Record, save and/or convert video in mp4 format?

You are doing right thing.. Now you need to convert this mov file to mp4 as below.

NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType];NSString *videoPath1 = @"";if (CFStringCompare ((__bridge_retained CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo) {   if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(moviePath))   {         NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];         NSString *moviePath = [[info objectForKey:UIImagePickerControllerMediaURL] path];         videoPath1 =[NSString stringWithFormat:@"%@/xyz.mov",docDir];         NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];         NSData *videoData = [NSData dataWithContentsOfURL:videoURL];         [videoData writeToFile:videoPath1 atomically:NO];       //  UISaveVideoAtPathToSavedPhotosAlbum(moviePath, self, nil, nil);   } }    AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:videoPath1] options:nil];    NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:avAsset];    if ([compatiblePresets containsObject:AVAssetExportPresetLowQuality])    {        AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetPassthrough];        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);        videoPath = [NSString stringWithFormat:@"%@/xyz.mp4", [paths objectAtIndex:0]];        exportSession.outputURL = [NSURL fileURLWithPath:videoPath];        NSLog(@"videopath of your mp4 file = %@",videoPath);  // PATH OF YOUR .mp4 FILE        exportSession.outputFileType = AVFileTypeMPEG4;      //  CMTime start = CMTimeMakeWithSeconds(1.0, 600);      //  CMTime duration = CMTimeMakeWithSeconds(3.0, 600);                 //  CMTimeRange range = CMTimeRangeMake(start, duration);                  //   exportSession.timeRange = range;              //  UNCOMMENT ABOVE LINES FOR CROP VIDEO           [exportSession exportAsynchronouslyWithCompletionHandler:^{            switch ([exportSession status]) {                case AVAssetExportSessionStatusFailed:                    NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);                    break;                case AVAssetExportSessionStatusCancelled:                    NSLog(@"Export canceled");                    break;                default:                    break;            }             UISaveVideoAtPathToSavedPhotosAlbum(videoPath, self, nil, nil);            [exportSession release];        }];    }[nextScreenButton setTitle:@"ПРОДЪЛЖИ" forState:UIControlStateNormal];[self dismissViewControllerAnimated:YES completion:nil];

Here is the code to convert mov video into mp4 for swift

func encodeVideo(videoURL: NSURL)  {let avAsset = AVURLAsset(URL: videoURL, options: nil)var startDate = NSDate()//Create Export sessionexportSession = AVAssetExportSession(asset: avAsset, presetName: AVAssetExportPresetPassthrough)// exportSession = AVAssetExportSession(asset: composition, presetName: mp4Quality)//Creating temp path to save the converted videolet documentsDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0]let myDocumentPath = NSURL(fileURLWithPath: documentsDirectory).URLByAppendingPathComponent("temp.mp4").absoluteStringlet url = NSURL(fileURLWithPath: myDocumentPath)let documentsDirectory2 = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as NSURLlet filePath = documentsDirectory2.URLByAppendingPathComponent("rendered-Video.mp4")deleteFile(filePath)//Check if the file already exists then remove the previous fileif NSFileManager.defaultManager().fileExistsAtPath(myDocumentPath) {    do {        try NSFileManager.defaultManager().removeItemAtPath(myDocumentPath)    }    catch let error {        print(error)    }} urlexportSession!.outputURL = filePathexportSession!.outputFileType = AVFileTypeMPEG4exportSession!.shouldOptimizeForNetworkUse = truevar start = CMTimeMakeWithSeconds(0.0, 0)var range = CMTimeRangeMake(start, avAsset.duration)exportSession.timeRange = rangeexportSession!.exportAsynchronouslyWithCompletionHandler({() -> Void in    switch self.exportSession!.status {    case .Failed:        print("%@",self.exportSession?.error)    case .Cancelled:        print("Export canceled")    case .Completed:        //Video conversion finished        var endDate = NSDate()        var time = endDate.timeIntervalSinceDate(startDate)        print(time)        print("Successful!")        print(self.exportSession.outputURL)    default:        break    }})}func deleteFile(filePath:NSURL) {guard NSFileManager.defaultManager().fileExistsAtPath(filePath.path!) else {    return}do {    try NSFileManager.defaultManager().removeItemAtPath(filePath.path!)}catch{    fatalError("Unable to delete file: \(error) : \(__FUNCTION__).")}}

Swift 3

func encodeVideo(_ videoURL: URL)  {    let avAsset = AVURLAsset(url: videoURL, options: nil)    let startDate = Foundation.Date()    //Create Export session    exportSession = AVAssetExportSession(asset: avAsset, presetName: AVAssetExportPresetPassthrough)    // exportSession = AVAssetExportSession(asset: composition, presetName: mp4Quality)    //Creating temp path to save the converted video    let documentsDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]    let myDocumentPath = URL(fileURLWithPath: documentsDirectory).appendingPathComponent("temp.mp4").absoluteString    let url = URL(fileURLWithPath: myDocumentPath)    let documentsDirectory2 = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0] as URL    let filePath = documentsDirectory2.appendingPathComponent("rendered-Video.mp4")    deleteFile(filePath)    //Check if the file already exists then remove the previous file    if FileManager.default.fileExists(atPath: myDocumentPath) {        do {            try FileManager.default.removeItem(atPath: myDocumentPath)        }        catch let error {            print(error)        }    }    exportSession!.outputURL = filePath    exportSession!.outputFileType = AVFileTypeMPEG4    exportSession!.shouldOptimizeForNetworkUse = true    let start = CMTimeMakeWithSeconds(0.0, 0)    let range = CMTimeRangeMake(start, avAsset.duration)    exportSession.timeRange = range    exportSession!.exportAsynchronously(completionHandler: {() -> Void in        switch self.exportSession!.status {        case .failed:            print("%@",self.exportSession?.error)        case .cancelled:            print("Export canceled")        case .completed:            //Video conversion finished            let endDate = Foundation.Date()            let time = endDate.timeIntervalSince(startDate)            print(time)            print("Successful!")            print(self.exportSession.outputURL)            self.mediaPath = self.exportSession.outputURL?.path as NSString!            //self.mediaPath = String(self.exportSession.outputURL!)        // self.mediaPath = self.mediaPath.substringFromIndex(7)        default:            break        }    })}func deleteFile(_ filePath:URL) {    guard FileManager.default.fileExists(atPath: filePath.path) else {        return    }    do {        try FileManager.default.removeItem(atPath: filePath.path)    }catch{        fatalError("Unable to delete file: \(error) : \(#function).")    }}

Here you can specify video type, quality and output url for compress video.

See below methods:

- (void) saveVideoToLocal:(NSURL *)videoURL {    @try {        NSArray *documentsDirectory = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);        NSString *docPath = [documentsDirectory objectAtIndex:0];        NSString *videoName = [NSString stringWithFormat:@"sampleVideo.mp4"];        NSString *videoPath = [docPath stringByAppendingPathComponent:videoName];        NSURL *outputURL = [NSURL fileURLWithPath:videoPath];        NSLog(@"Loading video");        [self convertVideoToLowQuailtyWithInputURL:videoURL outputURL:outputURL handler:^(AVAssetExportSession *exportSession) {             if (exportSession.status == AVAssetExportSessionStatusCompleted) {                 NSLog(@"Compression is done");             }         }];    }    @catch (NSException *exception) {        NSLog(@"Exception :%@",exception.description);    }}//---------------------------------------------------------------- (void)convertVideoToLowQuailtyWithInputURL:(NSURL*)inputURL outputURL:(NSURL*)outputURL handler:(void (^)(AVAssetExportSession*))handler {    [[NSFileManager defaultManager] removeItemAtURL:outputURL error:nil];    AVURLAsset *asset = [AVURLAsset URLAssetWithURL:inputURL options:nil];    AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetPassthrough];    exportSession.outputURL = outputURL;    exportSession.outputFileType = AVFileTypeMPEG4;    [exportSession exportAsynchronouslyWithCompletionHandler:^(void) {        handler(exportSession);    }];}

Yes, you can compress video using AVAssetExportSession. Here, I saved compress video to document directory of application. You can check detail working of this in this code.

If you have still issues, then refer this and this.