community/plasma-videoplayer: can not play certain videos / missing codecs

Fairly simple problem: I am unable to play certain video files per default on plasma-videoplayer.

Description

plasma-videoplayer installs only a base set of gstreamer plugins (through its dependency qt5-qtmultimedia). This doesn't cover many codecs regularly encountered in the wild.

The test video file was obtained via youtube-dl from here. Obtaining some information about it via ffmpeg -i yields

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'God Save The Queen (Remastered 2011)-8_hOex6cSWc.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2020-01-22T03:55:16.000000Z
  Duration: 00:01:15.37, start: 0.000000, bitrate: 212 kb/s
  Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 360x360 [SAR 1:1 DAR 1:1], 114 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2020-01-22T03:55:16.000000Z
      handler_name    : ISO Media file produced by Google Inc. Created on: 01/21/2020.
      vendor_id       : [0][0][0][0]
  Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 95 kb/s (default)
    Metadata:
      creation_time   : 2020-01-22T03:55:16.000000Z
      handler_name    : ISO Media file produced by Google Inc. Created on: 01/21/2020.
      vendor_id       : [0][0][0][0]

Logs gathered through executing vplayer in the terminal:

• It first refuses to play it at all, producing

GStreamer; Unable to play - "file:///home/user/Videos/God Save The Queen (Remastered 2011)-8_hOex6cSWc.mp4"
   Warning: "No decoder available for type 'video/quicktime, variant=(string)iso'."
   Error: "Your GStreamer installation is missing a plug-in."
   Warning: "No decoder available for type 'video/quicktime, variant=(string)iso'."
   Error: "Your GStreamer installation is missing a plug-in."
   Warning: "No decoder available for type 'video/quicktime, variant=(string)iso'."
   Error: "Your GStreamer installation is missing a plug-in."
   file:///usr/lib/qt5/qml/org/kde/kirigami.2/private/ActionButton.qml:216:13: QML Timer: ToolTip must be attached to an Item
   Warning: "No decoder available for type 'video/quicktime, variant=(string)iso'."
   Error: "Your GStreamer installation is missing a plug-in."

• After installing gst-plugins-good it plays the audio but fails at the video showing

Warning: "No decoder available for type 'video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)2.1, profile=(string)constrained-baseline, codec_
   data=(buffer)0142c015ffe100196742c015da05c2fe597011000003000100000300320f162ea001000468ce3c80, width=(int)360, height=(int)360, framerate=(fraction)25/1, pixel-aspect-
   ratio=(fraction)1/1, chroma-format=(string)4:2:0, bit-depth-luma=(uint)8, bit-depth-chroma=(uint)8, parsed=(boolean)true'."

Latter thing can also be fixed through installing an additional package, gst-libav (as mentioned in this StackOverflow post).

Resolution approach

Note: I'm still fairly unfamiliar with APKBUILDs so maybe there are better solutions to this.

1. Include all most commonly used gstreamer plugins in the depends.
   I feel that this goes against the Alpine philosophy to only include a basic feature set and let the user decide - some users maybe only want to install certain codecs for use with plasma-videoplayer. OTOH, plasma-videoplayer seems like an application more designed for end users than someone dealing with very terse storage requirements.

2. A subpackage plasma-videoplayer-codecs which includes most commonly used gstreamer plugins.
   AFAIK, there doesn't exist an equivalent to optdepends from Arch's PKGBUILDs, right?

3. Don't do anything since most Alpine (and for this matter, pmOS users) probably know how to install their required gstreamer plugins anyway.

Notes

Here is how some other similar Alpine packages handle this general issue:

• lollypop seems to follow the same approach as plasma-videoplayer: it gets gst-plugins-base through an external dependency (py3-gst).
• parole ships gst-plugins-good in addition to gst-plugins-base.
• rhythmbox only installs gst-plugins-base per default.
• gnome-sound-recorder has gst-plugins-bad in its depends.
• totem (currently disabled) used to install gst-plugins-good.