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MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sat Nov 13, 2021 10:13 pm
by PimpDiggler
Fighting with Plex this weekend because of subtitles I thought would show up and upon further investigation with MKVToolnix Ive discovered the "forced" flag for subtitles hasnt been set correctly even though the MakeMKV gui indicates the subtitle is forced. This is the latest Linux version of MakMKV on Fedora 35

Re: MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sat Nov 13, 2021 10:23 pm
by Woodstock
Two terms with the same name.

"Forced" for subtitles tracks means the individual subtitle has a "forced" flag on it. MakeMKV can optionally separate these subtitles out to their own track (this is the "Forced only" checkbox in the track selection window). Such subtitles are RARE. Personally, I've only seen it on two movies, but others tell me it's more popular on some genres.

"Forced" as an MKV track flag tells the player to always use the track. MakeMKV can be set up to set this flag on the FIRST subtitle track it finds, but this has only about a 50-50 shot at being correct. This is a profile option, which requires editing the controlling XML file. The profiles provided with MakeMKV have it set to OFF.

If you want to set the track "Forced" flag correctly, you should do it with mkvtoolnix, using the header editor.

Re: MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sat Nov 13, 2021 10:51 pm
by PimpDiggler
I wound up using MKVToolNix to set it correctly but that UI behavior is a little misleading and not very intuitive or needs better documentation. The not intuitive part of this is its a 2-step process using an external tool when MakeMKV has already identified that secondary track as a "forced" track. I have a few movies that I may need to go back and correct due to this issue. Plex also cant identify and utilize this track automatically because the flag is incorrect.

Re: MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sat Nov 13, 2021 10:58 pm
by PimpDiggler
Also the information contained in the "Info
Track information
Type: Subtitles
Flags: Forced subtitles
Language: English
Codec: HDMV PGS Subtitles
MKV Flags: Default
Clearly says Flags: Forced subtitles

If that has been identified the program may as well go ahead and set it to the appropriate flag without having to use another tool

Re: MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sun Nov 14, 2021 12:00 am
by Woodstock
Actually, from MakeMKV (and also handbrake), the track Forced flag is missing, rather than set incorrectly.

If you want to create a new profile, here are the current "WDTV" settings regarding tracks:

Code: Select all

    <mkvSettings 
        ignoreForcedSubtitlesFlag="true"
        useISO639Type2T="false"
        setFirstAudioTrackAsDefault="true"
        setFirstSubtitleTrackAsDefault="true"
        setFirstForcedSubtitleTrackAsDefault="true"
        insertFirstChapter00IfMissing="true"
    />
You could test setting ignoreForcedSubtitlesFlag="false" instead, and see if that makes it work "correctly".

I've not bothered with it, because it has been wrong too often for me, and it doesn't survive a handbrake encode anyway.

Re: MakeMkv not setting "forced" subtitle flag correctly in output MKV

Posted: Sun Nov 14, 2021 1:45 pm
by Chetwood
PimpDiggler wrote:
Sat Nov 13, 2021 10:51 pm
that UI behavior is a little misleading and not very intuitive or needs better documentation.
It's been discussed to death on this forum and in the FAQ.
PimpDiggler wrote:
Sat Nov 13, 2021 10:51 pm
The not intuitive part of this is its a 2-step process using an external tool when MakeMKV has already identified that secondary track as a "forced" track.
Has it though? In your screenshot above, the title information refers to the mlps and not the sub.
PimpDiggler wrote:
Sat Nov 13, 2021 10:58 pm
Also the information contained in the "Info

Track information
Type: Subtitles
Flags: Forced subtitles
Language: English
Codec: HDMV PGS Subtitles
MKV Flags: Default

Clearly says Flags: Forced subtitles
And clearly says: MKV Flags: default.
PimpDiggler wrote:
Sat Nov 13, 2021 10:58 pm
If that has been identified the program may as well go ahead and set it to the appropriate flag without having to use another tool
IF that has been identified and you select (forced only), in which case MakeMKV creates a new track from all forced items. If you don't, you'll end up with a regular track that is NOT flagged as forced and there's only a few players like MPC-HC that still will show forced items when the track itself is not set to forced.