[FFmpeg-user] Scaler effects when it doesn't have to scale

[Michael Kohne]

If I specify a "scale=w:h" to ffmpeg, and the input video is already at that resolution, will the scaler do anything to the video? Or will it just pass it through?

I have a situation where I must produce output video in a set frame size (the consumer of the video can't handle changes). Most of the time the input is of the correct size (it comes from a network camera that we pre-configure to the right size), but occasionally someone will muck with the camera, and then we've got a problem.

I'm thinking that if I always specify the scale option, then there's no chance of the output being the wrong size, but of course, I don't want to take an unnecessary quality hit in the normal case.

Thank you.

Michael Kohne 
michael.kohne at micromedgroup.com