"double black bars" on dolby vision mkv file

[martinmam61]

When I play the mkv file through Kodi there are solid black bars, then a set of faint black bars further into the screen. I have seen a few people having the same issue and agree this is not a Kodi issue, but incorrect DV metadata. Problem is I am a complete newby and would ask if anyone can point me in the right direction on how to use dovi_tool to fix this issue? I believe it may have something do do with "cropping" the black bars.
Much appreciated.

Martin.

[quietvoid]

The simplest way is to edit the metadata in the video itself.
You need to demux the video, edit the RPU within and mux it back in.

It could look something like this:

mkvextract input.mkv tracks 0:video.hevc
dovi_tool --edit-config crop.json convert video.hevc -o video-fixed.hevc

Where crop.json is a JSON file containing:

{
  "active_area": {
    "crop": true
  }
}

Then you just need to mux the video-fixed.hevc video file back with the rest.

[martinmam61]

Hi, Thanks for that. I'll give it a try and see how I get on. Martin. Sent from Outlook for Android<https://aka.ms/AAb9ysg>

…

________________________________ From: quietvoid ***@***.***> Sent: Monday, March 10, 2025 12:59:28 PM To: quietvoid/dovi_tool ***@***.***> Cc: martinmam61 ***@***.***>; Author ***@***.***> Subject: Re: [quietvoid/dovi_tool] "double black bars" on dolby vision mkv file (Discussion #341) The simplest way is to edit the metadata in the video itself. You need to demux the video, edit the RPU within and mux it back in. It could look something like this: mkvextract input.mkv tracks 0:video.hevc dovi_tool --edit-config crop.json convert video.hevc -o video-fixed.hevc Where crop.json is a JSON file containing: { "active_area": { "crop": true } } Then you just need to mux the video-fixed.hevc video file back with the rest. — Reply to this email directly, view it on GitHub<#341 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BQJ4O5FE5D2UXWSBWXK3SED2TWLEBAVCNFSM6AAAAABYWBXIJKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTENBUHA4TENY>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[martinmam61]

Hi, That worked perfectly. I used the mkvextract gui instead of command line, but all else as you instructed. Many thanks. Martin. Sent from Outlook for Android<https://aka.ms/AAb9ysg>

…

________________________________ From: martin menzies ***@***.***> Sent: Monday, March 10, 2025 1:12:09 PM To: quietvoid/dovi_tool ***@***.***>; quietvoid/dovi_tool ***@***.***> Cc: Author ***@***.***> Subject: Re: [quietvoid/dovi_tool] "double black bars" on dolby vision mkv file (Discussion #341) Hi, Thanks for that. I'll give it a try and see how I get on. Martin. Sent from Outlook for Android<https://aka.ms/AAb9ysg>

________________________________ From: quietvoid ***@***.***> Sent: Monday, March 10, 2025 12:59:28 PM To: quietvoid/dovi_tool ***@***.***> Cc: martinmam61 ***@***.***>; Author ***@***.***> Subject: Re: [quietvoid/dovi_tool] "double black bars" on dolby vision mkv file (Discussion #341) The simplest way is to edit the metadata in the video itself. You need to demux the video, edit the RPU within and mux it back in. It could look something like this: mkvextract input.mkv tracks 0:video.hevc dovi_tool --edit-config crop.json convert video.hevc -o video-fixed.hevc Where crop.json is a JSON file containing: { "active_area": { "crop": true } } Then you just need to mux the video-fixed.hevc video file back with the rest. — Reply to this email directly, view it on GitHub<#341 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BQJ4O5FE5D2UXWSBWXK3SED2TWLEBAVCNFSM6AAAAABYWBXIJKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTENBUHA4TENY>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[frandan74]

Sorry if i resume an old post but i have similar problem and i would correct directly the rpu.bin before the iniection?
I tried with the same command you suggest dovi_tool --edit-config crop.json convert rpuoriginal,bin -o rpumodified.bin but it didn't work becuase it aspects a video as input and so tried with dovi_tool editor -i RPU_original.bin -j crop.json -o RPU_nuovo.bin but the json structure in this case wasn't accepted.is there a possibility to do that or do i have to create a "wrong" hevc and correct it? Excuse me again for the "resuming"

[quietvoid]

The editor command should work with that JSON config.

You must be doing something wrong.
Since you're not providing any detail, it's impossible to help you.

[frandan74]

Sorry for my incomplete post.
This is the json i used like crop.json

{
"crop": true,
"presets": [
{
"id": 0,
"left": 0,
"right": 0,
"top": 68,
"bottom": 68
}
],
"edits": {
"0-186112": 0
}
}

I didn't it manualy but i obtained it with this command "dovi_tool export -i RPU_original.bin --data "level5=crop.json". Is this the problem?Now i'm noticing the jsons are a little different. Thank you again

[quietvoid]

It's all supposed to be in "active_area"
See example: https://github.com/quietvoid/dovi_tool/blob/main/assets/editor_examples/crop.json

[frandan74]

Therefore, it is sufficient to use this. {
"active_area": {
"crop": true
}
}
But if the crop is variable in the movie, for example in a movie with IMAX scene, is it always enough?

[quietvoid]

But if the crop is variable in the movie, for example in a movie with IMAX scene, is it always enough?

That's up to you, 99% of the time it doesn't matter.