Doom9's Forum - View Single Post - Invitation to 5th H.264/AVC codecs comparison

dj_tjerk · 31st March 2009, 21:30

The goal is to be as close to the original as possible right? I don't know how well eyes can compare two videos; I just have a feeling that ears are a lot better at picking out small differences in audio than eyes are at picking out differences in video. Add that eyes only focus on a very small part of the screen (1cm^2 at about 50cm distance). You'd need to compare iamges if you want to compare the quality of the entire frame, but then you get high-motion/slow-motion issues/grain retention/etc..

Comparing images is easier, there have a couple of those here at doom9 before. It's easier to see changes 'happening' when you click an the "original" and it changes to "encode". (And you can do so multiple times).

Anyway, if this comparison judges codecs based on SSIM, then the encoders should just optimize for SSIM. It might give some indication of how much detail (and what kind of) detail it retains and how long an encoder takes to do that.

31st March 2009, 21:30	#41 \| Link
dj_tjerk Registered User Join Date: Jun 2008 Posts: 15	The goal is to be as close to the original as possible right? I don't know how well eyes can compare two videos; I just have a feeling that ears are a lot better at picking out small differences in audio than eyes are at picking out differences in video. Add that eyes only focus on a very small part of the screen (1cm^2 at about 50cm distance). You'd need to compare iamges if you want to compare the quality of the entire frame, but then you get high-motion/slow-motion issues/grain retention/etc.. Comparing images is easier, there have a couple of those here at doom9 before. It's easier to see changes 'happening' when you click an the "original" and it changes to "encode". (And you can do so multiple times). Anyway, if this comparison judges codecs based on SSIM, then the encoders should just optimize for SSIM. It might give some indication of how much detail (and what kind of) detail it retains and how long an encoder takes to do that. Last edited by dj_tjerk; 31st March 2009 at 21:35.