What CRF for 4K video?

1. offizieller Beitrag

    Hello,

    for years I have been recording family videos with a camera. Videos are FHD/50p H.264, and I have encoded them using CRF 17. It was recommended it is save and i can not recognize different between original and export. It is true.

    Now i bought Pixel 8pro and i can take video in 4K/60p h.265. What CRF set for such videos?

    And what more, there is way to have HDR with larger gamut. What CRF set for such videos?

    I want the highest quality possible, but I don’t want to waste too much space. CRF17 is for me ok. I never cared about space on HDD for this videos. But by time now I have over 1200 these home videos and it takes 1TB(h.264). I started think about h.265 and h.266. I never send my videos to others people. I watch it only on 27in 2K monitor.

    What CRF for FHD/50p videos with h.265 or h.266?

    What CRF for 4K/60p videos with h.266?

    What CRF for 4K/60p HDR h.266 video?

    Please keep in mind that I am a fan of CRF 17 quality for FHD/50p H.264 videos. I never used CRF 16 or CRF 18. CRF 16 is indistinguishable from the original and just wastes space. CRF 18 - I have a bad feeling that there’s a small chance of losing some details. I know I’m not alone in this! 😆😆

    Thank you

    Einmal editiert, zuletzt von Xaver (21. April 2025 um 04:47)

  • Vouk 20. April 2025 um 22:25

    Hat das Thema freigeschaltet.
    • Offizieller Beitrag

    Maybe you should continue using CRF 17. And if it's not good enough use a value lower than 17. The lower the value the better is the visual quality (and bigger the file size).

    As far as I know in h.265 for the same result you can use CRF plus 5. So h.265 visually lossless will be at CRF 22. You can try. And it doesn't matter resolution or fps - CRF is just signal/noise parameter, codec will increase bitrate to maintain CRF.

    Einmal editiert, zuletzt von tyf (4. August 2025 um 15:28)

    HDR should have a lower CRF than SDR (at least 4 less in my testing), but I don't think resolution or frame rate should affect CRF much if at all.

    And I don't agree that you can have a higher CRF in x265 vs x264. I would say you actually need to go lower to match x264 quality. I don't think HEVC is quite as effective at compression as people like to claim. When I do side by side comparisons, I wouldn't go any higher than the same value I use for x264.

    I tend to use CRF 18 for SDR and 14 for HDR. H265 is absolutely not visually lossless at CRF 22. I see very visible artifacting at lower settings than that.

    No CRF changes needed, but you can use newer video codecs for sure, as long as you can play and share these videos.

    Video files are inherently large, so buy a larger storage instead (I personally buy refurbished data centre hard drives, but they are not convenient to use). Also, from your question, I guess you didn't perform any backup, if that's so, backup sooner than later.