Not able to convert MS ADPCM to MP3

[Wanny]

I'm trying dbpowearmp to convert some ADPCM files to mp3. When the conversion is about to begin, I get this:

Error converting to mp3 (Lame), 'I:\test\00000057.wav' to 'I:\test\00000057.mp3'
   Error Cannot Create Wave Decoder (Microsoft ADPCM)?  [clWaveDecoder::PrepareToDecodeAudio]

I'm pretty sure the file is Microsoft ADPCM, since I can play it on Media Player Classic after setting the codec for MS ADPCM to libavcodec.
What should I do?

[Spoon]

Re: Not able to convert MS ADPCM to MP3

dBpoweramp uses the built in ACM codecs for decoding anything that is non standard wave, if you do not have the system decoder dBpoweramp will not decode it.

[Wanny]

Re: Not able to convert MS ADPCM to MP3

Well, I HAVE the ACM codec installed. I have the msadp32.acm file in C:\Windows\System32.

If I remove or rename it, instead of the above message it says this:

Error converting to mp3, 'I:\test\00000057.wav' to 'I:\test\00000057.mp3'
   Error Cannot Create Wave Decoder (ADPCM (ACM decoder not installed))?  [clWaveDecoder::PrepareToDecodeAudio]

[Spoon]

Re: Not able to convert MS ADPCM to MP3

Media Player classic should have automatically used it, I am guessing that libavcodec has a built in ADPCM decoder.

[Wanny]

Re: Not able to convert MS ADPCM to MP3

Sorry for the late answer.
I tried on my laptop (that has Windows 7) and I get the same problem. In this case, the decoder for MS ADPCM is disabled in the ffdshow audio configuration, so I suppose the files are being played with the system built-in decoder...
They play only in Windows Media Player and Media Player Classic, though. Not on Winamp, foobar2000 or iTunes.

Checking the file with MediaInfo, I get this information:

Format: ADPCM
Format settings, Endinanness: Little
Codec ID: 2

[Wanny]

Re: Not able to convert MS ADPCM to MP3

... help? :(