[NUT-devel] r19110 - trunk/DOCS/tech/nut.txt

[Måns Rullgård]

michael <subversion at mplayerhq.hu> writes:

> Author: michael
> Date: Sat Jul 15 23:49:47 2006
> New Revision: 19110
>
> Modified:
>    trunk/DOCS/tech/nut.txt
>
> Log:
> clarify "extradata"
> comments welcome!
> if anyone disagrees ill reverse this and we can disscuss it, i just thought there wont be any disagreement and was too lazy to send a patch ...
>
> Modified: trunk/DOCS/tech/nut.txt
> ==============================================================================
> --- trunk/DOCS/tech/nut.txt	(original)
> +++ trunk/DOCS/tech/nut.txt	Sat Jul 15 23:49:47 2006
> @@ -512,6 +512,19 @@
>
>  codec_specific_data
>      private global data for a codec (could be huffman tables or ...)
> +    if a codec has a global header it SHOULD be placed in here instead of
> +    at the start of every keyframe
> +    the exact format is specified in the codec spec
> +    codecs which dont specify it in their spec are specified below
> +    for ogg based codecs (vorbis, theora) the following format shall be used
> +        number_of_headers_minus_1       u(8)
> +        for(i=0; i<number_of_headers; i++){
> +            -1                          u(8*(size[i]/255))
> +            size[i] % 255               u(8)
> +        }
> +        for(i=0; i<number_of_headers; i++)
> +            header[i]
> +    Note, this is the same format these codecs use in matroska

If I didn't already know how what that format looks like, I'd have a
hard time deciphering that description.

Could we perhaps generalize that format to include all codecs with
several chunks of extradata, not only ogg based codecs?  I'm not aware
of any others, but for all I know they might exist.

-- 
Måns Rullgård
mru at inprovide.com