I often download youtube videos to watch them later. But some of them does not show any thumbnail and if I try to play them in smplayer it only renders audio and doesn't support video. When I try to open them with ubuntu default video player error message is showing up as shown in the image.

AV1 decoder not found error

On clicking on find in software it doesn't find anything. I have already installed ubuntu restricted codecs. I know vlc can play this but vlc has other playback issues for me. It is playing in mpv but I want to use smplayer. Any workaround to play this type of video in smplayer? Thanks in advance.


3 Answers 3


It could be that there exists other missing codecs and decoders for multimedia. I have encountered it recently as well and got it solved by installing via terminal

$ sudo apt-get update
$ sudo apt install libdvdnav4 libdvd-pkg \
gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly libdvd-pkg

Crd - https://websiteforstudents.com/how-to-enable-ubuntu-18-04-lts-beta-to-play-videos-files/

  • Videos are started to work in ubuntu videos but smplayer still doesn't support video. If there any other solution, let me know.
    – Yogi Katba
    Jul 9, 2020 at 13:45

If mplayer will not play the video portion of your file (e.g. running "mplayer file.mkv" on the command line yields errors of the form "Cannot find codec matching selected -vo and video format 0x31307661," indicating lack of support for the av1 video codec), then you still might be able to play the video with smplayer by changing the multimedia engine that smplayer uses. In the "Options" tab, open "Preferences," and under General -> General, open the drop-down menu for the multimedia engine. If the options you see are "mplayer," "mpv," and "other," then select mpv in place of mplayer.

Of course, for this to work you do need mpv installed ("sudo apt-get install mpv").


Convert the file to mp4 For that install ffmpeg version 4

Commands to install that: (from: https://www.cloudbooklet.com/how-to-install-and-use-ffmpeg-on-ubuntu-18-04/)

sudo add-apt-repository ppa:jonathonf/ffmpeg-4
sudo apt install ffmpeg

Command to convert mkv to mp4:

ffmpeg -i filename.mkv filename.mp4

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