Question

i am creating a app to screen capture from the iphone. So after i did the coding i used profiling and analyzing to check memory leaks. I am getting only one memory leak in one section in the code. Here is my code which gives me the memory leak.

-(void) writeSample: (NSTimer*) _timer {

if (assetWriterInput.readyForMoreMediaData) {
    // CMSampleBufferRef sample = nil;

    CVReturn cvErr = kCVReturnSuccess;

    // get screenshot image!
    CGImageRef image = (CGImageRef) [[self screenshot] CGImage];
    NSLog (@"made screenshot");

    // prepare the pixel buffer
    CVPixelBufferRef pixelBuffer = NULL;
    CFDataRef imageData= CGDataProviderCopyData(CGImageGetDataProvider(image));
    NSLog (@"copied image data");
    cvErr = CVPixelBufferCreateWithBytes(kCFAllocatorDefault,
                                         FRAME_WIDTH,
                                         FRAME_HEIGHT,
                                         kCVPixelFormatType_32BGRA,
                                         (void*)CFDataGetBytePtr(imageData),
                                         CGImageGetBytesPerRow(image),
                                         NULL,
                                         NULL,
                                         NULL,
                                         &pixelBuffer);
    NSLog (@"CVPixelBufferCreateWithBytes returned %d", cvErr);

    // calculate the time
    CFAbsoluteTime thisFrameWallClockTime = CFAbsoluteTimeGetCurrent();
    CFTimeInterval elapsedTime = thisFrameWallClockTime - firstFrameWallClockTime;
    NSLog (@"elapsedTime: %f", elapsedTime);
    CMTime presentationTime =  CMTimeMake (elapsedTime * TIME_SCALE, TIME_SCALE);

    // write the sample
    BOOL appended = [assetWriterPixelBufferAdaptor appendPixelBuffer:pixelBuffer withPresentationTime:presentationTime];

    if (appended) {
        NSLog (@"appended sample at time %lf", CMTimeGetSeconds(presentationTime));
    } else {
        NSLog (@"failed to append");
        [self stopRecording];
        self.startStopButton.selected = NO;
    }
  }
}

it says Potential leak of an object stored into ‘imageData’. Can any one help me with finding the error in the above code. There is a memory leak in above code when i check it with the memory management tools too. If any one can help me it would be a great help.

Thanks in Advance !!

Answer 1

From comments –

Do a CFRelease on your imageData when your done with it?

You can put it right before or right after NSLog (@"CVPixelBufferCreateWithBytes returned %d", cvErr);

CFRelease(imageData);