AOMedia AV1 Codec: av1/encoder Directory Reference

| AOMedia AV1 Codec

encoder Directory Reference

## Files
| aq_cyclicrefresh.h
| bitstream.h
| block.h
| encode_strategy.h
| Declares frame encoding functions.
| encoder.h
| Declares top-level encoder structures and functions.
| encodetxb.h
| firstpass.h
| gop_structure.h
| intra_mode_search.h
| Declares high level functions to search through intra modes.
| intra_mode_search_utils.h
| Defines utility functions used in intra mode search.
| lookahead.h
| Describes look ahead buffer operations.
| nonrd_opt.h
| palette.h
| Declares functions used in palette search.
| partition_search.h
| pass2_strategy.h
| pickcdef.h
| picklpf.h
| pickrst.h
| ratectrl.h
| rc_utils.h
| rdopt.h
| speed_features.h
| svc_layercontext.h
| temporal_filter.h
| tpl_model.h
| tx_search.h
| txb_rdopt.h
| var_based_part.h