Question

我在为audioMix设置输入参数时遇到设置曲目ID的问题。我如何设置trackId？我也尝试过这种方式params.trackID（track2.trackID），但这给了我这个错误CMPersistantTrackID -> $T4 is not identical to CMPersistantTrackID。我正在尝试从https://developer.apple.com/library/ios/qa/qa1716/_index.html

翻译此行[audioInputParams setTrackID:[track trackID]];

错误当我运行以下代码时：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM trackID]: unrecognized selector sent to instance 0x7f98c34cbfc0'

代码：

        let type = AVMediaTypeAudio
        let asset1 = AVURLAsset(URL: beatLocationURL, options: nil)
        let arr2 = asset1.tracksWithMediaType(type)
        let track2 = arr2.last as AVAssetTrack


        let asset = AVURLAsset(URL: vocalURL, options:nil)
        let arr3 = asset.tracksWithMediaType(type)
        let track3 = arr3.last as AVAssetTrack



        var trackParams = NSMutableArray()

        let params = AVMutableAudioMixInputParameters(track:track2)
        params.setVolume(0.0, atTime:kCMTimeZero)
        params.trackID = track2.trackID <--- this line 
        trackParams.addObject(params)

        let params1 = AVMutableAudioMixInputParameters(track:track3)
        params1.setVolume(1.0, atTime: kCMTimeZero)
        params1.trackID = track3.trackID <-- this line also
        trackParams.addObject(params1)

        let mix = AVMutableAudioMix()
        mix.inputParameters = [trackParams]

设置轨道ID

0 个答案: