Record video while playing other video and export - ios

Question

I am using UIImagePickerController to record a video. And I am using AVPlayer to play video picked library, adding AVPlayerLayer to cameraOverlayView to see video while recording.
But I need to export the video that merge 2 videos (one is recorded video and one is library video). The result video should be the same with the view while I record (include 2 video).
Please help me the way to do that.

Answer 1

Finally, I found the solution. Simple than I think, AVFoundation make all for done my requirements.
//Load video using AVURLAsset
AVURLAsset *firstAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource: #"file1" ofType: #"mp4"]] options:nil];
AVURLAsset *secondAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource: #"file2" ofType: #"mp4"]] options:nil];
//Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack.
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
//Here we are creating the first AVMutableCompositionTrack.See how we are adding a new track to our AVMutableComposition.
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
//Now we set the length of the firstTrack equal to the length of the firstAsset and add the firstAsset to out newly created track at kCMTimeZero so video plays from the start of the track.
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
//Now we repeat the same process for the 2nd track as we did above for the first track.Note that the new track also starts at kCMTimeZero meaning both tracks will play simultaneously.
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
//Create instruction
AVMutableVideoCompositionInstruction * MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, secondAsset.duration);
//Create layer instruction for first video
AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];
CGAffineTransform Scale = CGAffineTransformMakeScale(0.7f,0.7f);
CGAffineTransform Move = CGAffineTransformMakeTranslation(200,120);
[FirstlayerInstruction setTransform:CGAffineTransformConcat(Scale,Move) atTime:kCMTimeZero];
//Create layer instruction for second video
AVMutableVideoCompositionLayerInstruction *SecondlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:secondTrack];
CGAffineTransform SecondScale = CGAffineTransformMakeScale(1.2f,1.2f);
CGAffineTransform SecondMove = CGAffineTransformMakeTranslation(0,0);
[SecondlayerInstruction setTransform:CGAffineTransformConcat(SecondScale,SecondMove) atTime:kCMTimeZero];
//Add the layer instruction to the composition instruction
MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,SecondlayerInstruction,nil];;
//Add composition instruction to video composition
AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition];
MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction];
MainCompositionInst.frameDuration = CMTimeMake(1, 30);
MainCompositionInst.renderSize = CGSizeMake(640, 480);
And if you want to play the video composition
AVPlayerItem * newPlayerItem = [AVPlayerItem playerItemWithAsset:mixComposition];
newPlayerItem.videoComposition = MainCompositionInst;
self.mPlayer = [[AVPlayer alloc] initWithPlayerItem:newPlayerItem];
[self.mPlayer addObserver:self forKeyPath:#"status" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:nil];
AVPlayerLayer *layer = [AVPlayerLayer playerLayerWithPlayer:self.mPlayer];
self.mPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;
layer.frame = CGRectMake(0, 0, 640, 480);
[self.view.layer addSublayer: layer];
[self.mPlayer play];
And if you want to export the video composition to document directory
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"outputFile_%#.mp4",#"Main"]];
NSURL* outputFileUrl = [NSURL fileURLWithPath:path];
exportSession = [[AVAssetExportSession alloc]initWithAsset:mixComposition presetName:AVAssetExportPreset640x480];
exportSession.videoComposition = MainCompositionInst;
exportSession.outputFileType = #"public.mpeg-4";
exportSession.outputURL = outputFileUrl;
NSLog(#"duration = %f", CMTimeGetSeconds(mixComposition.duration));
exportSession.timeRange=CMTimeRangeMake(kCMTimeZero, mixComposition.duration);
[exportSession exportAsynchronouslyWithCompletionHandler:^{
switch(exportSession.status){
case AVAssetExportSessionStatusExporting:
NSLog(#"Exporting...");
break;
case AVAssetExportSessionStatusCompleted:
NSLog(#"Export completed, wohooo!! \n Check %#", path2);
break;
case AVAssetExportSessionStatusWaiting:
NSLog(#"Waiting...");
break;
case AVAssetExportSessionStatusCancelled:
NSLog(#"Cancelled");
break;
case AVAssetExportSessionStatusUnknown:
NSLog(#"Unknown");
break;
case AVAssetExportSessionStatusFailed:
NSLog(#"Failed with error: %#, try to save on %#", exportSession.error, path2);
break;
}
}];
Finally, if you want to tracking the progress
//Add a NSTimer for refresh checking the progress of AVAssetExportSession
exportProgressBarTimer = [NSTimer scheduledTimerWithTimeInterval:.1 target:self selector:#selector(updateExportDisplay) userInfo:nil repeats:YES];
And show the progress
- (void)updateExportDisplay {
NSLog(#"Exporting: %f", exportSession.progress);
if (exportSession.progress > .99) {
[exportProgressBarTimer invalidate];
}
}