similar to: optimization patches

There is bit space in Bitstream Header to put Huffman codes in. However, This space can take only 80 kinds of Huffman code set. And This space is divded into DC Huffman code set and AC Huffman set, and There are only 16 choices in each DC and AC Huffman code set. If we want to use this space, we find out best(or proper) performance 80 frequency counts(Huffman code sets) from tens thousands of

Hi, all I am studying the ogg-vorbis algorithm but I have less knowledge about the codebook structure of vorbis. After tracing the release source code, I found it doesn't use huffman tree to decode the huffman code instead of using a special mapping and pre-look. The memory requirement seems similar with huffman tree decoding. Could anyone tell me how the vorbis huffman decoding works

> On Mon, Dec 15, 2014 at 9:57 AM, Chad Rosier <mcrosier at codeaurora.org> > wrote: >> All, >> About two months ago I posted a patch that hoisted the hottest case >> statement from a switch statement during ISelLowering. >> >> See: http://reviews.llvm.org/D5786 >> >> Sean was rather adamant about using a Huffman tree (and I agree this is

Good day! I'm creating HDL IP CORE (for using in FPGA) for theora encoder (now only I-frames). I don't undestand one moment. Now i develop such stages: 1. From RBG(byer) to YCbCr converter 2. DCT processing (8x8 pixels blocks) 3. Quantizator of DCT coeff. 4. Zig-Zag of quantized DCT coeff. and now i have uresolved last stage of compression - how i must send 8x8 blocks to huffman

> On Mon, Dec 15, 2014 at 2:26 PM, Chad Rosier <mcrosier at codeaurora.org> > wrote: >> >> > On Mon, Dec 15, 2014 at 9:57 AM, Chad Rosier <mcrosier at codeaurora.org> >> > wrote: >> >> All, >> >> About two months ago I posted a patch that hoisted the hottest case >> >> statement from a switch statement during

After messing around with this a bit recently, I've come to the following conclusions: 1. One issue is at what granularity to consider the PGO weightings. For example, should a set of 50 consecutive cases with 65% of the total weight distributed approximately evenly and which can be lowered to a table lookup be handled before the 3 remaining cases that 5%, 10%, and 20% probability,

I have developed a flexible arithmetic coder implementation and I am now looking to incorporate it into a compression system for some proper testing. It is my intention to incorporate the coder into the Vorbis codec to attempt to improve on the current Huffman tree system. It would be useful if someone could point me at the main c and h files that deal with the entropy coding as I am currently

Hi again! I have some other suggestions/modifications. 1. Bitrate scaling by frequency in vorbis_encode_init: bpch=(long)((float)nominal_bitrate/(float)channels*44100.0f/(float)rate); With this modification, if we use -b128 at 22khz files, the OGG file will be 128kbit/s, not 64kbit/s ... 2. Probable quality bug: I tested some floating point constants (recalculated them (see below) and encoded

Hello all, I've been working a little inside the Theora decoder when I found that it seems that many videos had the very same huffman tables encoded into their bitstreams (at least the ones that I could take my time to dissecate). I found that the tables are listed as TH_VP31_HUFF_CODES in the file huffenc.c. I tried to investigate a little bit more to see who was setting the bitstream

All, About two months ago I posted a patch that hoisted the hottest case statement from a switch statement during ISelLowering. See: http://reviews.llvm.org/D5786 Sean was rather adamant about using a Huffman tree (and I agree this is a more complete solution), so I'd like to put a patch together. That being said, I have a few questions. The current switch lowering code sorts based on case

https://bugs.freedesktop.org/show_bug.cgi?id=111199 Bug ID: 111199 Summary: Bug in dither.depth property set Product: xorg Version: unspecified Hardware: Other OS: All Status: NEW Severity: normal Priority: medium Component: Driver/nouveau Assignee: nouveau at

hello all, we are developing and porting vorbis1decoder on a 24 bit platform. in the process we came across somedoubts about node bytes and leaf words. from the specification we got that we are arranging the huffman codeword tree into an array. the nodebytes are the number of bytes that are required to represent a node and leafwords are the no. of bytes required to represent the leaf i.e the

Hi, I am trying to implement ogg vorbis real time decoder on SHARC ADSP 21364 processor. I am writing my own version of the decoder using the documentation vorbis_I_spec.pdf from xiph.org. However I am facing certain hurdles in floor curve decoding during audio packet decode. In the spec it says that [cval] = read from packet using codebook number [so and so] in *scalar context*.(page no 43).

I installed the Syncpeople textmate bundle ( http://syncpeople.com/downloads/syncpeople_on_rails_features ) and the commands all work from the menu, but the short-cuts never work for any of the snippets or commands ever work, because the scopes are not being selected properly. If I change the scope to just "source.ruby" it will work fine. But I cannot see why their scope selectors do not

I was just somewhat curious as to what lossless compression is used... is it just huffman? Tony Arcieri --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/

Hello, I am a computer engineering student and compression hobbyst and have recently developed a new entropy coding algorithm. It can be used to achieve compression proper of arithmetic coders at very high speeds -almost like Huffman codecs-. Since it could be of interest to you, I send it as an attachment -code and technical report-. Please, drop me a line in case you have any doubt or

Anyone have any tips for handling postgres constraints when using fixtures to load the database, other than to sort out the proper insertion orders or leaving the constraints out? I''d prefer not to do the former since I''d rather use my app to generate my fixture data (using a dump_fixtures task) and I''d prefer not to do the latter because leaving out constraints till the

I want to analyse compressed data between VQ and Huffman coding steps. Where in source code can I access to data massive for this goal. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/vorbis/attachments/20090916/4529e42d/attachment-0001.htm

Hiya, Here is the sources to my "rehuff" program. ./rehuff in.ogg out.ogg does a lossless recoding of a vorbis stream. (It generates optimal huffman codes for the particular stream). This code is meant for developers only, until someone is kind enough to provide good build and configure support for it. I won't. And no installation help questions please. There is a little patch

I did composition of butterfly8 and butterfly16 and I found, that these functions are well decomposed - decomposition doesn't lower computional speed. On the other hand the same can be done with butterfly8 - decomposition to butterfly4 (further decomposition is not possible) but there's no reason to do this. I think little improvement can be done by inlining them. Compiler and processor