Re: [AVT] profile-level-id definition

[Randell Jesup <rjesup at wgate.com>]

"Steve DeLaney" <onramp123 at yahoo.com> writes:

>Hello, 
>
>we are trying to better understand the definition of profile-level-id under
>RFC3984 section 8.1 Having browsed the archive threads including "SDP
>Negotiation based on Profile-Level-Id", I was hoping to get some
>clarification on this to break down the encoding for profile and level.
>
>we are integrating a codec which, when encoding at 1080P60, expresses
>profile-level-id=42001E as a hardcoded value.
>to break this down 
>
>profile_idc 42 is MAIN profile ?
>level_idc 1E is level 3.0 ?

Others answered what those are.

Note: Level 3.0 DOES NOT support the resolution you're using.  See
http://en.wikipedia.org/wiki/H.264#Levels

3.0 supports a max of 720x480 at 30 (or just over 60fps at 352x480).  You need
level 4.2 or above, OR with 3.0 you need to advertise that you do both a
larger number of macroblocks/frame, and larger number of macroblocks/second
(max-fs and max-mbps if I remember).

Also, read the sections (in 3984bis - the draft about to replace 3984)
about level negotiation.  Profile and constraints are fixed; level has some
negotiation possible.  

-- 
Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga OS team
rjesup at wgate.com
"The fetters imposed on liberty at home have ever been forged out of the weapons
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