Fully featured Ambisonic decoder implemented as a filter

Ambisonics is a full-sphere surround sound technique: in addition to the horizontal plane, it covers sound sources above and below the listener. FFmpeg as of now has no-support for decoding standard B-Format sound into any user-decided speaker configuration. The project would focus on implementing a fully-featured Ambisonic decoder, which decodes standard B-Format and converts it into the required speaker configuration. This would enable FFmpeg to decode Ambisonic files, right at the user-end and he/she will be able to create his/her own speaker configuration. This decoder would be implemented as a filter in FFmpeg/libavfilter.