FRAME_TYPE_I       72 libavfilter/vf_codecview.c         CONST("if", "I-frames", FRAME_TYPE_I, "frame_type"),
FRAME_TYPE_I      250 libavfilter/vf_codecview.c             const int is_iframe = (s->frame_type & FRAME_TYPE_I) && frame->pict_type == AV_PICTURE_TYPE_I;