在 Swift 4 中合并两个视频？

Question

因此，我已经录制了两个 .mp4 并存储在应用程序中，我想将一个附加到另一个，然后导出为新视频。它有点有效，但不完全有效！

    let composition = AVMutableComposition()
    var track = composition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID:Int32(kCMPersistentTrackID_Invalid))

    let videoAsset = AVAsset(url: AAA as URL) as AVAsset
    let videoAsset2 = AVAsset(url: BBB as URL) as AVAsset
    do {
        try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: videoAsset.tracks(withMediaType: AVMediaType.video)[0] as AVAssetTrack, at: kCMTimeZero)
        try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: videoAsset2.tracks(withMediaType: AVMediaType.video)[0] as AVAssetTrack, at: kCMTimeZero)

    } catch {
        print("darn")
    }

    let exporter = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetHighestQuality)
    exporter?.outputURL = CCC
    exporter?.outputFileType = AVFileType.mp4
    exporter?.shouldOptimizeForNetworkUse = true


    exporter?.exportAsynchronously {
        print("done?")
    }

这种方式组合了视频，但它在两个剪辑之间添加了大量黑屏，并删除了音频。我找不到这个问题的任何最新答案。感谢您的帮助！

Answer 1

视频时间线看起来不正确，例如，您在同一时间点（零）插入两个视频，并且使用了错误的持续时间videoAsset2。

缺少音频是因为您没有在作品中插入任何音轨。

尝试这样的（重复的）片段：

// video
try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: videoAsset.tracks(withMediaType:.video)[0] as AVAssetTrack, at: kCMTimeZero)
try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset2.duration), of: videoAsset2.tracks(withMediaType:.video)[0] as AVAssetTrack, at: videoAsset.duration)

// audio
try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: videoAsset.tracks(withMediaType:.audio)[0] as AVAssetTrack, at: kCMTimeZero)
try track?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset2.duration), of: videoAsset2.tracks(withMediaType:.audio)[0] as AVAssetTrack, at: videoAsset.duration)

免责声明：我不确定使用AVAssetTrack的拥有AVAsset持续时间作为轨道长度的代理是否是一个好习惯。也许你应该使用AVAssetTrack.timeRange.