Why can't Handbrake identify language of BluRay .m2ts files?

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pstrg
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Joined: Sat Apr 10, 2021 7:00 pm

Why can't Handbrake identify language of BluRay .m2ts files?

Post by pstrg »

Description of problem or question:
Handbrake is able to substantially reduce .m2ts files by converting them to .mkv.
However, subtitles in .m2ts files (BluRay) are not identified by language - they are listed as
1 Unknown [PGS]
2 Unknown [PGS]
3 etc.
In order to determine each language, one has to play the video (with e.g. VLC) and select each subtitle, one by one, and take note of the number of those of interest.
However, noted by chance that Daum PotPlayer does display the language of each subtitle; so, it's possible to determine languages of subtitles in a .m2ts file.

Steps to reproduce the problem (If Applicable):
n.a.

HandBrake version (e.g., 1.0.0):
1.3.3

Operating system and version (e.g., Ubuntu 16.04 LTS, macOS 10.13 High Sierra, Windows 10 Creators Update):
Windows 10 pro 64-bit 20H2

HandBrake Activity Log ***required*** (see How-to get an activity log)
n.a.

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Question: Why doesn't Handbrake display language identification of subtitles in .m2ts files after scanning them? Is there a design limitation?
Woodstock
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by Woodstock »

Probably because that information is usually stored in the playlist files, which control which transport streams are played when.
pstrg
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Joined: Sat Apr 10, 2021 7:00 pm

Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by pstrg »

Woodstock wrote: Sun Jun 06, 2021 12:44 am Probably because that information is usually stored in the playlist files, which control which transport streams are played when.
You're right.
To test,
1) played the file from within the BluRay folder structure - PotPlayer was able to list languages:
Image

2) removed the .m2ts from its folder structure - PotPlayer wasn't ableto list languages:
Image

Just for comparison, this is what Handbrake displays after scanning and .m2ts within its folder structure:
Image

Wouldn't it be a desirable enhancement to let Handbrake inspect playlist files in order to display subtitles languages?
From an user's point of view, it would be quite an improvement.
Woodstock
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by Woodstock »

Assuming they're already decrypted, you can open the play list and handbrake will assemble the required transport streams as needed.

A play list does not necessarily point to a single transport stream file. Seamless branching is a popular thing with Bluray authors, especially when they have different versions of the same movie available. If you watch MakeMKV constructing an MKV file, it will list the various m2ts files it reads as it goes.
pstrg
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Joined: Sat Apr 10, 2021 7:00 pm

Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by pstrg »

Woodstock wrote: Sun Jun 06, 2021 2:00 am Assuming they're already decrypted, you can open the play list and handbrake will assemble the required transport streams as needed.
Could you please explain a little further?
It seems that Handbrake can't open a .mpls file - how to open a playlist so that Handbrake is able to assemble the streams?
Woodstock wrote: Sun Jun 06, 2021 2:00 am A play list does not necessarily point to a single transport stream file. Seamless branching is a popular thing with Bluray authors, especially when they have different versions of the same movie available. If you watch MakeMKV constructing an MKV file, it will list the various m2ts files it reads as it goes.
Or are you suggesting to first convert the whole .m2ts then extract the desired subtitles form the resultant .mkv file?
rollin_eng
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by rollin_eng »

You need to use “Open Folder”, then select the root folder of your blu ray.

Your playlists should then be selectable as titles.
Woodstock
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by Woodstock »

Not sure what your objective is, here - If you open the play list file, it should make all the subtitles for that play list available for selection, with the metadata for the language attached.

Are you trying to extract the subtitle track individually, separate from the video?

I do not have a lot of experience with running handbrake against a directory structure. For me, MakeMKV creates MKV files of what I want, directly from the optical disk, and then handbrake has everything it needs to work with. The "Open Folder" method Rollin_eng mentions is probably exactly what you want, if you've already moved the BD file structure to your local drive.
pstrg
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Joined: Sat Apr 10, 2021 7:00 pm

Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by pstrg »

Woodstock wrote: Sun Jun 06, 2021 1:55 pm Not sure what your objective is, here - If you open the play list file, it should make all the subtitles for that play list available for selection, with the metadata for the language attached.
Objective is
- reduce the size of the .m2ts file while maintaining its visual quality;
- remove unwanted subtitles.
To do that, I play the file to identify subtitles' numbers then choose those I want then convert with Handbrake.
Perhaps it would be more straightforward to
- convert with Handbrake, maintaining all streams;
- remove unwanted streams from the much smaller resultant .mkv with MakeMKV.

p.s. Thank you for your time.
rollin_eng
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by rollin_eng »

Or…Just open the folder structure with handbrake :D
Woodstock
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Re: Why can't Handbrake identify language of BluRay .m2ts files?

Post by Woodstock »

You don't need to use MakeMKV to remove streams, though - just do not select them when you load the title into handbrake. :) You also have the option of using mkvtoolnix tools to remove the tracks a bit faster than MakeMKV can.

Your work flow seems a bit backward to me, though. If you rip with MakeMKV to MKV files, you can tell it to not include the unwanted stuff, making it faster when you process the MKV file in handbrake. You can also "rip everything" in MakeMKV, then use VLC or Kodi to identify which streams you want to leave out when it comes to handbrake.

But, as you've seen, the metadata for languages is in the play list, so it's better to encode from those if you're skipping MakeMKV.
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