Plugin Config
Go to Settings / Preferences / Viewer / Plugins and configure the Video & Audio (Opus 13) or Movie (Opus 12) plugin.
Make sure it includes the extension you are trying to play in its list.
Codecs
If videos aren't playing, a codec is probably needed. Any you're likely to need are listed below.
All are free, except where noted.
There are two main codec types:
1. Codecs provided by Microsoft
Directory Opus 13 (or above) is required to use these.
These are delivered via the Microsoft Store, and also enable playback in other software that uses the newer Windows video APIs (e.g. the Windows 10 & 11 Films & TV app).
Installing all of them is easiest, choosing the most appropriate of the two HEVC options. But, if you want to be selective, the Movies > Video Codec and Audio Codec columns may tell you what a particular file needs.
- AV1 Video Extension
- HEVC Video Extensions from the Device Manufacturer (Not always available.)
- HEVC Video Extensions (If above not available. Costs $1.)
- MPEG-2 Video Extension
- VP9 Video Extensions
- Web Media Extensions (Includes several video and audio codecs.)
- JPEG XL Image Extension (for images not video)
2. DirectShow Codecs
Alternatively, DirectShow codecs can be used in all versions of Opus:
- LAV Filters (Handles virtually anything.)
- There are many other DirectShow codecs out there, if your video needs something really esoteric.
- 64-bit codecs are required. (32-bit codecs will not work with Opus's normal video player.)
Alternative movie playback plugins
Directory Opus 13 has a new video player, which we recommend sticking with if you're on that version (or later).
If you're on Directory Opus 12 (or earlier), and the DirectShow codec suggested above hasn't fixed things, it may be easier to switch from the default Movie plugin to an alternative.
For something to work in the viewer pane (rather than as a separate application/window), it must provide a Preview Handler, an ActiveX control, or an Opus-specific plugin.
Disabling the Movie plugin may be enough to get playback to happen via something else. This is done via Settings / Preferences / Viewer / Plugins. (Note that this will also disable some of the metadata columns which the Movie plugin provides. The Opus 13 movie plugin allows you to separately configure playback and metadata, but the Opus 12 one doesn't.)
If you don't get the results you want after disabling the Movie plugin, configure the ActiveX + Preview + Office + Web plugin to tell it to use something else for the appropriate file extension. The ActiveX + Preview + Office + Web plugin acts as a bridge between Opus and other types of components which can display files.