Re: [rtcweb] m=section recycling and a=mid

Suhas Nandakumar <suhasietf@gmail.com> Thu, 19 September 2013 18:48 UTC

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Date: Thu, 19 Sep 2013 11:48:05 -0700
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From: Suhas Nandakumar <suhasietf@gmail.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
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Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] m=section recycling and a=mid
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Hello Christer

  Completely agree with you

My point with the above examples was

  "recycling of m=line should take into account its existing BUNDLE
membership and JS user's preference on requiring the added media track to
be BUNDLED or not"

This would imply, as suggested by you,

  - remove the mid from a=group:BUNDLE line if the JS user doesn't want the
new track to be BUNDLEd

 - or if the mid value is changed, then add the new mid value to the BUNDLE
group if the JS user want's the new track to be BUNDLED

- or just retain the mid value and its BUNDLE membership for the new track,
if it is going to be BUNDLEd


Cheers
Suhas







On Thu, Sep 19, 2013 at 9:24 AM, Christer Holmberg <
christer.holmberg@ericsson.com> wrote:

>  Hi Suhas,
>
>
>
> The mid attribute itself does not add an m- line to a BUNDLE group. The
> attribute value also needs to be listed in the group:BUNDLE attribute mid
> list.
>
>
>
> So, if you want to re-use an m- line and mid attribute, but you don't want
> the m- line to be in the BUNDLE group, simply remove the mid from the mid
> list.
>
>
>
> Regards,
>
>
>
> Christer
>
>
>  ------------------------------
> *From:* rtcweb-bounces@ietf.org [rtcweb-bounces@ietf.org] on behalf of
> Suhas Nandakumar [suhasietf@gmail.com]
> *Sent:* Wednesday, 18 September 2013 7:44 PM
> *To:* rtcweb@ietf.org
> *Subject:* [rtcweb] m=section recycling and a=mid
>
>   After thinking about it a bit, I think there are some side effects
> associated with changing/not changing mid attribute of a re-cycled m=
> section and it being part of a BUNDLE group or not..
>
>  example
>
>  say , we have these video m=section part of BUNDLE group as below
> a=group:BUNDLE 1, 2
>
>  m=video .....
> a=mid:1
> a=inactive
>
>  m=video .....
> a=mid:2
> a=sendrecv
>
>  Now If JS user adds a new video track and he wants it to be out of
> BUNDLE. If we recycle first video m=section and dont change mid attribute,
>  we end up BUNDLing even if the user dint want to
>
>  On the other hand, if we allowed mid value to be changed, we might end
> up UNBundling a video stream , when the user did want to BUNDLE them
>
>  So allowing a mid value to be changed or not should be tied to what the
> JS API is asking on behalf of the user
>
>
>  Any thoughts ?
>
>  Cheers
> Suhas
>
>
>