Question

我得出结论，视频必须在矩形上呈现为纹理。

为了达到这个目的，我来到了这些步骤：

我需要从视频中获取当前帧：
- 我使用过AVPlayerItemVideoOutput，然后调用copyPixelBufferForItemTime

这是一个简单的ViewController，我已经习惯了这个（我可以看到它正在工作，虽然imageview没有刷新 - 我想我没有正确使用它。）

class ViewController: UIViewController {

var player: AVPlayer!
var playerItem: AVPlayerItem!
var output: AVPlayerItemVideoOutput!
var displayLink : CADisplayLink!
var context: CIContext!

@IBOutlet weak var image: UIImageView!
override func viewDidLoad() {
    super.viewDidLoad()

    context = CIContext()
    let asset = AVURLAsset( URL:NSURL(string: "http://vevoplaylist-live.hls.adaptive.level3.net/vevo/ch1/appleman.m3u8")!, options:nil)
    asset.loadValuesAsynchronouslyForKeys(["tracks"]){

        var error: NSError?
        let status = asset.statusOfValueForKey("tracks", error: &error)

        if (status == AVKeyValueStatus.Loaded)
        {
            let settings: [String: AnyObject] = [kCVPixelBufferPixelFormatTypeKey as String : Int(kCVPixelFormatType_32BGRA)]
            let output = AVPlayerItemVideoOutput(pixelBufferAttributes: settings)
            let playerItem = AVPlayerItem(asset: asset)
            playerItem.addOutput(output)
            let  player = AVPlayer(playerItem: playerItem)

            self.player = player
            self.playerItem = playerItem
            self.output = output

            self.displayLink = CADisplayLink(target: self, selector: Selector("handleTimer"))
            self.displayLink.frameInterval = 1
            self.displayLink.addToRunLoop(NSRunLoop.mainRunLoop(), forMode: NSRunLoopCommonModes)
        }
        else
        {
            print("%@ Failed to load the tracks.")
        }
    }

}
func handleTimer() {
    let buffer = output.copyPixelBufferForItemTime(playerItem.currentTime(), itemTimeForDisplay:nil)
    if let bufferUnwrapped = buffer{
        let image = CIImage(CVPixelBuffer: bufferUnwrapped)
        let cgiImage = context.createCGImage(image, fromRect: image.extent)
        dispatch_async(dispatch_get_main_queue()){
            self.image.image = UIImage(CGImage: cgiImage)
            self.image.setNeedsDisplay()
        }
    }
}

}

第二步是使用pixelBuffer生成纹理这一步涉及大量代码，我发现的最佳样本来自raywenderlich http://www.raywenderlich.com/93997/ios-8-metal-tutorial-swift-part-3-adding-texture（对于swift 1.2）和来自Waren Moore的代码示例https://github.com/warrenm/slug-swift-metal/tree/master/SwiftMetalDemo

我没有找到另一种方法（在Metal中的矩形上显示实时流式视频）。有更好的方法吗？

如何在Metal with Swift中显示实时流媒体视频（m3u8）？

0 个答案: