1. A method for encoding a video signal having a plurality of frames, each frame having a plurality of blocks, the method comprising: calculating an inter-prediction variance for each test frame in a sequence of test frames, the test frames in the sequence of test frames having an original resolution; calculating a first peak signal-to-noise ratio (PSNR) for each test frame using the original resolution; determining an inter threshold using the inter-prediction variances and first PSNRs; and providing the inter threshold to an encoder to select a frame resolution for a first frame of the plurality of frames, the frame resolution being one of the original resolution or a resolution different from the original resolution.