Mix video streams on iOS - ios

Question

I need to mix two video stream from different inputs into single video file. I wanna embed one video frame into another.
My sources are: iOS app screen recording and frontal camera
Output: videofile of any format
How it can be done?

Answer 1

NSString * str_first=[NSString stringWithFormat:#"%#",[ary_urls objectAtIndex:0]];
NSString * str_secnd=[NSString stringWithFormat:#"%#",[ary_urls objectAtIndex:1]];
NSString * str_third=[NSString stringWithFormat:#"%#",[ary_urls objectAtIndex:2]];
NSURL *url_frst =[[NSURL alloc]initWithString:str_first];
NSURL *url_second =[[NSURL alloc]initWithString:str_secnd];
NSURL *url_third =[[NSURL alloc]initWithString:str_third];
firstAsset = [AVAsset assetWithURL:url_frst];
secondAsset = [AVAsset assetWithURL:url_second];
thirdAsset = [AVAsset assetWithURL:url_third];
if(firstAsset !=nil && secondAsset!=nil){
[ActivityView startAnimating];
//Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack.
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
//VIDEO TRACK
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:firstAsset.duration error:nil];
// AUDIO TRACK
// if(audioAsset!=nil){
// AVMutableCompositionTrack *AudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
// [AudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, CMTimeAdd(firstAsset.duration, secondAsset.duration)) ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
// }
AVMutableVideoCompositionInstruction *MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeAdd(firstAsset.duration, secondAsset.duration));
//FIXING ORIENTATION//
AVMutableVideoCompositionLayerInstruction *firstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];
AVAssetTrack * firstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
UIImageOrientation firstAssetOrientation_ = UIImageOrientationUp;
BOOL isFirstAssetPortrait_ = NO;
CGAffineTransform firstTransform = firstAssetTrack.preferredTransform;
if (firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0) {
firstAssetOrientation_ = UIImageOrientationRight;
isFirstAssetPortrait_ = YES;
}
if (firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0) {
firstAssetOrientation_ = UIImageOrientationLeft;
isFirstAssetPortrait_ = YES;
}
if (firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0) {
firstAssetOrientation_ = UIImageOrientationUp;
}
if (firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) {
firstAssetOrientation_ = UIImageOrientationDown;
}
[firstlayerInstruction setTransform:firstAsset.preferredTransform atTime:kCMTimeZero];
[firstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration];
CGFloat FirstAssetScaleToFitRatio = 320.0/firstAssetTrack.naturalSize.width;
if(isFirstAssetPortrait_)
{
FirstAssetScaleToFitRatio = 320.0/firstAssetTrack.naturalSize.height;
CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
[firstlayerInstruction setTransform:CGAffineTransformConcat(firstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero];
}else
{
CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
[firstlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(firstAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 0)) atTime:kCMTimeZero];
}
[firstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration];
AVMutableVideoCompositionLayerInstruction *secondlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:secondTrack];
AVAssetTrack *secondAssetTrack = [[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
UIImageOrientation secondAssetOrientation_ = UIImageOrientationUp;
BOOL isSecondAssetPortrait_ = NO;
CGAffineTransform secondTransform = secondAssetTrack.preferredTransform;
if (secondTransform.a == 0 && secondTransform.b == 1.0 && secondTransform.c == -1.0 && secondTransform.d == 0) {
secondAssetOrientation_= UIImageOrientationRight;
isSecondAssetPortrait_ = YES;
}
if (secondTransform.a == 0 && secondTransform.b == -1.0 && secondTransform.c == 1.0 && secondTransform.d == 0) {
secondAssetOrientation_ = UIImageOrientationLeft;
isSecondAssetPortrait_ = YES;
}
if (secondTransform.a == 1.0 && secondTransform.b == 0 && secondTransform.c == 0 && secondTransform.d == 1.0) {
secondAssetOrientation_ = UIImageOrientationUp;
}
if (secondTransform.a == -1.0 && secondTransform.b == 0 && secondTransform.c == 0 && secondTransform.d == -1.0) {
secondAssetOrientation_ = UIImageOrientationDown;
}
[secondlayerInstruction setTransform:secondAsset.preferredTransform atTime:firstAsset.duration];
CGFloat SecondAssetScaleToFitRatio = 320.0/secondAssetTrack.naturalSize.width;
if(isSecondAssetPortrait_){
SecondAssetScaleToFitRatio = 320.0/secondAssetTrack.naturalSize.height;
CGAffineTransform SecondAssetScaleFactor = CGAffineTransformMakeScale(SecondAssetScaleToFitRatio,SecondAssetScaleToFitRatio);
[secondlayerInstruction setTransform:CGAffineTransformConcat(secondAssetTrack.preferredTransform, SecondAssetScaleFactor) atTime:firstAsset.duration];
}else{
;
CGAffineTransform SecondAssetScaleFactor = CGAffineTransformMakeScale(SecondAssetScaleToFitRatio,SecondAssetScaleToFitRatio);
[secondlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(secondAssetTrack.preferredTransform, SecondAssetScaleFactor),CGAffineTransformMakeTranslation(0, 0)) atTime:firstAsset.duration];
}
MainInstruction.layerInstructions = [NSArray arrayWithObjects:firstlayerInstruction, secondlayerInstruction,nil];
AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
mainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction];
mainCompositionInst.frameDuration = CMTimeMake(1, 30);
CGSize naturalSizeFirst, naturalSizeSecond;
if(isFirstAssetPortrait_){
naturalSizeFirst = CGSizeMake(firstAssetTrack.naturalSize.height, firstAssetTrack.naturalSize.width);
} else {
naturalSizeFirst = firstAssetTrack.naturalSize;
}
if(isSecondAssetPortrait_){
naturalSizeSecond = CGSizeMake(secondAssetTrack.naturalSize.height, secondAssetTrack.naturalSize.width);
} else {
naturalSizeSecond = secondAssetTrack.naturalSize;
}
float renderWidth, renderHeight;
if(naturalSizeFirst.width > naturalSizeSecond.width) {
renderWidth = naturalSizeFirst.width;
} else {
renderWidth = naturalSizeSecond.width;
}
if(naturalSizeFirst.height > naturalSizeSecond.height) {
renderHeight = naturalSizeFirst.height;
} else {
renderHeight = naturalSizeSecond.height;
}
mainCompositionInst.renderSize = CGSizeMake(renderWidth, renderHeight);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"mergeVideo-%d.mp4",arc4random() % 1000]];
url_album = [NSURL fileURLWithPath:myPathDocs];
[ary_temp_url replaceObjectAtIndex:0 withObject:url_album];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL=url_album;
exporter.outputFileType = AVFileTypeQuickTimeMovie;
exporter.videoComposition = mainCompositionInst;
exporter.shouldOptimizeForNetworkUse = YES;
[exporter exportAsynchronouslyWithCompletionHandler:^
{
dispatch_async(dispatch_get_main_queue(), ^{
[self exportDidFinish:exporter];
});
}];
}
}