創建圖像的視頻並保存到相冊

Question

我是在視頻輸出圖像的陣列和音頻文件

，但我似乎無法將它保存到相機膠捲

一些時間它可以節省，但有時它不會，並給我一個奇怪的錯誤

outputFile.mp4無法保存到保存的照片相冊：錯誤域= NSOSStatusErrorDomain代碼= -12848「電影無法播放。」的UserInfo = 0x7bd7370 {。NSLocalizedDescription =電影無法播放}

這個函數從圖像陣列創建視頻：

-(void) writeImagesToMovieAtPath:(NSString *) path withSize:(CGSize) size 
{ 
    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]; 

    CVPixelBufferRef buffer = NULL; 

    //convert uiimage to CGImage. 

    int frameCount = 16; 
    int kRecordingFPS = 30; 
    UIImage * im = [UIImage imageNamed:@"IMG_0103.JPG"]; 

    NSArray * imageArray = [[NSArray alloc]initWithObjects:im,im,im,im,im,im,im,im,im,im,im,im,im,im,im,im, nil]; 

    for(UIImage * img in imageArray) 
    { 
     buffer = [self pixelBufferFromCGImage:[img 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) kRecordingFPS); 
       append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime]; 

       if(buffer) 
        CVBufferRelease(buffer); 
       [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]; 
    [videoWriter finishWriting]; 
    NSLog(@"Write Ended"); 
    [videoWriterInput release]; 
    [videoWriter release]; 
    [imageArray release]; 
} 

該函數添加音頻：

-(void)CompileFilesToMakeMovie{ 
     AVMutableComposition* mixComposition = [AVMutableComposition composition]; 

     NSString *documentsDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 

     NSString* audio_inputFileName = @"Rihanna-Take a Bow.mp3"; 

     NSString* audio_inputFilePath = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,audio_inputFileName]; 

     NSURL* audio_inputFileUrl = [NSURL fileURLWithPath:audio_inputFilePath]; 

     NSString* video_inputFileName = @"a.mp4"; 
     NSString* video_inputFilePath = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,video_inputFileName]; 
     NSURL* video_inputFileUrl = [NSURL fileURLWithPath:video_inputFilePath]; 

     NSString* outputFileName = @"outputFile.mp4"; 
     NSString* outputFilePath = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,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, videoAsset.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:AVAssetExportPresetMediumQuality]; 
     _assetExport.outputFileType = AVFileTypeMPEG4; 
     _assetExport.outputURL = outputFileUrl; 
     [_assetExport setTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)]; 
     [_assetExport exportAsynchronouslyWithCompletionHandler:nil]; 

     [audioAsset release]; 
     [videoAsset release]; 


     [_assetExport release]; 
    } 

的函數調用：

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    NSString *documentsDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 

    UIImage * i = [UIImage imageNamed:@"IMG_0103.JPG"]; 

    [self writeImagesToMovieAtPath:[NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,@"a.mp4"] withSize:CGSizeMake(i.size.width, i.size.height)]; 

    NSString* exportVideoPath1 = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,@"a.mp4"]; 


    NSString* exportVideoPath = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,@"outputFile.mp4"]; 

    UISaveVideoAtPathToSavedPhotosAlbum (exportVideoPath,self, @selector(video:didFinishSavingWithError: contextInfo:), nil); 

} 

Answer 1

在我的情況下，原因是AVAssetWriter還沒有完成d寫作。解決它與下面的一段代碼：

__block BOOL _finished = NO; 

[assetWriter finishWritingWithCompletionHandler:^{ 
    _finished = YES; 
}]; 

while (!_finished) { 
    [NSThread sleepForTimeInterval:0.1]; 
}