我正在使用AVFoundation在我的電影中放入水印。這適用於在互聯網和蘋果公司正在進行的代碼。但我不想在完整的時間顯示水印,並且我想在同一部電影中顯示不同的水印。如何用不同的圖像和不同的CMTimes使用AVFoundation爲您的視頻添加水印
我有一個AVAsset:
NSString *path = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"MOV"];
NSURL *url = [[NSURL alloc] initFileURLWithPath: path];
avasset_camera = [AVAsset assetWithURL:url];
一種AVMutableComposition:
AVMutableComposition *mix = [AVMutableComposition composition];
的UIImage的轉換爲CALayer的和比添加到另一個層與animationTool摻入:
UIImage *myImage = [UIImage imageNamed:@"watermark.png"];
CALayer *aLayer = [CALayer layer];
aLayer.contents = (id)myImage.CGImage;
aLayer.frame = CGRectMake(0, 0, 568, 320);
aLayer.opacity = 1.0;
CGSize videoSize = [avasset_camera 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];
而不是AVMutableVideoComposition:
AVMutableVideoComposition* videoComp = [[AVMutableVideoComposition videoComposition] retain];
videoComp.renderSize = videoSize;
videoComp.frameDuration = CMTimeMake(1, 30);
AVVideoCompositionCoreAnimationTool *animationVideoTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
videoComp.animationTool = animationVideoTool;
爲VideoComposition指令:
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, avasset_camera.duration);
而對於層次的指令:
AVAssetTrack *videoTrack = [[mix tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableVideoCompositionLayerInstruction *layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
instruction.layerInstructions = [NSArray arrayWithObject:layerInstruction];
videoComp.instructions = [NSArray arrayWithObject: instruction];
,並且比同VideoComposition的財產AVAssetExportSession出口它
這將導致帶有完整視頻水印的視頻。我想要實現的是一個來自攝像機的視頻,其中水印的前5秒。它會消失一段時間,而不是另一幅圖像(也是水印)。
我被卡住了...我已經看過WWDC上的AVFoundation數萬億次的視頻,但它缺乏深入的視野。
當我更改指令的timeRange時,它不會導出,因爲持續時間(範圍)必須與AVAssetTrack的持續時間(範圍)相同。我一直試圖插入多個指令,但迄今爲止沒有成功。
您是否找到解決方案?我也面臨同樣的問題。 – 2017-02-20 12:55:03