Hey there,
I am quite new to this forum and nextcloud in general though I have a little experiance with Linux systems as I am using several distributions as dialy drivers…
Anyway this is my problem. I have NC 21 running on my ubuntu server 20.04 as a substitution for google services with CalyxOs (which I really can recommend!). It works really well so far and i am quite happy with it but one thing is driving me crazy: Video-previews are not shown. Here is an excerpt of my config.php:
‘enabledPreviewProviders’ =>
array (
0 => ‘OC\Preview\TXT’,
1 => ‘OC\Preview\MarkDown’,
3 => ‘OC\Preview\PDF’,
4 => ‘OC\Preview\Image’,
5 => ‘OC\Preview\Photoshop’,
6 => ‘OC\Preview\TIFF’,
7 => ‘OC\Preview\SVG’,
8 => ‘OC\Preview\Font’,
9 => ‘OC\Preview\MP3’,
10 => ‘OC\Preview\Movie’,
11 => ‘OC\Preview\MKV’,
12 => ‘OC\Preview\MP4’,
13 => ‘OC\Preview\AVI’,
),
‘preview_max_x’ => 1024,
‘preview_max_y’ => 1024,
‘preview_max_scale_factor’ => 1,
Consider \ as doubled → seems to be a display error of this forum?
If I run
sudo -u www-data php /var/www/nextcloud/occ preview:pre-generate -vvv
Also video files are shown in the output but when I login to my nextcloud everything I see is the standard-thumbnail for every video file. Can anybody tell me how to make it work?
Oh and by the way: of course I installes ffmpeg and imagemagick. Also the www-data user can execute both.
Thank you very much in advance for your help! 
