Re: [MMUSIC] video media control draft

["Andreas Kassler" <[e-mail]>]

RE: [MMUSIC] video media control draftSanjoy et al,
we were also concerned about the expressability of quality attributes that
defines the quality of service at application level for a given video(audio) stream. 
In draft-guenkova-mmusic-e2enp-sdpng-00.txt we basically have identified a requirement
to ... introduce (per) codec parametrization attributes like frame-rate, frame-size, color-
quality-range, overall-quality-range, etc. which should be  uniquely interpreted by the end-systems.

When it comes to negotiation of such attributes with the peer for setting up quality enhanced
media streams, we propose to specify such parameters on a per codec basis. The reason is 
that not all codecs support all combinations of such parameters. For example with a given
hardware, a sender may be able to compress at 25 fps at CIF a H.261 stream but may
not be able to compress at 25 fps at CIF a MPEG-4 stream due to limited resources.

We propose also to work on these issues within the SDPng context.

-Andreas
  ----- Original Message ----- 
  From: Sanjoy Sen 
  To: 'Even, Roni' ; 'Nils Henrik Lorentzen' ; [e-mail] 
  Sent: Tuesday, August 13, 2002 1:55 AM
  Subject: RE: [MMUSIC] video media control draft


  I saw this pretty old thread. I do support proposing frame-size on a per codec (payload-type) basis. I would also like to throw in the requirement that we need to be able to specify the preferred media qualities (e.g., in a scale of 0-10) per payload-type (right now SDP defines a quality attribute per m line). Thoughts?

  Does it make sense to encode all these information as part of an "fmtp" attribute for the payload-type? - e.g., a:fmtp:<PT> res=QCIF/quality=5

  -Sanjoy 

  > -----Original Message----- 
  > From: Even, Roni [mailto:[e-mail]] 
  > Sent: Wednesday, August 07, 2002 1:21 AM 
  > To: 'Nils Henrik Lorentzen'; [e-mail]; Even, Roni 
  > Subject: RE: [MMUSIC] video media control draft 
  > 
  > 
  > Nils, 
  > I think your suggestion makes sense. I will update the draft Roni 
  > 
  > > -----Original Message----- 
  > > From: Nils Henrik Lorentzen [mailto:[e-mail]] 
  > > Sent: Tuesday, August 06, 2002 10:35 AM 
  > > To: [e-mail]; Even, Roni 
  > > Subject: Re: [MMUSIC] video media control draft 
  > > 
  > > 
  > > On Tuesday 06 August 2002 07:59, Even, Roni wrote: 
  > > 
  > > > Hi Petri, 
  > > > In my draft draft-even-mmusic-video-media-control-00.txt, 
  > I have a 
  > > > video-resolution attribute that allow to specify the 
  > > maximum frame rate 
  > > > supported per resolution. 
  > > 
  > > A difference between your draft and 
  > > draft-koskelainen-sdp263-02.txt is that 
  > > in the latter you may specify resolutions and options per 
  > > payload type, 
  > > instead of per media line. I think this is more flexible, and 
  > > would suit our 
  > > needs better. Any particular reason for having it per media-line ? 
  > > 
  > > In your draft it would be a simple change to make it per payload: 
  > > a=video-resolution:<size> to 
  > > a=video-resolution: <payload no> <size> 
  > > or possibly 
  > > a=video-resolution: [ PT=<payload no>] <size> 
  > > ie payload no is optional, so if not specified the 
  > > resolutions would apply to 
  > > all the payload types on the media line. 
  > > 
  > > > In the meeting this attribute was accepted for 
  > > > SDP. I could not find the draft mentioned 
  > > "draft-koskelainen-sdp263-02.txt" 
  > > 
  > > It expired quite some time ago, but can be found at: 
  > > http://www.dmn.tzi.org/ietf/mmusic/sdp-ng/input/draft-koskelai 
  > > nen-sdp263-02.txt 
  > > 
  > > Nils Henrik Lorentzen 
  > > 
  > 
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