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Joined 1 year ago
Cake day: September 19th, 2023
  • UndercoverUlrikHD@programming.devtoSelfhosted@lemmy.world•Comparing compression in AV1, x264, and x265English
    3·
    10 months ago

    Frankly, for anything other than real-time encoding, I don’t actually consider encoding time to be a huge deal. None of my encodes were slower than 3fps on my 5800x3d, which is plenty for running on my media server as overnight job. For real-time encoding, I would just grab a Intel Arc card, and redo the whole thing since the bitrates will be different anyways.

    Encoding speed heavily depends on your preset. Veryslow will give you better compression than medium or fast, but at a heavy expense of encoding speed. You’re not gonna re-encode a movie overnight on slow preset. GPU encoding will also give you worse result than CPU encode so that’s something one would have to take into consideration. It’s not a big deal when you’re streaming, but if it’s for video files, I’d much prefer using the CPU.

    I consider the ‘good enough’ level to be, if I didn’t pixel peep, I couldn’t tell the difference. The visually lossless levels were the first crf levels where I couldn’t tell a quality difference even when pixel peeping with imgsli. I also included VAMF results, which say that the quality loss levels are all the same at a pixel level.

    I was mostly talking about how you organised your table by using CRF values as the rows. It implies that one should compare the results in each row, however that wouldn’t be a comparison that makes much sense. E.g. looking at row “24” one might think that av1 is less effective than h264/5 due to greater file size, but the video quality is vastly different. A more “informative” way to present the data might have been to organise each row by their vmaf score.

    Hopefully I don’t come across as too cross or argumentative, just want to give some feedback on how to present the data in clearer way for people who aren’t familiar with how encoding works.