• SLR

  • h265/HEVC v AV1 masters fight

Hairsational They specifically say "streaming", I don't think people ever disputed the idea that AV1 will have better picture quality than HEVC at the same (low) bitrate that SLR uses. It's just that the comparison is pointless, because while AV1 might look better relatively, it still looks bad in an absolute sense, and definitely worse than the HEVC master.

      phiber I mean which of the 6 scenes in the first post, because the AV1 and HEVC streaming versions have different bitrates.

        HEVC seemed to me to be very slightly better in streaming than AV1 but for me, and in all codecs, the bitrate used is really too low for a site like SLR. I don't understand their goal of offering such low bitrates because it is the basis of their business. They can do the best video editing and tune their compression, a low bitrate will smooth out all the details. Maybe the majority of their customers are happy with the low bitrate but it is always better to satisfy advanced users to progress. Because one day these users will see the differences on other competing sites and will demand an increase in quality. And there are a lot of competing sites that offer bitrates above 50 mb/s. So if they want to save on licensing costs by using AV1, I have nothing against it, but the quality has to be there.

          Hairsational well I was looking at the slr her scene with Nathan, I started comparing, going back in forth between the two versions...but this why i think av1 better, so as I was testing out both I thought well they kinda the same, both skip at the same rate while streaming, so going back in forth for a Lil while, thinking yeah I could see av1 looks slightly better, but here's where I made my choice..
          Then I decided to change the file size version and bro the hevc version was at the highest version 4000 or something then I was going switch the av1, bro the whole time the av1 was on the second highest file, I was comparing two different file size but both looked the same, so I decided av1 looks better, for that particular video but I haven't tested the other examples.

            25 days later

            I downloaded two of them in the different versions to have a look and test them.

            The hevc encodes are often pretty good on this site. Not great, but passable. The same goes for the two videos I downloaded. The AV1 encodes here are worse. (Not to mention the horribly noise-reduced awful glowing encodes on recent AV1 releases from SLR Originals, but I digress.)

            Generally, AV1 tries to remove all skin detail, which it sees as noise, and since porn is all about skin you have to work around that. That is not being done here.

            First of all, don't encode on a GPU. It will be faster, but the result will be poor unless the bitrate is ridiculously high.
            Rather, encode on the CPU. Use SVT-AV1-PSY 3.0.2, or whatever is newest. It comes with Staxrip. You can just replace the codec build in the encoders folder if you want to use another build.
            Do not tune for SSIM or PSNR, they do not preserve skin detail. Outlines matter most for those. Tune for VQ.
            Do not use quantisation [quantization] matrices. They will blur skin and only save a small bit of size.
            You need to test-encode to see which bitrate (crf) is appropriate.
            Change the bit depth to 10 bits [ConvertBits(10) in AviSynth], before encoding. The codecs are most efficient when using 10 bits. (It's not the same as HDR, because it doesn't change the colorspace, and all players that I know of play it fine.)

            For the video: For Women: Royal Treatment
            The hevc version is okayish, but the av1 version looks really bad.
            Using the following non-default parameters to re-encode the large "original file" with SVT-AV1-PSY 3.0.2 I get a picture quality that is much better (a LOT better than the av1) than either of the two and a smaller file size:
            --rc 0 --crf 33 --preset 6 --tune 0 --tf-strength 3 --enable-qm 0 --sharpness 2 --enable-overlays 1 --qp-scale-compress-strength 2 --psy-rd 3 --hbd-mds 1

            For: Pink Me
            She's a bit of a porcelain doll, and the background is monotone so the video compresses well with any codec.
            Both the hevc and the av1 blur the skin however.
            You get better detail and the same file size with the "original" recoded with:
            --rc 0 --crf 23 --preset 6 --tune 0 --tf-strength 3 --enable-qm 0 --sharpness 2 --enable-overlays 1 --qp-scale-compress-strength 2 --psy-rd 3 --hbd-mds 1

            These encode at about 7 fps on a modern CPU, depending on what you have. Skip the two last parameters to speed it up a few fps, but it affects the quality slightly for the worse. By all means use preset 4 or even 2 if you have aeons or a supercomputer at your disposal. You might get a slightly smaller file size.

            Again: Do not encode on a GPU.

              sEARCHERNo00 I wish I understood what you were saying. I'm all about making the videos look better. I know the camera side, not really the computer side. If you'd care to help, feel free to send a direct message and I'll try some stuff.

                sEARCHERNo00
                Really hoping SLR staff takes notice of your explanations and testing. Working with tweaked encoding settings (especially adapted to the type of content to be encoded) could be beneficial both in terms of video quality and file sizes.
                @doublevr