Bug#967941: nautilus: fails to generate thumbnails for h264 encoded video files

[fred]

Package: nautilus
Version: 3.36.3-1
Severity: normal
X-Debbugs-Cc: contact at 666hellfire.club

Dear Maintainer,

Nautilus fails to generate thumbnails for certain video files (h264 encoded
video stream).

Fresh Debian testing (Gnome) installed today. Steps to reproduce :

(sudo apt install youtube-dl)

Using youtube-dl to download some short clips (Nature/scenery samples) :

$ youtube-dl https://www.youtube.com/watch?v=LTvFsTbyILg

webm container, VP9 video encoded : thumbnail will be generated OK


$ youtube-dl https://www.youtube.com/watch?v=l7GX_XII2K0

mkv container, h264 video encoded : thumbnail will not be generated



Both files will play fine with Totem media player


Producing a thumbnail using totem-video-thumbnailer :

$ totem-video-thumbnailer Beautiful\ Nature\ 1080p.-l7GX_XII2K0.mkv Beautiful\
Nature\ 1080p.-l7GX_XII2K0.mkv.png

will produce a thumbnail fine! But not nautilus.




-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 5.7.0-2-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages nautilus depends on:
ii  bubblewrap                      0.4.1-1
ii  desktop-file-utils              0.26-1
ii  gsettings-desktop-schemas       3.36.1-1
ii  gvfs                            1.44.1-1
ii  libatk1.0-0                     2.36.0-2
ii  libc6                           2.31-2
ii  libcairo-gobject2               1.16.0-4
ii  libcairo2                       1.16.0-4
ii  libgdk-pixbuf2.0-0              2.40.0+dfsg-5
ii  libgexiv2-2                     0.12.1-1
ii  libglib2.0-0                    2.64.4-1
ii  libglib2.0-data                 2.64.4-1
ii  libgnome-autoar-0-0             0.2.4-2
ii  libgnome-desktop-3-19           3.36.4-1
ii  libgstreamer-plugins-base1.0-0  1.16.2-4
ii  libgstreamer1.0-0               1.16.2-2
ii  libgtk-3-0                      3.24.20-1
ii  libnautilus-extension1a         3.36.3-1
ii  libpango-1.0-0                  1.44.7-4
ii  libpangocairo-1.0-0             1.44.7-4
ii  libselinux1                     3.1-2
ii  libtracker-sparql-2.0-0         2.3.4-1+b1
ii  nautilus-data                   3.36.3-1
ii  shared-mime-info                1.15-1
ii  tracker                         2.3.4-1+b1
ii  tracker-extract                 2.3.3-2+b1
ii  tracker-miner-fs                2.3.3-2+b1

Versions of packages nautilus recommends:
ii  gnome-sushi      3.34.0-2
ii  gvfs-backends    1.44.1-1
ii  librsvg2-common  2.48.7-1

Versions of packages nautilus suggests:
ii  eog                         3.36.3-1
ii  evince [pdf-viewer]         3.36.7-1
ii  nautilus-extension-brasero  3.12.2-6
ii  nautilus-sendto             3.8.6-3
ii  totem                       3.34.1-2+b1
ii  xdg-user-dirs               0.17-2

-- no debconf information