[Live-devel] RTP Marker bit (M bit)

[Ross Finlayson]

>The testMPEG2TransportStreamer sets the use of marker bit to False. Is
>there a specific reasoning for not using the marker bit? RFC2250 seems to
>indicate it could be set on all last frames, but doesn't mention TS files
>specifically from what I have understood.

Actualy, the RTP header fields for carrying MPEG Transport Streams 
are described in section 2.1 of RFC 2250:

	"M bit:  Set to 1 whenever the timestamp is discontinuous
           (such as might happen when a sender switches from one data
           source to another). This allows the receiver and any
           intervening RTP mixers or translators that are synchronizing
           to the flow to ignore the difference between this timestamp
           and any previous timestamp in their clock phase detectors."

However, we currently don't implement this - at either the sender or 
receiver end.  (When sending MPEG-Transport/RTP, we just leave the M 
bit at 0; when receiving MPEG-Transport/RTP, we don't look at the M 
bit at all.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/