I could guess and say it's the tape and those are what you call dropouts or comets from tape aging. But to be sure, I'd try a little process of elimination to be sure it's not something else. Try connecting tape player output straight to a TV or to the capture device in
Virtualdub Preview mode (if possible, otherwise just make another capture), just to see if the dots are still there. If you have another camera, you could try that. If it truly is just on the Video8 tapes (which predated Hi8), and not the Hi8 tapes, I would suppose it's just the tapes are older and are starting to show signs of deterioration.
If you cannot remove these dropouts/comets from the capture, it looks like you can get rid of most of them in post processing in avisynth. I did a quick pass of this test.avi through RemoveDirtMC avisynth plugin, and got most of the dots to disappear using fairly conservative settings. There may be other ways to fix dropouts. This is just one that's been mentioned a lot in the forums over the last few years.
Code:
v=AVISource("test.avi",pixel_type="YUY2")
AssumeTFF(v)
AssumeFrameBased(v)
ConvertToYV12(interlaced=true)
SeparateFields()
e=SelectEven().RemoveDirtMC(30,false)
o=SelectOdd().RemoveDirtMC(30,false)
Interleave(e,o)
AssumeFieldBased()
Weave()
One sacrifice in this example is you have to convert from YUY2 (4:2:2) to YV12 (4:2:0) in order to use the plugins used by the RemoveDirtMC.avs file which would go in your Avisynth plugins folder. I think there's multiple forum posts out there with this script file. I found a 2018 post that referred to this link
http://www.digitalfaq.com/forum/atta...emovedirtmcavs You'd also need some other plugins that are used by RemoveDirtMC. Refer to this forum post.
http://www.digitalfaq.com/forum/vide...html#post53877 I think that's all you'd need to get the above script working. Maybe there's a more recent version of plugins that don't require down-converting to YV12. Haven't checked on that in a while. If not, I guess, at worst, you could do this at the very end of your video filtering chain after you've done everything else you can in YUY2. Although lossy formats (i.e. MPEG2) can support 4:2:2, a lot of the time they are encoded with 4:2:0 anyway. What's important is to do the more important color related filtering in
Virtualdub or avisynth in 4:2:2 before decimating the color info to 4:2:0.
Best of luck to you.