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Re: [webrtc-pc] Regarding "a=msid"

From: henbos via GitHub <sysbot+gh@w3.org>
Date: Fri, 12 Oct 2018 13:49:29 +0000
To: public-webrtc-logs@w3.org
Message-ID: <issue_comment.created-429332000-1539352168-sysbot+gh@w3.org>
We could remove it or we could allow duplicates. ("Do we know why duplicates aren't allowed?" I personally don't.)

> Why do we need MediaStreams and msid at all?

I was tempted to say no, but I'm curious if this is still useful in order to signal which track is which without mapping mids.

Track IDs are no longer guaranteed to match, but stream IDs are. Associating a track with a stream is a way to carry information about which track is which inside of the SDP, at the same point in time as you previously would have cared about track IDs.

Using MIDs on the other hand requires SLD/SRD to have been performed. With streams you'd know the ID right there in "ontrack".

I have heard developers confused and frustrated about not being able to rely on track IDs anymore. Though I don't understand why they have a problem with simply using the MIDs... someone was creating a bunch of dummy transceivers because they didn't know how many tracks would be carried in the answer but thought they needed the MIDs before that or something?

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Received on Friday, 12 October 2018 13:49:31 UTC

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