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  1. Originally Posted by jagabo View Post
    Originally Posted by Boxcart View Post
    looks just a touch darker than reference.
    I'm not sure if it makes a difference with HDR, but could color_range be the issue?
    Just tried it without "-color_range 1" and it looked the same. I believe changing it from limited to full only would have made it darker. I think it just is what it is and is good enough like what the other poster was saying. Oh well.
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  2. I found another issue. While the banding was solved with v210, the weird pink/green blotch problem is less pronounced, but still around. Here are some frames I took screenshots of. You can see some areas with slight pink/green shades. I think the screenshots overemphasize the problem, it's barely noticeable watching through the output in realtime, and I feel like I've seen this before elsewhere. In realtime I sort of have to wonder if it's there or not, but when I go frame by frame there are some (not all or even most) instances where there is some of this going on. It does not look like it's there in the input, but after a while I can erroneously imagine I'm seeing it everywhere if I look hard enough.

    Image
    [Attachment 69884 - Click to enlarge]


    Image
    [Attachment 69885 - Click to enlarge]


    Image
    [Attachment 69886 - Click to enlarge]


    If you can't see it it's over the man in the first picture, around the window in the second picture, and to the left of the man in the third picture
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  3. Are those all at scene changes?
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  4. Originally Posted by jagabo View Post
    Are those all at scene changes?
    No it sort of filters through in patches during the same shot/scene.
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  5. Check the -report for details on the encoding

    How are the screenshots being taken ? What is the setup ?
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  6. Originally Posted by poisondeathray View Post
    Check the -report for details on the encoding

    How are the screenshots being taken ? What is the setup ?
    I'm using the snipping tool in Windows over MPC-HD playing back the file. Snipping tool brightens the frame since I think HDR is lost which makes the problem look way worse, but it's there. Here is the -report for a segment of this recording:

    https://docs.google.com/document/d/1GLLuH9dTdNHnXvb2jfX9_AcxnMLU9IWeeEqFks1SVYU/edit?usp=sharing
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  7. Double check the input, pause, etc...

    What about high bitrate or lossless encoding ? Does it affect the artifacts ?

    What about v210 encoding to ffv1 ? Skip the pixel format conversion ie. check if decklink is sending clean frames
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  8. Originally Posted by poisondeathray View Post
    Double check the input, pause, etc...

    What about high bitrate or lossless encoding ? Does it affect the artifacts ?

    What about v210 encoding to ffv1 ? Skip the pixel format conversion ie. check if decklink is sending clean frames
    Still happens with a lossless command but it looks different. More edgy than blotchy. Decklink is sending clean frames. OBS's standard NVENC encoder is able to record the same content without this problem (but drops frames and has other issues which is why I'm using ffmpeg) so I know the issue is either with ffmpeg's compression or the colors.
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  9. Originally Posted by Boxcart View Post
    Originally Posted by poisondeathray View Post
    Double check the input, pause, etc...

    What about high bitrate or lossless encoding ? Does it affect the artifacts ?

    What about v210 encoding to ffv1 ? Skip the pixel format conversion ie. check if decklink is sending clean frames
    Still happens with a lossless command but it looks different. More edgy than blotchy. Decklink is sending clean frames. OBS's standard NVENC encoder is able to record the same content without this problem (but drops frames and has other issues which is why I'm using ffmpeg) so I know the issue is either with ffmpeg's compression or the colors.
    Is OBS using ffmpeg or NVEncC ?

    Humor me and test it anyways, maybe the ffmpeg driver is buggy. You need to check each step. Record v210 or ffv1 directly from decklink (no filter_complex) . If it's "clean" it could be either the pixel format conversion or some ffmpeg nvenc implementation issue or some issue with commandline . If it's "not clean", then it's upstream problem, such as ffmpeg device interface issue . You rule out the swscale pixel format conversion by recording ffv1 (instead of nvenc) after the -filter_complex
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  10. Originally Posted by poisondeathray View Post
    Originally Posted by Boxcart View Post
    Originally Posted by poisondeathray View Post
    Double check the input, pause, etc...

    What about high bitrate or lossless encoding ? Does it affect the artifacts ?

    What about v210 encoding to ffv1 ? Skip the pixel format conversion ie. check if decklink is sending clean frames
    Still happens with a lossless command but it looks different. More edgy than blotchy. Decklink is sending clean frames. OBS's standard NVENC encoder is able to record the same content without this problem (but drops frames and has other issues which is why I'm using ffmpeg) so I know the issue is either with ffmpeg's compression or the colors.
    Is OBS using ffmpeg or NVEncC ?

    Humor me and test it anyways, maybe the ffmpeg driver is buggy. Record v210 or ffv1 . If it's "clean" it could be either the pixel format conversion or some ffmpeg nvenc implementation issue or some issue with commandline . If it's "not clean", then it's upstream problem, such as ffmpeg device interface issue
    OBS is using NVENC. You can have it use ffmpeg but it will not work (massive frame loss and crashing) with 10 bit color spaces (P010) so I had to select OBS' standard encoder (which will only do PCM audio, and I need AC3, which is why I moved to ffmpeg). It records clean in OBS, but occasionally drops frames which makes for a handful of somewhat choppy sequences in the OBS output. ffmpeg does not have any of these problems, but this pink/green blotch issue (plus being just a tad darker) is sticking around.
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  11. Update: Just to get a sense for the issue, I added the output file to my Plex library and fired up my 4K Sony laser projector, and amazingly the problem is barely visible at seating distance if not gone all together. Someone would have to tell you it's there and even then it's hard to see, and is barely visible. Maybe the Sony is doing some kind of processing? Before I was only watching the file in VLC and MPC-HD on my 4K HDR monitor up close. But with this display the problem is essentially gone. I have no clue why that is but I guess I'll take it. Here is a photo I took from my phone of the projector displaying a scene that had the issue (see previous photo of the same shot/scene around the window). You can still see it a tiny bit where the window shade looks a little pink but it's hardly a massive problem I think. In person it's even less visible than in the photo below. Very weird.

    Image
    [Attachment 69888 - Click to enlarge]


    On the "issue" of the ffmpeg output being a touch darker than reference, I was thinking maybe it's because the command (and NVENC as far as I'm aware) lacks what in libx265 would be the x265 params of master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP (15635,16450)L(10000000,1):hdr10=1:max-cll=1000,300" particularly white point, maxcll, and luminance. But adding those parameters into the MKV header of this file doesn't seem to have an effect in MPC-HD or VLC.
    Last edited by Boxcart; 20th Mar 2023 at 23:12.
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