[theora-dev] new patch

Dan Miller dan at on2.com
Wed May 28 10:20:54 PDT 2003

[standard disclaimer about my mail format]
in ftp.vp3.com/theora
user: vp3
pass: vp3dev
this implements a bitstream change; the header now contains a compressed huffman tree rather than the frequency counts (as discussed)
pardon my inability to use diff correctly.  The change in toplevel.c is trivial (new function names & params)
huffman.c is the important one.  I doubt anyone has touched it in a while so I suggest you use this (pulled out of CVS in the last couple days)

        -----Original Message----- 
        From: Mike Melanson [mailto:melanson at pcisys.net] 
        Sent: Tue 5/27/2003 2:55 PM 
        To: theora-dev at xiph.org 
        Subject: Re: [theora-dev] resolution issues

        On Tue, 27 May 2003, Henry Mason  wrote:
	> On a somewhat related note, is there any reason to
	> encode at dimensions which are multiples of 32 in
	> order to have full superblocks? How much do VP3
	> superblocks play a part in the video compression
	> efficiency?
                Well, a good reason to encode at superblock boundaries is that it
        makes an encoder's life (and source code) much simpler...:) Actually, to
        make it *really* easy, with no corner cases, the dimensions need to be
        divisible by 64 (so the U & V planes line up on 32-sample boundaries).
                I understand that the point of the superblocks and the associated
        Hilbert coding scan is to maximize proximate similarities (based on the
        principle that pixels close to each other tend to be similar). This will
        be true for most of the image frame; only the outlying areas (right and
        bottom) will not have the benefit of as many neighboring pixels.
                -Mike Melanson
        --- >8 ----
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