无法从AVURLAsset获取AVPlayer的HLS视频(.m3u8格式)的视频轨道? [英] Can't able to get Video Tracks from AVURLAsset for HLS videos(.m3u8 format) for AVPlayer?

问题描述

我正在开发一个自定义视频播放器，以从服务器流式传输HLS视频.我可以使用AVPlayerItem和AVPlayer成功播放HLS视频.

I am developing a custom video player to stream HLS videos from server. I can successfully play HLS videos using AVPlayerItem and AVPlayer.

之后，我想为视频播放器添加字幕轨道和音频轨道.因此，我使用了AVMutableComposition来做到这一点.所以现在的问题是，当我为HLS视频创建AVURLAsset时，我无法从AVURLAsset获取视频轨道.它总是给我0首曲目.我尝试了AVURLAsset的"loadValuesAsynchronously"，并尝试为AVPlayerItem的轨道"添加KVO.但是这些都没有给我带来任何积极的结果.

After that I want to add subtitle track and audio tracks for my video player. So I used AVMutableComposition to do so. So now the issue is when I am creating AVURLAsset for HLS Videos, I can't able to get video tracks from AVURLAsset. It is giving me always 0 tracks. I tried "loadValuesAsynchronously" of AVURLAsset and I tried adding KVO for "tracks" of AVPlayerItem. But None of these producing me any positive result.

我正在使用以下代码.

  func playVideo() {
    let videoAsset = AVURLAsset(url: videoURL!)
    let composition = AVMutableComposition()
    // Video
    let videoTrack = composition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)
    do {
        let tracks = videoAsset.tracks(withMediaType: .video)
        guard let track = tracks.first else {
            print("Can't get first video track")
            return
        }
        try videoTrack?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: track, at: kCMTimeZero)
    } catch {
        print(error)
        return
    }
    guard let subtitlesUrl = Bundle.main.url(forResource: "en", withExtension: "vtt") else {
        print("Can't load en.vtt from bundle")
        return
    }
    //Subtitles
    let subtitleAsset = AVURLAsset(url: subtitlesUrl)
    let subtitleTrack = composition.addMutableTrack(withMediaType: .text, preferredTrackID: kCMPersistentTrackID_Invalid)
    do {
        let subTracks = subtitleAsset.tracks(withMediaType: AVMediaType.text)
        guard let subTrack = subTracks.first else {
            print("Can't get first subtitles track")
            return
        }
        try subtitleTrack?.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: subTrack, at: kCMTimeZero)
    } catch {
        print(error)
        return
    }
    // Prepare item and play it
    let item = AVPlayerItem(asset: composition)
    self.player = AVPlayer(playerItem: item)
    self.playerLayer = AVPlayerLayer.init()
    self.playerLayer.frame = self.bounds
    self.playerLayer.contentsGravity = kCAGravityResizeAspect
    self.playerLayer.player = player
    self.layer.addSublayer(self.playerLayer)
    self.player.addObserver(self, forKeyPath: "currentItem.loadedTimeRanges", options: .new, context: nil)
    self.player.play()
}

此过程适用于.mp4视频，但不适用于HLS视频(.m3u8).有人对此有一些可行的解决方案吗?

This procedure working well for .mp4 videos but not for HLS Videos(.m3u8). Anyone have some working solution for this?

或

我们如何使用AVURLAsset从HLS视频中获取曲目?如果这不可能，那么如何才能达到类似的结果?

How can we get tracks from HLS videos using AVURLAsset? If this is not possible then How can achieve similar result ?

请让我知道您的反馈意见.

Please let me know you feedback.

非常感谢.

推荐答案

对于HLS视频， tracks(withMediaType:.video)将返回一个空数组.

For HLS video tracks(withMediaType: .video) will return an empty array.

改为使用此代码: player.currentItem.presentationSize.width 和 player.currentItem.presentationSize.height .

请让我知道它是否有效.

Pls let me know if it works.

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