MOV to Mp4 video conversion iPhone programmatically

presetName use "AVAssetExportPresetPassthrough" instead "AVAssetExportPresetLowQuality"

 AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetPassthrough];

MOV is very similar to MP4, you might be able to just change the extension and have it work, Windows Phone cant play .MOVS but can play mp4, all i did to get that to work is change the extension from .mov to .mp4 and it works fine, and this is from videos shot on the iphone...and if anything you can def try exporting with AVAssetExporter and try there is a file type in there for MP4 and M4A as you can see from the fileformat UTIs here

hope it helps

You can convert video in mp4 by AVAssets.

AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];
NSArray *compatiblePresets = [AVAssetExportSession     
exportPresetsCompatibleWithAsset:avAsset];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetLowQuality];

NSString* documentsDirectory=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
  exportSession.outputURL = url;
 //set the output file format if you want to make it in other file format (ex .3gp)
 exportSession.outputFileType = AVFileTypeMPEG4;
 exportSession.shouldOptimizeForNetworkUse = YES;

 [exportSession exportAsynchronouslyWithCompletionHandler:^{
 switch ([exportSession status])
 {
      case AVAssetExportSessionStatusFailed:
           NSLog(@"Export session failed");
           break;
      case AVAssetExportSessionStatusCancelled:
           NSLog(@"Export canceled");
           break;
      case AVAssetExportSessionStatusCompleted:
      {
           //Video conversion finished
           NSLog(@"Successful!");
      }
           break;
      default:
           break;
  }
 }];

To easily convert video to mp4 use this link.

You can also find sample project to convert video to mp4.

You need AVMutableComposition to do this. Because Asset can't be transcode to MP4 directly under iOS 5.0.

- (BOOL)encodeVideo:(NSURL *)videoURL
{
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];

    // Create the composition and tracks
    AVMutableComposition *composition = [AVMutableComposition composition];
    AVMutableCompositionTrack *videoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    AVMutableCompositionTrack *audioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    NSArray *assetVideoTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
    if (assetVideoTracks.count <= 0)
    {
            NSLog(@"Error reading the transformed video track");
            return NO;
    }

    // Insert the tracks in the composition's tracks
    AVAssetTrack *assetVideoTrack = [assetVideoTracks firstObject];
    [videoTrack insertTimeRange:assetVideoTrack.timeRange ofTrack:assetVideoTrack atTime:CMTimeMake(0, 1) error:nil];
    [videoTrack setPreferredTransform:assetVideoTrack.preferredTransform];

    AVAssetTrack *assetAudioTrack = [[asset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    [audioTrack insertTimeRange:assetAudioTrack.timeRange ofTrack:assetAudioTrack atTime:CMTimeMake(0, 1) error:nil];

    // Export to mp4
    NSString *mp4Quality = [MGPublic isIOSAbove:@"6.0"] ? AVAssetExportPresetMediumQuality : AVAssetExportPresetPassthrough;
    NSString *exportPath = [NSString stringWithFormat:@"%@/%@.mp4",
                                     [NSHomeDirectory() stringByAppendingString:@"/tmp"],
                                     [BSCommon uuidString]];

    NSURL *exportUrl = [NSURL fileURLWithPath:exportPath];
    AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:mp4Quality];
    exportSession.outputURL = exportUrl;
    CMTime start = CMTimeMakeWithSeconds(0.0, 0);
    CMTimeRange range = CMTimeRangeMake(start, [asset duration]);
    exportSession.timeRange = range;
    exportSession.outputFileType = AVFileTypeMPEG4;
    [exportSession exportAsynchronouslyWithCompletionHandler:^{
            switch ([exportSession status])
            {
                case AVAssetExportSessionStatusCompleted:
                       NSLog(@"MP4 Successful!");
                       break;
                case AVAssetExportSessionStatusFailed:
                       NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);
                       break;
                case AVAssetExportSessionStatusCancelled:
                       NSLog(@"Export canceled");
                       break;
                default:
                       break;
            }
    }];

    return YES;
}

Use the below code

    NSURL * mediaURL = [info objectForKey:UIImagePickerControllerMediaURL];
    AVAsset *video = [AVAsset assetWithURL:mediaURL];
    AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:video presetName:AVAssetExportPresetMediumQuality];
    exportSession.shouldOptimizeForNetworkUse = YES;
    exportSession.outputFileType = AVFileTypeMPEG4;

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
    basePath = [basePath stringByAppendingPathComponent:@"videos"];
    if (![[NSFileManager defaultManager] fileExistsAtPath:basePath])
        [[NSFileManager defaultManager] createDirectoryAtPath:basePath withIntermediateDirectories:YES attributes:nil error:nil];

    compressedVideoUrl=nil;
    compressedVideoUrl = [NSURL fileURLWithPath:basePath];
    long CurrentTime = [[NSDate date] timeIntervalSince1970];
    NSString *strImageName = [NSString stringWithFormat:@"%ld",CurrentTime];
    compressedVideoUrl=[compressedVideoUrl URLByAppendingPathComponent:[NSString stringWithFormat:@"%@.mp4",strImageName]];

    exportSession.outputURL = compressedVideoUrl;

    [exportSession exportAsynchronouslyWithCompletionHandler:^{

        NSLog(@"done processing video!");
        NSLog(@"%@",compressedVideoUrl);

        if(!dataMovie)
            dataMovie = [[NSMutableData alloc] init];
        dataMovie = [NSData dataWithContentsOfURL:compressedVideoUrl];

    }];