Videoclip导出错误：Objective-C中的“无效的输出文件类型”

Question

I am trying to trim an existing videoclip and re-save the clip in the same location as the original file. However when I run my app I get this error:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid output file type'

I have found recommendations but they require me to change the outputfiletype from AVMediaTypeVideo. I would like to keep AVMediaTypeVideo because this is what the original video file is saved as.

This is what I have so far:

AVMutableComposition *finalClip = [[AVMutableComposition alloc]init];

NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output.mov"];

NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];

AVURLAsset *videoclip = [AVURLAsset URLAssetWithURL:outputURL options:nil];

AVMutableCompositionTrack *finalClipTrack = [finalClip addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];

[finalClipTrack insertTimeRange:CMTimeRangeMake(CMTimeMake((duration*indexNum), 1), CMTimeMake(duration,1)) ofTrack:[[videoclip tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];

NSString *outputPathwe = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"outputwe.mov"];

NSURL *outputURLwe = [[NSURL alloc] initFileURLWithPath:outputPathwe];

if ([[NSFileManager defaultManager] fileExistsAtPath:outputPathwe])
    [[NSFileManager defaultManager] removeItemAtPath:outputPathwe error:nil];

AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:finalClip presetName:AVAssetExportPresetHighestQuality];

exporter.outputFileType = AVMediaTypeVideo;

exporter.outputURL=outputURLwe;

[exporter exportAsynchronouslyWithCompletionHandler:^{

    dispatch_async(dispatch_get_main_queue(), ^{

        [self exportDidFinish:exporter];

    });
}];

I feel like it something really easy that I am just missing. This is my first time using AVFoundation so any help would be appreciated!

Answer 1

AVMediaTypeVideo is a "media type" not an "output file type". Your original video has tracks that are of type AVMediaTypeVideo. The original video is not of type AVMediaTypeVideo .

The outputFileType of AVAssetExportSession are constants of type NSString . The allowed values are listed in AVFoundation/AVMediaFormat.h. For video, they are:

• AVFileTypeQuickTimeMovie
• AVFileTypeMPEG4
• AVFileTypeAppleM4V

You must choose one of the allowed values to use for your AVAssetExportSession 's outputFileType .