@mitu good day!
I was testing some mame video snaps on retropie.
Im well aware of the new default being VLC and that retropie is moving away from omxplayer.

On my system, video snaps from same source, some play ok some other not. They produce the blackscreen as per this post.

In VLC settings ffmpeg HW acceleration is disabled in codecs section. I cant find yet what is VLC missing and cant paly these files.

This is on a pi4 2GB model with latest updates and retropie.

For testing im providing this small 900KB argus.mp4 video snap
https://mega.nz/folder/2HAxmYJR#nNsMz6pZDkn1T36ASe5ZCg

I have on my system also installed the MPV. This one works great on all problematic video snaps.
VLC requires re-encoding of the files to work ok

ae13d584-3e56-48cc-9d12-2257fd6ddd05-image.png

Here is my testing from command line
MPV

mpv ~/RetroPie/roms/trackball/snaps/argusg.mp4 Playing: /home/pi/RetroPie/roms/trackball/snaps/argusg.mp4 (+) Video --vid=1 (*) (h264 256x240 29.970fps) (+) Audio --aid=1 (*) (aac 2ch 48000Hz) File tags: Artist: Progetto VideoSnaps by motoschifo & AntoPISA [gameplay by motoschifo] Comment: Created with: Mame version 0.161, Played by: motoschifo, Game name: argusg - Argus (Gottlieb, prototype), Date game played: 23 maggio 2015, Date video creation: 2 novembre 2015, Type: shortplay single-screen, Manufacturer: Gottlieb, Display resolution: 256x240px, Link for info: http://adb.arcadeitalia.net/?mame=argusg, Copyright (C) - All rights reserved - Tutti i marchi e loghi appartengono ai rispettivi proprietari Genre: MAME video preview (shortplay) Title: Argus (Gottlieb, prototype) [MAME] [vo/sdl] Using opengl [autoconvert] Converting yuv444p -> yuv420p AO: [pulse] 48000Hz stereo 2ch float VO: [sdl] 256x240 => 320x240 yuv420p AV: 00:00:37 / 00:00:37 (99%) A-V: 0.000 Exiting... (End of file)

VLC

vlc ~/RetroPie/roms/trackball/snaps/argusg.mp4 VLC media player 3.0.12 Vetinari (revision 1.0.6-1618-g917488b78) [0152e490] main interface error: no suitable interface module [014a5b58] main libvlc error: interface "globalhotkeys,none" initialization failed [014a5b58] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface. [0152e490] skins2 interface error: cannot initialize OSFactory [0152e490] [cli] lua interface: Listening on host "*console". VLC media player 3.0.12 Vetinari Command Line Interface initialized. Type `help' for help. > [a026ea18] mmal_codec decoder: VCSM init succeeded: CMA [a026ea18] main decoder error: buffer deadlock prevented

And running the re-encoded (as per above) video snap, which now vlc can play OK!

vlc argusg.mp4 VLC media player 3.0.12 Vetinari (revision 1.0.6-1618-g917488b78) [00f0b2e8] main interface error: no suitable interface module [00e81b58] main libvlc error: interface "globalhotkeys,none" initialization failed [00e81b58] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface. [00f0b2e8] skins2 interface error: cannot initialize OSFactory [00f0b2e8] [cli] lua interface: Listening on host "*console". VLC media player 3.0.12 Vetinari Command Line Interface initialized. Type `help' for help. > [a025f258] mmal_codec decoder: VCSM init succeeded: CMA [a2701f88] gles2 generic error: parent window not available [a27027d0] mmal_xsplitter vout display error: Failed to open Xsplitter:opengles2 module [a2701f88] xcb generic error: window not available [a27027d0] mmal_xsplitter vout display error: Failed to open Xsplitter:xcb_x11 module

Also Im providing MediaInfo fro both files:

8f5ad46f-3da2-4c4b-9630-95b9a86a37e6-image.png

8e3c3e57-849b-4242-80c9-6862ccd503eb-image.png

0299c00d-adeb-42c1-a709-7c1c22d05ca6-image.png

You could try lakka