Detailed codec attributes used in configuring a codec and in querying the capability of codec factories. Default attributes of any codecs could be queried using pjmedia_vid_codec_mgr_get_default_param() and modified using pjmedia_vid_codec_mgr_set_default_param().
Please note that codec parameter also contains SDP specific setting, dec_fmtp and enc_fmtp, which may need to be set appropriately based on the effective setting. See each codec documentation for more detail.