similar to: Macroblock Coding Issues

Displaying 20 results from an estimated 4000 matches similar to: "Macroblock Coding Issues"

2003 May 04
0
VP3 In ffmpeg
Hi, Sorry for taking so long with this, but I finally committed a first pass of my own VP3 decoder to the ffmpeg codebase. You can browse the source here: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ffmpeg/ffmpeg/libavcodec/ vp3.c and vp3data.h are the files in question. Attached is a message I sent to the ffmpeg-devel list about the new decoder and its present shortcomings.
2003 May 28
1
new patch
[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
2003 May 28
2
autoconf problem
./configure: line 524: syntax error near unexpected token `AM_INIT_AUTOMAKE(libtheora,0.0)' ./configure: line 524: `AM_INIT_AUTOMAKE(libtheora,0.0)' I'm sure I'm doing something pro-stupid, but --- my setup works fine for ogg & vorbis. autoconf ver 2.13 automake (GNU automake) 1.4-p4 if that matters hey let's put tool version numbers into the README -dan
2003 May 28
2
encoder discrepancy
the files produced by windows compile vs. Linux are indeed significantly different in size (about 140K vs. 160) However I'm not convinced all the default parameters are set the same way in the two example files. This needs to be verified to see if there really is a bug, or can the two versions produce byte-equal output streams? <p> ___ Dan Miller (++,) Founder, On2 Technologies
2003 Oct 09
4
Updated VP3 Document
Hi, I have been on a documentation kick recently. I finally updated my VP3 format document tonight: http://www.pcisys.net/~melanson/codecs/vp3-format.txt v0.2: October 9, 2003 - expanded section "Reversing the DC Prediction" - added Appendix B: Theora Differences Feel free to look it over and point out any glaring mistakes. I can't wait to see how much sense it makes to
2011 Mar 21
0
Contents of theora digest...
---------- Forwarded message ---------- From: digital design <developer.fpga at gmail.com> Date: 21 March 2011 13:38 Subject: Re: [theora] alghorithm of working encoder in libtheora To: bens at alum.mit.edu Cc: Reply-All at xiph.org On 18 March 2011 23:15, Benjamin M. Schwartz <bmschwar at fas.harvard.edu>wrote: > On 03/18/2011 01:44 PM, digital design wrote: > > Now i
2002 Aug 06
1
VP3 Patch For xine
Hi, Since a number of people are eager to try out the native VP3 decoder in xine, I have made a patch available, bz2-compressed: http://www.pcisys.net/~melanson/codecs/xine-vp3-decoder-patch.bz2 To work with this patch: 1) Get the latest xine-lib from CVS. Visit this page for more details: http://sourceforge.net/cvs/?group_id=9655 The module name is xine-lib, but you will also need
2004 Mar 02
1
VP3 Format Doc, v0.4
Hi, Check it out-- another update in the space of a week: http://home.pcisys.net/~melanson/codecs/vp3-format.txt v0.4: March 2, 2004 - renamed and expanded section "Initializing The Quantization Matrices" - outlined section "Reconstructing The Frame" - moved Theora Differences Appendix to its own section entitled "Theora Specification" - added Appendix:
2003 Mar 09
4
Proof of Concept
Hi, So it took a little while to get here but VP3 through ffmpeg is finally starting to achieve viewable results. It partially works right now. Keyframes only. And monochrome. Oh, and the picture is upside down (something I did not realize about VP3 until I let it fly just now). Anyway, here is a picture of ffmpeg's VP3 decoder in action using xine:
2003 Jun 14
6
dead DCSearchPoints code
Dan, In reviewing the code, derf came across the DCSearchPoints array in QuadCodeDisplayFragments(), encode.c:696. It looks like it specifies a search order for nearby coded fragments for prediction if there isn't a nearest neighbor. However, the upper search bound is defined as *0*, so the search loop (line 917) is never executed and it always falls back to the last coded fragment.
2003 Jan 29
0
VP3 for xine 1.0-beta4
Hi, Some of you may recall that I got the VP3 decoder working with the xine multimedia player some time ago and posted a patch for anyone else to try. I really messed up when I did that since I generated the patch against some random CVS snapshot of xine-lib. I did better this time and generated the patch against the latest release of xine-lib (1.0-beta4, released today). If you
2003 Feb 26
7
[OT] Just saying hi!
I hope this list is small enough for not beeing banned when introducing oneself. So... Hi, I just subscribed to the theora-lists. I'm from the XVID project, so I know a deal about video and MPEG-4 in particular, but nothing about Vorbis/Theora etc., That's why I'm here, because I'm interested in patent-free alternatives. I guess there is no documentation of the current status
2003 Feb 23
6
More Missing Pieces
Hi, I am making good progress on understanding, documenting, and re-implementing VP3. I have found some more deadwood in the decoder code and I just wanted to verify that it really has no place: * Version 3.3 tables: There are 2 sets of VLCs: One for v3.1 and one for v3.3. The v3.1 set is always selected. Are the v3.3 tables in production, or will they ever be? * DC Search Points: VP3
2003 Mar 05
5
VP3 IDCT
Hi, Is there anything special I need to know about VP3's IDCT? I mean besides the fact that there are separate IDCTs to handle sparse coefficient matrices. Are the IDCT functions mathematically equivalent to any textbook IDCT functions? Thanks... -- -Mike Melanson --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To
2003 Feb 27
1
NSV and VP3
Hi, Quick note: In case anyone has not heard, Nullsoft, the people behind Winamp, have seen fit to develop their own multimedia container format. It can hold any kind of data, but their primary codecs are MP3 for audio and VP3 for video: http://www.nullsoft.com/nsv/ I and a few other people are still working out the details of the format:
2003 May 07
2
VP30
Hi, Can anyone tell me the significant differences between VP30 and VP31 (or are you allowed to)? Are there different token and quantizer tables? Are there algorithmic differences? I have a VP30-encoded file that plays with the VP3 VfW DLL but not with the open source decoder. Thanks... -- -Mike Melanson --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project
2002 Aug 05
3
Cross-Compiling VP3 lib on Linux
Hi, I have been working with VP3 for some time now. Dan Miller from On2 just told me about this list. A few months ago, I managed to get On2's VP3 source snapshot to compile under Linux, a feat that many have apparently attempted and quickly abandoned. I compiled a small console app and the results of the experiment are explained here:
2003 Mar 27
1
Blockiness
I tried out Theora to see what the future holds, and see some pros and cons. As a great plus, I have noticed that, even at the lowest quality (ie. "-v 0"), the detail, and overally quality is clearly better than anything else available. On the negative side, at qualities comparable to MPEG4, I've notcied a great deal of blockiness. It's not as bad as blockiness from other
2005 Mar 28
0
Theora and software patents
The list probably did not get this reply from D Richard Felker III. Having read quite a few patents I tend to agree with Richard: Software patents are very broad and even if I have not read the source code of Theora I would be surprised if it did not infringe several patents. However, I believe the argument that On2 has not been sued for infringing the MPEG-patents is a very strong argument.
2003 Feb 19
4
Block Coding Pattern
Hi, There seem to be 2 sets of block coding patterns in the VP3x/Theora algorithm. Based on the comments in the code, the first pattern is used if encoder version < 6 and the second pattern is used in encoder version >= 6. None of the code to support the second pattern is ever called. Is there an encoder with a version >= 6? The code in question is