我有一個.mp4視頻，我可以如何添加水印

Question

我有.mp4視頻，並且我希望通過在適當位置上加水印來生成新視頻。

有可能性，我可以創建功能和通過視頻它會返回給我水上標記的視頻。

Answer 1

試試這個：

此代碼是添加在視頻文本或字符串並保存視頻後，你將在任何播放器上播放。 此代碼的最大優點是提供有聲視頻。所有的東西在一個代碼中（即文本和圖像）。

#import <AVFoundation/AVFoundation.h> 

    -(void)MixVideoWithText 
    { 
     AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:url options:nil]; 
     AVMutableComposition* mixComposition = [AVMutableComposition composition]; 

     AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid]; 
     AVAssetTrack *clipVideoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; 
     AVMutableCompositionTrack *compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
     AVAssetTrack *clipAudioTrack = [[videoAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]; 
     //If you need audio as well add the Asset Track for audio here 

     [compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:clipVideoTrack atTime:kCMTimeZero error:nil]; 
     [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:clipAudioTrack atTime:kCMTimeZero error:nil]; 

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

     CGSize sizeOfVideo=[videoAsset naturalSize]; 

     //TextLayer defines the text they want to add in Video 
     //Text of watermark 
     CATextLayer *textOfvideo=[[CATextLayer alloc] init]; 
     textOfvideo.string=[NSString stringWithFormat:@"%@",text];//text is shows the text that you want add in video. 
     [textOfvideo setFont:(__bridge CFTypeRef)([UIFont fontWithName:[NSString stringWithFormat:@"%@",fontUsed] size:13])];//fontUsed is the name of font 
     [textOfvideo setFrame:CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height/6)]; 
     [textOfvideo setAlignmentMode:kCAAlignmentCenter]; 
     [textOfvideo setForegroundColor:[selectedColour CGColor]]; 

     //Image of watermark 
     UIImage *myImage=[UIImage imageNamed:@"one.png"]; 
     CALayer layerCa = [CALayer layer]; 
     layerCa.contents = (id)myImage.CGImage; 
     layerCa.frame = CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height); 
     layerCa.opacity = 1.0; 

     CALayer *optionalLayer=[CALayer layer]; 
     [optionalL addSublayer:textOfvideo]; 
     optionalL.frame=CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height); 
     [optionalL setMasksToBounds:YES]; 

     CALayer *parentLayer=[CALayer layer]; 
     CALayer *videoLayer=[CALayer layer]; 
     parentLayer.frame=CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height); 
     videoLayer.frame=CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height); 
     [parentLayer addSublayer:videoLayer]; 
     [parentLayer addSublayer:optionalLayer]; 
     [parentLayer addSublayer:layerCa]; 

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

     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]; 
     videoComposition.instructions = [NSArray arrayWithObject: instruction]; 

     NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0]; 
     NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
     [dateFormatter setDateFormat:@"yyyy-MM-dd_HH-mm-ss"]; 
     NSString *destinationPath = [documentsDirectory stringByAppendingFormat:@"/utput_%@.mov", [dateFormatter stringFromDate:[NSDate date]]]; 

     AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetMediumQuality]; 
     exportSession.videoComposition=videoComposition; 

     exportSession.outputURL = [NSURL fileURLWithPath:destinationPath]; 
     exportSession.outputFileType = AVFileTypeQuickTimeMovie; 
     [exportSession exportAsynchronouslyWithCompletionHandler:^{ 
     switch (exportSession.status) 
     { 
      case AVAssetExportSessionStatusCompleted: 
       NSLog(@"Export OK"); 
       if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(destinationPath)) { 
        UISaveVideoAtPathToSavedPhotosAlbum(destinationPath, self, @selector(video:didFinishSavingWithError:contextInfo:), nil); 
       } 
       break; 
      case AVAssetExportSessionStatusFailed: 
       NSLog (@"AVAssetExportSessionStatusFailed: %@", exportSession.error); 
       break; 
      case AVAssetExportSessionStatusCancelled: 
       NSLog(@"Export Cancelled"); 
       break; 
     } 
     }]; 
    } 
Shows the error they will come after saving video. 

    -(void) video: (NSString *) videoPath didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo 
    { 
     if(error) 
      NSLog(@"Finished saving video with error: %@", error); 
    } 

來源：https://stackoverflow.com/a/22016800/3901620