[FFmpeg-user] ADPCM block size for XAudio

[Martin Wahnschaffe]

> Can't you install msys and test yourself?
>

I expected there would be problems, so I tried to avoid it. I'm giving it a
try now.

Using this guide: https://trac.ffmpeg.org/wiki/CompilationGuide/MinGW (with
mingw-get-setup).

master branch, commit 4f6b34f1f803a103f321330bc5f9e4a01f788925

- Configure failed with "nasm/yasm not found or too old", so I used
"./configure --disable-x86asm".
- Received the "WARNING: pkg-config not found, library detection may fail."
- make failed with "ffbuild/common.mak:174: *** missing separator. Stop."