The last possibility of matching imageattr and config/sprop-parameter-set might be as follows.
In this case, the role of imageattr will be rather limited. (negotiation -> designation)
m=video 49154 RTP/AVPF 97 98 99
b=AS:48
b=RS:0
b=RR:2500
a=rtpmap:97 MP4V-ES/90000
a=imageattr:97 [x=x1,y=y1]
a=fmtp:97 profile-level-id=a; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_1
a=rtpmap:98 MP4V-ES/90000
a=imageattr:98 [x=x2,y=y2]
a=fmtp:98 profile-level-id=b; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_2
a=rtpmap:99 MP4V-ES/90000
a=imageattr:99 [x=x3,y=y3]
a=fmtp:99 profile-level-id=c; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_3
Comments on these possibilities will be welcomed.
Sincerely yours,
Kyunghun Jung
------- Original Message -------
Sender : Kyunghun Jung<kyunghun.jung at samsung.com> E5(??)/Global Standards & Research Lab./Samsung Electronics
Date : 2008-07-30 09:01 (GMT+09:00)
Title : Re: RE: [MMUSIC] [AVT] spatial-resolution parameter for RFC 3984bis
Thank you Mr. Even Roni for the information.
We would like to ask experts in MMUSIC and AVT to pay a special interest to the relationship
between imageattr and config/sprop-parameter-set. How to stack the set of information in the SDP offer
will influence the session setup.
For example, suppose imageattr specifies image sizes over multiple levels. The following form might be necessary.
m=video 49154 RTP/AVPF 99
b=AS:48
b=RS:0
b=RR:2500
a=rtpmap:99 MP4V-ES/90000
a=imageattr:99 [x=x1,y=y1] [x=x2,y=y2] [x=x3,y=y3]
a=fmtp:99 profile-level-id=a; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_1a=fmtp:99 profile-level-id=b; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_2
a=fmtp:99 profile-level-id=c; \
config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_3
In case imageattr specifies image sizes within a single level.
a=imageattr:99 [x=x1,y=y1] [x=x2,y=y2] [x=x3,y=y3]
a=fmtp:99 profile-level-id=8
a=fmtp:99 config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_1
a=fmtp:99 config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_2
a=fmtp:99 config=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx_3
The above forms are only basic possibilities and more systematic design and suggestion are
requested from MMUSIC and AVT experts.
Have a nice meeting at Dublin!
Kyunghun Jung
------- Original Message -------
Sender : Even, Roni<roni.even at polycom.co.il>
Date : 2008-07-30 00:13 (GMT+09:00)
Title : RE: [MMUSIC] [AVT] spatial-resolution parameter for RFC 3984bis
Hi,
First of all, ITU-T documents in pdf format are free at
http://www.itu.int/rec/T-REC/e
As for custom format inH.263. RFC 4629 section 8.1.1 had the custom
resolution, no relation to specific level.
CUSTOM: Specifies the MPI (Minimum Picture Interval) for a
custom-defined resolution. The custom parameter receives three
comma-separated values, Xmax, Ymax, and MPI. The Xmax and Ymax
parameters describe the number of pixels in the X and Y axis and
must be evenly divisible by 4. The permissible values for MPI are
integer values from 1 to 32, which correspond to a maximum frame
rate of 30/(1.001 *the specified value).
Also note the next sentence
A system that declares support of a specific MPI for one of the
resolutions SHALL also implicitly support a lower resolution with
the same MPI.
Roni Even
_______________________________________________ Audio/Video Transport Working Group avt at ietf.org https://www.ietf.org/mailman/listinfo/avt