avdec_wmalossless: Add support for 24-bit format
Submitted by Olivier Crête
The upstream ffmpeg now fully supports 24-bit PCM output for WMA Lossless, not only 16 bit.
The problem is that when getting data in this mode, it produces one valid output frame for 3 input frames. I'm attaching a patch that makes it work, but I'm totally unsure if it does the right thing.
Here is a test file: http://people.freedesktop.org/~tester/45s-96khz-24bit-51ch-lossless.wma