Subject: [payload] I-D Action: draft-ietf-payload-vp8-05.txt

From: [email-masked]
Date: Fri, 31 Aug 2012 09:59:13 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
 This draft is a work item of the Audio/Video Transport Payloads Working Group of the IETF.

	Title           : RTP Payload Format for VP8 Video
	Author(s)       : Patrik Westin
                          Henrik F Lundin
                          Michael Glover
                          Justin Uberti
                          Frank Galligan
	Filename        : draft-ietf-payload-vp8-05.txt
	Pages           : 29
	Date            : 2012-08-31

Abstract:
   This memo describes an RTP payload format for the VP8 video codec.
   The payload format has wide applicability, as it supports
   applications from low bit-rate peer-to-peer usage, to high bit-rate
   video conferences.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-payload-vp8

There's also a htmlized version available at:
http://tools.ietf.org/html/draft-ietf-payload-vp8-05

A diff from the previous version is available at:
http://www.ietf.org/rfcdiff?url2=draft-ietf-payload-vp8-05

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

---

From: Stephan Wenger <[email-masked]>
Date: Fri, 31 Aug 2012 19:12:07 +0000

Hi,

I had a quick look at the diff file only.  I think the introduction of the
two new (optional) parameters max_fs and max_fr address the concerns I
raised earlier.  I hope implementers will read 6.2.2 carefully and
understand that "optional" really meant "conditionally mandatory" :-)

The one substantial thing that needs further discussion (though not
necessarily a change in the draft, IMO), is Sandy's idea of including a
parameter for signaling the maximum number of coefficient
partitions--something that apparently may be useful for multi-threaded
decoders.  You google guys may want to comment on his idea.

A small nit for section 6.2.2: the final sentence of the section starts
with "In *many* practical applications, the max frame size and max frame
rate are known from other information; [...]".  I personally don't believe
that the word "many" is justified, and it may even be misleading.  I would
claim that in the vast majority of video-over-RTP implementations, there
is no pre-arranged knowledge of decoder capabilities before the
negotiation.  I don't see why VP8 is different here.  I believe that not
even in the webrtc case (which is, AFAIK, the main customer for this
payload format) there is pre-arranged knowledge of receiver capabilities.
So perhaps it's better to replace "many applications" with "some
applications". 

Regards,
Stephan

On 8.31.2012 09:59 , "[email-masked]" <[email-masked]>
wrote:

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