iphone - 录制视频上的 iPhone 水印。

Question

在我的应用程序中，我需要捕获视频并在该视频上添加水印。水印应该是文本（时间和注释）。我看到了一个使用“QTKit”框架的代码。但是我读到该框架不适用于 iPhone。

提前致谢。

Answer 1

添加水印要简单得多。您只需要使用 CALayer 和 AVVideoCompositionCoreAnimationTool。代码可以按照相同的顺序复制和组装。我只是试图在两者之间插入一些评论以便更好地理解。

假设您已经录制了视频，因此我们将首先创建 AVURLAsset：

AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:outputFileURL options:nil];
AVMutableComposition* mixComposition = [AVMutableComposition composition];

AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo  preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *clipVideoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) 
                               ofTrack:clipVideoTrack
                                atTime:kCMTimeZero error:nil];

[compositionVideoTrack setPreferredTransform:[[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] preferredTransform]]; 

仅使用此代码，您就可以导出视频，但我们想先添加带有水印的图层。请注意，有些代码可能看起来是多余的，但它是一切正常工作所必需的。

首先，我们使用水印图像创建图层：

UIImage *myImage = [UIImage imageNamed:@"icon.png"];
CALayer *aLayer = [CALayer layer];
aLayer.contents = (id)myImage.CGImage;
aLayer.frame = CGRectMake(5, 25, 57, 57); //Needed for proper display. We are using the app icon (57x57). If you use 0,0 you will not see it
aLayer.opacity = 0.65; //Feel free to alter the alpha here

如果我们不想要图像而想要文本：

CATextLayer *titleLayer = [CATextLayer layer];
titleLayer.string = @"Text goes here";
titleLayer.font = @"Helvetica";
titleLayer.fontSize = videoSize.height / 6;
//?? titleLayer.shadowOpacity = 0.5;
titleLayer.alignmentMode = kCAAlignmentCenter;
titleLayer.bounds = CGRectMake(0, 0, videoSize.width, videoSize.height / 6); //You may need to adjust this for proper display

以下代码按正确顺序对图层进行排序：

CGSize videoSize = [videoAsset naturalSize]; 
CALayer *parentLayer = [CALayer layer];
CALayer *videoLayer = [CALayer layer];   
parentLayer.frame = CGRectMake(0, 0, videoSize.width, videoSize.height);
videoLayer.frame = CGRectMake(0, 0, videoSize.width, videoSize.height);
[parentLayer addSublayer:videoLayer];
[parentLayer addSublayer:aLayer];
[parentLayer addSublayer:titleLayer]; //ONLY IF WE ADDED TEXT

现在我们正在创建合成并添加插入图层的说明：

AVMutableVideoComposition* videoComp = [[AVMutableVideoComposition videoComposition] retain];
videoComp.renderSize = videoSize;
videoComp.frameDuration = CMTimeMake(1, 30);
videoComp.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];

/// instruction
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, [mixComposition duration]);
AVAssetTrack *videoTrack = [[mixComposition tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableVideoCompositionLayerInstruction* layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
instruction.layerInstructions = [NSArray arrayWithObject:layerInstruction];
videoComp.instructions = [NSArray arrayWithObject: instruction];

现在我们准备导出：

_assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetMediumQuality];//AVAssetExportPresetPassthrough   
_assetExport.videoComposition = videoComp;

NSString* videoName = @"mynewwatermarkedvideo.mov";

NSString *exportPath = [NSTemporaryDirectory() stringByAppendingPathComponent:videoName];
NSURL    *exportUrl = [NSURL fileURLWithPath:exportPath];

if ([[NSFileManager defaultManager] fileExistsAtPath:exportPath]) 
{
    [[NSFileManager defaultManager] removeItemAtPath:exportPath error:nil];
}

_assetExport.outputFileType = AVFileTypeQuickTimeMovie; 
_assetExport.outputURL = exportUrl;
_assetExport.shouldOptimizeForNetworkUse = YES;

[strRecordedFilename setString: exportPath];

[_assetExport exportAsynchronouslyWithCompletionHandler:
 ^(void ) {
     [_assetExport release];
     //YOUR FINALIZATION CODE HERE
 }       
 ];   

[audioAsset release];
[videoAsset release];

Answer 2

使用AVFoundation. 我建议用 抓取帧AVCaptureVideoDataOutput，然后用水印图像覆盖捕获的帧，最后将捕获和处理的帧写入文件 user AVAssetWriter。

搜索堆栈溢出，有大量出色的示例详细说明了如何执行我提到的这些事情。我还没有看到任何提供代码示例的代码示例来完全符合您想要的效果，但是您应该能够很容易地混合和匹配。

编辑：

看看这些链接：

iPhone：AVCaptureSession 捕获输出崩溃 (AVCaptureVideoDataOutput) - 这篇文章可能会因为包含相关代码的性质而有所帮助。

AVCaptureDataOutput将图像作为CMSampleBufferRefs 返回。CGImageRef使用以下代码将它们转换为s：

    - (CGImageRef) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer // Create a CGImageRef from sample buffer data
{

    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); 
    CVPixelBufferLockBaseAddress(imageBuffer,0);        // Lock the image buffer 

    uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);   // Get information of the image 
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); 
    size_t width = CVPixelBufferGetWidth(imageBuffer); 
    size_t height = CVPixelBufferGetHeight(imageBuffer); 
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 

    CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); 
    CGImageRef newImage = CGBitmapContextCreateImage(newContext); 
    CGContextRelease(newContext); 

    CGColorSpaceRelease(colorSpace); 
    CVPixelBufferUnlockBaseAddress(imageBuffer,0); 
    /* CVBufferRelease(imageBuffer); */  // do not call this!

    return newImage;
}

从那里您将转换为 UIImage，

  UIImage *img = [UIImage imageWithCGImage:yourCGImage];  

然后使用

[img drawInRect:CGRectMake(x,y,height,width)]; 

要将帧绘制到上下文中，在其上绘制水印的 PNG，然后使用AVAssetWriter. 我建议实时添加它们，这样你就不会用大量的 UIImages 填满内存。

如何将 UIImage 数组导出为电影？- 这篇文章展示了如何在给定的持续时间内将您处理的 UIImages 添加到视频中。

这应该可以让您顺利地为视频添加水印。请记住练习良好的内存管理，因为以 20-30fps 的速度进入的泄漏图像是使应用程序崩溃的好方法。

Answer 3

@Julio 给出的答案在 Objective-c 的情况下已经可以正常工作了这是Swift 3.0的相同代码库：

WATERMARK & 生成像 Instagram 一样的 SQUARE 或 CROPPED 视频

从 Documents Directory 获取输出文件并创建 AVURLAsset

    //output file
    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
    let outputPath = documentsURL?.appendingPathComponent("squareVideo.mov")
    if FileManager.default.fileExists(atPath: (outputPath?.path)!) {
        do {
           try FileManager.default.removeItem(atPath: (outputPath?.path)!)
        }
        catch {
            print ("Error deleting file")
        }
    }



    //input file
    let asset = AVAsset.init(url: filePath)
    print (asset)
    let composition = AVMutableComposition.init()
    composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)

    //input clip
    let clipVideoTrack = asset.tracks(withMediaType: AVMediaTypeVideo)[0]

使用水印图像创建图层：

    //adding the image layer
    let imglogo = UIImage(named: "video_button")
    let watermarkLayer = CALayer()
    watermarkLayer.contents = imglogo?.cgImage
    watermarkLayer.frame = CGRect(x: 5, y: 25 ,width: 57, height: 57)
    watermarkLayer.opacity = 0.85

使用文本作为水印而不是图像创建图层：

    let textLayer = CATextLayer()
    textLayer.string = "Nodat"
    textLayer.foregroundColor = UIColor.red.cgColor
    textLayer.font = UIFont.systemFont(ofSize: 50)
    textLayer.alignmentMode = kCAAlignmentCenter
    textLayer.bounds = CGRect(x: 5, y: 25, width: 100, height: 20)

以正确的顺序在视频上添加图层以添加水印

  let videoSize = clipVideoTrack.naturalSize
    let parentlayer = CALayer()
    let videoLayer = CALayer()

    parentlayer.frame = CGRect(x: 0, y: 0, width: videoSize.height, height: videoSize.height)
    videoLayer.frame = CGRect(x: 0, y: 0, width: videoSize.height, height: videoSize.height)
    parentlayer.addSublayer(videoLayer)
    parentlayer.addSublayer(watermarkLayer)
    parentlayer.addSublayer(textLayer) //for text layer only

以正方形格式裁剪视频 - 大小为 300*300

 //make it square
    let videoComposition = AVMutableVideoComposition()
    videoComposition.renderSize = CGSize(width: 300, height: 300) //change it as per your needs.
    videoComposition.frameDuration = CMTimeMake(1, 30)
    videoComposition.renderScale = 1.0

    //Magic line for adding watermark to the video
    videoComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayers: [videoLayer], in: parentlayer)

    let instruction = AVMutableVideoCompositionInstruction()
    instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30))

旋转到纵向

//rotate to potrait
    let transformer = AVMutableVideoCompositionLayerInstruction(assetTrack: clipVideoTrack)
    let t1 = CGAffineTransform(translationX: clipVideoTrack.naturalSize.height, y: -(clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height) / 2)
    let t2: CGAffineTransform = t1.rotated(by: .pi/2)
    let finalTransform: CGAffineTransform = t2
    transformer.setTransform(finalTransform, at: kCMTimeZero)
    instruction.layerInstructions = [transformer]
    videoComposition.instructions = [instruction]

导出视频的最后一步

        let exporter = AVAssetExportSession.init(asset: asset, presetName: AVAssetExportPresetMediumQuality)
    exporter?.outputFileType = AVFileTypeQuickTimeMovie
    exporter?.outputURL = outputPath
    exporter?.videoComposition = videoComposition

    exporter?.exportAsynchronously() { handler -> Void in
        if exporter?.status == .completed {
            print("Export complete")
            DispatchQueue.main.async(execute: {
                completion(outputPath)
            })
            return
        } else if exporter?.status == .failed {
            print("Export failed - \(String(describing: exporter?.error))")
        }
        completion(nil)
        return
    }

这会将带有水印的方形视频导出为文本或图像

谢谢

Answer 4

只需下载代码并使用它。它位于 Apple 开发人员文档页面中。

http://developer.apple.com/library/ios/#samplecode/AVSimpleEditoriOS/Listings/AVSimpleEditor_AVSERotateCommand_m.html

Answer 5

这是关于 swift3如何在录制的视频中插入动画（图像/幻灯片/帧数组）和静态图像水印的示例。

它使用 CAKeyframeAnimation 为帧设置动画，并使用AVMutableCompositionTrack、AVAssetExportSession和AVMutableVideoComposition以及AVMutableVideoCompositionInstruction将所有内容组合在一起。

Answer 6

通过使用mikitamanko 博客中的 swift 示例代码向视频添加 CALayer我做了一些小的更改来修复以下错误：

Error Domain=AVFoundationErrorDomain Code=-11841 "Operation Stopped" UserInfo={NSLocalizedFailureReason=The video could not be composed., NSLocalizedDescription=Operation Stopped, NSUnderlyingError=0x2830559b0 {Error Domain=NSOSStatusErrorDomain Code=-17390 "(null)"}}

解决方案是在设置图层指令时使用合成的视频轨道而不是原始视频轨道，如下面的 swift 5 代码：

    static func addSketchLayer(url: URL, sketchLayer: CALayer, block: @escaping (Result<URL, VideoExportError>) -> Void) {
        let composition = AVMutableComposition()
        let vidAsset = AVURLAsset(url: url)
        
        let videoTrack = vidAsset.tracks(withMediaType: AVMediaType.video)[0]
        let duration = vidAsset.duration
        let vid_timerange = CMTimeRangeMake(start: CMTime.zero, duration: duration)
        
        let videoRect = CGRect(origin: .zero, size: videoTrack.naturalSize)
        let transformedVideoRect = videoRect.applying(videoTrack.preferredTransform)
        let size = transformedVideoRect.size
                
        let compositionvideoTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: CMPersistentTrackID(kCMPersistentTrackID_Invalid))!
        
        try? compositionvideoTrack.insertTimeRange(vid_timerange, of: videoTrack, at: CMTime.zero)
        compositionvideoTrack.preferredTransform = videoTrack.preferredTransform
        
        let videolayer = CALayer()
        videolayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        videolayer.opacity = 1.0
        sketchLayer.contentsScale = 1
        
        let parentlayer = CALayer()
        parentlayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        sketchLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        parentlayer.addSublayer(videolayer)
        parentlayer.addSublayer(sketchLayer)
        
        let layercomposition = AVMutableVideoComposition()
        layercomposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
        layercomposition.renderScale = 1.0
        layercomposition.renderSize = CGSize(width: size.width, height: size.height)

        layercomposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayers: [videolayer], in: parentlayer)
        
        let instruction = AVMutableVideoCompositionInstruction()
        instruction.timeRange = CMTimeRangeMake(start: CMTime.zero, duration: composition.duration)
        let layerinstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: compositionvideoTrack)
        layerinstruction.setTransform(compositionvideoTrack.preferredTransform, at: CMTime.zero)
        instruction.layerInstructions = [layerinstruction] as [AVVideoCompositionLayerInstruction]
        layercomposition.instructions = [instruction] as [AVVideoCompositionInstructionProtocol]
        
        let compositionAudioTrack:AVMutableCompositionTrack? = composition.addMutableTrack(withMediaType: AVMediaType.audio, preferredTrackID: CMPersistentTrackID(kCMPersistentTrackID_Invalid))
        let audioTracks = vidAsset.tracks(withMediaType: AVMediaType.audio)
        for audioTrack in audioTracks {
            try? compositionAudioTrack?.insertTimeRange(audioTrack.timeRange, of: audioTrack, at: CMTime.zero)
        }
        
        let movieDestinationUrl = URL(fileURLWithPath: NSTemporaryDirectory() + "/exported.mp4")
        try? FileManager().removeItem(at: movieDestinationUrl)
        
        let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality)!
        assetExport.outputFileType = AVFileType.mp4
        assetExport.outputURL = movieDestinationUrl
        assetExport.videoComposition = layercomposition
        
        assetExport.exportAsynchronously(completionHandler: {
            switch assetExport.status {
            case AVAssetExportSessionStatus.failed:
                print(assetExport.error ?? "unknown error")
                block(.failure(.failed))
            case AVAssetExportSessionStatus.cancelled:
                print(assetExport.error ?? "unknown error")
                block(.failure(.canceled))
            default:
                block(.success(movieDestinationUrl))
            }
        })
    }

enum VideoExportError: Error {
    case failed
    case canceled
}

请注意，根据AVFoundation Crash on Exporting Video With Text Layer此代码仅在模拟器上崩溃，但在真实设备上有效

另请注意，在应用首选视频变换后使用宽度和高度。