[MPlayer-dev-eng] Doubt regarding parsing of MPEG2 macroblocks

[Chandra Raghavan]

Hi:
I'm trying to design a selective FEC system for transmission of MPEG2
video streams over the internet (I'm using the live.com liveMedia
library). To decided whether I need to send an FEC packet for a given
RTP packet, I need to know which macroblocks of a particular frame the
packet is carrying.

So, I need to go through every macroblock examining its location, i.e.
check its address increment alone and skip to the next mb. However, I
realized that with multiple variable length codes, it is not easy to
skip to the next macroblock after extracting the address increment.

Is there an easier way to do this than to go through all the variable
length codes until the "eob" is reached? Is there an MPlayer source
file that I can use as template to do this parsing? Thank you very
much for your help! If I've posted on the wrong mailing list, I would
appreciate it if you could direct me to the right one.
-- 
   _ /\ _      Chandrashekar
   \ oo /      National University of Singapore
   /_  _\      Computer Engineering 
      \/         Class of 2005