ios - 在 ios 中合并音频和视频文件的问题

Question

 error is Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array'
line :-[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil];

我的代码在这里 ------------------------------

- (void) getAndPlayAVideoTest
{
    NSString *bundleDirectory = [[NSBundle mainBundle] bundlePath];

    NSString *videoOutputPath=[bundleDirectory stringByAppendingPathComponent:@"abc.mp3"];
    NSString *outputFilePath = [bundleDirectory stringByAppendingPathComponent:@"final_video.mp4"];
    if ([[NSFileManager defaultManager]fileExistsAtPath:outputFilePath])
        [[NSFileManager defaultManager]removeItemAtPath:outputFilePath error:nil];


    NSURL    *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
    NSString *filePath = [bundleDirectory stringByAppendingPathComponent:@"abc.mov"];
    AVMutableComposition* mixComposition = [AVMutableComposition composition];

    NSURL    *audio_inputFileUrl = [NSURL fileURLWithPath:filePath];
    NSURL    *video_inputFileUrl = [NSURL fileURLWithPath:videoOutputPath];

    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];

    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:AVAssetExportPresetMediumQuality];
    _assetExport.outputFileType = @"com.apple.quicktime-movie";
    _assetExport.outputURL = outputFileUrl;

    [_assetExport exportAsynchronouslyWithCompletionHandler:
     ^(void ) {
         if (_assetExport.status == AVAssetExportSessionStatusCompleted) {

             //Write Code Here to Continue
         }
         else {
             //Write Fail Code here
         }
     }
     ];
//}
}

Answer 1

在这种情况下 [b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil]; 这无法读取数组。

因为 Sound/Audio 不存在于特定文件中。此错误仅出现在这些情况下，即多媒体文件中不存在声音/音频时。