Swift: Merge audio and video files

Question

I want to merge a video with an audio file, but i wasn't able to do that. Video gets exported but audio file don't wants to be merged :)

func mergeAudio(audioURL: NSURL, moviePathUrl: NSURL, savePathUrl: NSURL) {
    var composition = AVMutableComposition()
    let trackVideo:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
    let trackAudio:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
    let option = NSDictionary(object: true, forKey: "AVURLAssetPreferPreciseDurationAndTimingKey")
    let sourceAsset = AVURLAsset(URL: moviePathUrl, options: option)
    let audioAsset = AVURLAsset(URL: audioURL, options: option)

    println(sourceAsset)
    println("playable: \(sourceAsset.playable)")
    println("exportable: \(sourceAsset.exportable)")
    println("readable: \(sourceAsset.readable)")

    let tracks = sourceAsset.tracksWithMediaType(AVMediaTypeVideo)
    let audios = audioAsset.tracksWithMediaType(AVMediaTypeAudio)

    if tracks.count > 0 {
        let assetTrack:AVAssetTrack = tracks[0] as AVAssetTrack
        let assetTrackAudio:AVAssetTrack = audios[0] as AVAssetTrack

        let audioDuration:CMTime = assetTrackAudio.timeRange.duration
        let audioSeconds:Float64 = CMTimeGetSeconds(assetTrackAudio.timeRange.duration)
        println(audioSeconds)

        trackVideo.insertTimeRange(CMTimeRangeMake(kCMTimeZero,audioDuration), ofTrack: assetTrack, atTime: kCMTimeZero, error: nil)
        trackAudio.insertTimeRange(CMTimeRangeMake(kCMTimeZero,audioDuration), ofTrack: assetTrackAudio, atTime: kCMTimeZero, error: nil)
    }

    var assetExport: AVAssetExportSession = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetPassthrough)
    assetExport.outputFileType = AVFileTypeMPEG4
    assetExport.outputURL = savePathUrl
    self.tmpMovieURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true
    assetExport.exportAsynchronouslyWithCompletionHandler({
        self.performSegueWithIdentifier("previewSegue", sender: self)
    })

}

Where is the problem? What am i missing?

Did you ever figure this out? – user3344977 Mar 13 '16 at 14:51 — user3344977, Mar 13 '16 at 14:51

Govind Prajapati · Accepted Answer · 2020-10-12T08:46:58.667

I was looking for the code to Merge audio and video files into one video but couldn't find anywhere so after spending hours while reading apple docs I wrote this code.

NOTE : This is tested and 100% working code for me.

Stap : 1 Import these modules in your viewController.

import UIKit
import AVFoundation
import AVKit
import AssetsLibrary

step 2: Add this function in your code

func mergeFilesWithUrl(videoUrl:NSURL, audioUrl:NSURL)
{
    let mixComposition : AVMutableComposition = AVMutableComposition()
    var mutableCompositionVideoTrack : [AVMutableCompositionTrack] = []
    var mutableCompositionAudioTrack : [AVMutableCompositionTrack] = []
    let totalVideoCompositionInstruction : AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()
    
    
    //start merge
    
    let aVideoAsset : AVAsset = AVAsset(URL: videoUrl)
    let aAudioAsset : AVAsset = AVAsset(URL: audioUrl)
    
    mutableCompositionVideoTrack.append(mixComposition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid))
    mutableCompositionAudioTrack.append( mixComposition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid))
    
    let aVideoAssetTrack : AVAssetTrack = aVideoAsset.tracksWithMediaType(AVMediaTypeVideo)[0]
    let aAudioAssetTrack : AVAssetTrack = aAudioAsset.tracksWithMediaType(AVMediaTypeAudio)[0]
    
    
    
    do{
        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aVideoAssetTrack, atTime: kCMTimeZero)
        
        //In my case my audio file is longer then video file so i took videoAsset duration
        //instead of audioAsset duration
        
        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)
        
        //Use this instead above line if your audiofile and video file's playing durations are same
        
        //            try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aAudioAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)
        
    }catch{
        
    }
    
    totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(kCMTimeZero,aVideoAssetTrack.timeRange.duration )
    
    let mutableVideoComposition : AVMutableVideoComposition = AVMutableVideoComposition()
    mutableVideoComposition.frameDuration = CMTimeMake(1, 30)
    
    mutableVideoComposition.renderSize = CGSizeMake(1280,720)
    
    //        playerItem = AVPlayerItem(asset: mixComposition)
    //        player = AVPlayer(playerItem: playerItem!)
    //
    //
    //        AVPlayerVC.player = player
    
    
    
    //find your video on this URl
    let savePathUrl : NSURL = NSURL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4")
    
    let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
    assetExport.outputFileType = AVFileTypeMPEG4
    assetExport.outputURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true
    
    assetExport.exportAsynchronouslyWithCompletionHandler { () -> Void in
        switch assetExport.status {
            
        case AVAssetExportSessionStatus.Completed:
            
            //Uncomment this if u want to store your video in asset
            
            //let assetsLib = ALAssetsLibrary()
            //assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completionBlock: nil)
            
            print("success")
        case  AVAssetExportSessionStatus.Failed:
            print("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.Cancelled:
            print("cancelled \(assetExport.error)")
        default:
            print("complete")
        }
    }
    
    
}

Step 3: Call function where u want like this

let videoUrl : NSURL =  NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("SampleVideo", ofType: "mp4")!)
let audioUrl : NSURL = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("SampleAudio", ofType: "mp3")!)
        
mergeFilesWithUrl(videoUrl, audioUrl: audioUrl)

hope this will help you and will save your time.

@Govind it is not working if the a recorder sound was is format AVFileTypeAppleM4A, any suggestions? — Dumitru Rogojinaru, Jan 20 '17 at 09:02
@DumitruRogojinaru, Sorry brother i have no idea about this format. — Govind Prajapati, Jan 23 '17 at 05:50
@GovindPrajapati Hey, great work, but this code removes the sound of original video. How can I keep that? — Faruk, Jul 25 '17 at 16:15
I found a way, please check https://stackoverflow.com/questions/45313680/composing-video-and-audio-videos-audio-is-gone/45327843#45327843 — Faruk, Jul 26 '17 at 13:04
@sharadchauhan I am sorry but I dont. Can you share your code? — Faruk, Sep 09 '17 at 09:36
@Faruk https://stackoverflow.com/questions/46129090/merging-video-audio-transparent-blank-video-exported please find it here. — Sharad Chauhan, Sep 09 '17 at 10:25
@Faruk I found the issue. Now the issue is related to orientation of exported vide. — Sharad Chauhan, Sep 09 '17 at 11:36
I know this is an old post, but it seems to have a typo in the do-catch block. n the comment about the bid and audio size the two lines are identical... I do not this this was the intent... just fyi to anyone interested in this snipet — LilMoke, Oct 06 '19 at 16:11

score -1 · Answer 2 · edited Nov 28 '20 at 20:48

I for it to work, I wrote this code.

assetExport.exportAsynchronouslyWithCompletionHandler { () -> Void in
    switch assetExport.status {
    case AVAssetExportSessionStatus.Completed:
        let assetsLib = ALAssetsLibrary()
        assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completionBlock: nil)
    case  AVAssetExportSessionStatus.Failed:
        println("failed \(assetExport.error)")
    case AVAssetExportSessionStatus.Cancelled:
        println("cancelled \(assetExport.error)")
    default:
        println("complete")
    }
}

Also, please note that such can not be overwritten with the same file name.

Swift: Merge audio and video files

2 Answers2