Export doesn't match preview

[Emrys100]

Hi. I've been editing clips together which look fine in the preview, but when I export I get really blocky distortion on several of the inserted clips for several seconds before they revert to normal. I've tried different frame rates and resolutions, and different formats but with the same outcome. I'm currently on version 13.5 free. Any ideas? Thanks.

[borate]

A few thoughts...

What are your PC's specs:  CPU/GPU/RAM?

Confirm that the PC video driver and Direct-X are current...   https://www.nchsoftware.com/videopad/kb/1772.html

Under OPTIONS | ADVANCED, in the GPU Processor section, click the caret and choose None (CPU Only). 

Report your results, please.

[Emrys100]

I'm on a Rizen 3 with AMD Vega8 and 14 GB ram, dx 12 and latest drivers. Have also tried the CPU option you mention. I've done plenty of similar edits before but never come across this. I was on the latest version of videopad but tried rolling back to no effect too. The odd things is, after 3 or 4 attempts the preview (right below) starts to show the distortion too. I've tried re-loading the source foortage (which is all from a single file with single aspect ratio and resolution) but when I do the original footage seems fine in the preview again, but still get the corruption (as left) on a number of transitions (but weirdly, not all of them) when I export (tried MP4, Mpeg, avi etc all with same result). Any thoughts very welcome.

edit - I tried to paste screenshots in to this but they vanish on posting

[borate]

Hints at an AMD compatibility issue.  Have you tested on another PC, if available?

Let's see the project or file, so it can be analyzed.  The process is easy, quick and can be done privately.  Just follow these steps...

•     Back up --- With your project on the timeline, click on MENU at the top-left.  Click FILE|BACK UP PROJECT FILES TO FOLDER.  Choose a folder and SELECT FOLDER.
•     Upload ---  Use a free server - Google Drive, MS OneDrive, etc.* - to upload the saved, numbered FOLDER.    Do NOT upload the individual VPJ or export file. 
•     Get link --- Get a public link.  If using Google Drive click GET SHAREABLE LINK. If necessary change "restricted" to "anyone with the link can view" 
•     Share ---     Click COPY LINK | DONE.  Paste that link here, or click the folder at the top-right of this forum to message it privately to me.  It won't be shared.

          *    Before uploading, right-click the folder, click PROPERTIES.  Look at the File Size to confirm that it's not too big for the free space on the server.

Similarly, links to images or video can be posted here.  Upload the file/s to a free server, such as Google Drive or MS OneDrive, get a shared (public) link, copy the link and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum.  When using Google Drive, if necessary change "restricted" to "anyone with link can view."

[Emrys100]

Thanks, sent by message. Update - tried on an Intel i5 and same issue on export sadly

 

[borate]

Thanks for sharing privately.

The VHS transfer was apparently bad, as the distortion is evident on the original files in several players.

Try again.

[Emrys100]

Will do, thanks