DidOutputSampleBuffer it's not called on GPUVideoCamera

[edenilsonfe]

DidOutputSampleBuffer(from AVCaptureVideoDataOutputSampleBufferDelegate) method is called when a frame is available on the output, so I can use this frame to do something that I can. This method is called normally when I use GPUImageStillCamera but not when I use GPUImageVideoCamera. This method is called just two times when I use GPUImageVideoCamera so I can't get a frame on the output. Is there any way to force the call to this method?