I found this post https://www.moviecodec.com/audio-codecs ... 50-109206/
It seems to be the Micronas SC4 codec. I downloaded the .acm file, installed it, and didn't have any luck.
It came with a sample .WAV file which does appear to be similar to my file, and it opens in Audacity with the same very poor quality as my two files with custom settings in the raw data import.
I tried a couple things including downloading MPlayer, which seems to let you easily load .acm codecs, but that also didn't work. The link above had a codecs.conf file which is similar to what Mplayer uses.
I think the only sign of hope right now is that I can't play the sample .wav file that came with the codec, which means there is probably some way to get the codec working? Anyone know much about loading really old .acm files into some player? Being a total noob in audio related things the only next step I can think of is standing up an older system like a Win XP VM and trying there...
Here are the MPlayer failure results
C:\Users\Mitch\Downloads\mplayer-svn-38117>mplayer.exe -ao pcm MI-SC4_example.wav
MPlayer Redxii-SVN-r38117-6.2.0 (i686) (C) 2000-2018 MPlayer Team
Using FFmpeg N-92461-gd3621b2321 (2018-11-17 18:06:58 +0100)
Compiled on 2018-11-17 20:04:15 EST (rev. 1)
Playing MI-SC4_example.wav.
libavformat version 58.22.100 (internal)
Audio only file format detected.
Load subtitles in ./
Load subtitles in C:/Users/Mitch/Downloads/mplayer-svn-38117/mplayer/sub/
==========================================================================
Opening audio decoder: [acm] Win32/ACM decoders
Loading codec DLL: 'mi-sc4.acm'
MPlayer interrupted by signal 11 in module: init_audio_codec
- MPlayer crashed by bad usage of CPU/FPU/RAM.
Help recovering PCM audio!
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Please state which version of Windows you are using,
and the exact three-section version number of Audacity from "Help menu > About Audacity".
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This forum is for Audacity on Windows.Please state which version of Windows you are using,
and the exact three-section version number of Audacity from "Help menu > About Audacity".
Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at https://www.audacityteam.org/download/.
The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.
Re: Help recovering PCM audio!
I assume these are spoken word files? (I'm assuming that because the bitrate sort-of implies "telephone quality".)with the same very poor quality as my two files with custom settings in the raw data import.
If it is voice and you can understand what's being said a "typed" transcript might be your best option.