totem unable to play h.264 and many videos 20.04 Ubuntu can i tried adding many decorder

[dev]

totem can't able to play h.264 videos or acc audio file in videos.
Also old totem in 20.04 can play most of the file. after upgrading it stops playing.
Before installing any encoder it shows download h.264 decoder from ubuntu software but after clicking it it show you need to enable 3rd party repo. also clicking it doesn't enable it. after installing encoder different codec it doesn't show download from ubuntu software still. can't play.
Ultimately I have to install vlc from snap

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: libgstreamer1.0-0 1.16.2-2ubuntu1
ProcVersionSignature: Ubuntu 5.8.0-16.17-generic 5.8.0
Uname: Linux 5.8.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu45
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Fri Aug 28 12:01:51 2020
InstallationDate: Installed on 2020-08-13 (14 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
ProcEnviron:
 LANGUAGE=en_IN:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IN
 SHELL=/bin/bash
SourcePackage: gstreamer1.0
UpgradeStatus: Upgraded to groovy on 2020-08-21 (6 days ago)
XorgLog: Error: [Errno 2] No such file or directory: '/var/log/Xorg.0.log'

[dev (darkraspberry)]

I make the totem at first case all dependences and encoders.

[dev (darkraspberry)]

All logs shows the first case