Hi, uncomment (#) this line in your sources.list...

deb http://deb.devuan.org/merged daedalus main non-free-firmware non-free contrib

...and, you may remove the first line with just "main", as it is now in the un-commented line. It won't hurt but will cut down on the noise (complaints) in logs and on screen when running

apt update

I hope this helps.

Thank you.

You may misunderstand me.
I really used "no-free" sources.list and updated.
deb http://deb.devuan.org/merged daedalus main non-free-firmware non-free contrib

then I commented out "no-free" sources.list.
Now, I did it again. Nothing changed.

Kaffeine only cannot play some special mp4 file well.
I give up the problem.

Thank you for your kindness.

deb http://deb.devuan.org/merged daedalus main non-free-firmware non-free contrib

...and, you may remove the first line with just "main", as it is now in the un-commented line. It won't hurt but will cut down on the noise (complaints) in logs and on screen when running

apt update

I hope this helps.

Can this be caused by missing firmware for the graphics device?
If so, and since you upgraded from chimaera, is 'non-free-firmware' in sources.list?

Thank you.

My sources.list is as below:
sudo nano /etc/apt/sources.list

deb http://deb.devuan.org/merged daedalus main
deb http://deb.devuan.org/merged daedalus-updates main
deb http://deb.devuan.org/merged daedalus-security main
#deb http://deb.devuan.org/merged daedalus-backports main
#deb http://deb.devuan.org/merged daedalus main non-free-firmware non-free contrib

I used "no-free" sources for the first,second...times, but later, I commented out "no-free‘ sources.
Today, I used "no-free“ sources again, but Kaffeine does not play some special mp4 files well, many mosaics.
Any way, I can use Kaffeine to play other mp4 files.

Thank you.

HelenSmith wrote:

use command line to change the Kaffeine settings?

I haven't used kaffeine in about 500 years, but the bottom of the readme provides some hints WRT passing options to libvlc and/or setting the VDPAU driver.

Thank you.

I added "export VDPAU_DRIVER=none" to  " /home/UserX/.bashrc" ,

but using Kaffeine to play the mp4 file, there are still some mosaics.

So, I will not use Kaffeine for a while.

use command line to change the Kaffeine settings?

I haven't used kaffeine in about 500 years, but the bottom of the readme provides some hints WRT passing options to libvlc and/or setting the VDPAU driver.

VLC: Hardware-accelerated decoding-> Disable"
------------------------------------------------------------
I did not find a way to change the Kaffeine mp4 player default settings.

How to use command line to change the Kaffeine settings?

If there is no way, I will not use Kaffeine for a while.

Thank you.

In any case, all disabling hardware decoding will really cost you is some power efficiency. Any modern CPU should be fast enough to decode [insert whatever stupid number of "K" everyone wants today] video without it.

I'm not downloading a 700MB file from such an unreasonably slow filehost.
That aside, your problem is likely down to hardware accelerated (VAAPI) decoding. Does VLC render the file correctly if you disable "Hardware-accelerated decoding" on the "Input/Codecs" settings page?

Thank you. It works. Now VLC plays the same mp4 file normally.

VLC->Tools->Preferences->Input/Codecs->Input&Codecs Settings-> Codecs->Hardware-accelerated decoding-> Disable(choose: Automatic/VDPAU video decoder/Disable)->Save.

Many thanks to you all.

...  used ffmpeg to cut the mp4 file to the first 30 seconds. ...

Playing the file with ffplay gives me a clear picture. See https://test.szaktilla.de/Bildschirmfoto.png
Same picture with vlc here.

I used ffmpeg to cut the mp4 file to the first 30 seconds.

Japanese movie:
size: 5.9MB
brush_up_life_0.5minutes.mp4

download link: may take some time to download.
https://bin.nixnet.services/?b40244cb96 … w86YWVCS2i

another download link:
https://privatebin.arch-linux.cz/?0a693 … t9iARqbDcn

Thank you.

It is strange that the same vlc version works well in MXlinux-23.

vlc message:
https://paste.nolog.cz/?bcad128b3763b19 … mHtXJ9yoLf

mp4 file
Warning: size, 715.86MB
brush_up_life_japanese_movie.mp4 (715.86 MB)
Expiration: Saturday, September 9, 2023 2:16 AM

download link: may take a long time to download.
https://upload.disroot.org/r/ReA6f33n#E … nxjknMia0=

Thank you.

Only VLC, when play some mp4 files(not all mp4 files), the pictures sometimes(not always) are blurry, many mosaics.
Yes, there are sounds, but the pictures sometimes are not acceptable.
VLC version 3.0.18 Vetinari (3.0.13-8-g41878ff4f2)
Maybe the problem occurred before I updated my pc to Devuan 5.0.

Playing the same mp4 file, I have tried some mp4 players:
work well: mpv/smplayer/gnome videos/parole/celluloid/xine/dragon player,
not work well(same as VLC): kaffeine(VLC based mp4 player).

I tried to play the same mp4 file in the virtualbox on the same pc:
MXlinux-23
VLC version 3.0.18 Vetinari (3.0.13-8-g41878ff4f2)
Open the mp4 file, at the beginning, there are some mosaics, but quickly disappeared, and works normally.

Rocky Linux 9.2 (Blue Onyx)
VLC media player 3.0.19 Vetinari (revision )
There are no problem to play the same mp4 file.

In the Devuan 5.0 and MXlinux-23, VLC is the same version,

How to let Devuan 5.0 VLC play some mp4 files well?

Thank you in advance.