How to convert a WAV file to a G729 format

I need to convert a WAV file to a G729 format and a G723 format. Somebody told me that it’s possible with Audicity, but I don’t know how to do it. Does somebody know?

If you install the FFMpeg software, Audacity will export G.726. That’s as close as I could get.


Where do I find the FFMpeg software?[b]ffdown[/b]

G.726 is a later implementation of ADPCM and nothing to do with G.729 which is the heavily patented CS-ACELP.

G.723 is an earlier 24/40 kbps ADPCM variant.

Audacity does not directly support either, only the earlier G.721 32 kbps ADPCM (which doesn’t require FFmpeg).

Even if you install the FFmpeg from Trebor’s link, it is unlikely to help used from the standard Audacity export menus because I suspect FFmpeg G.723 and G.729 support is recent. Their documentation says FFmpeg will encode “G.729 BIT” but I have no idea what that means unless they have reverse-engineered it to break the patents.

So in a nutshell you may be able to encode both G.723 and G.729 if you use FFmpeg standalone at the command-line (not using Audacity at all) but I suspect because of patents you may have to build FFmpeg from source to be able to get it to write G.729 files.

If you are still interested I suggest you ask on the ffmpeg-user list and they will tell you what you need to do build FFmpeg with G.723/9 write support (or if the latest binaries that others supply include this support) and what command-line syntax is needed.


Can you make it work? I think it’s one of those combinations that just exports an empty file. I tried leaving bit rate empty, and 32 kbps.