Copiez ce qui suit dans votre fichier. J'ai eu le même problème et j'ai résolu le problème il y a deux semaines:
-(void)forStackOverflow:(NSURL*)url{
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:url options:nil];
AVMutableComposition* mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *clipVideoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableCompositionTrack *compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *clipAudioTrack = [[videoAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
//Si vous avez besoin de l'audio également, ajoutez ici la piste audio de l'Asset
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:clipVideoTrack atTime:kCMTimeZero error:nil];
[compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:clipAudioTrack atTime:kCMTimeZero error:nil];
[compositionVideoTrack setPreferredTransform:[[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] preferredTransform]];
CGSize sizeOfVideo=compositionVideoTrack.naturalSize;
CGFloat scaleWidth = sizeOfVideo.height/self.view.frame.size.width;
CGFloat scaleHeight = sizeOfVideo.width/self.view.frame.size.height;
// ajouter une image
UIImage *myImage=[UIImage imageNamed:@"YOUR IMAGE PATH"];
CALayer *layerCa = [CALayer layer];
layerCa.contents = (id)myImage.CGImage;
layerCa.frame = CGRectMake(5*scaleWidth, 0, self.birdSize.width*scaleWidth, self.birdSize.height*scaleWidth);
layerCa.opacity = 1.0;
// ajouter du texte sur l'image
CATextLayer *textOfvideo=[[CATextLayer alloc] init];
textOfvideo.alignmentMode = kCAAlignmentLeft;
[textOfvideo setFont:(__bridge CFTypeRef)([UIFont fontWithName:@"Arial" size:64.00])];//fontUsed est le nom de la police
[textOfvideo setFrame:CGRectMake(layerCa.frame.size.width/6, layerCa.frame.size.height/8*7-layerCa.frame.size.height/3, layerCa.frame.size.width/1.5, layerCa.frame.size.height/3)];
[textOfvideo setAlignmentMode:kCAAlignmentCenter];
[textOfvideo setForegroundColor:[[UIColor redColor] CGColor]];
UILabel*label = [[UILabel alloc]init];
[label setText:self.questionString];
label.textAlignment = NSTextAlignmentCenter;
label.numberOfLines = 4;
label.adjustsFontSizeToFitWidth = YES;
[label setFont:[UIFont fontWithName:@"Arial" size:64.00]];
//[label.layer setBackgroundColor:[[UIColor blackColor] CGColor]];
[label.layer setFrame:CGRectMake(0, 0, textOfvideo.frame.size.width, textOfvideo.frame.size.height)];
[textOfvideo addSublayer:label.layer];
[layerCa addSublayer:textOfvideo];
CALayer *parentLayer=[CALayer layer];
CALayer *videoLayer=[CALayer layer];
parentLayer.frame=CGRectMake(0, 0, sizeOfVideo.width, sizeOfVideo.height);
videoLayer.frame=CGRectMake(0, 0, sizeOfVideo.height,sizeOfVideo.width);
[parentLayer addSublayer:videoLayer];
//[parentLayer addSublayer:optionalLayer];
[parentLayer addSublayer:layerCa];
[parentLayer setBackgroundColor:[UIColor blueColor].CGColor];
AVMutableVideoComposition *videoComposition=[AVMutableVideoComposition videoComposition] ;
videoComposition.frameDuration=CMTimeMake(1, 30);
videoComposition.animationTool=[AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
//AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, [mixComposition duration]);
AVAssetTrack *videoTrack = [[mixComposition tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableVideoCompositionLayerInstruction* layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
UIImageOrientation videoAssetOrientation_ = UIImageOrientationUp;
BOOL isVideoAssetPortrait_ = NO;
[layerInstruction setTransform:videoTrack.preferredTransform atTime:kCMTimeZero];
CGSize naturalSize;
naturalSize = videoTrack.naturalSize;
float renderWidth, renderHeight;
renderWidth = naturalSize.width;
renderHeight = naturalSize.height;
videoComposition.renderSize = naturalSize = CGSizeMake(videoTrack.naturalSize.height, videoTrack.naturalSize.width);
instruction.layerInstructions = [NSArray arrayWithObject:layerInstruction];
videoComposition.instructions = [NSArray arrayWithObject: instruction];
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd_HH-mm-ss"];
NSString *destinationPath = [documentsDirectory stringByAppendingFormat:@"/utput_%@.mov", [dateFormatter stringFromDate:[NSDate date]]];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exportSession.videoComposition=videoComposition;
exportSession.outputURL = [NSURL fileURLWithPath:destinationPath];
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
[exportSession exportAsynchronouslyWithCompletionHandler:^{
switch (exportSession.status)
{
case AVAssetExportSessionStatusCompleted:
NSLog(@"Export OK");
if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(destinationPath)) {
UISaveVideoAtPathToSavedPhotosAlbum(destinationPath, self, @selector(video:didFinishSavingWithError:contextInfo:), nil);
}
break;
case AVAssetExportSessionStatusFailed:
NSLog (@"AVAssetExportSessionStatusFailed: %@", exportSession.error);
break;
case AVAssetExportSessionStatusCancelled:
NSLog(@"Export Cancelled");
break;
}
self.currentUrl = exportSession.outputURL;
dispatch_async(dispatch_get_main_queue(), ^{
});
}];
}