It's non ideal IMO, I like the current system where the only packets that can appear during normal demuxing is only frame, syncpoint, or main header. But still, my suggestion for just info packets is: all info packets with chapter_id >= 0 MUST appear at BOF (or maybe MUST appear after all copies of main headers), and chapter_id <0 carry no restrictions... I still preffer an info stream solution if possible... - ods15