Aim of this package is to provide the best MS-MPEG4 codec/decompressor
available for MS-MPEG4 V3 and V2 compression and playback. It comes with the Windows Media Audio V2 codec enabled for use in AVI as well
which is newer than the one DivX 3.11alpha uses.
Installation Package (installation executable for Win95/98/ME/NT/2000/XP) (368kB)
Package (Rar archive for Win95/98/ME/NT/2000/XP) (654kB)
Execute the file to install, and click OK for the warning about missing
digital signature. The package can also be opened with WinRar.
Note: If DivX Audio remains installed after the installation, you should reboot and install again. This happens if you play AVI with DivX Audio prior to installation which often causes the codec to remain in memory until reboot.
9/12/2003: Upgraded MPG4c32.dll to 18.104.22.16827, MPG4ds32.ax to 22.214.171.12487, msadds32.ax to 126.96.36.19987, and msaud32.acm to 188.8.131.5287.
4/16/2001: Downgraded MPG4ds32.ax from 7.00.00.1958_Official to 4.1.00.3917_Hacked due to quality slider issues.
4/1/2001: Upgraded WMA codec (msaud32.acm) from 7.00.00.1954 to 7.00.00.1956. Now it should be truely newest, finally.
4/1/2001: All packages now supports NT/2000.
4/1/2001: Upgraded Windows Media Audio V1/V2 codec (msaud32.acm) from 4.1.00.3920_Hacked (aka DivX Audio) to 7.00.00.1954_Hacked, the newest version available from WMP7 Auto-Update. This WMA codec is newer than one DivX uses. Now all Microsoft codecs provided is the currently newest versions available.
3/31/2001: Replaced the default MPEG4 DirectShow decoder with MPG4ds32.ax_7.00.00.1958_Official (latest official release from Microsoft) It already allows the playback of V3 to begin with. I say start using V3 now and stop using V2 because this decoder is officially available from Microsoft. Also you can now tell anyone using DivX they are using such an outdated decoder ;-)
3/30/2001: Added Windows Media Audio (msaud32.acm, hacked) aka DivX Audio (DivXa32.acm). This allows the use of Windows Media Audio V1/V2 in AVIs without using DivX Audio. Installer will now remove DivX Audio since it uses the same ACM Format ID as WMA codec and is not needed. All of your existing AVIs with DivX Audio will play fine and will just be identified as Windows Media Audio V2. PCs without this codec pack but have DivX installed will play it as DivX Audio.
2/25/2001: Added AC3 DirectShow decoder to all packages.
2/22/2001: Added MPG4ds32.ax_7.00.00.1958_Official to Full Package as additional version.
It will install/register MPG4C32.dll, MPG4ds32.ax, msaud32.acm, and
msadds32.ax. Also it will rename MPG4DMOD.dll in your windows/system folder (winnt/system32 and winnt/system32/dllcache on NT/2000/XP) to MPG4DMOD.dll.bak as it interfares with MPG4ds32.ax decompressor which is superior.
It will remove DivX Audio (DivXa32.acm) since WMA which is installed will do all of its functions including playback all AVIs with DivX Audio. They will simply be identified as Windows Media Audio V2. This is due to the fact that DivX Audio uses the same Format ID as WMA but just assigns itself in higher priority. Simply choose Windows Media Audio V2 to encode in same format as DivX Audio. People without this codec pack will still be able to play it too if they have DivX Audio codec.
MPG4C32.dll (Microsoft MPEG-4 Video Codec)
MPEG4 Compressor/Decompressor 4.1.00.3920 (latest) patched to enable V3 compression/decompression with info obtained from http://www.moemoe.gr.jp/~anipeg/mpeg4.html
18:03:75 -> 18:03:EB
18:03:75 -> 18:03:EB
CRC(3920) [AD29] -> [2FF1]
MS-MPEG4 V3 3920 is identical to DiVX Low Motion. Beside the enabled V3 compression, there are no other changes/hacks from the official Microsoft release. V1/V2 video created with this codec is identical to the official release.
Microsoft official release. Use this version if you wish to stay Microsoft compliant and only need MPEG4 V2. This is fully supported and is the latest version by Microsoft.
This is an old favorite. It is an official release from Microsoft with support for MPEG4 V3. However, it is extremely old and is not recommended unless you need to be Microsoft compliant and need to use V3. Use V2 with official 3920 if you just want to play safe.
MPG4ds32.ax (Microsoft MPEG-4 Video Decompressor)
mpg4ds32.ax is a DirectShow MPEG4 decompressor filter used with most video players such as WMP. With the MPG4c32.dll compressor/decompressor, it is not required for playback of MPEG4 files. However, it provides much improved playback quality and options during playback
This is 4.1.00.3917 decompressor with hacks to enable playback capability of MPEG4 V3 and quality slider. This decompressor have the same feature as that of DivX decompressor, DIVX_c32.ax.
The latest decompressor which comes with WMP7 Auto-update. For this version, Microsoft has re-enabled the playback capability of MPEG4 V3 which previously has been locked. One problem (or mystery rather) still remaining with this decompressor is that it does not have the quality slider enabled for large resolutions.
This decompressor is 100% supported and is the latest version by Microsoft with capability to play MPEG4 V3.
Also of note is the expanded list of FourCC codes that are contained in the file. Along with old MP32 (MS-MPEG4 V2) and MP43 (MS-MPEG4 V3), there is WMV1, which indicates to me that it may be possible to unlock the capability to play WMV8 files within AVI. Since WMV is a subset of ASF (basically a rename), it may work the same way.
Previous official release. Also have V3 playback unlocked.
The official 4.1.00.3917 is also included for reference straight off of Windows 2000 SP1 CD. This will not play MS MPEG4 V3 nor have quality slider enabled. Currently Windows 2000 CD is the only source for this decompressor since Microsoft has put the old version for auto-download where this version used to be.
msaud32.acm (Windows Media Audio)
msaud32.acm is ACM compressor/decompressor for Windows Media Audio V1 and V2 audio compression. Windows Media Audio V2 is same as DivX Audio, right down to ACM Format ID. This means that with this codec, DivX Audio codec is never needed. I guess we should thank DivX for not hacking it far enough to create its own format ID which'll make it tough to replace it, like with DivX video. DivX Audio simply placed itself in higher priority than official WMA codec so that whenever AVIs with WMA audio is played back, it was used to decode it instead. When encoding, it worked exactly the same as official WMA codec except it was allowed to do so in AVIs with a minor hex edit hack.
Newest version of Windows Media Audio V1/V2 codec available from Microsoft with minor hack (4 bytes) to enable encoding/playback in AVIs.
The official codec the hacked one above is based on. This will not play nor compress WMA in AVI.
Hacked version of old WMA codec. Same version and feature as the one DivX uses.
The official codec that hacked version above and the DivX Audio is based on. Comparing this to DivX Audio, you can see there was very little hack was done except name changes.
MPG4DMOD.dll (Windows Media MPEG-4 Video Decoder DMO for Windows Media Services)
I'm not sure what this is used for, but it will interfare with MPG4ds32.ax decompressor if you have this in your windows/system folder and will cause MS MPEG4 V1/V2/V3 video to be played back in lesser quality. This is another major contributer to why many sees DivX playing back better than MS-MPEG4. The installer will automatically rename this to MPG4DMOD.dll.bak to take care of the problem. On NT/2000, you may need to do little more work than that to remove this, as it keeps copies of dlls for backup. Do find on your winnt dir and remove all of them.