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.水印应为文本(时间和注释).我看到使用"QTKit"Frame工作的代码.但是我读到该框架不适用于iPhone.

提前致谢.

Answer 1

添加水印非常简单.您只需要使用CALayer和AVVideoCompositionCoreAnimationTool.代码可以按照相同的顺序进行复制和组装.我刚刚尝试在其间插入一些评论以便更好地理解.

我们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]]; 

只需使用此代码,您就可以导出视频,但我们希望首先添加带有水印的图层.请注意,某些代码可能看起来多余,但一切都必须工作.

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];

现在我们准备出口了:

_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用户AVAssetWriter.

搜索堆栈溢出,有大量精彩的例子详细说明了如何处理我提到的每一件事.我还没有看到任何代码示例来说明你想要的效果,但你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) - 这篇文章可能仅仅包含相关代码的性质.

AVCaptureDataOutput将返回图像为CMSampleBufferRefs.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;
}

从那里你将转换为UIImage,

  UIImage *img = [UIImage imageWithCGImage:yourCGImage];  

然后用

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

要将帧绘制到上下文,在其上绘制水印的PNG,然后使用将处理后的图像添加到输出视频AVAssetWriter.我建议实时添加它们,这样你就不会用大量的UIImages来填充内存.

如何将UIImage数组导出为电影？ - 这篇文章展示了如何将您处理过的UIImages添加到视频中给定的持续时间.

这样可以让您在为视频添加水印方面取得成功.记住要练习良好的内存管理,因为以20-30fps的速度泄漏图像是破坏应用程序的好方法.

Answer 3

@Julio 给出的答案已经在objective-c 的情况下工作正常这是Swift 3.0的相同代码库：

水印和像 Instagram 一样生成方形或裁剪的视频

从文档目录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)

以适当的顺序在视频上添加图层以获得水印

  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