"In the case of the 499kbit/sec H.264 I believe that under careful comparison many people would prefer the H.264 video. However, the difference is not especially great. I expect that most casual users would be unlikely to express a preference or complain about quality if one was substituted for another and I've had several people perform a casual comparison of the files and express indifference. Since Theora+Vorbis is providing such comparable results, I think I can confidently state that reports of the internet's impending demise are greatly exaggerated."
480x270 ~529 kbit/s combined, H.264, Theora,
"To my eyes both encodings looks mostly the same - but (somewhat unexpected to me) Theora seems to preserve more detail on face, shirt and hair. In this single test in this configuration I declare Theora winner over the H.264 encoding-setup at YouTube."
1280x720, ~2135 kbit/s combined, H.264, Theora,
"This is much closer and both encodings look "mostly the same" and one has to look rather closely (also watch at the actual video, not just the screenshots!) to see a difference. In this case I'd say the YouTube H.264 encoding may actually preserve a tiny bit more details on the shirt, so to my eyes YouTube's H.264 is perhaps is a tiny bit better than Theora here. Apparently there are some people who can't tell those videos apart, though. No big deal either way."
nem arról volt szó, hogy jobb a Theora mint a h.264, hanem arról, hogy a " tesztek szerint a különbség nem behozhatatlan".