Memory leak in CVPixelBufferPoolCreatePixelBuffer

Question

At the moment I am debugging some code. What it does it reads movie file into frames array, applies some transformations to the frames and compiles everything back to the video file. I have fixed all memory leaks which were called by myself the remaining one is pretty serious. It leaves almost 400 mb of memory after the process. Here is the screenshot of the leak.

As you can see, the higher level call is only in VideoToolbox library. Hovever, I do not even include this library into my project. I don't believe that this leak comes with Apple's library and there is nothing I can do about it.

Here is the only code that uses something related to h264 and decoding which were mentioned in the call tree.

-(void)writeImageAsMovie:(NSArray *)array toPath:(NSString*)path size:(CGSize)size
{

if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
    [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
}

NSError *error = nil;

// FIRST, start up an AVAssetWriter instance to write your video
// Give it a destination path (for us: tmp/temp.mov)
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];

AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
                                                                                                                 sourcePixelBufferAttributes:nil];
NSParameterAssert(writerInput);
NSParameterAssert([videoWriter canAddInput:writerInput]);
[videoWriter addInput:writerInput];
//Start a SESSION of writing.
// After you start a session, you will keep adding image frames
// until you are complete - then you will tell it you are done.
[videoWriter startWriting];
// This starts your video at time = 0
[videoWriter startSessionAtSourceTime:kCMTimeZero];

CVPixelBufferRef buffer = NULL;


//int frameDuration = (1/fps)*600.0;
//NSLog(@"FRAME DURATION: %d",frameDuration);
int i = 0;
while (1)
{
    // Check if the writer is ready for more data, if not, just wait
    if(writerInput.readyForMoreMediaData){

        CMTime frameTime = CMTimeMake(1, fps);
        // CMTime = Value and Timescale.
        // Timescale = the number of tics per second you want
        // Value is the number of tics
        // For us - each frame we add will be 1/4th of a second
        // Apple recommend 600 tics per second for video because it is a
        // multiple of the standard video rates 24, 30, 60 fps etc.
        CMTime lastTime=CMTimeMake(i, fps);
        CMTime presentTime=CMTimeAdd(lastTime, frameTime);

        if (i == 0) {presentTime = CMTimeMake(0, 600);}
        // This ensures the first frame starts at 0.


        if (i >= [array count])
        {
            buffer = NULL;
        }
        else
        {
            // This command grabs the next UIImage and converts it to a CGImage

            CVPixelBufferRef tempBuffer = buffer;

            CVPixelBufferRelease(tempBuffer);

            buffer = [self pixelBufferFromCGImage:[[array objectAtIndex:i] CGImage]andSize:size];
        }


        if (buffer)
        {
            // Give the CGImage to the AVAssetWriter to add to your video
            [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
            i++;
        }
        else
        {
            //Finish the session:
            // This is important to be done exactly in this order
            [writerInput markAsFinished];
            // WARNING: finishWriting in the solution above is deprecated.
            // You now need to give a completion handler.
            [videoWriter finishWritingWithCompletionHandler:^{
                NSLog(@"Finished writing...checking completion status...");
                if (videoWriter.status != AVAssetWriterStatusFailed && videoWriter.status == AVAssetWriterStatusCompleted)
                {
                    NSLog(@"Video writing succeeded.");

                    // Move video to camera roll
                    // NOTE: You cannot write directly to the camera roll.
                    // You must first write to an iOS director then move it!
                    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
                    NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder

                    NSString *audioTemp = [documentsDirectory stringByAppendingPathComponent:@"/temp-audio.m4a"];
                    NSString *finalTemp = [documentsDirectory stringByAppendingPathComponent:@"/temp.mov"];

                    [self mergeVideoFromPath:[NSURL fileURLWithPath:path] withAudioFromPath:[NSURL fileURLWithPath:audioTemp] atPath:[NSURL fileURLWithPath:finalTemp]];

                } else
                {
                    NSLog(@"Video writing failed: %@", videoWriter.error);
                }

            }]; // end videoWriter finishWriting Block


            CVPixelBufferRelease(buffer);

            CVPixelBufferPoolRelease(adaptor.pixelBufferPool);

            NSLog (@"Done");
            break;
        }
    }
}
}