Fedora 39 Silverblue with rpm-fusion: Some video playback laggy/does not start with Fedora' Firefox

Steps to reproduce

Visit E-Fuel vs E-Auto: Mythos Technologieoffenheit - ZDFmediathek in Firefox and play video.

What happens: It first does not start correctly and stays at frame 1. If you pause and replay, it starts, but this is very laggy.

What should happen: Just play.

Important to note: Most other videos play well in ZDF mediathek, also YouTube and other players usually work fine. Often, however, I also see issues for ARD mediathek e.g. this video here was laggy though I could not reproduce it.

Also, playing the same video by using the URL https://nrodlzdf-a.akamaihd.net/none/zdf/24/03/240315_maithink_x_sendung35_efuels_mai/1/240315_maithink_x_sendung35_efuels_mai_3328k_p36v14.mp4 retrieved from MediathekViewWeb (highest quality) shows the same issues. Also even if I use the lowest quality it just staggers/lags…

Control test

Playing the same videos in the Firefox 124.0.1 flatpak from Flathub works flawlessly.

$ flatpak info org.mozilla.firefox

Firefox - Fast, Private & Safe Web Browser

          ID: org.mozilla.firefox
         Ref: app/org.mozilla.firefox/x86_64/stable
        Arch: x86_64
      Branch: stable
     Version: 124.0.1
     License: MPL-2.0
      Origin: flathub
  Collection: org.flathub.Stable
Installation: system
   Installed: 258.9 MB
     Runtime: org.freedesktop.Platform/x86_64/23.08
         Sdk: org.freedesktop.Sdk/x86_64/23.08

      Commit: c1d22d88365e2464dd1d6dbe4d8b671922b3d1fea4d8fcb63f99ddd589e4367a
      Parent: 1547fd77d2b042d745ca8d50602d740e384561c2429b313e16f0c9d9c685c093
     Subject: Export org.mozilla.firefox
        Date: 2024-03-22 12:55:01 +0000

Here a link to the about:support information for the working flatpak version.

Video

Here tested in private browsing mode to prevent most add-ons to interfere:

(Link in case the embedding does not work)

FYi the (auto-generated)embedding of this video also does not work and just looks like this in the same browser for me (i.e. media/mime type not supported).

Debug information

From ZDF:

ZDF-Player Debug-Information
Version: 3.5.1-stable
Type: hls.js v1.2.0
Dimensions: 1052x591.75
Resolution: 1280x720
Quality: auto
Protocol: https
MimeType: application/x-mpegURL
Volume: 100%
Duration: 1800s
CurrentTime: 19.275305s
Buffer: 198s
Adaptive: aktiv
AdaptiveQuality: 5 of 5
BitRate: 2725888 Kbit/s
PlaybackRate: 1
ArticleUrl: https://www.zdf.de/show/mai-think-x-die-show/maithink-x-sendung35-efuels-vs-eauto-100.html
UserAgent: Mozilla/5.0 (X11; Linux x86_64; rv:124.0) Gecko/20100101 Firefox/124.0

about:support information: Video playback issue · GitHub

The about:support page also shows the supported codecs, which looks fine:

(It’s the same in the flatpak version.)

System

This is Firefox 124.0.1, the Fedora-distribution version installed in Fedora Silverblue 39. I have layered the necessary rpm-fusion repository/

$ rpm -q firefox
firefox-124.0.1-1.fc39.x86_64
$ rpm-ostree status -v
State: idle
AutomaticUpdates: stage; rpm-ostreed-automatic.timer: last run 1 day 21h ago
Deployments:
● fedora:fedora/39/x86_64/silverblue (index: 1)
                  Version: 39.20240325.0 (2024-03-25T00:37:19Z)
               BaseCommit: 8b2ab1dc8e53e928d23de9ed3be548c0338c3dec3fcb1c28b1caa0df70b35b7f
                           ├─ repo-0 (2023-11-01T00:12:39Z)
                           ├─ repo-1 (2024-03-25T00:16:24Z)
                           └─ repo-2 (2024-03-25T00:23:02Z)
                   Commit: def9b08e2c7fe12425846c7be578337db17535c8bf605fbf291e18a27cf83cc4
                           ├─ fedora (2023-11-01T00:12:39Z)
                           ├─ fedora-cisco-openh264 (2023-12-12T17:22:46Z)
                           ├─ rpmfusion-free (2023-11-04T16:49:08Z)
                           ├─ rpmfusion-free-updates (2024-03-24T12:21:36Z)
                           ├─ updates (2024-03-25T01:01:46Z)
                           └─ updates-archive (2024-03-25T01:29:06Z)
                StateRoot: fedora
             GPGSignature: 1 signature
                           Signature made Mo 25 Mär 2024 01:38:19 CET using RSA key ID 75CF5AC418B8E74C
                           Good signature from "Fedora <fedora-39-primary@fedoraproject.org>"
          LayeredPackages: ***** gparted gstreamer1-plugin-openh264 heimdall htop httpie keepassxc kid3 lshw
                           mozilla-openh264 ****
                           pipewire-codec-aptx podman-compose rpmfusion-free-release ****
$ uname -a               
Linux ****** 6.7.9-200.fc39.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Mar  6 19:35:04 UTC 2024 x86_64 GNU/Linux

Here a link to the full lshw output. The TL;DR is: AMD Ryzen 7 4800U with Radeon Graphics / Renoir Radeon High Definition Audio Controller.

More information

The mailab videos may have a different encoding or something compared to other videos, I also have the issue Video download not detected on ZDF.de (ZDF mediathek) sometimes · Issue #505 · downthemall/downthemall · GitHub that one such video is not detected by a download extension.

Hmm opened this as a bug report for the Firefox package now:
https://bugzilla.redhat.com/show_bug.cgi?id=2275817

Or this rpm-fusion at fault here? Should I (rather?) report it there? If so, for which package? How can I find out which codec is used?