For Vegas darker renders, is a solution possible to solve this?

1. offizieller Beitrag

    That would be heaven sent and greatly appreciated if a brightness/contrast/gamma filter could be added yes! Allowing us to render out exactly what we are seeing in the Vegas Preview Window.

    As for the bt709 color range that you mentioned, i don't really think it has anything to do with this particular Vegas issue in this situation.

    Vegas Pro export does not (and never did) touch the luma range in any way. It's the external players which then often does an additional expansion to full range levels which already was full range. Vegas Pro also does not touch video levels when viewed via the internal preview which is what confuses some people. All of that said assumes 8 bit projects.

    The only problem is that for some export formats (H.264 MP4) Vegas Pro adds a limited range flag to full range video. And some players read this flag, some don't.

    Adapting the levels from Vegas itself also isn't a problem. You could use an appropriate output fx or the SeMW Levels extension for switching the Vegas preview.

    • Offizieller Beitrag

    @MajorBubble

    Right, most YUV 8 bit content is supposed to be limited. The internal preview expands it to full (black = 0x101010, white = 0xebebeb) and that's what it makes look brighter.

    People apply a brightness correction to make it look like the original again, render it and the external player shows it darker - Which is correct.

    And I even know the technical reason for this issue: The preview is a direct pointer to the uncompressed framebuffer. (I once vertically flipped the framebuffer and the preview flipped too).

    Still this is a very, very bad design as most 8 bit video is actually limited.

    "The internal preview expands it to full (black = 0x101010, white = 0xebebeb)"

    Actually it does not. The internal preview does not touch the given source levels and it ignores any given level flag. External players would do often instead.

    • Offizieller Beitrag

    My mistake. It does not expand it, it just displays it.

    What I meant: the preview just displays what is in the framebuffer.

    If you load a limited frame into it where 0x10 is supposed to be black it will display it as dark grey. The preview simply ignores any color range setting.

    In the projects "Pixel format" setting dropdown box there should be actually:

    8 bit (Full)

    8 bit (Limited)

    Zitat

    In the projects "Pixel format" setting dropdown box there should be actually:

    8 bit (Limited)
    8 bit (Full)


    Yes. And many Vegas Pro users use the SeMW Levels extension to be able to switch the internal preview between original, PC and TV levels.

    MajorBubble,

    I am not one of the confused bunch you are speaking of. I know exactly what i am talking about!

    I've been on this Vegas road for many years, and have tested all the theories mentioned above, other issues, and with varied media players!

    The SeMW Levels extension is not a solution.

    An appropriate output fx is not a solution either!

    Vegas does touches video levels during rendering, the only time it does not touches it is when its rendering out in an uncompressed format.

    As for what we have discussed on the matter Vouk, about adding a filter, that would be great.

    Or add it as an option if possible, if a user don't want this option. But if not, no problem, we are eternally grateful for the tremendous work you are putting in this little gem of a software.

    I'm not going to start this one again.

    Marco

    3 Mal editiert, zuletzt von MajorBubble (30. Oktober 2019 um 10:19)

    I now also notice the much darker colors for the output-

    Before Voukouder i used x264vfw with these additional commands (Extra command line):

    --range tv --colorprim bt709 --transfer bt709 --colormatrix bt709

    With these commands i get proper colors/brightness (I think --range tv is the important one?)

    When i use the Vegas Pro effect levels preset: "Computer-RGB to Studio-RGB", the colors looks correct with voukouder (slightly different when i compare it directly to the x264vfw output).

    • Offizieller Beitrag

    First, FFmpegs Equalizer / eq filter will be available in the next version to adjust brightness, contrast saturation and gamma (even per color channel). https://ffmpeg.org/ffmpeg-filters.html#eq

    Second, Magix has confirmed the vegas preview shows full color range only. So if your source file is based on the limited color range (which is the case for 99% of all YUV 4:2:0 8 bit files) it will appear brighter than it actually is (in the preview). This does not affect the rendering process itself, so your rendered file appears darker than the preview (but still matches the original clips brightness / colors).