Fritz!Box Cable DVB-C .m3u file not played (network stream)

[rugk]

The media player can open the .m3u file apparently, but does not play it. Neither for a single channel nor for multiple ones.

STR

Have a Fritz!Box Cable with "Live TV" aka DVB-C receiver. Maybe any other device providing a network stream would work, too.

You get a .m3u file like this:

#EXTM3U
#EXTINF:0,Das Erste HD
#EXTVLCOPT:network-caching=1000
rtsp://192.168.178.1:554/?avm=1&freq=386&bw=8&msys=dvbc&mtype=256qam&sr=6900&specinv=1&pids=0,16,17,18,20,5100,5101,1170,1176,2171,2172,5102,5103,5104,5105,5107
#EXTINF:0,All Channels
http://192.168.178.1/dvb/m3u/channellist.m3u

Now open that in Clapper.

What happens

Nothing, it does not play (it renders the [channel] title, though):

What should happen

Play video stream.

VLC (flatpak) does play the same.

More information

VLC shows the following codec information (sorry screenshot because I cannot copy it from that window in VLC):

GNOME "official" video application (as a flatpak from Flathub) also cannot play it. See https://gitlab.gnome.org/GNOME/totem/-/work_items/652

System

$ LANG=en flatpak info com.github.rafostar.Clapper               

Clapper - Lean back and enjoy videos

            ID: com.github.rafostar.Clapper
           Ref: app/com.github.rafostar.Clapper/x86_64/stable
          Arch: x86_64
        Branch: stable
       Version: 0.10.0
       License: GPL-3.0-or-later
        Origin: flathub
    Collection: org.flathub.Stable
  Installation: system
Installed Size: 60.7?MB
       Runtime: org.gnome.Platform/x86_64/47
           Sdk: org.gnome.Sdk/x86_64/47

        Commit: 5fe4a3554636fcfb64ccbe8ed4e8c6d5b4e9e2eea71aba1233eab68155f577e8
        Parent: 4a06618f8b2d882e175411a5bfd489f63250a932d12116526d5237e6a5c6604c
       Subject: Merge pull request #73 from Erick555/Erick555-patch-1 (bd28acbe4250)
          Date: 2026-02-09 17:31:08 +0000
$ rpm-ostree status -b 
State: idle
AutomaticUpdates: stage; rpm-ostreed-automatic.timer: inactive
BootedDeployment:
● ostree-image-signed:docker://ghcr.io/ublue-os/bluefin-dx:stable
                   Digest: sha256:67051954fb6d05e479260388c03f806c373567a9a410ef4f998c5bb48ce5f480
                  Version: 43.20260505 (2026-05-05T01:52:31Z)
      RemovedBasePackages: code 1.118.1-1777475026.el8
      ***

[Rafostar]

Hi. First of all lets check if our backend can play that RTSP stream alone. Please copy your rtsp:// URL line from that playlist file and paste it into Clapper "Open URI" dialog to check if it plays that way.

[rugk]

Okay, it does not work either, but at least I got an error message:

Missing plugin: Teletext-Decoder

Now yes that stream has teletext and VLC e.g. can decode it (loosely related issue here that has some screenshots on how it looks though)

[Rafostar]

This is a mix of 2 different issues.

First is that Clapper playlist item demuxer expects 1 URI = 1 STREAM which is wrong assumption for RTSP which uses "sometimes GstPads".

Another issue is that Clapper currently refuses to play videos that have some unplayable stream/codec (here its teletext). It should play such media as long as there are any playable video or audio streams in there and inform user about missing codecs (already open issue #440). Adding missing plugins to Flatpak might work-around this here through (probably missing is teletextdec and dvbsuboverlay).

Can you share short sample of such video?

[rugk]

It's a stream so hardly "sharable" or maybe can I record it with vlc? But if it is recorded I guess it's reencoded/not the same as the "original"?

[Rafostar]

Try with ffmpeg from terminal:

ffmpeg -rtsp_transport tcp -i "rtsp://192.168.178.1:554/YOUR_PATH" -map 0 -c copy output.mkv

Hit Ctrl+C after you have about 30-60s recorded.