similar to: Doubts in codebook decoding

Hello Monty, Sorry for the wrong subject title last time. A little more clarification needed. When reading bit-by-bit, there is no MSb/LSb, just 'first bit' and 'last bit'. The Huffman tree is traversed from 'first bit' to last bit'. This is a conceptual layer above the bitpacker; all you need to know is what order the bits come out, which happens to be LSb-first.

Hello folks, The codebook infrastructure for Vorbis is now well underway. This is it! The last piece needed for *real* bitstreams. To that end, I have a decent VQ codebook generator running. I was originally using some farily typical merge/split algorithms and then decided that the right way to do this was to model a VQ codebook as an m-dimensional set of bubbles (like a foam). I know there

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, We are porting the Ogg Vorbis fixed point decoder to a 24 bit fixed point precision processor. We are trying to reduce the number of cycles for MIPS optimization. In this process we observed that most of the songs do not have "maximum codeword length" greater than 24 bits. We are planning to reduce most of the double word operations (in our case 32 bit data is stored as double

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, does anybody know whether the codewords have a special meaning? whether they have a different influence like the quantization matriy in jpeg? e.g. do lower or the first entries have a greater influence than the last or higher codewords? thanks gerald

Dear Sir or Maddam, we're in the progress of developing a multimedia framework for Java. We started with programming a Vorbis (ogg) codec and demultiplexer and have still some problems with this. The problem occured when trying to read the setup header of a vorbis file. After a certain time we have to decode the codebook_lengths but this does not work. We followed the instructions in the

Áô©~ªº ¦Ñ¤H wrote: > Dear Segher > > Thanks for your information. Besides, the mechanism of the huffman > decoding seems can not work in a 24-bit processor if the code length > exceeds 24, though I have checked several vorbis file from network and > they are all below 24 bit True; but you can special case the >24 bit codebook to use a more "traditional" decoding

The following has been committed to the Vorbis I spec as of r19445: Errata 20150226: Single entry codebooks A ?single-entry codebook? is a codebook with one active codeword entry. A single-entry codebook may be either a fully populated codebook with only one declared entry, or a sparse codebook with only one entry marked used. The Vorbis I spec provides no means to specify a codeword length of

Hi, I am a bit confused on how code-words are derived from the codeword lengths. I will appreciate if someone can point me in the correct direction. I will take the example of an actual codebook that i found in a valid vorbis encoded file as shown below. [SK] +------Codebook [0] -------- [SK] Codebook Dimensions = 1 [SK] Codebook Entries = 8 [SK] Unordered [SK] 1, 6, 3, 7, 2, 5, 4, 7, [SK] NO

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

hi kuhlen, what you said is correct. i am talking about how you are going to arrange these codewords into an array, i.e. in the function _make_decode_table. there he uses node bytes and leaf words for memory management. i got a 24 bit platform. so if i assume that max. codeword length that could be possible as 24 bits can i allocate a memory of (2 * used entries - 2), to arrange the whole tree in

I'm trying to understand the residuevqtrain program, and I have some questions for Monty, Erik, or anyone that understands how it's supposed to work. I captured TRAIN_RES data from an encoding of a single track (about 4:43), producing two files, residue_0.vqd (3727 lines, = 3727 points?) and residue_1.vqd (huge). I then did a run with the parameters from the usage message

Hi, From the vorbis decoder specification, it is clear that the decoder needs to have all the codebooks before decoding can actually begin. I will appreciate if someone can clear the following questions: 1. I guess the codebooks are derived from the actual input data. Probably the encoder may be making two passes through the input. The first pass finds out the frequency of different symbols

Hi folks, My wife and I are taking a long weekend to celibrate our anniversary. I won't be around again until Wednesday to answer email or do anything else on Vorbis. Yeah, I know, I usually answer my email once a month anyway (so likely no one would notice me being gone), but just so folks know if anything really juicy comes up :-) I'll be merging my latest branch with mainline

Hi, Does anybody know how codebooks are generated in OggVorbis encoder? We are porting oggorbis encoder on embedded platform for which VQ codebook memory is hugeeee to imagine. How can we reduce that? Can we do VQ with less codebooks and if yes how? If any help available? Parul Embedded Engineer Einfochips Ltd

>There's plenty of areas for improvements that don't require incompatible changes like this one. can u please tell me what do I do to make it more exact waveform coder for music rather than speech. I understand that its meant for speech, but I was just using it for music... I am interested in getting the residual as small as possible using speex. Can you please tell me the areas to

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

Well, here you are. 24k; sorry if I'm not supposed to put this size things in your mailbox, didn't know where else to put it. And you all are subscribed to vorbis-dev, after all. I'm not that good at breaking patches apart, so it's one big patch. Sorry. Overview: configure.in make profiling easier & more useful decoder-example.c (#if 0'ed) dither output;

Hi, I've been using the Vorbis codec for a while and recently I got the source code and had a look at the spec (great job on the doc BTW). I don't have any former experience with audio compression, but I do know what a DCT does and I totally grok Huffman coding (so I guess I'm not that much of a newbie, am I?). Anyway I just had some questions about how VQ works on the encoding side.