similar to: Query on Codewords length

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

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

Hi, While following the developer mailing list, I came across "tremor-lowmem" version. I did some search of it in Xiph.org and "tremor" source code but wasn't able to find it. I would like to know if there is any separate thread for the "tremor-lowmem" version as we are working on the fixed point implementation of Vorbis code and we are looking forward for

Hi radeonhd, nouveau, mesa3d developers, Firstly, thank you all very much for all the important work you do. I've been working as a part-time developer on the "Spring RTS" project (open-source game engine) which runs on linux (and other os). Some time ago I tried the engine on the open-source ATI radeonhd driver, which I understand to be partly based on mesa 3d, and all textures

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

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).

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

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/

Hi, I need another clarification regarding the standard. In floor0 header decode (setup), the point no.7 says that if any of [floor0_order], [floor0_rate], [floor0_bark_map_size], floor0_amplitude_bits], [floor0_amplitude_offset] or [floor0_number_of_books] are less than zero, the stream is not decodable But as we see, all those values are read as unsigned integers. Now I'm not able to

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

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Hi, All help is appreciated. I am looking at the function "vorbis_staticbook_unpack" in codebook.c I guess this function just reads the codebooks in some structure (static_codebook) and does not actually map the codewords to the codevalues. Does anyone know what functions can I use in this function to actually view this mapping? I just want to display something like below: I can

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

During the interesting interview that binaryfreedom has made with Monty and Jack, Monty mentions cascading, a feature that will be added, quote: "Cascading is the ability to make multiple passes through the frequency spectrum, iteratively filling in more detail, like a progressive jpeg". What are the advantages of something like this - does this generally improves quality or is it used

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 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.

Hi, I am trying to understand the building of Huffman codes from the code lengths. In the Tremor code first I see that the codewords are being generated by the function _make_words() and then sorted. After this I see some magic code and something related to unused entries. Does the code generate code words for unused entries too? Are these unused entry code words used during the decode

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.

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

James A. Peltier <jpeltier at sfu.ca> wrote: > While I can't assure you that upgrading to 7 will fix the problem, > the likeliness that will work is at least 50% better being as 7 is > based on a newer kernel. I've installed CentOS 7 with the latest kernel from elrepo (4.11.8), and I can't get Grub to install. I think I'll have to conclude that it really