similar to: Vorbis Codebooks

I've made a block diagram of the encoder because I tried to find out, how it works http://stoffke.freeshell.65535.net/ogg/block.html Although there are specifiation docs, that give very detailed information about single aspects of the encoding (or decoding) , I'm missing documenations that give a more general overview, about how the encoder works. (Vorbis Illuminated seems a bit

Hello, I'd like to know in detail how does the creation of VQ and Huffman codebooks work in Vorbis. I've used the source code from *encoder_example* as guide, but the only reference I've found is the function *_make_words *inside * vorbis_book_init_encode*, which creates the Huffman tree if I'm not wrong. So I have two doubts. The first is that, for creating the Huffman tree (and

I've made block diagram of the encoder because I tried to find out, how it works http://stoffke.freeshell.65535.net/ogg/block.html Although there are specifiation docs, that give very detailed information about single aspects of the encoding (or decoding) , I'm missing documenations that give a more general overview, about how the encoder works. (Vorbis Illuminated seems a bit outdated,

Hello, I have a few questions about the block size in ogg vorbis 1. The allowed blocksizes are powers of two between 64 and 8192 Samples. As I understood , there are fixed sizes for long and short blocks . The encoder can pick any allowed value for long blocks and onother value, that must be smaller or equal to the first one, for short blocks. On which base does the encoder choose the size for

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

Hi, Please brace yourselves for some possibly stupid questions. Why are there only 2 codebooks for floors and many more for residue values? What makes the encoding of floor values fundamentally different from encoding residue values? I have a basic understanding of VQ, and looking at the floor decode function, it all makes sense 1) Read the codebook index from the stream 2) Do a

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, I'm trying to write a Vorbis decoder (just as a hobby) but I've got a problem with reading the setup header. According to the Vorbis documentation the first data that should be read after the initial 'vorbis' string is an eight bit integer which when incremented by one, contains the number of codebooks in the header. My problem is that whenever I read this number it seems

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

Hello I had an idea about judging the quality of ogg vorbis (or any other lossy codec) I took a wave-file and encoded it to ogg. Then decoded ogg to wav and inverted it's phase. When mixing the original wav with the phase-inverted decoded ogg-file, any identic parts of compressed and uncompressed audio should be eliminated. Of course there's always a "rest" of sound because

I'm having trouble decoding the number of codebooks out of an ogg file, and was wondering if anyone here could lend a hand? I read in the sync pattern, and I think the codebook dimensions properly, but when I try and read in the number of codebook entries, I get a number larger than the number of bytes in the file, which I have to assume is wrong :) Anyway this is how I read in the numbers :

Hi, Am I correct in understanding that the codebooks are *not* adaptive during compression? I see that Packet #3 is written to the stream in the beginning of the encode process with no modification. If the codebooks are not adaptive, then why are codebooks included in the stream at all? Why not pass the mode type (A or B or C...) instead of all the mode info and let the decoder load it's

We've implemented a vorbis decoder based on Tremor and as part of the documentation we're also writing about psycho acoustic models and encoding. We're quite up to date with the decoding process and psycho acoustics in general but unfortunately not on the psycho acoustic encoding used in Vorbis. We have a few questions that would we would be very thankful to have answer to: Which

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, I try to build codebooks for Vorbis at sampling frequencies other than 32/44/48 KHz. As the first step, I started with residual codebooks. I generated training data on a one minute long 44 KHz audio, using Vorbis compiled with the TRAIN_RES define. I think it worked fine, it generated .vqd files for me. Then I compiled ResVQTrain, which complied OK. Then I run it on the previously

I found this sentence in the Ogg format specs: http://www.xiph.org/ogg/vorbis/doc/vorbis-spec-res.html "A residue vector may represent spectral lines, spectral magnitude, spectral phase or hybrids as mixed by channel coupling." But where does the spectral phase information come from ? AFAIK MDCT doesn't provide any phase information. And in OGG-encoding, MDCT is taking place a few

Pardon my ignorance or laziness (as the case may turn out), but is there documentation or a script/Makefile somewhere that describes exactly how the current codebooks were produced? (I mean, the exact arguments, as opposed to "in general") Are the (exact) training data sets available somewhere? Thanks, --Mike -- [O]ne of the features of the Internet [...] is that small groups of

Hello, There is a coodebook for the pitch gains stored in pgain_table.h. How can we get such a table? I have read in the CELT's paper that the codebook is trained, but I do not understand what that realy means. Can anyone give me an idea about that? Thank you very much. -------------- next part -------------- An HTML attachment was scrubbed... URL:

Anexed is my function for reading codebooks and the Vq Table. My problem is: I read a codeBook number of 41, so i called this function above 41 times. The firtst time, the sync patterns (BCV) is alligned correctly, so it reads correctly. the sencond time it is executed, the patter is not there anymore and there are only 8 BCV in my file. function fReadBits1 is the same as the ogg's read bit

Hi all, I'm in the final stages of putting a new Vorbis RTP draft together, the new sections are below. There are a number of open questions: 1.) At present there is a 16 bit length field for the codebooks. As they are spec'd as being unbound in length, but typically around 15K, are there situations where they may be greater than 64KB? The size limit can be extended to 2MB as there