Question

我为存储在不同位置的视频和音频文件传递了不同的URL。我面临的问题是我无法在音频文件中找到任何曲目，可以完美地检测到视频文件的曲目。下面是我正在使用的代码。

func mergeFilesWithUrl(videoUrl:NSURL, audioUrl:NSURL)
{
    let mixComposition : AVMutableComposition = AVMutableComposition()
    var mutableCompositionVideoTrack : [AVMutableCompositionTrack] = []
    var mutableCompositionAudioTrack : [AVMutableCompositionTrack] = []
    let totalVideoCompositionInstruction : AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()


    //start merge

    let aVideoAsset : AVAsset = AVAsset(url: videoUrl as URL)
    let aAudioAsset : AVAsset = AVAsset(url: audioUrl as URL)

    mutableCompositionVideoTrack.append(mixComposition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: kCMPersistentTrackID_Invalid)!)
    mutableCompositionAudioTrack.append(mixComposition.addMutableTrack(withMediaType: AVMediaType.audio, preferredTrackID: kCMPersistentTrackID_Invalid)!)

    let aVideoAssetTrack : AVAssetTrack = aVideoAsset.tracks(withMediaType: AVMediaType.video)[0]
    let aAudioAssetTrack : AVAssetTrack = aAudioAsset.tracks(withMediaType: AVMediaType.audio)[0]



    do{
        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: kCMTimeZero)

        //In my case my audio file is longer then video file so i took videoAsset duration
        //instead of audioAsset duration

        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: kCMTimeZero)

        //Use this instead above line if your audiofile and video file's playing durations are same

        //            try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)

    }catch{
        print(error.localizedDescription)
    }

    totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(kCMTimeZero,aVideoAssetTrack.timeRange.duration )

    let mutableVideoComposition : AVMutableVideoComposition = AVMutableVideoComposition()
    mutableVideoComposition.frameDuration = CMTimeMake(1, 30)

    mutableVideoComposition.renderSize = CGSize(width: 1280, height: 720)

    //        playerItem = AVPlayerItem(asset: mixComposition)
    //        player = AVPlayer(playerItem: playerItem!)
    //
    //
    //        AVPlayerVC.player = player



    //find your video on this URl
    let savePathUrl : NSURL = NSURL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4")

    let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
    assetExport.outputFileType = .mp4
    assetExport.outputURL = savePathUrl as URL
    assetExport.shouldOptimizeForNetworkUse = true

    assetExport.exportAsynchronously { () -> Void in
        switch assetExport.status {

        case AVAssetExportSessionStatus.completed:

            //Uncomment this if u want to store your video in asexportAsynchronouslyt assetsLib = ALAssetsLibrary()
            //assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completioncompletedl)
            UISaveVideoAtPathToSavedPhotosAlbum(savePathUrl.path!, nil, nil, nil)

            print("success")
        case  AVAssetExportSessionStatus.failed:
            print("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.cancelled:
            print("cancelled \(assetExport.error)")
        default:
            print("complete")
        }
    }
}

这是我得到的错误：-

由于未捕获的异常“ NSRangeException”而终止应用程序，原因：“ *-[__ NSArray0 objectAtIndex：]：索引0超出了空NSArray的范围” * 第一个调用堆栈：（0x1853a3164 0x1845ec528 0x1852fe020 0x100dbfdac 0x100dd27e4 0x1009c5388 0x1009c4c54 0x1009aa9d4 0x10188128c 0x101893fbc 0x1018939dc 0x18abee67c 0x18abee278 0x18abef1fc 0x18abef49c 0x18abedc9c 0x1018812cc 0x10188128c 0x10188ff80 0x1018847ec 0x1018929d0 0x1018940b8 0x184fcc2b4 0x184fcc180 0x184fcab74） libc ++ abi.dylib：以类型为NSException的未捕获异常终止

如何从AVAsset获取AVAssetTrack以合并视频和音频

0 个答案: