[Theora-dev] aspect ratio ?
j at thing.net
Wed Jul 14 07:02:20 PDT 2004
<1089811034.25780.7.camel at x30>
Message-ID: <1089813740.25780.13.camel at x30>
its also in the theora spec(http://svn.xiph.org/trunk/theora/doc/spec/)
you can find a compiled pdf at http://v2v.cc/~j/Theora_I_spec.pdf
6.2. IDENTIFICATION HEADER DECODE [xpdf page 63ff]
PARN Integer 24 No The pixel aspect-ratio numerator.
PARD Integer 24 No The pixel aspect-ratio denominator.
13. Read a 24-bit unsigned integer as PARN.
14. Read a 24-bit unsigned integer as PARD. Together with PARN,
these specify the aspect ratio of the pixels within a frame, defined as
the ratio of the physical width of a pixel to its physical height. This
is given by the ratio PARN : PARD. Either of these fields MAY be
zero, in which case the pixel aspect ratio defaults to 1 : 1.
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