- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
    CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    size_t frameWidth = CVPixelBufferGetWidth(pixelBuffer);
    size_t frameHeight = CVPixelBufferGetHeight(pixelBuffer);
    CVOpenGLESTextureRef texture = NULL;
    CVReturn err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault,
                                                                videoTextureCache,
                                                                pixelBuffer,
                                                                NULL,
                                                                GL_TEXTURE_2D,
                                                                GL_RGBA,
                                                                frameWidth,
                                                                frameHeight,
                                                                GL_BGRA,
                                                                GL_UNSIGNED_BYTE,
                                                                0,
                                                                &texture);


    if (!texture || err) {
        NSLog(@"CVOpenGLESTextureCacheCreateTextureFromImage failed (error: %d)", err);
        return;
    }
}

[output setVideoSettings:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey]];

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

CFRelease(texture);
CVOpenGLESTextureCacheFlush(videoTextureCache, 0);