我想在特定部分裁剪视频。给定高度、宽度、x 和 y,我想裁剪视频上的特定区域。有没有人知道。
我做了很多研究,但没有发现任何成果。我尝试使用 GPUImage Cropfilter 进行裁剪,但它花费了太多时间。
我想尽快执行此操作,请建议我如何执行此操作的技术或示例。 提前致谢
最佳答案
您可以使用 AVMutableComposition
和 AVAssetExportSession
它们在 AVFoundation Framework< 中可用
有关更多详细信息,请访问苹果的引用资料库 AVMutableComposition Class Reference和 AVAssetExportSession Class Reference
AVAsset* asset = // Create your asset with source video url
AVMutableComposition *videoComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionVideoTrack = [videoComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *clipVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableVideoComposition* videoComposition = [[AVMutableVideoComposition videoComposition]retain];
videoComposition.renderSize = CGSizeMake(320, 240);
videoComposition.frameDuration = CMTimeMake(1, 30);
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30) );
AVMutableVideoCompositionLayerInstruction* transformer = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:clipVideoTrack];
CGAffineTransform finalTransform = // setup a transform that grows the video, effectively causing a crop
[transformer setTransform:finalTransform atTime:kCMTimeZero];
instruction.layerInstructions = [NSArray arrayWithObject:transformer];
videoComposition.instructions = [NSArray arrayWithObject: instruction];
CGSize videoSize = myVideoComposition.renderSize;
CALayer *parentLayer = [CALayer layer];
CALayer *videoLayer = [CALayer layer];
NSLog(@"%f %f",_playerLayer.frame.origin.x,_playerLayer.frame.size.width);
parentLayer.frame = CGRectMake( 0, 0 , cropsize.x , cropsize.y );
[videoLayer setPosition:CGPointMake(videoLayer.position.x, videoSize.height)];
[parentLayer addSublayer:videoLayer];
videoComposition.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
exporter = [[AVAssetExportSession alloc] initWithAsset:saveComposition presetName:AVAssetExportPresetHighestQuality] ;
exporter.videoComposition = videoComposition;
exporter.outputURL=url3;
exporter.outputFileType=AVFileTypeQuickTimeMovie;
[exporter exportAsynchronouslyWithCompletionHandler:^(void){}];
关于iphone - 如何裁剪视频?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18606635/