我正在用Swift开发基于视频的应用程序。我要在其中导出带有水印徽标和淡入效果的视频剪辑。这是我的代码：
func watermark(video videoAsset:AVAsset, videoModal:VideoModel, watermarkText text : String!, imageName name : String!, saveToLibrary flag : Bool, watermarkPosition position : PDWatermarkPosition, withMode mode: SpeedoVideoMode, completion : ((_ status : AVAssetExportSessionStatus?, _ session: AVAssetExportSession?, _ outputURL : URL?) -> ())?) {
var arrayLayerInstructions:[AVMutableVideoCompositionLayerInstruction] = []
let servicemodel = ServiceModel()
DispatchQueue.global(qos: DispatchQoS.QoSClass.default).sync {
let mixComposition = AVMutableComposition()
let compositionVideoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
if videoAsset.tracks(withMediaType: AVMediaTypeVideo).count == 0
{
completion!(nil, nil, nil)
return
}
let clipVideoTrack = videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0]
self.addAudioTrack(composition: mixComposition, videoAsset: videoAsset as! AVURLAsset, withMode: mode, videoModal:videoModal)
do {
try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: clipVideoTrack, at: kCMTimeZero)
}
catch {
print(error.localizedDescription)
}
let videoSize = clipVideoTrack.naturalSize //CGSize(width: 375, height: 300)
//to add Watermark
let parentLayer = CALayer()
let videoLayer = CALayer()
parentLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height)
videoLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height)
//videoLayer.backgroundColor = UIColor.red.cgColor
parentLayer.addSublayer(videoLayer)
if name != nil {
let watermarkImage = UIImage(named: name)
let imageLayer = CALayer()
//imageLayer.backgroundColor = UIColor.purple.cgColor
imageLayer.contents = watermarkImage?.cgImage
var xPosition : CGFloat = 0.0
var yPosition : CGFloat = 0.0
let imageSize : CGFloat = 150
switch (position) {
case .TopLeft:
xPosition = 0
yPosition = 0
break
case .TopRight:
xPosition = videoSize.width - imageSize - 100
yPosition = 80
break
case .BottomLeft:
xPosition = 0
yPosition = videoSize.height - imageSize
break
case .BottomRight, .Default:
xPosition = videoSize.width - imageSize
yPosition = videoSize.height - imageSize
break
}
imageLayer.frame = CGRect(x: xPosition, y: yPosition, width: imageSize, height: imageSize)
imageLayer.opacity = 0.75
parentLayer.addSublayer(imageLayer)
if text != nil {
let titleLayer = CATextLayer()
titleLayer.backgroundColor = UIColor.clear.cgColor
titleLayer.string = text
titleLayer.font = "Helvetica" as CFTypeRef
titleLayer.fontSize = 20
titleLayer.alignmentMode = kCAAlignmentRight
titleLayer.frame = CGRect(x: 0, y: yPosition - imageSize, width: videoSize.width - imageSize/2 - 4, height: 57)
titleLayer.foregroundColor = UIColor.lightGray.cgColor
parentLayer.addSublayer(titleLayer)
}
}
let videoComp = AVMutableVideoComposition()
videoComp.renderSize = videoSize
videoComp.frameDuration = CMTimeMake(1, 30)
videoComp.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer)
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration)
_ = mixComposition.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack
let layerInstruction = self.videoCompositionInstructionForTrack(track: compositionVideoTrack, asset: videoAsset)
//Add Fade In Out effects
let startTime = CMTime(seconds: Double(0), preferredTimescale: 1000)
let endTime = CMTime(seconds: Double(1), preferredTimescale: 1000)
let timeRange = CMTimeRange(start: startTime, end: endTime)
layerInstruction.setOpacityRamp(fromStartOpacity: 0.1, toEndOpacity: 1.0, timeRange: timeRange)
let startTime1 = CMTime(seconds: videoAsset.duration.seconds-1, preferredTimescale: 1000)
let endTime1 = CMTime(seconds: videoAsset.duration.seconds, preferredTimescale: 1000)
let timeRange1 = CMTimeRange(start: startTime1, end: endTime1)
layerInstruction.setOpacityRamp(fromStartOpacity: 1.0, toEndOpacity: 0.1, timeRange: timeRange1)
arrayLayerInstructions.append(layerInstruction)
instruction.layerInstructions = arrayLayerInstructions
videoComp.instructions = [instruction]
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let url = URL(fileURLWithPath: documentDirectory).appendingPathComponent("\(videoModal.fileID).mov")
let filePath = url.path
let fileManager = FileManager.default
do {
if fileManager.fileExists(atPath: filePath) {
print("FILE AVAILABLE")
try fileManager.removeItem(atPath:filePath)
} else {
print("FILE NOT AVAILABLE")
}
} catch _ {
}
let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)
exporter?.outputURL = url
exporter?.outputFileType = AVFileTypeQuickTimeMovie
let timeRangetoTrim = CMTimeRange(start: CMTime(seconds: Double(videoModal.leftRangeValue), preferredTimescale: 1000),
end: CMTime(seconds: Double(videoModal.rightRangeValue), preferredTimescale: 1000))
exporter?.timeRange = timeRangetoTrim
exporter?.shouldOptimizeForNetworkUse = false
exporter?.videoComposition = videoComp
exporter?.exportAsynchronously() {
DispatchQueue.main.async {
if exporter?.status == AVAssetExportSessionStatus.completed {
let outputURL = exporter?.outputURL
if flag {
if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(outputURL!.path) {
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: outputURL!)
}) { saved, error in
if saved {
completion!(AVAssetExportSessionStatus.completed, exporter, outputURL)
}
}
}
} else {
completion!(AVAssetExportSessionStatus.completed, exporter, outputURL)
}
} else {
// Error
completion!(exporter?.status, exporter, nil)// Getting error here
}
}
}
}
}
func addAudioTrack(composition: AVMutableComposition, videoAsset: AVURLAsset, withMode mode: SpeedoVideoMode, videoModal:VideoFileModel) {
let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
let audioTracks = videoAsset.tracks(withMediaType: AVMediaTypeAudio)
for audioTrack in audioTracks {
try! compositionAudioTrack.insertTimeRange(audioTrack.timeRange, of: audioTrack, at: kCMTimeZero)
}
}
func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {
let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)
let assetTrack = asset.tracks(withMediaType: AVMediaTypeVideo)[0]
let transform = assetTrack.preferredTransform
let assetInfo = orientationFromTransform(transform: transform)
var scaleToFitRatio = UIScreen.main.bounds.width / 375
if assetInfo.isPortrait {
scaleToFitRatio = UIScreen.main.bounds.width / assetTrack.naturalSize.height
let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
instruction.setTransform(assetTrack.preferredTransform.concatenating(scaleFactor),
at: kCMTimeZero)
} else {
let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
var concat = assetTrack.preferredTransform.concatenating(scaleFactor).concatenating(CGAffineTransform(translationX: 0, y: 0))
if assetInfo.orientation == .down {
let fixUpsideDown = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
let windowBounds = UIScreen.main.bounds
let yFix = 375 + windowBounds.height
let centerFix = CGAffineTransform(translationX: assetTrack.naturalSize.width, y: CGFloat(yFix))
concat = fixUpsideDown.concatenating(centerFix).concatenating(scaleFactor)
}
instruction.setTransform(concat, at: kCMTimeZero)
}
return instruction
}
private func orientationFromTransform(transform: CGAffineTransform) -> (orientation: UIImageOrientation, isPortrait: Bool) {
var assetOrientation = UIImageOrientation.up
var isPortrait = false
if transform.a == 0 && transform.b == 1.0 && transform.c == -1.0 && transform.d == 0 {
assetOrientation = .right
isPortrait = true
} else if transform.a == 0 && transform.b == -1.0 && transform.c == 1.0 && transform.d == 0 {
assetOrientation = .left
isPortrait = true
} else if transform.a == 1.0 && transform.b == 0 && transform.c == 0 && transform.d == 1.0 {
assetOrientation = .up
} else if transform.a == -1.0 && transform.b == 0 && transform.c == 0 && transform.d == -1.0 {
assetOrientation = .down
}
return (assetOrientation, isPortrait)
}
我的代码在某些视频中运行良好，有时对某些视频也不起作用。由于AVAssetExportSessionStatus失败，我遇到以下错误：
Error Domain = AVFoundationErrorDomain代码= -11800“该操作可能 未完成” UserInfo = {NSLocalizedFailureReason =未知错误 发生（-12780），NSLocalizedDescription =无法执行该操作 已完成，NSUnderlyingError = 0x28262c240 {Error Domain = NSOSStatusErrorDomain Code = -12780“（null）”}}
有人可以帮我吗？预先谢谢你。
答案 0 :(得分：0)
此方法func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {是错误的，因为您需要提供AVAssetTrack并包含实际视频。
但是，相反，您传递的AVCompositionTrack仍然需要组成，因此请用此func videoCompositionInstructionForTrack(track: AVAssetTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {替换您的方法。
现在，当您调用实际方法时，需要传递clipVideoTrack，即let layerInstruction = self.videoCompositionInstructionForTrack(track: clipVideoTrack, asset: videoAsset)。
如果您仍然遇到错误，请告诉我！