Question about TC functionality

Good morning,

I am writing software that implements DPI to shape traffic flow. I have already done packet sniffing and recognition (e.g. ICMP, Skype, HTTP, etc). However I would like to implement HTB for just those packets that I select, so I can "slow" or "speed" them up. I know that tc can do that, but I can't find how to do that basing on packets.

Kind Regards,
Tomasz