WLX Plugin - mpv_alt - Volume issue with video

[advice2020]

I had noticed this for a while now but was never able to figure out a solution.
The WLX plugin mpv_alt when used with audio based formats the volume works fine.
However when used with any video formats the volume is very low.
I do not remember there being such a difference in volume between the two, seems strange that the volume would be different for audio then it would for video?

I was wondering by any chance does anyone else experience this?
Does anyone know what the cause of this could be?

I tried two past versions and both reacted the same, I will get newer version and compile again and see if I notice any difference, but just wanted to mention just in case I do not figure this out myself.

Thank You

[j2969719]

cant hear any difference on my end. this plugin simply passes the file to mpv for playback, and the default plugload.lua also doesnt distinguish between audio and video or set the volume level ¯_(ツ)_/¯

[advice2020]

@j2969719
OMG how are you keeping your right hand floating like that without a right arm?

Oh don't say that, how can this be?
This is strange, I compiled newer version and this still occurs.
All audio formats = volume is fine
All video formats = cannot hear volume, have to max system volume and then bring MPV plugin volume itself to max as well to slightly hear volume.

If I try my actual MPV application itself, both audio and video work fine.
So it specific to this plugin.

If any other users read this, who also use this mpv_alt plugin, please share results.
Wonder if anyone else experiences anything like this / or not.

Thank You

[j2969719]

OMG how are you keeping your right hand floating like that without a right arm?

[advice2020]

I knew it!
This explains so much :)

[advice2020]

@Skif-off
@JonnyTech
Sorry to tag you guys specifically, but I was wondering if by any chance either of you use this WLX plugin mpv_alt?
If so do either of you experience this issue where if you open QPP (Quick Preview Pane) and
-place cursor on audio file the volume works fine but if you
-place cursor on a video file the volume is very low (almost silent)?
Thank You

[JonnyTech]

Download link?

[j2969719]

either ubuntu bins or arch bins if this plugin doesnt work on your distro after install, find the j2969719.ini file in the DC config folder and try to change the libpath to the correct one.

[JonnyTech]

The volume level is correct - tested with mp3, wav and m4a audio files and mp4 video files, all from the quick view panel.

[j2969719]

open QPP (Quick Preview Pane) and
-place cursor on audio file the volume works fine but if you
-place cursor on a video file the volume is very low (almost silent)?

test.webm

[advice2020]

@j2969719
:)

@JonnyTech
Thank you for taking the time to try this out and for sharing the results.

This might not have anything to do with it but in j2969719s example I think he is using gtk2 version, I am using QT5 version of this mpv_alt plugin that I compiled.

Also here is a little more information to share, I keep thinking everyone is using the QT5 version of DC.
I am also using the alpha AppImage QT5 version provided by DC that can be found here
https://doublecmd.sourceforge.io/site/eng/snapshots.php

Double Commander
Version: 1.2.0 alpha AppImage
Revision: 12278
Commit: 1836be8e
Build date: 2025/06/24
Lazarus: 3.8.0.0
FPC: 3.2.2
Platform: x86_64-Linux-qt5
OS version: Debian based Linux distro / GTK based DE (x11)
Widgetset library: Qt 5.15.8

I have to use older version of DC AppImage, not sure if it is due to newer version now comes with newer Lazarus (something like 4.2.0?)
but for some reason the newer AppImages randomly instantly close DC. I have reported it but have not recieved any response from developer or other users.

I think this mpv_alt happens in both older and newer AppImage versions so not Lazarus issue.
-Probably not but could toolkit have anything to do with this? Has anyone tried this in QT5 DC with QT5 compiled mpv_alt plugin?
-Also, I wonder if using AppImage could have anything to do with this mpv_alt volume issue?
Again just strange that it would only be volume issue with video and not all audio sources.

Thank you guys again

[j2969719]

test.webm

[JonnyTech]

I tested with qt6:

Double Commander
Version: 1.1.29 gamma
Revision: 800
Commit: b4b2d9a36
Build: 2025/10/12
Lazarus: 3.8.0.0
Free Pascal: 3.2.2
Platform: x86_64-Linux-qt6
System: MX 25 Infinity
Desktop Environment: XFCE (x11)
Widgetset library: Qt 6.8.2

Try this:
open quick view panel and select a file
click the three horizontal bars in bottom left
in popup menu select stats for nerds
look at the audio section displayed
test with different files
see if device or volume differs

[Skif-off]

@JonnyTech

click the three horizontal bars in bottom left

How do I add this? Lua script?

[j2969719]

Does it make sense to break? The behavior has already been documented and INI file may be useful in the future.

dunno, the idea was that with a modified file, when a new user downloads binaries for ubuntu or changes the plugin version, there would be no need to edit the configs, and its unlikely that any new settings would be added, since all mpv customization is done through a script

[j2969719]

I just don't really understand the consequences of replacing GTK_SOCKET

if you were using the old mpv.wlx from the very first commits before 2020, you were already using it without gtk_socket. irrc the main difference is that without gtk_socket, mpv's hotkeys didnt work (thats why bayrookie created wlxmpv). And at some point, the mpv process stopped closing under debian/ubuntu (thats why i initially added a kill call, but eventually just made gtk_socket the default).

[Skif-off]

@JonnyTech

FYI my system is Trixie - let me know if you need me to try any tests.

I forgot, you wrote above:

I also tried the gtk2 version of the plugin with doublecmd-gtk2 and experienced exactly the same crash.

It already looks like a test :)
If mpv 0.40 and mpv_alt_gtk2 work fine in Arch Linux, the problem may be caused by GTK2 library patches in Debian and its derivatives...

The mpv.wlx does not work with doublecmd qt6.

mpv.wlx for GTK2 only.

@j2969719

what kind of gpu do you have? only checked with amdgpu, maybe its something hardware-specific like with my potato?

Maybe: radeon & r600, but so far, it hasn't been a problem.

if you were using the old mpv.wlx from the very first commits before 2020, you were already using it without gtk_socket.

I meant mpv_alt_gtk2 vs. mpv_alt_gtk2_drawing_area :)

[j2969719]

i mean there probably shouldnt be much of a difference especially considering that with libmpv profile input is also set to no and there is no child process

[j2969719]

X Error of failed request:  BadWindow (invalid Window parameter)                                                                                         20:11:57 [5/1852]
  Major opcode of failed request:  4 (X_DestroyWindow)                                                                                                                    
  Resource id in failed request:  0x3000002
  Serial number of failed request:  56
  Current serial number in output stream:  59

welp updated my potato on which i still use the gtk2 builds, and this crap appeared here too, so its not just a debian issue. looked at the output of the old mpv.wlx with gtk_socket enabled

[vo/gpu/libplacebo] EnumeratePhysicalDevices(inst, &num, NULL): VK_ERROR_INITIALIZATION_FAILED (../src/vulkan/context.c:957)                                              
[vo/gpu/libplacebo] Found no suitable device, giving up.                                                                                                                  
[vo/gpu/libplacebo] Failed initializing vulkan device     

and it seems like its coz my potato cant do vulkan?

[advice2020]

Oooooo look at all this activity :)

Seems like this uncovered a different issue.
Thank you for asking that question Skif, I was going to ask the same thing when I saw those 3 lines :)
I am using 0.39.0 as well so my GUI does not include them either.
Nice to see the information it offers, but I would prefer they did not add that to the GUI.

Anyways, should these issues be separated/moved into the "Issues" section?

@JonnyTech
Thank you, as mentioned above I unfortunately only have access to 0.39.0 so I do not have the 3 line icon like you do to check this.

As mentioned, I wonder if this stopped working when I switched to AppImage version?

Thank all again
At least this post was able to revealed a possible future issue with the mpv_alt plugin.

[advice2020]

@j2969719 @Skif-off @JonnyTech

OOOOooo I got something.
AppImage did not have anything to do with it because I compiled DC standalone and this still occurs.

As mentioned this volume issue does not occur with audio files, only video files.
But I have come across something if any of you guys are interested.

STEPS TO REPRODUCE
-Put 1 audio file and 1 video file into the same folder.
-If you start Quick Preview with cursor on a video file FIRST, then this volume issue will occur.
-However if you instead, start Quick Preview with cursor on an audio file FIRST the volume will work, and then move cursor to the video file, then the videos volume works as well!
-Also noticed that vice versa, if you start Quick Preview with cursor on video file FIRST, and then you move cursor to the audio file, then the audio files volume is low.

So it is something with the volume of the first item being played that transfers to any others.

Now Sloth, I don't want to see any of your floating hand magic tricks, this has be something, work your magic on this issue instead........ please :)
Just kidding, but I kind of remember talking about a volume setting, whether volume would remember previous state of last item or if it would reset with each item, but that might have been with the other media player plugin. Do you by any chance know of any volume settings like this in mpv / mpv_alt plugin?

If anyone performs the test above and experiences these issues with the test above please mention your results.
This maybe can help narrow down if this is something Debian/Ubuntu based, if j2969719 does not experience this issue in Arch.

Hope this was helpful
Thank you guys again

[j2969719]

still nope test.webm
no idea whats going on there. all plugin settings are in plugload.lua, if its been changed, try the default one. you can also try temporarily renaming the mpv dotfiles

[JonnyTech]

STEPS TO REPRODUCE
-Put 1 audio file and 1 video file into the same folder.
...

No problems here. The issue is within your environment. Reinstall your operating system.