How to display frames of a Library Video in an UIImageView?
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {


    [self dismissModalViewControllerAnimated:NO];


    /// incoming video
    NSURL *videoURL = [info valueForKey:UIImagePickerControllerMediaURL];
    NSLog(@"Video : %@", videoURL);

    // AVURLAsset to read input movie (i.e. mov recorded to local storage)
    NSDictionary *inputOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
    AVURLAsset *inputAsset = [[AVURLAsset alloc] initWithURL:videoURL options:inputOptions];

    // Load the input asset tracks information
    [inputAsset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler: ^{


        NSError *error = nil;

        // Check status of "tracks", make sure they were loaded
        AVKeyValueStatus tracksStatus = [inputAsset statusOfValueForKey:@"tracks" error:&error];
        if (!tracksStatus == AVKeyValueStatusLoaded)
            return;


        AVAssetReader *reader = [AVAssetReader assetReaderWithAsset:inputAsset error:&error];

        NSMutableDictionary *outputSettings = [NSMutableDictionary dictionary];
        [outputSettings setObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]  forKey: (NSString*)kCVPixelBufferPixelFormatTypeKey];
        AVAssetReaderTrackOutput *readerVideoTrackOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:[[inputAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]
                                                                                 outputSettings:outputSettings];


        // Assign the tracks to the reader and start to read
        [reader addOutput:readerVideoTrackOutput];
        if ([reader startReading] == NO) {
            // Handle error
            NSLog(@"Error reading");
        }


        NSAutoreleasePool *pool = [NSAutoreleasePool new];
        while (reader.status == AVAssetReaderStatusReading) {

            CMSampleBufferRef sampleBufferRef = [readerVideoTrackOutput copyNextSampleBuffer];
            if (sampleBufferRef) {
                CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBufferRef);


                CVPixelBufferLockBaseAddress(pixelBuffer,0);
                /*Get information about the image*/
                uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(pixelBuffer);
                size_t bytesPerRow = CVPixelBufferGetBytesPerRow(pixelBuffer);
                size_t width = CVPixelBufferGetWidth(pixelBuffer);
                size_t height = CVPixelBufferGetHeight(pixelBuffer);

                NSLog(@"Display Frame : %zu %zu %zu", width, height, bytesPerRow);


                /*We unlock the  image buffer*/
                CVPixelBufferUnlockBaseAddress(pixelBuffer,0);

                /*Create a CGImageRef from the CVImageBufferRef*/
                CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
                CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);

                UIImage *image= [UIImage imageWithCGImage:newImage scale:1.0 orientation:UIImageOrientationRight];

                imageView.image = image;

                CGImageRelease(newImage);

                CGContextRelease(newContext);
                CGColorSpaceRelease(colorSpace);



                CMSampleBufferInvalidate(sampleBufferRef);
                CFRelease(sampleBufferRef);
            }
        }
        [pool release];

        NSLog(@"Finished");
    }];

}