Here are the data structures with brief descriptions:

Cdaala_comment	The comment information
Cdaala_info	Configuration parameters for a codec instance
Cdaala_plane_info	Subsampling factors for a plane as a power of 2
Cod_accounting
Cod_accounting_dict	Dictionary for translating strings into id
Cod_acct_symbol
Cod_img	Representation of an image or video frame
Cod_img_plane	Representation of a single component within an image or frame