Incorrect available bitrate selections?

2006-03-23 01:59:21

I've a problem with available bitrate selections in Cdex and other apps.
I normally use the LAME encoder in Cdex but if I choose windows fraunhofer mp3 encoder or another encoder, the bitrate selections are just plain weird and look completely screwy.
The same thing occurs if I'm video editing with virtualdub and wish to compress the soundtrack to some other format.

I'd expect the maximum bitrate to be 320kbps but the highest available is usually listed as 56kbps.
For example, the fraunhofer mp3 bitrange available in Cdex is
56kbps, 22050Hz
48kbps, 22050Hz
40kbps, 22050Hz
32kbps, 11025Hz
24kbps, 11025Hz
20kbps, 11025Hz
18kbps, 11025Hz
.....etc.

It's a similar problem in virtualdub.
I've also found the same problem with my TVcard in my notebook and not just with mp3 format - other audio formats seem to be affected in a similar way.  It's as though the available bitrates are listed as having been divided by 6 or 8 or something.
For example if I look at the properties of divx movie, the audio bitrate is listed as 24kbps even though it's been encoded at 192kbps.
The only app that seems to show a correct selection of bitrates for mp3 and wma is windows media player but I never use that for encoding.

I'm sure I was able to select much higher and correct bitrates before but I'm stumped as to what's altered these bitrate listing selections.  It's the same on my Win2k desktop, with wmp9 and WinXP notebook with wmp10.

Anyone come across this before and is there some registry hack or other cure to fix things?

Incorrect available bitrate selections?

Reply #1 – 2006-03-23 06:27:49

By default Microsoft has hidden the higher bitrate options that came available inside WMP10 from common ACM choices.

You can find a registry tweak in this thread: http://www.hydrogenaudio.org/forums/index....showtopic=26956

EDIT

That was for the Fraunhofer MP3 encoder included in WMP10.

You may want to install the LAME ACM codec too. It is included in the LAME 3.97b2 bundle that is available at Rarewares. After unzipping right-click > install the LameACM.inf file.

Incorrect available bitrate selections?

Reply #2 – 2006-03-23 08:26:24

Thanks for confirming I was on the right track.
I've been up all night googling for info and all my searching led me back to here.

That registry hack did the trick but I missed out the line
"msacm.l3codec" = l3codecp.acm" as it had the effect of creating 2 entries for the fraunhofer pro codec in the audio codecs list in audio hardware property page - also the MS PCM codec was overwritten in the list with the second entry.  It also created 2 identical MPEG-Layer-3 entries in the 'select audio compression' dialogue in virtualdub.

Everything seems to be working correctly so I don't see the need to add that string value in the registry.

The only odd thing left to solve now is the TVcard's mp3 bitrate listings are all listed as '0 bit stereo' or '0 bit mono'  instead of 16bit or 8bit but the sample rates and kbps rates are all there but the kbps rates are showing as 5-8kbps less than what they really are - eg.  256kbps is listed as 250kbps and 320kbps is listed as 312kbps.
I'm thinking now that this might be a bug in the TVcard's software (AverMedia) but I can live with it because test recordings are at the correct bitrate.

Now I have to re-install all my apps again after restoring an earlier image which now I find I needn't have done.