Install video extensions on Windows
If an imported video has a blank preview, plays sound without a picture, or cannot play, Windows may be missing its decoder. Check the video codec named in the dialog, then follow these steps.
Install the matching extension
- Find the codec in the table and open its Microsoft Store page. You can also use the dialog's Store-search button.
- Check the extension name, publisher, device compatibility, and current price, then select Get or Buy.
- After installation, quit ClipSeek completely, reopen it, and try the same video.
| Codec in the dialog | Official extension |
|---|---|
| HEVC / H.265 | HEVC Video Extensions |
| AV1 | AV1 Video Extension |
| MPEG-1 / MPEG-2 | MPEG-2 Video Extension |
| VP9 | VP9 Video Extensions |
HEVC may require payment. Check the Store page for the current price and compatibility.
Check the codec, not just the filename
Extensions such as .mp4, .mov, and .mkv identify containers, which can hold different codecs. Importing a file or creating its thumbnail does not guarantee direct playback in Windows.
If the dialog says H.264 / AVC
Test the original in a Windows system player first. Do not install AVC Encoder Video Extension just because the name looks relevant: it mainly provides encoding and is not guaranteed to fix H.264 playback.
If playback still fails
- Test the same original file in the system player.
- If it also fails there, check that the file is complete and that its codec is compatible with the system.
- If only ClipSeek fails, or the extension will not install, contact support with the ClipSeek version, Windows version, codec, and exact message.
Extensions solve only some decoding problems. Damaged files, container or codec settings, and player limitations can also cause failures. You do not need to send private media when reporting an issue.
If Microsoft Store is unavailable: third-party installation
Microsoft Store is the preferred source. If you need a third-party distributor such as Uptodown, review the files on these product pages:
- HEVC Video Extensions from Device Manufacturer
- AV1 Video Extension
- MPEG-2 Video Extension
- VP9 Video Extensions
Check the publisher, Windows version, and architecture before downloading. Open .appxbundle or .appx packages with Windows App Installer. If Windows reports missing dependencies, an unsupported device, or incompatibility, review the requirements before trying another package.
The HEVC manufacturer edition is a different listing from the Store extension and may have different installation conditions. A free or newer package is not necessarily suitable for your device; follow its current listing and the Windows installation result.