Subtitles not showing when interSubs is active — works only when disabled (WSL2 + VCXsrv setup)

[cch4v3z]

Description:

Hi, I'm trying to use interSubs (v2.7) on WSL2 with mpv and VCXsrv, and I’ve followed all installation and troubleshooting steps. The script starts correctly, video plays fine, and the F5 key toggles interSubs, but subtitles only show when I disable interSubs. When it’s active, nothing is displayed on screen.

Here’s what I’ve verified and done:

---

✅ My Setup:

WSL2 (Ubuntu) with VCXsrv running in Windows host

DISPLAY=:0 and LIBGL_ALWAYS_INDIRECT=1 are correctly exported

python3, pyqt5, numpy, requests, lxml, socat, xdotool, etc., are all installed

xeyes and mpv render correctly in the X server window

xcompmgr fails with “Another composite manager is already running (Weston WM)”, but I confirmed Weston is not running anymore

interSubs is correctly installed under ~/.config/mpv/scripts/

I run everything as normal user (not root)

---

🧪 Behavior Observed:

mpv plays the video and loads subtitles (tested separately)

Pressing F5 runs interSubs and hides default subtitles as expected

But nothing is displayed from interSubs — no translated subs, no overlay

When I press F5 again to stop it, the normal subtitles appear again

No error is printed in the terminal or MPV logs when pressing F5

---

🧩 Investigation Results:

Socket file (e.g. /tmp/mpvsocket_12345678) is not always created

Subtitle file (e.g. /tmp/mpv_sub_12345678) is created but remains empty (0 bytes)

Running:

echo '{ "command": ["get_property", "sub-text"] }' | socat - /tmp/mpvsocket_*

returns no response, suggesting IPC is not working

Both MPV and interSubs are run in the same environment (same user, same session)

I verified that the Lua script calls the Python script with correct arguments using mp.msg.warn(...)

[cch4v3z]

What I need help with:

I’ve done everything I could think of — is there something else that could prevent interSubs.py from extracting the subtitle text from MPV’s IPC socket?

Could it be related to sub-visibility or ass-override settings? Or does it require additional config when using VCXsrv?

---

Thanks for your work on this tool — I’d love to get it running properly!

[oltodosel]

WSL2 and VCXsrv

meaning you're using Windows? if so, see the last paragraph here

[cch4v3z]

Hi, I'm trying to use interSubs (v2.7) and have tested it in two different environments:

1. WSL2 with Ubuntu 22.04, using VCXsrv and exporting DISPLAY=:0

2. Linux Mint (Cinnamon) running in VirtualBox, with full Xorg and xcompmgr

In both cases, interSubs starts up, the F5/F6 keys toggle as expected, and MPV plays the video with subtitles. However, I’m running into the same issue in both environments:

---

❗ Problem:

Subtitles only appear when I disable interSubs (F5 to stop it).
When interSubs is active, no subtitles are shown — not even the translated ones or any overlay.

---

✅ What I've done / Verified:

Installed all required packages:

mpv 0.35+

python3, pyqt5, numpy, requests, lxml, beautifulsoup4, httpx

xdotool, socat, pkill, lua, wget

Set up VCXsrv (for WSL) and tested with xeyes, mpv, etc. — everything displays properly

Confirmed DISPLAY=:0 and LIBGL_ALWAYS_INDIRECT=1 are exported

xcompmgr says “Another composite manager is already running (Weston WM)”, but Weston is not running anymore

In Linux Mint VBox, used Xorg with xcompmgr — same issue persists

interSubs.py, interSubs.lua, and interSubs_config.py are installed in ~/.config/mpv/scripts/

Subtitles work fine when playing directly with --sub-file, just not with interSubs

---

🧪 Behavior:

Pressing F5 starts interSubs, hides default subtitles (expected behavior)

No translated subtitles or overlay ever appear

Pressing F5 again to stop interSubs brings back the original subtitles

MPV shows no error

Running interSubs manually:

python3 interSubs.py /tmp/mpvsocket_xxxxxxx /tmp/mpv_sub_xxxxxxx

also starts without crashing, but no output is written to the sub file

Socket file /tmp/mpvsocket_xxxxxxx is often missing

Subtitle file is created but stays empty (0 bytes)

---

🧩 My guess:

It looks like interSubs can't extract subtitle text from MPV, either because:

MPV's IPC socket isn't being created properly

The Lua script can't trigger the Python script as expected

Or MPV is not returning sub-text over IPC

This happens in both WSL2 and Linux Mint VBox.

[oltodosel]

Are you sure your subtitles are text-based, and not images? To make sure try with subtitles that come in a file with extenstion *.srt

Alternatively, try writing some text into /tmp/mpv_sub_xxxxxxx then run manually python3 interSubs.py /tmp/mpvsocket_xxxxxxx /tmp/mpv_sub_xxxxxxx and see whether that text would appear on the screen.

[cch4v3z]

The subtitle file I'm using is .srt is fully in base of text , I just discovered when I pressed F for full screen the overlay showed up but in full black background and is underlined with read color every word in the sentence when I point a single word it shows me the translation but still I can't get the others features, and the overlay is not over the main window like you have in your post, in my case is like both are different entities.

[oltodosel]

full black background

It seems like a problem with composite manager. Try xcompmgr

Though I'm not sure what you meant by the overlay is not over the main window like you have in your post, in my case is like both are different entities. Provide a screenshot.

[cch4v3z]

I’m running into a few issues:

1. The video is very dark, and subtitles are not visible or hard to read. I’ve tried tweaking --vo=gpu, but it seems to glitch. Switching to --vo=x11 or --vo=sdl helps somewhat.

2. Subtitles only show when fullscreen (F) is pressed, likely due to hide_when_not_fullscreen_B = True.

3. Audio errors appear (ALSA/JACK), which I know is a WSL limitation. I’m using --ao=null as a workaround.

4. Translation popups are visible, but sometimes content appears broken or hard to read, possibly due to CSS or fallback fonts.

Any tips on resolving the display/overlay issues and improving readability would be greatly appreciated. Also, if you have recommendations for styling style_subs or adding an offline

[oltodosel]

Your system seems to have trouble rendering transparency.
In interSubs_config.py - in style_subs variable try changing css background: transparent; to background: blue; or something like that
Because the translations do show, means there are problems with css config. Try different fonts.

I'd try setting it up in a proper linux(even if virtually), and then try all that in windows.

You might want to try Tk version - https://github.com/oltodosel/interSubs/tree/master/Tk
Though I don't know whether it still works.