iOS: Memory leak in VideoToolBox while Creating Video file from list of Image
(BOOL)appendPixelBuffer:(CVPixelBufferRef)pixelBuffer withPresentationTime:(CMTime)presentationTime

#import "ImageToVideo.h"

@implementation ImageToVideo

//global pixcel buffer.
CVPixelBufferRef pxbuffer = NULL;

- (void) pixelBufferFromCGImage:(CGImageRef)image size:(CGSize)size
{
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
                             nil];

    CVBufferRelease(pxbuffer);
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, size.width,
                                          size.height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options,
                                          &pxbuffer);
    options = nil;
    [options release];

    status=status;//Added to make the stupid compiler not show a stupid warning.
    NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);

    CVPixelBufferLockBaseAddress(pxbuffer, 0);
    void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
    NSParameterAssert(pxdata != NULL);

    CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(pxdata, size.width,
                                                 size.height, 8, 4*size.width, rgbColorSpace,
                                                 kCGImageAlphaNoneSkipFirst);
    NSParameterAssert(context);

    CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
                                           CGImageGetHeight(image)), image);
    CGColorSpaceRelease(rgbColorSpace);
    CGContextRelease(context);

    CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

}


- (void)writeImageAsMovietoPath:(NSString*)path size:(CGSize)size
{
    NSError *error = nil;
    AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
                                  [NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
                                                              error:&error];
    NSParameterAssert(videoWriter);

    NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                   [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                                   nil];
    AVAssetWriterInput* writerInput = [[AVAssetWriterInput
                                        assetWriterInputWithMediaType:AVMediaTypeVideo
                                        outputSettings:videoSettings] retain];

    AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
                                                     assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
                                                     sourcePixelBufferAttributes:nil];
    NSParameterAssert(writerInput);
    NSParameterAssert([videoWriter canAddInput:writerInput]);
    [videoWriter addInput:writerInput];

    NSMutableArray *photoImages = [[[NSMutableArray alloc] init] autorelease];

    //Creating a image Array
    for (int i = 0; i = [photoImages count])
            {
                CVBufferRelease(pxbuffer);
                pxbuffer = NULL;

            }
            else
            {
                //creating the pixcel buffer.
                [self pixelBufferFromCGImage:[[photoImages objectAtIndex:i] CGImage] size:CGSizeMake(640, 980)];
            }


            if (pxbuffer)
            {
                // append buffer
                [adaptor appendPixelBuffer:pxbuffer withPresentationTime:presentTime];
                CVBufferRelease(pxbuffer);
                pxbuffer = NULL;
                i++;
            }
            else
            {
                //Finish the session:
                [writerInput markAsFinished];
                [videoWriter finishWriting];

                CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
                [videoWriter release];
                [writerInput release];
                NSLog (@"Done");
                break;
            }
        }
    }

    //release the photoImage array.
    [photoImages removeAllObjects];
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    // Unable to save the image
    if (error)
    {
        UIAlertView *alert;
        alert = [[UIAlertView alloc] initWithTitle:@"Error"
                                           message:@"Unable to save image to Photo Album."
                                          delegate:self cancelButtonTitle:@"Ok"
                                 otherButtonTitles:nil];
        [alert show];
        [alert release];
    }
}



- (void) main
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSLog(@"Operation Started");

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents/movie.mp4"]];
    CGSize size = CGSizeMake(640, 960);

    [self writeImageAsMovietoPath:path size:size] ;

    [pool drain];
}


@end