我正在使用这个简短的片段来设置我的视频。由于某些未知原因 - 有时视频根本不会显示,而对于其他视频,它会完美运行。
let videoTrack: AVAssetTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0]
let composition: AVMutableComposition = AVMutableComposition()
let videoComposition: AVMutableVideoComposition = AVMutableVideoComposition()
var videoSize: CGSize = videoTrack.naturalSize
let isPortrait_: Bool = self.isVideoPortrait(asset)
if isPortrait_ {
NSLog("video is portrait ")
videoSize = CGSizeMake(videoSize.height, videoSize.width)
}
composition.naturalSize = videoSize
videoComposition.renderSize = videoSize
// videoComposition.renderSize = videoTrack.naturalSize; //
videoComposition.frameDuration = CMTimeMake(1, 30)
let compositionVideoTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: 1)
let timeRange = videoTrack.timeRange
do {
try compositionVideoTrack.insertTimeRange(timeRange, ofTrack: videoTrack, atTime: kCMTimeZero)
} catch {
print("error")
}
let layerInst = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
layerInst.setTransform(videoTrack.preferredTransform, atTime: kCMTimeZero)
let inst: AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()
inst.timeRange = timeRange
inst.layerInstructions = [layerInst]
videoComposition.instructions = [inst]
let playerItem = AVPlayerItem(asset: composition)
playerItem.videoComposition = videoComposition
对于某些视频,它根本不会显示出来。
有什么建议么?谢谢!!