Can I generate a real time SSIM/PSNR plot while playing a video in FFmpeg?

Question

If I have both reference and test videos and I want to play the test video while also observing a plot of SSIM or PSNR, can this be done using FFmpeg's filter?

Answer 1

Basic template is

ffplay -f lavfi "movie='source.mp4'[s];movie='encode.mp4',split[p][e];[e][s]psnr,drawgraph=m1='lavfi.psnr.psnr_avg':min=0:max=60:slide=scroll,scale=640:-1,drawgrid=h=ih/10[g];[p][g]vstack"

The graph should be rescaled to the same width as the encoded video (640 in this case).

For SSIM, use the ssim filter in place of psnr. Change m1 to lavfi.ssim.All and min, max to 0 and 1 resp.

See the docs for these filters at http://ffmpeg.org/ffmpeg-filters.html