:

    -(void) writeImagesToMovieAtPath:(NSString *) path withSize:(CGSize) size
    {
      NSString *documentsDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
      NSArray *dirContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:documentsDirectoryPath error:nil];
      for (NSString *tString in dirContents) 
      {
        if ([tString isEqualToString:@"essai.mp4"]) 
        {
            [[NSFileManager defaultManager]removeItemAtPath:[NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,tString] error:nil];
    
        }
      }
    
      NSLog(@"Write Started");
    
      NSError *error = nil;
    
      AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
                                  [NSURL fileURLWithPath:path] fileType:AVFileTypeMPEG4
                                                              error:&error];    
      NSParameterAssert(videoWriter);
    
      NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                   [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                                   nil];
    
    
      AVAssetWriterInput* videoWriterInput = [[AVAssetWriterInput
                                             assetWriterInputWithMediaType:AVMediaTypeVideo
                                             outputSettings:videoSettings] retain];
    
    
    
    
      AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
                                                     assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput
                                                     sourcePixelBufferAttributes:nil];
    
      NSParameterAssert(videoWriterInput);
    
      NSParameterAssert([videoWriter canAddInput:videoWriterInput]);
      videoWriterInput.expectsMediaDataInRealTime = YES;
      [videoWriter addInput:videoWriterInput];
      //Start a session:
      [videoWriter startWriting];
      [videoWriter startSessionAtSourceTime:kCMTimeZero];
    
    
      //Video encoding
    
      CVPixelBufferRef buffer = NULL;
    
      //convert uiimage to CGImage.
    
      int frameCount = 0;
    
      for(int i = 0; i<[m_PictArray count]; i++)
      {
        buffer = [self pixelBufferFromCGImage:[[m_PictArray objectAtIndex:i] CGImage] andSize:size];
    
    
        BOOL append_ok = NO;
        int j = 0;
        while (!append_ok && j < 30) 
        {
            if (adaptor.assetWriterInput.readyForMoreMediaData) 
            {
                printf("appending %d attemp %d\n", frameCount, j);
    
                CMTime frameTime = CMTimeMake(frameCount,(int32_t) 10);
    
                append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
                CVPixelBufferPoolRef bufferPool = adaptor.pixelBufferPool;
                NSParameterAssert(bufferPool != NULL);
    
                [NSThread sleepForTimeInterval:0.05];
            } 
            else 
            {
                printf("adaptor not ready %d, %d\n", frameCount, j);
                [NSThread sleepForTimeInterval:0.1];
            }
            j++;
        }
        if (!append_ok) 
        {
            printf("error appending image %d times %d\n", frameCount, j);
        }
        frameCount++;
        CVBufferRelease(buffer);
      }
    
      [videoWriterInput markAsFinished];
      [videoWriter finishWriting];
    
      [videoWriterInput release];
      [videoWriter release];
    
      [m_PictArray removeAllObjects];
    
      NSLog(@"Write Ended"); 
    }
    
  • After that you must put together movie file and audio file. To do this follow my code:

    -(void)CompileFilesToMakeMovie
    {
      AVMutableComposition* mixComposition = [AVMutableComposition composition];
    
      NSString* audio_inputFileName = @"deformed.caf";
      NSString* audio_inputFilePath = [Utilities documentsPath:audio_inputFileName];
      NSURL*    audio_inputFileUrl = [NSURL fileURLWithPath:audio_inputFilePath];
    
      NSString* video_inputFileName = @"essai.mp4";
      NSString* video_inputFilePath = [Utilities documentsPath:video_inputFileName];
      NSURL*    video_inputFileUrl = [NSURL fileURLWithPath:video_inputFilePath];
    
      NSString* outputFileName = @"outputFile.mov";
      NSString* outputFilePath = [Utilities documentsPath:outputFileName];
      NSURL*    outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
    
      if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath]) 
        [[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];
    
    
    
      CMTime nextClipStartTime = kCMTimeZero;
    
      AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:video_inputFileUrl options:nil];
      CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
      AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
      [a_compositionVideoTrack insertTimeRange:video_timeRange ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:nextClipStartTime error:nil];
    
      //nextClipStartTime = CMTimeAdd(nextClipStartTime, a_timeRange.duration);
    
      AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:audio_inputFileUrl options:nil];
      CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);
      AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
      [b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil];
    
    
    
      AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];   
      _assetExport.outputFileType = @"com.apple.quicktime-movie";
      _assetExport.outputURL = outputFileUrl;
    
      [_assetExport exportAsynchronouslyWithCompletionHandler:
     ^(void ) {
         [self saveVideoToAlbum:outputFilePath]; 
     }       
     ];  
    }
    

Sorry if there are some leak, I'm doing the optimization of memory.


The AVChannelLayoutKey should point to an NSData instance containing an AudioChannelLayout.

Yours points to an NSNumber.