user26392: I need to measure streaming video from various different codecs and be able to tell which one is better.
What will be the best metrics to look for? 
Is there a free tool that can help with this. 

user14523: There are a number of comparison algorithms available beginning with PSNR through SSIM/SSIMPLUS to VMAF. VMAF is implemented as an ffmpeg filter.

26392: <p>I need to measure streaming video from various different codecs and be able to tell which one is better.</p>

<p>What will be the best metrics to look for? </p>

<p>Is there a free tool that can help with this. </p>
 14523: <p>There are a number of comparison algorithms available beginning with <a href="https://tools.ietf.org/id/draft-ietf-netvc-testing-06.html" rel="nofollow noreferrer">PSNR</a> through <a href="https://www.ssimwave.com/technology/" rel="nofollow noreferrer">SSIM/SSIMPLUS</a> to <a href="https://medium.com/netflix-techblog/toward-a-practical-perceptual-video-quality-metric-653f208b9652" rel="nofollow noreferrer">VMAF</a>. VMAF is implemented as an ffmpeg <a href="https://ffmpeg.org/ffmpeg-filters.html#libvmaf" rel="nofollow noreferrer">filter</a>.</p>
