[standard disclaimer about my mail format] in ftp.vp3.com/theora user: vp3 pass: vp3dev theora_dbm_5-28.zip 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) -dan -----Original Message----- From: Mike Melanson [mailto:melanson@pcisys.net] Sent: Tue 5/27/2003 2:55 PM To: theora-dev@xiph.org Cc: 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 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered. -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 5763 bytes Desc: winmail.dat Url : http://lists.xiph.org/pipermail/theora-dev/attachments/20030528/0cd330d1/winmail-0001.bin
Mauricio Piacentini
2003-May-30 13:46 UTC
[theora-dev] Updated win encoder project to use "common" encoder sample
Hi. I have updated the win32/experimental/encoderwin project to use the common encoder_sample.c file. In order not to modify the existing sample (I only added one #ifdef at the top) I chose to supply the missing functions in a separate file for Windows only (rint(), getopt(), getopt_long()). These reside in the win32/experimental/wincompat tree. This should help us verify if there are really differences in the bitstream caused by compiler differences, using the exact same source code for the encoder. Hope it helps. Regards, Mauricio Piacentini --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.