Hello,
Thumbnails for videos encoded in av1 format are not displaying. I don't have any issues with other formats :

My VPS runs on Debian 13 and I have ffmpeg installed.

Here is my installation log:
Files Gallery 0.14.2
photos.oxmail.fr
PHP 8.4.11
Apache
root
storage_path
index.php
gd
exif
mbstring
imagick
imagick PDF support
ZipArchive
mime_content_type()
finfo_file()
iptcparse()
exif_imagetype()
session_start()
ini_get()
exec()
ffmpeg
imagemagick 'magick'
ghostscript
memory_limit 1024M
file_uploads 1
upload_max_filesize 512M
post_max_size 1024M
max_file_uploads 50
Config
<?php

return [
'root' => '',
'root_url_path' => NULL,
'root_lock' => NULL,
'start_path' => '',
'username' => '',
'password' => '',
'load_images' => true,
'load_files_proxy_php' => false,
'load_images_max_filesize' => 1000000,
'image_resize_enabled' => true,
'image_resize_use_imagemagick' => true,
'image_resize_cache' => true,
'image_resize_cache_use_dir' => false,
'image_resize_dimensions' => 320,
'image_resize_dimensions_retina' => 480,
'image_resize_dimensions_allowed' => '',
'image_resize_quality' => 85,
'image_resize_function' => 'imagecopyresampled',
'image_resize_sharpen' => true,
'image_resize_memory_limit' => 256,
'image_resize_max_pixels' => 60000000,
'image_resize_min_ratio' => 1.5,
'image_resize_cache_direct' => false,
'folder_preview_image' => true,
'folder_preview_default' => 'filespreview.jpg',
'menu_enabled' => true,
'menu_max_depth' => 5,
'menu_sort' => 'name_asc',
'menu_cache_validate' => true,
'menu_load_all' => false,
'menu_recursive_symlinks' => true,
'layout' => 'rows',
'cache' => true,
'cache_key' => 0,
'clean_cache_interval' => 7,
'clean_cache_allow_manual' => false,
'image_cache_file' => 'cache.txt',
'image_cache_max_last_access_time' => 90,
'image_cache_validate_time' => true,
'storage_path' => '',
'files_include' => '',
'files_exclude' => '',
'dirs_include' => '',
'dirs_exclude' => '',
'allow_symlinks' => true,
'get_mime_type' => false,
'license_key' => '',
'download_dir' => 'browser',
'download_dir_cache' => 'dir',
'assets' => 'files/assets',
'allow_all' => false,
'allow_upload' => false,
'allow_delete' => false,
'allow_rename' => false,
'allow_new_folder' => false,
'allow_new_file' => false,
'allow_duplicate' => false,
'allow_text_edit' => false,
'allow_zip' => false,
'allow_unzip' => false,
'allow_move' => false,
'allow_copy' => false,
'allow_download' => true,
'allow_mass_download' => false,
'allow_mass_copy_links' => false,
'allow_settings' => false,
'allow_check_updates' => true,
'allow_tests' => true,
'allow_tasks' => false,
'demo_mode' => false,
'upload_allowed_file_types' => '',
'upload_max_filesize' => 0,
'upload_exists' => 'increment',
'ffmpeg_path' => 'ffmpeg',
'imagemagick_path' => 'convert',
'imagemagick_image_types' => 'heif, heic, tiff, tif, psd, dng',
'use_google_docs_viewer' => false,
'lang_default' => 'fr',
'lang_auto' => true,
'index_cache' => false,
];