[Live-devel] Fwd: testMPEG2TransportStreamer support

[Ross Finlayson]

>In a first moment I'm using testMPEG2TransportStreamer at testProgs 
>folder and the transmission looks great at RTP protocol.
>
>I have 3 questions.
>
>- Is it possible to transmit over udp protocol ? After reading the 
>testMPEG2TransportStreamer code I didn't found nothing that mention 
>udp protocol. Is there another example program that does this task?

RTP *does* use the UDP protocol, by default.  I.e., RTP packets are 
sent as UDP packets (which, of course, are sent as IP packets).

However, are you asking instead if you can stream the Transport 
Stream data without using RTP - i.e., using raw UDP packets only? 
This is not recommended, because RTP/RTCP provides useful 
functionality.  In particular, it corrects for packets that get 
misordered over the network (because RTP contains a sequence number). 
Also, RTCP lets you monitor the stream's status (packet loss rates, 
etc).

However, if you *really* want to stream using raw UDP (the only real 
reason why you would want to do this is if you have a client - that 
you cannot change - that receives raw UDP only), then the way you can 
do this (in applications like "testMPEG2TransportStreamer") is to 
modify the application's code to use a "BasicUDPSink" instead of a 
"SimpleRTPSink".  You should also remove the code that creates a 
"RTCPInstance" (because RTCP is used only with RTP).


>- My machine has 4 ethernet devices (eth0, eth1, eth2 and eth3). How 
>can I select a specific device to use?

"testMPEG2TransportStreamer" (being a multicast streaming 
application) uses whatever network interface is configured with IP 
multicast routing - i.e., a route for 224.0.0/4 .  Therefore, if you 
want to use a different interface, you'll need to reconfigure your 
routes so that IP multicast is roufed on this new interface.


>- The output rate is defined by the PCR rate in a Transport Stream, 
>right? In case I have a ts with more than one PCR pid, which one is 
>choosen?

The PCRs from the first 'video' substream that's found within the 
Transport Stream.


>  Is there a way to set a fixed output rate?

No.
-- 

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