[Theora] a question about Bitstream Header.
Atsuhiko Yamanaka
ymnk at jcraft.com
Sun Oct 31 20:36:40 PST 2004
Hi,
I have a question about the format of Theora bitstream header.
It seems to me that there are differences between the specification[1]
(version 2004 Oct 1) and its reference implementation in
libtheora 1.0alpha3 released at 2004 Jun 1.
I mean that... please refer to Section 6.2 'Identification Header Decode'
in that specification[1] and the function '_theora_unpack_info()'
included in 'lib/toplevel.c'[2] of libtheora 1.0alpha3.
In developing some pure Java program[3], I had required to implement
some function, which converts granulepos to time in pure Java, and needed
to parse Theora header in pure Java. Now, I have followed the format
implemented in libtheora 1.0alpha3, and I have done to implement
that function and confirmed it works well.
So, my question is 'is it really OK to ignore its formal specification?'.
I have heard 'Theora I pecification' has been frozen and I hope
that specification has not been updated yet.
[1] http://www.theora.org/doc/Theora_I_spec.pdf
[2] http://svn.xiph.org/trunk/theora/lib/toplevel.c
[3] http://www.jcraft.com/jroar/
Thanks,
--
ymnk
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