too dark image (cut blacks) in prores 422HQ renders (Resolve 17.3.2 Build 8, Win10)

1. offizieller Beitrag

    Hello! (This is my first post)

    I've noticed that prores 422HQ movs rendered with Voucoder are a bit darker than source footage. The workaround, producing nearly identical images, I've figured out is to use Filters in Video settings and set Input Range to Full and Output Range to Limited. The remaining variables (Input and Output) are BT.709 as project is 709 (with Gamma 2,2).

    I wonder if you can have a look at that. The difference is visible of a well-calibrated (full range) monitor and when comparing Scopes.

  • Vouk 16. Oktober 2021 um 22:29

    Hat das Thema freigeschaltet.
    • Offizieller Beitrag
    • I created an SMTPE bars MXF clip with premiere:

    • Renderer this with DVR / Voukoder to ProRes 422HQ:

    Code
    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '..\..\..\Desktop\smtpehd.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf59.2.101
  Duration: 00:00:05.00, start: 0.000000, bitrate: 21835 kb/s
  Stream #0:0: Video: prores (HQ) (apch / 0x68637061), yuv422p10le(tv, bt709, progressive), 1920x1080, 21562 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 12800 tbn, 12800 tbc (default)

    Can you please provide exact steps on how to reproduce this issue?

    What player do you use?

    The main problem is the prores mov rendered with Voukoder is misinterpreted by NLE software (Resolve in my case). For some mysterious reason "Full Range" is taken for "Limited Range"/"Video", which results in "cut" low blacks.

    But even if you set the interpretation mode correctly, something bad happens with the low end blacks. They are "squashed"...

    Einmal editiert, zuletzt von Edixth (17. Oktober 2021 um 15:40)

    ProRes by its spec should be always limited range. There is no flag in its private stream nor in MOV headers which specifies video range.

    You can create full range ProRes, but then you have to ALWAYS manually interpret such a files as full range as not a single app will know it's full range. Some apps (like Premiere) assume by default that full range is used for ProRes444, but there is no rule to it. Resolve itself still loads all ProRes files as limited range which is how it should be.