快速视频中的图像/文本叠加
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【中文标题】快速视频中的图像/文本叠加【英文标题】：Image/Text overlay in video swift 【发布时间】：2015-09-08 06:07:29 【问题描述】：我正在使用 swift 处理视频中的水印效果的图像叠加。我为此使用AVFoundation，但不知何故我没有成功。
以下是我的叠加图像/文本代码
let path = NSBundle.mainBundle().pathForResource("sample_movie", ofType:"mp4")
let fileURL = NSURL(fileURLWithPath: path!)
let composition = AVMutableComposition()
var vidAsset = AVURLAsset(URL: fileURL, options: nil)
// get video track
let vtrack = vidAsset.tracksWithMediaType(AVMediaTypeVideo)
let videoTrack:AVAssetTrack = vtrack[0] as! AVAssetTrack
let vid_duration = videoTrack.timeRange.duration
let vid_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)
var error: NSError?
let compositionvideoTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
compositionvideoTrack.insertTimeRange(vid_timerange, ofTrack: videoTrack, atTime: kCMTimeZero, error: &error)
compositionvideoTrack.preferredTransform = videoTrack.preferredTransform
// Watermark Effect
let size = videoTrack.naturalSize
let imglogo = UIImage(named: "image.png")
let imglayer = CALayer()
imglayer.contents = imglogo?.CGImage
imglayer.frame = CGRectMake(5, 5, 100, 100)
imglayer.opacity = 0.6
// create text Layer
let titleLayer = CATextLayer()
titleLayer.backgroundColor = UIColor.whiteColor().CGColor
titleLayer.string = "Dummy text"
titleLayer.font = UIFont(name: "Helvetica", size: 28)
titleLayer.shadowOpacity = 0.5
titleLayer.alignmentMode = kCAAlignmentCenter
titleLayer.frame = CGRectMake(0, 50, size.width, size.height / 6)
let videolayer = CALayer()
videolayer.frame = CGRectMake(0, 0, size.width, size.height)
let parentlayer = CALayer()
parentlayer.frame = CGRectMake(0, 0, size.width, size.height)
parentlayer.addSublayer(videolayer)
parentlayer.addSublayer(imglayer)
parentlayer.addSublayer(titleLayer)
let layercomposition = AVMutableVideoComposition()
layercomposition.frameDuration = CMTimeMake(1, 30)
layercomposition.renderSize = size
layercomposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videolayer, inLayer: parentlayer)
// instruction for watermark
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, composition.duration)
let videotrack = composition.tracksWithMediaType(AVMediaTypeVideo)[0] as! AVAssetTrack
let layerinstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videotrack)
instruction.layerInstructions = NSArray(object: layerinstruction) as [AnyObject]
layercomposition.instructions = NSArray(object: instruction) as [AnyObject]
// create new file to receive data
let dirPaths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let docsDir: AnyObject = dirPaths[0]
let movieFilePath = docsDir.stringByAppendingPathComponent("result.mov")
let movieDestinationUrl = NSURL(fileURLWithPath: movieFilePath)
// use AVAssetExportSession to export video
let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality)
assetExport.outputFileType = AVFileTypeQuickTimeMovie
assetExport.outputURL = movieDestinationUrl
assetExport.exportAsynchronouslyWithCompletionHandler(
switch assetExport.status
case AVAssetExportSessionStatus.Failed:
println("failed \(assetExport.error)")
case AVAssetExportSessionStatus.Cancelled:
println("cancelled \(assetExport.error)")
default:
println("Movie complete")
// play video
NSOperationQueue.mainQueue().addOperationWithBlock( () -> Void in
self.playVideo(movieDestinationUrl!)
)
)
通过这段代码，我没有实现覆盖……我不知道我做错了什么……
问题：
此代码中是否缺少任何内容？或者这段代码有什么问题？ 此代码是否仅适用于录制的视频或所有视频，包括图库中的视频？【问题讨论】：
你曾经解决过这个问题吗？寻找相同的答案。 你能在哪里解决这个问题？ 【参考方案1】：@El Captain 提供的代码可以使用。它只是缺少：
assetExport.videoComposition = layercomposition
您可以在 AVAssetExportSession
实例化之后立即添加它注意：最初提供的代码只会导出视频轨道，而不是音频轨道。如果您需要音轨，您可以在配置 compositionvideoTrack 后添加类似的内容：
let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
for audioTrack in audioTracks
try! compositionAudioTrack.insertTimeRange(audioTrack.timeRange, ofTrack: audioTrack, atTime: kCMTimeZero)
【讨论】：
甜蜜！希望它可以帮助其他有同样问题的人。【参考方案2】：以下是 Swift 4 中的更新：
import UIKit
import AVFoundation
import AVKit
import Photos
class ViewController: UIViewController
var myurl: URL?
override func viewDidLoad()
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
@IBAction func saveVideoTapper(_ sender: Any)
let path = Bundle.main.path(forResource: "sample_video", ofType:"mp4")
let fileURL = NSURL(fileURLWithPath: path!)
let composition = AVMutableComposition()
let vidAsset = AVURLAsset(url: fileURL as URL, options: nil)
// get video track
let vtrack = vidAsset.tracks(withMediaType: AVMediaType.video)
let videoTrack: AVAssetTrack = vtrack[0]
let vid_timerange = CMTimeRangeMake(start: CMTime.zero, duration: vidAsset.duration)
let tr: CMTimeRange = CMTimeRange(start: CMTime.zero, duration: CMTime(seconds: 10.0, preferredTimescale: 600))
composition.insertEmptyTimeRange(tr)
let trackID:CMPersistentTrackID = CMPersistentTrackID(kCMPersistentTrackID_Invalid)
if let compositionvideoTrack: AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: trackID)
do
try compositionvideoTrack.insertTimeRange(vid_timerange, of: videoTrack, at: CMTime.zero)
catch
print("error")
compositionvideoTrack.preferredTransform = videoTrack.preferredTransform
else
print("unable to add video track")
return
// Watermark Effect
let size = videoTrack.naturalSize
let imglogo = UIImage(named: "image.png")
let imglayer = CALayer()
imglayer.contents = imglogo?.cgImage
imglayer.frame = CGRect(x: 5, y: 5, width: 100, height: 100)
imglayer.opacity = 0.6
// create text Layer
let titleLayer = CATextLayer()
titleLayer.backgroundColor = UIColor.white.cgColor
titleLayer.string = "Dummy text"
titleLayer.font = UIFont(name: "Helvetica", size: 28)
titleLayer.shadowOpacity = 0.5
titleLayer.alignmentMode = CATextLayerAlignmentMode.center
titleLayer.frame = CGRect(x: 0, y: 50, width: size.width, height: size.height / 6)
let videolayer = CALayer()
videolayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
let parentlayer = CALayer()
parentlayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
parentlayer.addSublayer(videolayer)
parentlayer.addSublayer(imglayer)
parentlayer.addSublayer(titleLayer)
let layercomposition = AVMutableVideoComposition()
layercomposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
layercomposition.renderSize = size
layercomposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videolayer, in: parentlayer)
// instruction for watermark
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(start: CMTime.zero, duration: composition.duration)
let videotrack = composition.tracks(withMediaType: AVMediaType.video)[0] as AVAssetTrack
let layerinstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videotrack)
instruction.layerInstructions = NSArray(object: layerinstruction) as [AnyObject] as! [AVVideoCompositionLayerInstruction]
layercomposition.instructions = NSArray(object: instruction) as [AnyObject] as! [AVVideoCompositionInstructionProtocol]
// create new file to receive data
let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let docsDir = dirPaths[0] as NSString
let movieFilePath = docsDir.appendingPathComponent("result.mov")
let movieDestinationUrl = NSURL(fileURLWithPath: movieFilePath)
// use AVAssetExportSession to export video
let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality)
assetExport?.outputFileType = AVFileType.mov
assetExport?.videoComposition = layercomposition
// Check exist and remove old file
FileManager.default.removeItemIfExisted(movieDestinationUrl as URL)
assetExport?.outputURL = movieDestinationUrl as URL
assetExport?.exportAsynchronously(completionHandler:
switch assetExport!.status
case AVAssetExportSession.Status.failed:
print("failed")
print(assetExport?.error ?? "unknown error")
case AVAssetExportSession.Status.cancelled:
print("cancelled")
print(assetExport?.error ?? "unknown error")
default:
print("Movie complete")
self.myurl = movieDestinationUrl as URL
phphotoLibrary.shared().performChanges(
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: movieDestinationUrl as URL)
) saved, error in
if saved
print("Saved")
self.playVideo()
)
func playVideo()
let player = AVPlayer(url: myurl!)
let playerLayer = AVPlayerLayer(player: player)
playerLayer.frame = self.view.bounds
self.view.layer.addSublayer(playerLayer)
player.play()
print("playing...")
extension FileManager
func removeItemIfExisted(_ url:URL) -> Void
if FileManager.default.fileExists(atPath: url.path)
do
try FileManager.default.removeItem(atPath: url.path)
catch
print("Failed to delete file")
【讨论】：
【参考方案3】：对我来说（我在你的代码中看到的），你没有将parentlayer 添加到屏幕上。
您创建一个 CALayer() 以将 videolayer、imglayer 和 titleLayer 添加到新层中，但您没有在屏幕上添加最后一层。
yourView.layer.addSublayer(parentlayer)
希望对你有帮助
【讨论】：
检查layercomposition.animationTool这行...它使用父层处理视频的位置
尝试在let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality)中使用layercomposition而不是composition
您能否添加完整的解决方案作为答案。
如果以后有类似问题的人发现这个问题，有答案可能对他们有用。你问了这个问题，你现在有了答案。
嗨@Dolwen 你知道如何纠正视频中的模糊吗？这里的问题：***.com/questions/34912050/…。感谢您的宝贵时间！【参考方案4】：
@Rey Hernandez 这对我帮助很大！如果有人想进一步说明如何在视频中添加音频资产，这里是合并它们的代码
let vtrack = vidAsset.tracksWithMediaType(AVMediaTypeVideo)
let videoTrack:AVAssetTrack = vtrack[0]
let vid_duration = videoTrack.timeRange.duration
let vid_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)
let atrack = vidAsset.tracksWithMediaType(AVMediaTypeAudio)
let audioTrack:AVAssetTrack = atrack[0]
let audio_duration = audioTrack.timeRange.duration
let audio_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)
do
let compositionvideoTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
try compositionvideoTrack.insertTimeRange(vid_timerange, ofTrack: videoTrack, atTime: kCMTimeZero)
compositionvideoTrack.preferredTransform = videoTrack.preferredTransform
let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
try! compositionAudioTrack.insertTimeRange(audio_timerange, ofTrack: audioTrack, atTime: kCMTimeZero)
compositionvideoTrack.preferredTransform = audioTrack.preferredTransform
catch
print(error)
【讨论】：
【参考方案5】：作为补充，这里有一个函数，它基于通过复制其旋转、缩放和字体提供的数组 UITextViews 创建 CATextLayers。只需将这些添加到提供给 AVVideoCompositionCoreAnimationTool 的容器层：
private static func createTextLayer(totalSize: CGSize,
textView: UITextView) -> CATextLayer
let textLayer: CACenteredTextLayer = CACenteredTextLayer()
textLayer.backgroundColor = UIColor.clear
textLayer.foregroundColor = textView.textColor?.cgColor
textLayer.masksToBounds = false
textLayer.isWrapped = true
let scale: CGFloat = UIScreen.main.scale
if let font: UIFont = textView.font
let upscaledFont: UIFont = font.withSize(font.pointSize * scale)
let attributedString = NSAttributedString(
string: textView.text,
attributes: [NSAttributedString.Key.font: upscaledFont,
NSAttributedString.Key.foregroundColor: textView.textColor ?? UIColor.white])
textLayer.string = attributedString
// Set text alignment
let alignment: CATextLayerAlignmentMode
switch textView.textAlignment
case NSTextAlignment.left:
alignment = CATextLayerAlignmentMode.left
case NSTextAlignment.center:
alignment = CATextLayerAlignmentMode.center
default:
alignment = CATextLayerAlignmentMode.right
textLayer.alignmentMode = alignment
let originalFrame: CGRect = textView.frame
// Also take scale into consideration
let targetSize: CGSize = CGSize(width: originalFrame.width * scale,
height: originalFrame.height * scale)
// The CALayer positioning is inverted on the Y-axes, so apply this
let origin: CGPoint = CGPoint(x: originalFrame.origin.x * scale,
y: (totalSize.height - (originalFrame.origin.y * scale)) - targetSize.height)
textLayer.frame = CGRect(x: origin.x,
y: origin.y,
width: targetSize.width,
height: targetSize.height)
// Determine the scale
textLayer.anchorPoint = CGPoint(x: 0.5,
y: 0.5)
var newTransform: CATransform3D = CATransform3DMakeScale(textView.transform.xScale,
textView.transform.yScale,
0)
// Convert to degrees, invert the amount and convert back to radians to apply
newTransform = CATransform3DRotate(newTransform,
textView.transform.radiansFor3DTransform,
0,
0,
1)
textLayer.transform = newTransform
return textLayer
将它与 CATextLayer 的这个子类结合起来，使文本垂直居中：
final class CACenteredTextLayer: CATextLayer
override func draw(in ctx: CGContext)
guard let attributedString = string as? NSAttributedString else return
let height = self.bounds.size.height
let boundingRect: CGRect = attributedString.boundingRect(
with: CGSize(width: bounds.width,
height: CGFloat.greatestFiniteMagnitude),
options: NSStringDrawingOptions.usesLineFragmentOrigin,
context: nil)
let yDiff: CGFloat = (height - boundingRect.size.height) / 2
ctx.saveGState()
ctx.translateBy(x: 0.0, y: yDiff)
super.draw(in: ctx)
ctx.restoreGState()
private extension CGAffineTransform
var xScale: CGFloat
return sqrt((a*a) + (c*c))
var yScale: CGFloat
return sqrt((b*b) + (d*d))
var radiansFor3DTransform: CGFloat
let radians: CGFloat = atan2(b, a);
let degrees: CGFloat = -(radians * 180 / CGFloat.pi)
let convertedRadians: CGFloat = CGFloat(degrees * (CGFloat.pi / 180))
return convertedRadians
【讨论】：
嘿，我尝试了您的解决方案，但没有运气。可以分享一下xScale、yScale、radiansFor3DTransform 我已经附加了它们。以上是关于快速视频中的图像/文本叠加的主要内容，如果未能解决你的问题，请参考以下文章
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