Merging NSData video files into one video file

问题:

I have a bunch of video files that I want to merge into one video file, I am using NSMutableData to achieve the task

NSMutableData *concatenatedData = [[NSMutableData alloc] init];
for (int i=0; i <[videoArray count]; i ++) {
  [concatenatedData appendData: [videoArray objectAtIndex:i]];
}
[concatenatedData writeToFile:[[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"outputConct.mov"] atomically:YES];
UISaveVideoAtPathToSavedPhotosAlbum([[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(),@"outputConct.mov"], nil, nil, nil);

after the video is saved in my camera roll I try to play it but only the first NSData video is in it. I am not sure why.

edit

I tried AVMutableComposition, even then I am having the same issues

AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
        AVURLAsset* firstAsset;
        AVMutableCompositionTrack *firstTrack;
        CMTime time = kCMTimeZero;
        for (int i=0; i<[videoArray count]; i++) {
            firstAsset = [[AVURLAsset alloc]initWithURL:[NSURL fileURLWithPath:[[NSString alloc] initWithFormat:@"%@%d%@", NSTemporaryDirectory(),i, @"output.mov"]] options:nil];
            firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
            [firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:time error:nil];
            time = firstAsset.duration;
        }

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *myPathDocs =  [documentsDirectory stringByAppendingPathComponent:
                                 [NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000]];
        NSURL *url = [NSURL fileURLWithPath:myPathDocs];
        // 5 - Create exporter
        AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
                                                                          presetName:AVAssetExportPresetHighestQuality];
        exporter.outputURL=url;
        exporter.outputFileType = AVFileTypeQuickTimeMovie;
        exporter.shouldOptimizeForNetworkUse = YES;
        [exporter exportAsynchronouslyWithCompletionHandler:^{
            dispatch_async(dispatch_get_main_queue(), ^{
                if (exporter.status == AVAssetExportSessionStatusCompleted) {
                    //NSURL *outputURL = exporter.outputURL;
                    UISaveVideoAtPathToSavedPhotosAlbum(myPathDocs, nil, nil, nil);
                }
            });
        }];

edit

I also tried this, but it gives me an error, it says [__NSArrayM insertObject:atIndex:]: object cannot be nil'

AVMutableComposition *mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
NSError * error = nil;
NSMutableArray * timeRanges = [NSMutableArray arrayWithCapacity:[videoArray count]];
NSMutableArray * tracks = [NSMutableArray arrayWithCapacity:[videoArray count]];
for (int i=0; i<[videoArray count]; i++) {
    AVURLAsset *assetClip = [[AVURLAsset alloc]initWithURL:[NSURL fileURLWithPath:[[NSString alloc] initWithFormat:@"%@%d%@", NSTemporaryDirectory(),i, @"output.mov"]] options:nil];
    AVAssetTrack *clipVideoTrackB = [[assetClip tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

    [timeRanges addObject:[NSValue valueWithCMTimeRange:CMTimeRangeMake(kCMTimeZero, assetClip.duration)]];
    [tracks addObject:clipVideoTrackB];
}
[compositionTrack insertTimeRanges:timeRanges ofTracks:tracks atTime:kCMTimeZero error:&error];

This is the line where the program is crashing.

[compositionTrack insertTimeRanges:timeRanges ofTracks:tracks atTime:kCMTimeZero error:&error];

I am not sure why as both timeRanges and tracks have values in them

回答1:

You can merge multiple videos and create a single video by appending one after other using AVFoundation classes- AVURLAsset, AVMutableComposition, AVMutableCompositionTrack etc.

You can check this Append/merge multiple video files into one final output video

There is a nice tutorials also 1.Tutorial 1 2.Tutorial 2

Hope it helps you.