libavcodec: How do I use AVOptions to set up encoder parameters?

libavcodec seems to have 3 ways to specify parameters for a codec:

• Certain members of the AVCodecContext struct
• values in an AVDictionary passed to avcodec_open2
• AVOptions, which seem to cover everything the other two do

Can I use AVOptions to setup all of the encoding parameters? In addition, can AVOptions provide sensible defaults? Google doesn't yield any results and there's no example provided in the documentation.

Sure. Look at the examples of av_opt_* calls in doc/examples. For defaults, call av_opt_set_defaults