Re: [MMUSIC] Scope of RTP payload types in BUNDLE?

Paul Kyzivat <> Mon, 27 May 2013 19:14 UTC

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Date: Mon, 27 May 2013 15:13:52 -0400
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Subject: Re: [MMUSIC] Scope of RTP payload types in BUNDLE?
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On 5/27/13 2:52 PM, Colin Perkins wrote:

>>>> In the example above the same payload format, within the same RTP session, is used in two separate m- lines. But, I still can't use the same PT value for both m- lines, even if the payload format is the same, can I?
>>> Why not? I don't see any problem mapping the same payload type to the exact same payload format in two different m= lines.
>> But, when I receive media with that payload format, how do I know to which m- line it "belongs", as the same PT value is used for both m- lines?
> You don't. If you care about that, you need to either use distinct PT values for each m= line, or signal SSRCs.

I assert that if you don't care about associating a packet to a 
particular m-line in a bundle that you don't need to use bundle.

So if you used bundle, you must care, and so there must be a way to 
achieve that association.

The reason you care is because doing so allows you to discover all the 
other things in that media section of the SDP that may be pertinent to 
this packet.