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Re: [AVT] imageattr and codec parameter sets (with embedded image size info)
Hi
With the disclaimer that I am not an implementer:
Even though sprop-paramteter-sets (or MPEG4 config) string on the fmtp
looks horrible, it is nontheless possible to parse by a SPD parser that
has the ambition to understand imageattr. But if this capability does
not exist in the parser I would guess that imageattr can only be
ignored.
I hope that the next update of the draft will cover these issues better.
/Ingemar
> -----Original Message-----
> From: Randell Jesup [mailto:rjesup at wgate.com]
> Sent: den 31 juli 2008 14:38
> To: Ingemar Johansson S
> Cc: kyunghun.jung at samsung.com; Even, Roni; mmusic at ietf.org;
> avt at ietf.org
> Subject: Re: imageattr and codec parameter sets (with
> embedded image size info)
>
> "Ingemar Johansson S" <ingemar.s.johansson at ericsson.com> writes:
> >My assumption here is that:
> >while the profile-level-id is the limiting factor for imageattr the
> >pic_width_in_mbs_minus_1 and pic_height_in_map_units_minus_1 in
> >sprop-parameter-sets should not be used if imageattr is used.
> >This is expressed in the first bullet in the section 5 in the draft.
>
> That's not a practical proposal - the parameter sets are fed
> to the decoders directly, and affect how much buffer space is
> reserved in the codec for each frame, for example. Also, you
> can't know if the answer will understand imageattr.
>
> --
> 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
> provided for defence against real, pretended, or imaginary
> dangers from abroad."
> - James Madison, 4th US president (1751-1836)
>
>
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