Speedhq Codecs For Mac

We want to add a new decoder to VLC. We have two plans:

Lagarith is a lossless video codec intended for editing and archiving. Lagarith offers better compression than codecs like Huffyuv, Alparysoft, and CorePNG. There are a few lossless codecs that can compress better than Lagarith, such as MSU and FFV1; however Lagarith tends to be faster than these codecs. Sep 17, 2016  As more software moves away from using the Apple QuickTime libraries, codec issues will probably get a bit worse before they get better. If someone makes a QuickTime codec that will mean that the target application will need to directly add support for it or that some media library package (like FFMPEG) has added support for it. Kane Peterson.

1. add new decoder to FFmpeg, then VLC load FFmpeg to decode with new decoder;
2. add new decoder to VLC (like theora decoder), then VLC load new decoder to decode directly.
Which one is better? And which one is less work?
If using plan 1, we have some questions:
When we compiling VLC, we download the dependence package, it concludes FFmpeg library. But only .h and .a file are in the library. There are no source code. We don't know which verison of FFmpeg VLC used. How do we get the source code of FFmpeg which VLC used?
If using plan 2, how do we add new decoder to VLC? As a decoder module like theora?
Thank you!