PapaSmurf, I did your suggested test, but instead of using FFMPEG/Xvid to do the output, I used the “AVI codec” option and specified Xvid as the codec. That let me confirm that the Xvid version being used is correct – 1.2.2 – since FFMPEG gives you no codec configuration/info options.
VDub plays the silent .avi made with this option just fine.
Made new output with same input, using FFMPEG/Xvid, also silent (no muxing) – VDub won’t play it, says it needs a VFW-compatible codec.
Tried other forms of input source in the VSE (image sequence, etc.), same results. Only the FFMPEG/Xvid combination fails in VDub. This is on the Vista machine. On my XP machine they worked fine.
I dug into the system files and found that the .dll’s for Xvid are the same for both machines, just different versions according to the file dates, as expected. And there are no other xvid files laying about to screw things up. (Hmm…“Xvid files”… sounds familiar… Scully? You there?) The two files are xvidcore.dll and xvidvfw.dll – the latter seems to the the VFW library that VDub says it needs, but maybe FFMPEG isn’t using it properly. With the “AVI codec” option that does work OK, the “About” box in Blender’s codec config dialog identifies xvidcore.dll, but how these libs are linked together when used is Geek to me.
Bottom line seems to be that FFMPEG with the Xvid codec in 2.49b acts differently under XP than under Vista, since all other ways of using Xvid seem to work OK.
Since I have DivX on the Vista machine (an MPEG-4 codec like Xvid), it could be taking over in other players (I know it does in WMP, not sure about VLC) to play the FFMPEG-generated .avi’s. VDub won’t do that because DivX isn’t a VFW codec afaik.
Could be that something in the newer Xvid version is not playing as well with FFMPEG as it used to, but I don’t really want to hassle with testing the old version on my Vista machine.
The biggest hit all this is delivering to my workflow is not great, mostly convenience. I used the FFMPEG muxed output to review all my editing of both playblast and final renderings, the WIP parts. For final-final output I’ll be outputting PNGs from the VSE and muxing in VDub because it invariably results in smaller files sizes. But doing that for every intermediate test of the editing cuts is a lot more time consuming.
Does this new info raise any new ideas among the videophiles?
EDIT: Yet another test with confusing results:
Back on my old XP machine I found I could burn FFMPEG/Xvid .avi movies to CD-RW and after d/l’ing a patch, play them on my Xbox.
My Xbox will NOT play a .avi movie muxed with VDub on my Vista machine – says it doesn’t have the proper codec. It WILL play a .avi file muxed using FFMPEG w/Xvid. Same source material for both versions.
Obviously, FFMPEG is NOT using the same Xvid version as VDub, nor even the same as used by the “AVI codec” option in Blender.
So where is FFMPEG getting its Xvid codec from? It can’t be the one I installed on my system. Does the FFMPEG code in Blender have its own set of codec libs, separate from what everything else uses? That seems to be the case.
I may have to revert to my older Xvid version for system use if I want VDub to be able to play FFMPEG output, since that setup seems compatible.