AVMutableComposition Video Creation Issue

Question

I am creating video using AVMutableComposition and exporting it using AVAssetExportSession giving it preset AVAssetExportPresetHighestQuality.

Video is created fine when video's dimension is small. But when video's dimension is large e.g. (1280 × 1920), the video is not created properly. A green overlay is added to Video as below image:

But when I use AVAssetExportPresetPassthrough instead AVAssetExportPresetHighestQuality, the video is created fine.

Any idea why this happens?

Thanks in Advance!!

Olsen

Some more detials please. About the assets, if you are merging assets or something? – Sodomy

Is this problem specific to retina iPad?? – Lucier

To add to @Maverick’s question, are the assets created programmatically? If so, is it from within your own app, or are you importing them from somewhere else? – Muskmelon

Answer 1

try this code:

-(void)convertVideo:(NSString *)videoPath{
        AVURLAsset *firstAsset=[[AVURLAsset alloc]initWithURL:[NSURL URLWithString:    [NSString stringWithFormat:@"%@", videoPath]] options:nil];
        AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];

        //VIDEO TRACK
        AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];

        [firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];

        AVMutableVideoCompositionInstruction * MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
        MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);

        CMTime audioTime = kCMTimeIndefinite;
        CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);

        AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
        [audioSession setActive:YES error:nil];

        if (OS_VERSION>=7) {
            if (firstAsset!=NULL) {
                AVMutableCompositionTrack *compositionCommentaryTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

                [compositionCommentaryTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
            }
        }
        else{
            AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
            [b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:audioTime error:nil];
        }

        //FIXING ORIENTATION//
        AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];

        AVAssetTrack *FirstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
        UIImageOrientation FirstAssetOrientation_  = UIImageOrientationUp;
        BOOL  isFirstAssetPortrait_  = NO;
        CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform;

        if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0){
            FirstAssetOrientation_= UIImageOrientationRight;
            isFirstAssetPortrait_ = YES;
        }
        if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0){
            FirstAssetOrientation_ =  UIImageOrientationLeft;
            isFirstAssetPortrait_ = YES;
        }
        if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0){
            FirstAssetOrientation_ =  UIImageOrientationUp;
        }
        if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0){
            FirstAssetOrientation_ = UIImageOrientationDown;
        }

        [FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration];

        CGFloat FirstAssetScaleToFitRatio = 0;


        MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,nil];

        AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition];
        MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction];
        MainCompositionInst.frameDuration = CMTimeMake(1, 30);

        /*if(isFirstAssetPortrait_){
            FirstAssetScaleToFitRatio = 0.67;
            CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
            [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero];
            naturalSizeFirst = CGSizeMake(FirstAssetTrack.naturalSize.height, FirstAssetTrack.naturalSize.width);
            }else{

                naturalSizeFirst = FirstAssetTrack.naturalSize;
        }
         */

        CGSize naturalSizeFirst;
        if(isFirstAssetPortrait_){
            FirstAssetScaleToFitRatio = FirstAssetTrack.naturalSize.width/FirstAssetTrack.naturalSize.height;
            CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
            [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero];
            naturalSizeFirst = CGSizeMake(FirstAssetTrack.naturalSize.height, FirstAssetTrack.naturalSize.width);

        }else {
            naturalSizeFirst = FirstAssetTrack.naturalSize;
        }

        MainCompositionInst.renderSize = CGSizeMake(naturalSizeFirst.width, naturalSizeFirst.height);

        NSString *tmpDirectory = NSTemporaryDirectory();
        NSString *fname = [NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000];
        NSString *tmpFile = [tmpDirectory stringByAppendingPathComponent:fname];

        NSURL *url = [NSURL fileURLWithPath:tmpFile];

        AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
        exporter.outputURL=url;
        exporter.outputFileType = AVFileTypeQuickTimeMovie;
        exporter.videoComposition = MainCompositionInst;
        exporter.shouldOptimizeForNetworkUse = YES;

        [exporter exportAsynchronouslyWithCompletionHandler:^{

            if (AVAssetExportSessionStatusCompleted == exporter.status) {
                [self.progressStatus setText:@"Converted..."];

                selectedVideo = selectedVideo+1;
            } else if (AVAssetExportSessionStatusFailed == exporter.status) {
                // a failure may happen because of an event out of your control
                // for example, an interruption like a phone call comming in
                // make sure and handle this case appropriately
                //ALog(@"AVAssetExportSessionStatusFailed %@",exporter.error);

            } else {
                //ALog(@"Export Session Status: %d", exporter.status);
            }
        }];
    }
}

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