我捕捉使用的UIImagePickerController視頻影像顯示方向,我可以使用下面的代碼裁剪視頻,廣場種植和修復iOS中
AVAsset *asset = [AVAsset assetWithURL:url];
//create an avassetrack with our asset
AVAssetTrack *clipVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
//create a video composition and preset some settings
AVMutableVideoComposition* videoComposition = [AVMutableVideoComposition videoComposition];
videoComposition.frameDuration = CMTimeMake(1, 30);
//here we are setting its render size to its height x height (Square)
videoComposition.renderSize = CGSizeMake(clipVideoTrack.naturalSize.height, clipVideoTrack.naturalSize.height);
//create a video instruction
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30));
AVMutableVideoCompositionLayerInstruction* transformer = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:clipVideoTrack];
//Here we shift the viewing square up to the TOP of the video so we only see the top
CGAffineTransform t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.height, -20);
//Use this code if you want the viewing square to be in the middle of the video
//CGAffineTransform t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.height, -(clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height) /2);
//Make sure the square is portrait
CGAffineTransform t2 = CGAffineTransformRotate(t1, M_PI_2);
CGAffineTransform finalTransform = t2;
[transformer setTransform:finalTransform atTime:kCMTimeZero];
//add the transformer layer instructions, then add to video composition
instruction.layerInstructions = [NSArray arrayWithObject:transformer];
videoComposition.instructions = [NSArray arrayWithObject: instruction];
//Create an Export Path to store the cropped video
NSString *outputPath = [NSString stringWithFormat:@"%@%@", NSTemporaryDirectory(), @"video.mp4"];
NSURL *exportUrl = [NSURL fileURLWithPath:outputPath];
//Remove any prevouis videos at that path
[[NSFileManager defaultManager] removeItemAtURL:exportUrl error:nil];
//Export
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetLowQuality] ;
exporter.videoComposition = videoComposition;
exporter.outputURL = exportUrl;
exporter.outputFileType = AVFileTypeMPEG4;
[exporter exportAsynchronouslyWithCompletionHandler:^
{
dispatch_async(dispatch_get_main_queue(), ^{
//Call when finished
[self exportDidFinish:exporter];
});
}];
但我不知道如何解決的方向問題。就像instagram和vine應用程序一樣,即使我在橫向模式下捕捉視頻,它也應該處於縱向模式,並且需要將視頻裁剪爲正方形。請給我的解決方案...我這個問題掙扎......
哎,我使用的代碼中的答案,得到了我的莊稼工作,但我看到周圍的底部這個奇怪的綠色輪廓和右側,你有過這樣的問題嗎? – iqueqiorio 2015-04-07 15:57:09