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RE: How does MPE handle the last byte?



I am using SkyStream SMR24 and here's what it does:
If there is only one byte left, it will reset the PUSI to zero and insert FF
in the last byte
If there are two bytes left it will set the PUSI to 1 and the last byte to
3E (table ID)
Dor 

-----Original Message-----
From: Dr G Fairhurst [mailto:gorry@erg.abdn.ac.uk]
Sent: Thursday, August 21, 2003 1:44 PM
To: ip-dvb@erg.abdn.ac.uk
Subject: How does MPE handle the last byte?



Before we suggest a strategy for the new encapsulation formats, 
can someone tell me what happens in real implementations when MPE 
employs section packing (i.e. is allowed to start a new encapsulated
MPE packet following the rpeviosu in the same MPEG-2 TS Packet).

Problem case:

When TS Packet payload is nearly full... i.e. when
a SNDI (IP packet, etc) occupies all but the last byte of
the final MPEG-2 TS-Packet Payload, and there is another 
IP packet waiting to be sent.

What does the encapsulator do if this TS-Packet has no PUSI
set, since setting the PUSI flag implies that encapsulator
would also include a Payload start pointer in the first
position after the TS-Packet header. This pointer consumes
the last byte... leaving nothing for it to point at.

A picture:

+----------------------\\------------------+--+
|........................ \\ SNDU..........|XX|
+--------------------------\\--------------+--+

^
|
NO PUSI - and Hence no payload pointer here.


Gorry