Re: [payload] temporal scalability in draft-ietf-payload-vp8-09.txt

Bernard Aboba <bernard_aboba@hotmail.com> Fri, 06 December 2013 03:19 UTC

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From: Bernard Aboba <bernard_aboba@hotmail.com>
To: payload@ietf.org
Date: Thu, 05 Dec 2013 19:19:25 -0800
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Subject: Re: [payload] temporal scalability in draft-ietf-payload-vp8-09.txt
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Section 1 states: 

 

   In summary, the payload format described in this document enables a

   number of features in VP8, including:

 

*        Temporal scalability.

 

However, Section 6 doesn't include information on format parameters or O/A
considerations relating to temporal scaling. 

 

It appears that VP8 transports all temporal layers in a single RTP session
utilizing a single SSRC (e.g. Single Session Transport), correct? 

 

Other than the max-fr parameter, is there anything that provides an
indication of the capabilities of the receiver?  Or is the encoder free to
utilize any configuration that fits within the max-fr parameter? 

 

For example, if the Offer includes max-fr=60, does that mean that the
receiver is prepared to handle any of the following? 

a.       T0 = 60 fps (no temporal scalability)

b.      T0 = 15 fps, T1 = 15 fps, T2=30 fps

c.       T0 = 7.5 fps, T1 = 7.5 fps, T2 = 15 fps, T3 = 30 fps

Re: [payload] temporal scalability in draft-ietf-… Bernard Aboba