I can’t see a good business reason in 2006 to encode to WMV7 and ACELP audio.
Windows Media Player 7.1 on the PC can play WMV9 files. There’s a free component update that doesn’t require an update to the player version itself. I have an old Windows Media 98 box (PRE 98SE) that I’ve used for backwards compatibility testing. Mind you, we’re talking about an EIGHT YEAR OLD OS! That said, Cleaner 6 (and earlier) and 6.5 can create WMV7.
IMHO using WMV7 instead of WMV9 at the lower data rates requested by your client compounds the problem. It will look much worse as WMV7 then WMV9.
ACELP has been replaced by Windows Media Voice. I don’t know of a way to create WMA Voice on the Mac but certainly you can do a low data rate audio encode using Windows Media Audio Standard but, yes, it’s not quite as efficient as WMA Voice.
Although I do most of my compression on the Mac, I just took a look at my Windows XP box with Microsoft Windows Media Encoder. While it can do WMV7, even it does not have ACELP. It does have WMA Voice though.
As a professional compressionist I’d consider having a meeting with your client to discuss their target viewer and how best to hit that target. Do they have to target people with Windows 95 and WMP 6.4? I’d suspect that market can’t be much more that 1% at this point. I supect targeting a market that hasn’t updated their computers in 8-11 years and is still using dial-up, isn’t signs of a good business plan. Even older computers internal to a business should have moved beyond that. Worse still is they’re basing all three of their data rates on WMV7. Even if your client is serving and economically restricted community, those people will likely find better internet service at a public library.
Your client may have no idea what current compression standards are so I’d suggest a meeting is in order.