最近项目中遇到在拍视频和图片(类似微信发朋友圈那种)之后添加水印的需求，此处记录相关代码
//self.fileNameString //类似这种20190522175147-部门-姓名-地址,需求是把地址作为水印内容
#define degreesToRadians( degrees ) ( ( degrees ) / 180.0 * M_PI )
#define textLabelHeight 300
#define textLabelFontSize 40
- (void)addWaterTextWithVideoPath:(NSString*)path complete:(void (^)(NSString *compressStr))complete{
//1 创建AVAsset实例
AVURLAsset*videoAsset = [AVURLAsset assetWithURL:[NSURL fileURLWithPath:path]];
AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
//3 视频通道
AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
[videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] firstObject]
atTime:kCMTimeZero error:nil];
//2 音频通道
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 视频轨道中的一个视频，可以缩放、旋转等
AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
// 3.2 AVMutableVideoCompositionLayerInstruction 一个视频轨道，包含了这个轨道上的所有视频素材
AVMutableVideoCompositionLayerInstruction *videolayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
[videolayerInstruction setOpacity:0.0 atTime:videoAsset.duration];
//AVMutableVideoComposition：管理所有视频轨道，水印添加就在这上面
AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
//视频旋转处理
CGAffineTransform t1 = CGAffineTransformMakeTranslation(videoTrack.naturalSize.height, 0.0);
// Rotate transformation
CGAffineTransform t2 = CGAffineTransformRotate(t1, degreesToRadians(90.0));
[videolayerInstruction setTransform:t2 atTime:kCMTimeZero];
// 3.3 - Add instructions
mainInstruction.layerInstructions = [NSArray arrayWithObjects:videolayerInstruction,nil];
AVAssetTrack *videoAssetTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] firstObject];
// CGSize naturalSize = videoAssetTrack.naturalSize;
CGSize naturalSize = CGSizeMake(videoAssetTrack.naturalSize.height, videoAssetTrack.naturalSize.width);
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];
// // 4 - 输出路径
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:
[NSString stringWithFormat:@"%@.mp4",self.fileNameString]];
//判断文件是否存在，如果已经存在删除
[[NSFileManager defaultManager] removeItemAtPath:myPathDocs error:nil];
NSURL* videoUrl = [NSURL fileURLWithPath:myPathDocs];
// 5 - 视频文件输出
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL = videoUrl;
exporter.outputFileType = AVFileTypeMPEG4;
exporter.shouldOptimizeForNetworkUse = YES;
exporter.videoComposition = mainCompositionInst;
[exporter exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
if( exporter.status == AVAssetExportSessionStatusCompleted ){
NSLog(@"导出完成");
NSURL *compressURL = exporter.outputURL;
NSLog(@"导出完毕,导出后大小 %f MB",[self ytfileSize:compressURL]);
NSString *compressUrlStr = compressURL.absoluteString;
if ([compressUrlStr containsString:@"file://"]) {
compressUrlStr = [compressUrlStr substringFromIndex:7];
}
complete(compressUrlStr);
}else if( exporter.status == AVAssetExportSessionStatusFailed ){
NSLog(@"导出failed");
complete(nil);
}
});
}];
}
- (void)applyVideoEffectsToComposition:(AVMutableVideoComposition *)composition size:(CGSize)size
{
// 文字
CATextLayer *subtitle1Text = [[CATextLayer alloc] init];
// [subtitle1Text setFont:@"Helvetica-Bold"];
[subtitle1Text setFontSize:textLabelFontSize];
subtitle1Text.wrapped = YES;//自动换行
[subtitle1Text setFrame:CGRectMake(10, size.height-10-textLabelHeight, size.width-20, textLabelHeight)];
[subtitle1Text setString:[self cutAddressFromFileName]];
// [subtitle1Text setAlignmentMode:kCAAlignmentCenter];
[subtitle1Text setForegroundColor:[[UIColor whiteColor] CGColor]];
//图片
// CALayer*picLayer = [CALayer layer];
// picLayer.contents = (id)[UIImage imageNamed:@"videoWater2"].CGImage;
// picLayer.frame = CGRectMake(size.width-15-87, 15, 87, 26);
// 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];
}
-(NSString *)cutAddressFromFileName{
NSString *addressStr = @"test";
if ([self.fileNameString containsString:@"-"]) {
NSArray *infoArr = [self.fileNameString componentsSeparatedByString:@"-"];
addressStr = (NSString *)infoArr.lastObject;
}
return addressStr;
}
//计算文件大小
-(CGFloat)ytfileSize:(NSURL *)path{
return [[NSData dataWithContentsOfURL:path] length]/1024.00 /1024.00;
}
//给图片添加文字水印
-(UIImage *)imageWithimage:(UIImage *)image content:(NSString *)content frame:(CGRect)frame {
// 开启图形'上下文'
UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);
// 绘制原生图片
[image drawAtPoint:CGPointZero];
// 在原生图上绘制文字
NSString *str = content;
// 创建文字属性字典
NSDictionary *dictionary = @{NSForegroundColorAttributeName: [UIColor whiteColor], NSFontAttributeName: [UIFont systemFontOfSize:textLabelFontSize]};
// 绘制文字属性
[str drawInRect:frame withAttributes:dictionary];
// 从当前上下文获取修改后的图片
UIImage *imageNew = UIGraphicsGetImageFromCurrentImageContext();
// 结束图形上下文
UIGraphicsEndImageContext();
return imageNew;
}
后续有时间再记录微信发朋友圈拍摄页面代码
补充：2020.7.3
最近同事出现一个问题，文字水印有的时候不显示，后来还是他自己找到了解决方法：
在CATextLayer属性设置都OK后调用display方法
[subtitle1Text display];
测试有效，感谢我牛逼的同事
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