Subject: [MMUSIC] RID parametrs

From: "Roni Even" <[email-masked]>
Date: Mon, 2 Nov 2015 07:59:30 +0200

Hi,

I want to explain my concern with the propose solution of using RID only in
Simulcast and what I think should be available in RID to address this
concerns

When using pt for simulcast the offerer can offer and ask for specific image
size using the SDP as in figure 3 of the current simulcast draft (just the
video m-line) note that two specific resolutions that has to do with needing
an HD image and a thumbnail from the same media source

   m=video 49300 RTP/AVP 97 98

   a=rtpmap:97 H264/90000

   a=rtpmap:98 H264/90000

   a=fmtp:97 profile-level-id=42c01f; max-fs=3600; max-mbps=108000

   a=fmtp:98 profile-level-id=42c00b; max-fs=240; max-mbps=3600

   a=imageattr:97 send [x=1280,y=720] recv [x=1280,y=720]

   a=imageattr:98 send [x=320,y=180] recv [x=320,y=180]

   a=simulcast: send pt=97;98 recv pt=97

Now when using RID from figure 5 to achieve the same functionality

   m=video 49300 RTP/AVP 97 98

   a=rtpmap:97 H264/90000

   a=rtpmap:98 H264/90000

   a=fmtp:97 profile-level-id=42c01f; max-fs=3600; max-mbps=108000

   a=fmtp:98 profile-level-id=42c00b; max-fs=240; max-mbps=3600

        a=rid:1 send pt=97;max-width=1280;max-height=720;max-fr=30

   a=rid:2 send pt=98;max-width=320;max-height=180 - may have higher
max-width and max-height

        a=rid:3 recv pt=97;max-width=1280;max-height=720;max-fr=30

   a=rid:4 recv pt=98;max-width=320;max-height=180 - may have higher
max-width and max-height

   a=imageattr:97 send [x=1280,y=720] recv [x=1280,y=720]

   a=imageattr:98 send [x=320,y=180] recv [x=320,y=180]

   a=simulcast: send rid=1;2 recv rid=3;4

So you still end up with two pt numbers. If you want to be able to use just
one there is a need to have the imageattr as a rid parameter

Which will make the offer

   m=video 49300 RTP/AVP 97 

   a=rtpmap:97 H264/90000

   a=fmtp:97 profile-level-id=42c01f; max-fs=3600; max-mbps=108000

   a=rid:1 send pt=97;max-width=1280;max-height=720;max-fr=30 imageattr:97
send [x=1280,y=720] recv [x=1280,y=720]

   a=rid:2 send pt=97;max-width=320;max-height=180 imageattr:97 send
[x=320,y=180] recv [x=320,y=180]

    a=rid:3 recv pt=97;max-width=1280;max-height=720;max-fr=30 imageattr:97
send [x=1280,y=720] recv [x=1280,y=720]

   a=rid:4 recv pt=97;max-width=320;max-height=180 imageattr:97 send
[x=320,y=180] recv [x=320,y=180]

   a=simulcast: send rid=1;2 recv rid=3;4