How to trim the video using AVFoundation

Question

Iam able to record the video by using AVFoundation or UIImagePickerController. But i am unable to trim the video from one particular second to another particular duration/time. Can any one help me.

Thanks, Siva Krishna.

Answer 1

You can have the UIImagePickerController enable trimming

UIImagePickerController *videoRecorder = [[UIImagePickerController alloc]init];         
        NSArray *sourceTypes = [UIImagePickerController availableMediaTypesForSourceType:videoRecorder.sourceType];
        NSLog(@"Available types for source as camera = %@", sourceTypes);
        if (![sourceTypes containsObject:(NSString*)kUTTypeMovie] ) {
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil 
                                                            message:@"Device Not Supported for video Recording."                                                                       delegate:self 
                                                  cancelButtonTitle:@"Yes" 
                                                  otherButtonTitles:@"No",nil];
            [alert show];
            [alert release];
            return;
        }
        videoRecorder.allowsEditing = YES;

Unfortunately after you get back from the imagePickerController, You are forced to convert the video manually.

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{
    if ([self.popoverLibraryBrowser isPopoverVisible])
    {
        [self.popoverLibraryBrowser dismissPopoverAnimated:YES];
    }
    NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
    if ([type isEqualToString:(NSString *)kUTTypeVideo] || 
        [type isEqualToString:(NSString *)kUTTypeMovie]) { // movie != video
        NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];


        NSNumber *start = [info objectForKey:@"_UIImagePickerControllerVideoEditingStart"];
        NSNumber *end = [info objectForKey:@"_UIImagePickerControllerVideoEditingEnd"];

        // if start and end are nil then clipping was not used.
        // You should use the entire video.


        int startMilliseconds = ([start doubleValue] * 1000);
        int endMilliseconds = ([end doubleValue] * 1000);

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSFileManager *manager = [NSFileManager defaultManager];

        NSString *outputURL = [documentsDirectory stringByAppendingPathComponent:@"output"] ;
        [manager createDirectoryAtPath:outputURL withIntermediateDirectories:YES attributes:nil error:nil];

        outputURL = [outputURL stringByAppendingPathComponent:@"output.mp4"];
        // Remove Existing File
        [manager removeItemAtPath:outputURL error:nil];


        //[self loadAssetFromFile:videoURL];

        [self.recorder dismissModalViewControllerAnimated:YES];

        AVURLAsset *videoAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil]; 


        AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:videoAsset presetName:AVAssetExportPresetHighestQuality];
        exportSession.outputURL = [NSURL fileURLWithPath:outputURL];
        exportSession.outputFileType = AVFileTypeQuickTimeMovie;
        CMTimeRange timeRange = CMTimeRangeMake(CMTimeMake(startMilliseconds, 1000), CMTimeMake(endMilliseconds - startMilliseconds, 1000));
        exportSession.timeRange = timeRange;

        [exportSession exportAsynchronouslyWithCompletionHandler:^{
            switch (exportSession.status) {
                case AVAssetExportSessionStatusCompleted:
                    // Custom method to import the Exported Video
                    [self loadAssetFromFile:exportSession.outputURL];
                    break;
                case AVAssetExportSessionStatusFailed:
                    //
                    NSLog(@"Failed:%@",exportSession.error);
                    break;
                case AVAssetExportSessionStatusCancelled:
                    //
                    NSLog(@"Canceled:%@",exportSession.error);
                    break;
                default:
                    break;
            }
        }];



        //NSData *videoData = [NSData dataWithContentsOfURL:videoURL];
        //NSString *videoStoragePath;//Set your video storage path to this variable
        //[videoData writeToFile:videoStoragePath atomically:YES];
        //You can store the path of the saved video file in sqlite/coredata here.
    }
}