MP42 Decompressor for VirtualDub

posted in Video Codecs
Page 1 of 21

I’m trying to edit .avi video file using VirtualDub, but everytime I try to load the file, I get message “Cannot locate decompressor for format MP42..."
I checked various places and installed alot of codecs I found but still not working. I installed codecs I found on Microsoft website, FFDshow, Divx, mpeg4x, all-in-one pack, etc etc.
Does anyone know exactly what I should install?
I’m using Windows XP.

thanks. reply

I had the same problem. A quick Google search cam up with this website

I installed downloaded and installed the codec headed “nAVI video codec - vids:nAVI, MP4, MP42, MP43 decompressors”.

And VirtualDub now works fine, as does Boilsoft AVI joiner

Hope this helps someone reply

6 people found this useful

Thanks, the nAVI codec solved my problem perfectly, thanks! reply


I want to decode MP42 compressed .avi files and extract each frames using C++. Any pointers?
Thanks. reply


worked perfek


p reply


The russian site with the nAVI codec contains spyware... reply


If anyone else is having trouble with MP42 MPG4 or MP43 in VirtualDub: the newer versions of the decoders released by Microsoft are DirectShow-only. has an older version that is VfW-compatible. If you get a warning about overwriting an older version or lack of digital signature (the old versions didn’t have them I don’t think), just click continue. reply


Warner wrote:
The russian site with the nAVI codec contains spyware...

Hi Warner

Works for me.

I cannot find spyware code with Etheral, Mcafee, Adaware or looking in the file!
Why do you assume this? reply


You can also get the nAVI codec @ under “Mpeg4 Codec - FOURCC: nAVI” (I found it to be a lot less confusing than the Russian site). reply


The last listed nAVI file here is the same as the first and neither work for me. Another site listed here has sql server problems, but I’m sure its pkg is no different. I tried installing them both “active” and normal. Sherlock says I have it already, but neither VirtualDub nor Video Inspector can find it. I tried re-booting too. reply


Remembering that I tried the pkg from only as an active install, I tried one more time as only “install” and this time it worked, and VD opened the files. I converted some flv’s with Media Converter SA Edition using default settings and it made them mp42 which play fine in WMP, etc but I wanted to join them. reply


Just to confirm that the codec obtained from
solved my V Dub MP42 problem. Saved me risking a Russian site ;-) Thanks... reply


Had this same problem with latest 64bit v. of Vdub.
was about to go install all these codecs/etc. but just re-booted my machine instead. That did not help.
However, VirtualDub V. 1.9.4 will open all my mpeg4 and other formats just fine. Only Vdub V.1.9.8 64bit will NOT open them.

No idea why... but just to let you know you may not need to go visiting iffy sites.
Also, you can try downloading the mpeg4 pack here as well:
It appears more reputable, but I did not install it, so can not vouch for it. reply


If you’re using the old MS MPEG-4 codecs, use them with the 32-bit version of VirtualDub (yes, 32-bit VirtualDub works fine with 64-bit Windows).
If you’re using 64-bit VirtualDub, you need 64-bit VfW decoders. ATM the only one for MP42 I know of is bundled in the 64-bit version of ffdshow-tryouts. It’s still experimental.
Of course, check the VfW box during setup. To minimize the chances of problems, I’d suggest disabling the decoding of all other codecs (during install there’s a box that lets you choose which codecs ffdshow should decode - uncheck them all). When you’re done, find ffdshow in your start menu and run the vfw configuration (or do it from the box at the end of setup). go to the DEcoder tab. Under MP42, set it to libavcodec. remember to click apply. reply


Thanks dude it works !! reply


Thanks Anonymous - the ffdshow thing worked for me too! reply


TNX man works perfectly reply


KYAHHHHHHHHH! Thank youuuuuuuuu!!!!!! It has really fixed my problem!!!!!!!! Thanks!!!!!!!!!!!!!!! reply


install (any video converter)

try it and see reply


When I click on to download the decompressor (below the line:

“nAVI video codec - vids:nAVI, MP4, MP42, MP43 decompressors”

I come to a site with nothing on it...



Page 1 of 21

Post Your Answer

Your reply
Your name

or log in
Verify you're human

By submitting this form you agree to our posting rules,
privacy policy and our disclaimer.