Is there a kde dolphin thumbnail creator for video files that would use built-in thumbnails?
Solution 1:
KDE thumbnail creator with an option to use built-in thumbnails
A KDE bug/wish: Bug 238909 - Enabling of embedded mkv /mka cover art to display as icon - https://bugs.kde.org/show_bug.cgi?id=238909
Meanwhile: A KDE thumb creator plugin with an option to use the external pictures as thumbnails: http://kde-apps.org/content/show.php/FFMpegThumbs-MattePaint?content=153902 . The external is at this same as attached/embedded thumbnail.
Both the MPEG-4 container and the Matroska container could have cover art as attachments.
The FFMpegThumbs-MattePaint is capable to use the embedded/attached mp4/Matroska cover art as the thumbnail. The thumbnailer is using AtomicParsley /1/ command-line tool (mp4) and Matroska /2/ command-line tools (mkv) to extract the cover art and use it as the thumbnail. Both tools are available from the Ubuntu repositories.
As default the FFMpegThumbs-MattePaint, 0.42 or later, is using the attched/embedded mp4/Matroska cover art for the thumbnail. If there is no attached picture or the picture extraction is not possible (missing tool etc) then the thumbnail creator will pick a random frame from the media.
A YouTube clip https://www.youtube.com/watch?v=iRz3aWnD21Q&feature=youtu.be
The user has an option to override the default by writing an empty, 0 byte, file to the ../ffmpegthumbs-mattepaint/NoAuto.
KDE4:
This can be done by the command:
touch ~/.kde/share/apps/ffmpegthumbs-mattepaint/NoAuto
KF5:
This can be done by the command:
touch ~/.config/ffmpegthumbs-mattepaint/NoAuto
If there is more than one picture file attached the user has an option to hand pick the wanted cover.
Thumbnail picking from the Matroska cover art sample file: http://matroska.org/news/cover_art.html
Links
- http://atomicparsley.sourceforge.net/
- https://www.bunkus.org/videotools/mkvtoolnix/