The 1.1 version of MS-MPEG4v1 Codec for Mac is available as a free download on our website. The application lies within Audio & Video Tools, more precisely General. This free Mac app is a product of Henry Mason.
From the developer:
MS-MPEG4v1 Codec is a codec based almost exclusively on FFMpeg and DivOSX. You can find them at http://ffmpeg.sf.net/ and http://mpeg4.jamby.net/, respectively. This codec plays (flawlessly, as far as the developer knows) video encoded in the MS-MPEG4v1 codec.
You may want to check out more software for Mac, such as Ogg Vorbis Codec Help, codecity or TC Console, which might be similar to MS-MPEG4v1 Codec.