Dear readers, do proceed with caution on something like this. I suggest creating a system restore point before modifying the registry.

There are lots of threads on the Net from people trying to get mp3 to encode, but this definitely works. Actually this is not a Vegas fault, it occurs because the Registry does not point to the correct encoder file. I had been struggling to find an answer for a long time.

First, go to http://blog.komeil.com/2008/06/enabling-fraunhofer-mp3-codec-vista.html

There is a fix file which changes 2 registry entries.

Download but do not run it yet.

If you do not already have it, download and install the free Fraunhofer codec. Just do a Google search, there are lots of links.

Now look in Windows System32 folder (and Wow64 folder if running 64 bit).

If you have l3codecp.acm in the folder(s) then just run the fix file. (The ‘p’ at the end indicates the professional version).

If you only have l3codeca.acm (‘a’ indicates the non professional version) in the system folder(s), then do not despair. Windows Media Player 11 uses it. Do a search on your PC for l3codecp.acm. Once found copy it to the system folder(s) above, and run the fix file.

You should now be able to select mp3 as an audio encoding option in Vegas, and pick your audio preferences.

In case the fix file disappears here are instructions taken from the Blog for the Registry alterations:-
Registry Changes Required for the Activation of Fraunhofer IIS MPEG Layer-3 Codec (Professional)
1.In HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\drivers.desc remove the whole name and data for “C:\Windows\System32\l3codeca.acm”, then create a REG_SZ named “l3codecp.acm” with a value of “Fraunhofer IIS MPEG Layer-3 Codec (professional)”.
2.In HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32 change the value for “msacm.l3acm” from “C:\Windows\System32\l3codeca.acm” to “l3codecp.acm”.

Thanks!

so … I try to provide my own solution.

After some tests, finally it works ….

This solution is based on a slight modification of the file “LameACM.inf”, deleting and adding other needed files.

Steps to follow:

1) uninstall all the video codes installed on the machine (using the Control Panel).

2) deleting from your system32 folder this files (if they exist of course):
– LameACM.acm
– Lame_acm.xml
– L3codeca.acm
– L3codecp.acm.

3) reboot

4) install “lameACM-3.98″ that I modified (http://www.4shared.com/file/LlNhhX2l/gooood_lameACM-398__from_tunis.html) :
– Right click on “LameACM.inf” and “install”.
– Restart if necessary (if the program requires it).
– Double click on “l3codecp.reg and answere yes…yes.

5) reboot the machine.

6) end of installation

7) tries to use “lame mp3″ sony vegas 9.0

bye the error: “An error occurred When Opening the codec

you talk about the LAME ACM encoder?
So I tried it, however, I got the “An error occured when opening the codec” error box
why?????

thanks