您好我正在尝试使用叠加效果录制视频。
我写道：
-(void)addOvelayViewToVideo:(NSURL *)videoURL
在录制的视频上添加叠加视图但不起作用。
我使用viewDidLoad编写了使用AVCaptureSession在//In ViewDidLoad
//CONFIGURE DISPLAY OUTPUT
self.previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
[self.previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
self.previewLayer.frame = self.view.frame;
[self.view.layer addSublayer:self.previewLayer];
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{
if(error.code != noErr)
{
id value = [[error userInfo] objectForKey:AVErrorRecordingSuccessfullyFinishedKey];
if(value)
{
isSuccess = [value boolValue];
}
}
if(isSuccess)
{
ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];
if([assetsLibrary videoAtPathIsCompatibleWithSavedPhotosAlbum:outputFileURL])
{
[self addOverviewToVideo:outputFileURL];
}
else{
NSLog(@"could not saved to photos album.");
}
}
}
-(void)addOvelayViewToVideo:(NSURL *)videoURL
{
AVAsset *asset = [AVAsset assetWithURL:videoURL];
AVMutableComposition *composition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *compositionTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration) ofTrack:[[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVMutableVideoCompositionInstruction *compositionInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
compositionInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, asset.duration);
AVMutableVideoCompositionLayerInstruction *videoLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:compositionTrack];
AVAssetTrack *assetTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
UIImageOrientation videoAssetOrientation_ = UIImageOrientationUp;
BOOL isVideoAssetPortrait_ = NO;
CGAffineTransform videoTransform = assetTrack.preferredTransform;
if (videoTransform.a == 0 && videoTransform.b == 1.0 && videoTransform.c == -1.0 && videoTransform.d == 0) {
videoAssetOrientation_ = UIImageOrientationRight;
isVideoAssetPortrait_ = YES;
}
if (videoTransform.a == 0 && videoTransform.b == -1.0 && videoTransform.c == 1.0 && videoTransform.d == 0) {
videoAssetOrientation_ = UIImageOrientationLeft;
isVideoAssetPortrait_ = YES;
}
if (videoTransform.a == 1.0 && videoTransform.b == 0 && videoTransform.c == 0 && videoTransform.d == 1.0) {
videoAssetOrientation_ = UIImageOrientationUp;
}
if (videoTransform.a == -1.0 && videoTransform.b == 0 && videoTransform.c == 0 && videoTransform.d == -1.0) {
videoAssetOrientation_ = UIImageOrientationDown;
}
[videoLayerInstruction setTransform:assetTrack.preferredTransform atTime:kCMTimeZero];
[videoLayerInstruction setOpacity:0.0 atTime:asset.duration];
compositionInstruction.layerInstructions = [NSArray arrayWithObject:videoLayerInstruction];
AVMutableVideoComposition *videoComposition = [AVMutableVideoComposition videoComposition];
CGSize naturalSize = CGSizeMake(assetTrack.naturalSize.height, assetTrack.naturalSize.width);
float renderWidth, renderHeight;
renderWidth = naturalSize.width;
renderHeight = naturalSize.height;
videoComposition.renderSize = CGSizeMake(renderWidth, renderHeight);
videoComposition.instructions = [NSArray arrayWithObject:compositionInstruction];
videoComposition.frameDuration = CMTimeMake(1, 30);
CALayer *overlayLayer = [CALayer layer];
UIImage *overlayImage = [UIImage imageNamed:@"sampleHUD"];
[overlayLayer setContents:(id)[overlayImage CGImage]];
overlayLayer.frame = CGRectMake(0, 0, naturalSize.width, naturalSize.height);
[overlayLayer setMasksToBounds:YES];
CALayer *parentLayer = [CALayer layer];
CALayer *videoLayer = [CALayer layer];
parentLayer.frame = CGRectMake(0, 0, naturalSize.width, naturalSize.height);
videoLayer.frame = CGRectMake(0, 0, naturalSize.width, naturalSize.height);
[parentLayer addSublayer:videoLayer];
[parentLayer addSublayer:overlayLayer];
videoComposition.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
NSLog(@"renderSize:%f,%f", videoComposition.renderSize.width, videoComposition.renderSize.height);
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetHighestQuality];
exportSession.outputURL = videoURL;
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
exportSession.shouldOptimizeForNetworkUse = YES;
exportSession.videoComposition = videoComposition;
[exportSession exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
//save the video in photos album
});
}];
}
中录制视频的代码。
{{1}}
我仍然无法弄清楚这里出了什么问题。需要有关此的指导。
录制视频时可以添加叠加效果吗？
任何帮助将不胜感激。