iOS視頻添加水印兩種方式（不用到第三方框架）

1、視頻加水印，並保存到沙盒當中

//原視頻sureasset，有外界傳進來
 AVURLAsset *asset = (AVURLAsset *)[self addPhotoTitleWithAsset:sureasset][0];
    AVMutableVideoComposition *mainCompositionInst = [self addPhotoTitleWithAsset:sureasset][1];
    sureasset = asset;
    
    AVAssetExportSession *session = [[AVAssetExportSession alloc] initWithAsset: sureasset presetName:AVAssetExportPresetMediumQuality];
    NSString *failPath = [self getVideosPath:@"localVideo"];//獲取路徑
    NSURL *filUrl = [NSURL fileURLWithPath:failPath];
    session.outputURL = filUrl;//視頻輸出地址
    session.outputFileType = AVFileTypeMPEG4;//AVFileTypeQuickTimeMovie;//AVFileTypeMPEG4;
    
    // 這個一般設置爲yes（指示輸出文件應針對網絡使用進行優化，例如QuickTime電影文件應支持“快速啓動”）
    session.shouldOptimizeForNetworkUse = YES;
    // 文件的最大多大的設置
    session.fileLengthLimit = 30 * 1024 * 1024;
    
    session.shouldOptimizeForNetworkUse = YES;
    session.videoComposition = mainCompositionInst;
    
    [session exportAsynchronouslyWithCompletionHandler:^(void){
        dispatch_async(dispatch_get_main_queue(), ^{
            //視頻導入成功
            //failPath爲本地視頻地址
            completeBlock(failPath,YES);
        });
    }];
    

//獲取路徑
- (NSString *)getVideosPath:(NSString *)videoName{
    NSString *documents = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
    documents = [documents stringByAppendingPathComponent:@"CCTV5"];
    documents = [self action_addFiles:documents];//判斷文件是否存在
    NSString *failPath = [documents stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.mp4",videoName]];
    return failPath;
}

#pragma mark- 視頻加水印
//添加水印
-(NSArray *)addPhotoTitleWithAsset:(AVAsset *)videoAsset
{
    //1 創建AVAsset實例
    //AVURLAsset*videoAsset = [AVURLAsset assetWithURL:[NSURL fileURLWithPath:path]];
    
    AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
    
    
    //3 視頻通道
    AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
                                                                        preferredTrackID:kCMPersistentTrackID_Invalid];
    [videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
                        ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] firstObject]
                         atTime:kCMTimeZero error:nil];
    
    
    //2 音頻通道
    AVMutableCompositionTrack *audioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio
                                                                        preferredTrackID:kCMPersistentTrackID_Invalid];
    [audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
                        ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeAudio] firstObject]
                         atTime:kCMTimeZero error:nil];
    
    //3.1 AVMutableVideoCompositionInstruction 視頻軌道中的一個視頻，可以縮放、旋轉等
    AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
    mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
    
    // 3.2 AVMutableVideoCompositionLayerInstruction 一個視頻軌道，包含了這個軌道上的所有視頻素材
    AVMutableVideoCompositionLayerInstruction *videolayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
    
    [videolayerInstruction setOpacity:0.0 atTime:videoAsset.duration];
    
    // 3.3 - Add instructions
    mainInstruction.layerInstructions = [NSArray arrayWithObjects:videolayerInstruction,nil];
    
    //AVMutableVideoComposition：管理所有視頻軌道，水印添加就在這上面
    AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
    
    AVAssetTrack *videoAssetTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] firstObject];
    CGSize naturalSize = videoAssetTrack.naturalSize;
    //防崩潰處理，這個width可能爲空，按比例給他值
    if (naturalSize.width == 0) {
        CGFloat a = (1280.f / 720);
        naturalSize.width =  a * naturalSize.height;
    }
    
    float renderWidth, renderHeight;
    renderWidth = naturalSize.width;
    renderHeight = naturalSize.height;
    mainCompositionInst.renderSize = CGSizeMake(renderWidth, renderHeight);
    mainCompositionInst.instructions = [NSArray arrayWithObject:mainInstruction];
    mainCompositionInst.frameDuration = CMTimeMake(1, 30);
    
    
    [self applyVideoEffectsToComposition:mainCompositionInst size:naturalSize];
 
    NSArray *arrar = [NSArray arrayWithObjects:mixComposition,mainCompositionInst, nil];
    return arrar;;
}
/**
 設置水印及其對應視頻的位置
 
 @param composition 視頻的結構
 @param size 視頻的尺寸
 */
- (void)applyVideoEffectsToComposition:(AVMutableVideoComposition *)composition size:(CGSize)size
{
    // 文字
    CATextLayer *subtitle1Text = [[CATextLayer alloc] init];
    //    [subtitle1Text setFont:@"Helvetica-Bold"];
    [subtitle1Text setFontSize:36];
    [subtitle1Text setFrame:CGRectMake(10, size.height-10-230, size.width, 100)];
    [subtitle1Text setString:@"央視體育5 水印"];
    //    [subtitle1Text setAlignmentMode:kCAAlignmentCenter];
    [subtitle1Text setForegroundColor:[[UIColor whiteColor] CGColor]];
    
    //圖片
    CALayer*picLayer = [CALayer layer];
    
    //picLayer.contents = (id)[UIImage imageNamed:@"CTVITTRIMSource.bundle/QQ"].CGImage; //本地圖片
    picLayer.contents = (id)self.videoWaterMarkImage.CGImage; //本地圖片2
    //NSString *imageUrl = @"http://p1.img.cctvpic.com/photoAlbum/templet/special/PAGEQ1KSin2j2U5FERGWHp1h160415/ELMTnGlKHUJZi7lz19PEnqhM160415_1460715755.png";
    //picLayer.contents = (id)[self getImageFromURL:imageUrl].CGImage; //遠程圖片
    CGFloat width = 63;
    CGFloat leftMargin = 16 * [self scaleSizeWithHeight:size.height];
    CGFloat topMargin = 20 * [self scaleSizeWithHeight:size.height];
    if (self.videoWaterMarkPlace == WaterMarkTopLeft) {
        picLayer.frame = CGRectMake(leftMargin, size.height-topMargin-[self scaleSizeWithHeight:size.height]*50, [self scaleSizeWithHeight:size.height]*width, [self scaleSizeWithHeight:size.height]*width);
    }
    if (self.videoWaterMarkPlace == WaterMarkBottomLeft) {
        picLayer.frame = CGRectMake(leftMargin, 20, [self scaleSizeWithHeight:size.height]*50, [self scaleSizeWithHeight:size.height]*50);
    }
    if (self.videoWaterMarkPlace == WaterMarkTopRight) {
        picLayer.frame = CGRectMake(size.width - 20 - [self scaleSizeWithHeight:size.height]*50, size.height-20-[self scaleSizeWithHeight:size.height]*50, [self scaleSizeWithHeight:size.height]*50, [self scaleSizeWithHeight:size.height]*50);
    }
    if (self.videoWaterMarkPlace == WaterMarkBottomRight) {
        picLayer.frame = CGRectMake(size.width - 20 - [self scaleSizeWithHeight:size.height]*50, 20, [self scaleSizeWithHeight:size.height]*50, [self scaleSizeWithHeight:size.height]*50);
        
    }
    
    // 2 - The usual overlay
    CALayer *overlayLayer = [CALayer layer];
    [overlayLayer addSublayer:picLayer];
    //    [overlayLayer addSublayer:subtitle1Text];
    overlayLayer.frame = CGRectMake(0, 0, size.width, size.height);
    [overlayLayer setMasksToBounds:YES];
    
    CALayer *parentLayer = [CALayer layer];
    CALayer *videoLayer = [CALayer layer];
    parentLayer.frame = CGRectMake(0, 0, size.width, size.height);
    videoLayer.frame = CGRectMake(0, 0, size.width, size.height);
    [parentLayer addSublayer:videoLayer];
    [parentLayer addSublayer:overlayLayer];
    
    composition.animationTool = [AVVideoCompositionCoreAnimationTool
                                 videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
    
}

//ios 從網絡上獲取圖片
-(UIImage *) getImageFromURL:(NSString *)fileURL {
    //https://vod.cctv.cn/cctvsports/cctv5/img/advertisingImage.jpg
    NSLog(@"執行圖片下載函數");
    
    UIImage * result;
    
    NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:fileURL]];
    
    result = [UIImage imageWithData:data];
    
    return result;
    
}

2、另一種實現方式

    //    [self applyVideoEffectsToComposition:mainCompositionInst size:naturalSize];
    
    CIFilter *watermarkFilter = [CIFilter filterWithName:@"CISourceOverCompositing"];
    
    mainCompositionInst = [AVMutableVideoComposition videoCompositionWithAsset:videoAsset applyingCIFiltersWithHandler:^(AVAsynchronousCIImageFilteringRequest * _Nonnull request) {
        
        CIImage *watermarkImage  =  [[CIImage alloc] initWithCGImage:self.videoWaterMarkImage.CGImage];
        
        CIImage *source = request.sourceImage;
        
        [watermarkFilter setValue:source forKey:kCIInputBackgroundImageKey];
        
        [watermarkFilter setValue:[watermarkImage imageByApplyingTransform:CGAffineTransformMakeScale(0.5, 0.5)] forKey:kCIInputImageKey];
        
        
        
        [watermarkFilter setValue:[watermarkImage imageByApplyingTransform:CGAffineTransformMakeTranslation(14, source.extent.size.height - 14 - watermarkImage.extent.size.height)] forKey:kCIInputImageKey];
        [request finishWithImage:watermarkFilter.outputImage context:nil];
        
    }];
    
    
    //       //    // 4 - 輸出路徑