Just some more troubleshooting today.
I reinstalled WinXP on a fresh (SD) drive and threw in my AIW 128 Pro AGP card (swapping out the AIW Radeon 9000), reinstalled all new drivers from these forums (other than the main video drivers, which are on the AMD website legacy section
... and it worked. No stuttering / extra frames etc So I'll put the issue down to a driver (capture? video? TBD) issue, so I can now experiment with the Radeon 9000 again.
Worst case I just stick with the AIW 126 Pro
-- merged --
Just a final note on this one.
I re-installed my AIW Radeon 9000
card along with fresh WinXP SP base install, but instead of my original convoluted driver installation
, I just used the drivers from the AMD site
ie Catalyst Software Suite 6.11
just the Display Driver
and WDM drivers.
(Catalyst Control Center failed - I don't need it anyway).
package (Windows Media Encoder 9, DAO/MDAC.
I dont use MMC, so I didnt bother messing with an install attempt.
No more stuttering issue!
Looking at some of my original test captures from a month ago, I have a feeling the original issue is something to do with the field order getting messed up somewhere in the capture eg video is playing BFF, but codec is capturing as TFF, then I'm trying to play / post process BFF. Just a theory
Just an aside; After solving the stutter, I thought I had introduced an audio sync problem ie 50fps YUV2 playback in vdub will drift out of sync pretty fast, but plays fine if I ConvertToYV12
(rather than keep it in YUV2) or keep it at 25fps. Turned out it's just vdub's playback. The video would save fine
I have to read up on more colorspace stuff anyway.