我尝试通过截取精确的尺寸来裁剪视频,但是 asset.tracks(withMediaType:AVMediaType.video)[0] 行出现错误,该行返回了索引0为空。我精确到该网址下有一个视频...
iOS:[NSArray0 objectAtIndex:]索引0超出了具有asset.tracks(withMediaType:AVMediaType.video)[0]的空NSArray的范围
// input file
let composition = AVMutableComposition()
composition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)
// input clip
let asset = AVAsset(url: URL(fileURLWithPath: video))
let videoTrack: AVAssetTrack = asset.tracks(withMediaType: AVMediaType.video)[0]
//=> problem is here
// crop clip to screen ratio
let orientation: UIInterfaceOrientation = self.orientation(forTrack: asset)
// make render size square
let videoComposition = AVMutableVideoComposition.init()
let height: CGFloat = 960
let width: CGFloat = 960
videoComposition.renderSize = CGSize(width: CGFloat(width), height: CGFloat(height))
videoComposition.frameDuration = CMTimeMake(1, 30)
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30))
// rotate and position video
let transformer = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
var txWidth: CGFloat = (videoTrack.naturalSize.width - width) / 2
let txHeight: CGFloat = (videoTrack.naturalSize.height - height) / 2
if orientation == .portrait || orientation == .landscapeRight {
// invert translation
txWidth *= -1
}
// t1: rotate and position video since it may have been cropped to screen ratio
let t1: CGAffineTransform = videoTrack.preferredTransform.translatedBy(x: txWidth, y: -txHeight)
transformer.setTransform(t1, at: kCMTimeZero)
instruction.layerInstructions = [transformer]
videoComposition.instructions = [instruction] as [AVVideoCompositionInstructionProtocol]
// export
let exporter = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetHighestQuality)
exporter?.videoComposition = videoComposition
exporter?.outputURL = URL(fileURLWithPath: video)
exporter?.outputFileType = .mov
exporter?.exportAsynchronously(completionHandler: {
print("Exporting done!")
})
Any ideas?
答案 0 :(得分:1)
在处理视频处理时,您需要确保所有导入的文件都具有可接受的扩展名,例如
let acceptableVideoExtensions = ["mov", "mp4", "m4v"]
if acceptableVideoExtensions.contains(videoURL.pathExtension) {
// Process the video
}
else {
//Alert the user
}