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AV1 Codec Library libaom v3.2 Brings More Performance Optimizations

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  • #11
    Originally posted by sophisticles View Post
    Michael

    Either the graphs are mislabeled or something is very wrong with the test systems, specifically the EPYC one. According to your graphs, a Ryzen 9 5900X (12C/24T) beats an Epyc 7742 (64C/128T) by 40% to 100%!

    I'm sorry but these results can not be trusted, AV1 scales very well, there has to be some misconfiguration in the EPYC system.
    Labels are correct.

    It may also be due to needing to tune the parameters, the most recent commendations I have from Google/AV1 engineers was to use "--tile-columns=2 --tile-rows=2 --row-mt=1" but unsure since that guidance if anything has changed.
    Michael Larabel
    https://www.michaellarabel.com/

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    • #12
      Originally posted by sophisticles View Post
      The only people that expect such a thing are those that do not understand video encoding or the evolution of AV1.
      i dont know where things are at presently, my only point was that the opposite of what you just said is true. people unfamiliar with how video codec implementations actually evolve in the real world naively expect a next gen video codec to just immediately be better, when it in fact tends to take quite a while, especially against something as good as x264. notice how understanding what im saying here requires you to grok the difference between spec and implementation, and also how notions of quality with respect to video compression is a massively subjective matter of human perception.

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      • #13
        Originally posted by quaz0r View Post

        i dont know where things are at presently, my only point was that the opposite of what you just said is true. people unfamiliar with how video codec implementations actually evolve in the real world naively expect a next gen video codec to just immediately be better, when it in fact tends to take quite a while, especially against something as good as x264. notice how understanding what im saying here requires you to grok the difference between spec and implementation, and also how notions of quality with respect to video compression is a massively subjective matter of human perception.
        There are people that are so acustomed to the big macroblocks in jpeg and h.264 that they don´t like the smooth transitions in AV1 / h.265 that´s true.
        I agree that it´s harder to get the same results with a "click a button" solution with AV1 than with x.264. But if you know what you are doing and
        - choose an appropriate bandwidth for the video resolution / framerate
        - do 2-pass encoding
        - dont´t use excessive tilling / threading

        All common AV1 encoders can compress a video better with lower quality loss than x264 in the same bitrate budget. This is evident by multiple experiments + 1000ths of users asked, so perceived quality is overall better not just meassured one. There might be personal preferences for the other codec / how the encoded material looks, but the majority of users disagree with that opinion.

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        • #14
          Originally posted by quaz0r View Post

          i dont know where things are at presently, my only point was that the opposite of what you just said is true. people unfamiliar with how video codec implementations actually evolve in the real world naively expect a next gen video codec to just immediately be better, when it in fact tends to take quite a while, especially against something as good as x264. notice how understanding what im saying here requires you to grok the difference between spec and implementation, and also how notions of quality with respect to video compression is a massively subjective matter of human perception.
          I have tested SVT-AV1 extensively against both x264 and x265 and SVT-AV1 beats them handily:

          https://forum.videohelp.com/threads/...-encoding-test

          Here's a test i did with SVT-AV1 against x264+placebo and x265+placebo, with samples.

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          • #15
            Originally posted by sophisticles View Post
            I'm sorry but these results can not be trusted, AV1 scales very well, there has to be some misconfiguration in the EPYC system.
            Does libaom actually scale that well, or just SVT-AV1? They're two completely different implementations.

            I think libaom hasn't been that well tuned and may be targeted more towards a youtube like service that does 1 thread per video and extracts parallelism through having tons of videos, rather than a workstation oriented process that tries to do 1 video as fast as possible.

            But i haven't followed av1 codecs that closely, so maybe you are right.
            Last edited by smitty3268; 15 October 2021, 11:57 PM.

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            • #16
              Originally posted by sophisticles View Post
              I have tested SVT-AV1 extensively against both x264 and x265 and SVT-AV1 beats them handily
              interesting, thanks

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              • #17
                Originally posted by smitty3268 View Post
                Does libaom actually scale that well, or just SVT-AV1? They're two completely different implementations.
                No, libaom and libvpx before are known to be rather bad at multi-threading.

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                • #18
                  I must say that these benchmarks aren't really helpful without also checking the quality as the developers are still tuning the speed levels. So they might disable some expensive coding tool or do a less exhaustive search at a certain speed level and we would see a performance increase but what we wouldn't see is that the quality also dropped. Similarly they could enable some coding tool at a certain level and we would see a performance regression in benchmarks, but there would also be a quality increase, which we wouldn't see...

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                  • #19
                    Originally posted by sophisticles View Post

                    You are doing something very wrong, x265 and vp9 have both been proven much better than x264 and vp9 has been shown to be superior than x265 at resolutions above 1080p.

                    Since AV1 is the continuation of vp10, which was supposed to replace vp9m there is no way that you "need larger AV1 files to get the same quality as x264".
                    Have you actually tried encoding any thing and then looked at it carefully? If not try it. The common recomendation is to use -crf 20 but when I compare that to even the defaults for x264 it has lost a LOT of detail. I have to get down to -crf 8 before they are equivalent. I suspect a lot of people talking about how great the compression with AV1 is ether don't actually care about quality and are looking for the most squeeze because they are going to watch on their cell phone or don't know what to look for.

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                    • #20
                      Originally posted by smitty3268 View Post
                      Does libaom actually scale that well, or just SVT-AV1? They're two completely different implementations.
                      If you look at the benchmarks closely, the Ryzen 9 5900X (12C/24T) is 2 to 3 times faster than the Ryzen 5 5500U (6C/12T), since the 5900X has a base clock of 3.7ghz (4.8ghz boost) and the 5500U has a base clock of 2.1ghz (4ghz boost), I would say that the performance cap is right on the money.

                      But the Ryzen 9 5900X (12C/24T) beats an Epyc 7742 (64C/128T) by 40% to 100%, and the Epyc 7742 has a base clock of 2.25ghz with a boost of 3.4ghz.

                      So let's do some half-baked performance predictions:

                      Ryzen 9 5900X - 12C*3.7ghz + 12C/2*3.7ghz = 66.6ghz of base processing power
                      Epyc 7742 - 64C*2.25ghz + 64C/2*2.25ghz = 216ghz of base processing power
                      Ryzen 5 5500U - 6C*2.1ghz + 6C/2*2.1ghz = 18.9ghz of base processing power

                      66.6 / 18.9 = 3.5

                      Which is close to the performance difference we are seeing between Ryzen 9 5900X and Ryzen 5 5500U, which means not only is this software not scaling but the Ryzens are even boosting up for any significant length of time. If the Epyc was boosting then at the very least it would be coming close to the 5900X but it's getting blown away.

                      I still think there's something wrong, possibly with the governor the systems are using.

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