similar to: Changing the IDCT spec

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

Hi The Theora specification states, in section 7.9.3 ("The 1D Inverse DCT") steps 14-16: 14. Assign T[5] the value T[4] - T[5]. 15. Truncate T[5] to a 16-bit representation by dropping any higher-order bits. 16. Assign T[5] the value C4 * (-T[5]) >> 16. However, the relevant section of code in the reference decoder (lib/dec/idct.c line 50) is:

I try to merge VP3's mmx decoder into theora. http://kyoto.cool.ne.jp/vp3/developers/theora-alpha3-MMXd-src.zip You can see the change by searching the keyword "_UsingMMX_" in all lib folder's file. From VP3???YO vp3@go8.enjoy.ne.jp

Hi people, As I said before: I did the IDCT to run on the FPGA. My friends from university did the Reconstruction routines running on the FPGA. I'm helping with the LoopFilter, and it is almost there. (all VHDL) I did a small profiling of the libTheora running on a Altera Stratix II device: The processor used was the NIOS II with 8Kb of data and instruction cache, branch prediction and

Hi all, Just a stupid question The IDctSlow function on file idct.c has this line : ip[0] = (ogg_int16_t)((_Gd + _Cd ) >> 0); The ip[0] , _Gd and _Cd are of type ogg_int32_t My question is: The result of (_Gd + _Cd) can be a number with more than 16 bits ? (yes, it can be because they are int32, but the algorithm could guarantee something about that... I dont know...) If

Hi. I am trying to find calls of idct/fdct.c functions by tracing png2theora.c calls. But found only: analyze.c:oc_dct_cost2() Where and when idct/fdct/mmxidct/mmxfdct.c functions are used? Mentions of "dct" word: ==== pacify at optima-amd64:/usr/src/libtheora-1.2.0alpha1/lib$ grep dct *.c | cut -f1 -d":" | uniq -c ???? 19 analyze.c ???? 28 decode.c ???? 22 encode.c ????? 4

Hello, I'm attaching IDCT MMX patch. I reused IDCT from theora-a3-MMXd.zip. It should work on 64bit X86 platform too. Here is most used functions when playing video with jet aircrafts (gripen) Ogg logical stream 310b2968 is Theora 720x480 29.97 fps video Encoded frame content is 720x480 with 0x0 offset I can play this video with like 200-300 frame drops on Athlon XP 1700+ CPU load (with

The vp3 / theora decoder in FFmpeg project received a major speedup: http://multimedia.cx/eggs/profiling-and-optimizing-theora/#comment-150751 http://git.ffmpeg.org/?p=ffmpeg;a=commit;h=6e8061980c9a18a0eb9802f5dc5becc349066680 http://git.ffmpeg.org/?p=ffmpeg;a=commit;h=8476744ba50d26a3e188def192cd9086b0f781d7 http://git.ffmpeg.org/?p=ffmpeg;a=commit;h=a51faef9b61bd80499a28322802ef4b22be44d43

Hi, I don't know how much of the old VP3 codebase is incorporated into Theora. I wrote ffmpeg's VP3 decoder from scratch but eventually ported in the original VP3 IDCT function. A BSD conflict cropped up that I thought I would pass along. -- -Mike Melanson <p>---------- Forwarded message ---------- Date: Wed, 10 Sep 2003 13:06:37 -0700 (PDT) From: Steven M. Schultz

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.

When using the IDCT routines, the C version [ lib/idct.c: oc_idct8x8_c(ogg_int16_t _y[64],int _last_zzi)] in libtheora 1.1.1, the decoded image is garbled. Is it functionally equivalent to the MMX optimized version [lib/x86/mmxidct.c: oc_idct8x8_mmx(ogg_int16_t _y[64],int _last_zzi)] ? I used some of the Theora video files from here: http://wiki.xiph.org/index.php/List_of_Theora_videos for

Hi everyone, I just landed into the theora planet, as a game programmer, I searched for a free video fomat/codec and the theora choice became obvious. However I experienced rather bad performance (at least from a game programming point of view) After a couple a profiling, I discovered, as previous discused in a post found via Google, that the bottleneck is in the ogg library. An unsane part of the

can anyone confirm that, unlike VP3, Theora in fact decodes images right-side-up? (VP3 managed to turn everything upside down on encode and reverse it on decode) The tests I'm doing indicate that Theora doesn't reverse the image -- the first coefficients encoded correspond to the upper-left corner of the frame. ___ Dan Miller (++,) Founder, On2 Technologies --- >8 ---- List

1) What are you doing "mathematically" in a procedure x86/x86enquant: oc_enc_quantize_sse2()? This - the assembler code, and I do not understand mathematically - that's going on there. --- A: 120 121 28 73 -20 -99 -98 -100 123 122 112 108 73 -32 -102 -98 123 123 117 121 100

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

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

just added to the WIKI: * Ideas with some concensus after discussion on IRC, it was provisionally agreed (by those present at the time) that Theora should support arbitrary pixel sizes (presently it is limited to multiples of 16 both horizontally and vertically). It is felt that this can be achieved with minimal pain by adding four values to the page header, immediately following the present

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:

Supposedly On2 transferred their Video Recorder and TrueCast5 streaming server into opensource along with VP3. Theora is obviously the VP3 project, and while I can find nothing on Xiph about it, the recorder source is offered on vp3.com; but I can find nothing on Xiph or vp3.com about what happened to Truecast5. I contacted On2 about whether TrueCast5 was really going to be open source, and they

hi folks I've posted a new version of the Theora spec, same place as before: ftp.vp3.com/theora/spec name: vp3 pass: vp3dev This one actually works (the old one had a significant bug). Many editorial changes too. Please review & comment. - dan ps Rillian, I would have updated CVS myself but my pub key stuff is not working. --- >8 ---- List archives: http://www.xiph.org/archives/