similar to: Vorbis memory consumption

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

Monty Montgomery wrote: > Yes. Without the first three packets (which hold all the codec > settings and all the instruction how to handle the subsequent packets) > the rest of the stream is gibberish. Vorbis can't even unpack the > bits without the codebooks packed into the third header. Curiosity man here. Is there a finite set of predetermined codebooks or is the codebook

Hello, Vorbis uses codebooks, for example to do vectorquantization and huffman-encoding. My question is - are all these codebook dynamicly generated ("trained") or are there also static codebooks used ? If yes, what specific tasks are these 2 types used for, during encoding ? Thanks Stoffke <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project

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

Hi all, I'm porting the Tremor code to an ARM platform. Unfortunately, we didn't use the low mem branch code for CPU performance consideration, and now I find the memory use in it is huge for the embedded system. After looking into the code, I found the header parse, especially, the codebook unpack part takes a lot of memory. Tremor decodes the codebooks to a cache to store

Mandag, 2 juni 2003, skrev du: >On Mon, 02 Jun 2003 21:22, Vitaly Nechyos wrote: >This is what people usually want when they say 'normalization'. AFAIK, you >can't easily tinker with the vorbis frames to add a scale factor in the same >way you can with MP3, but I could be wrong. I could be wrong too, but if I haven't overseen anything, it should be possible to

alpha. (that about sums it up) Will encode and play back via an sdp file and multicast on one computer (over the net if you transfer the sdp file over by hand). rc/rtenc3 and src/rtdec3 are in the style of encoder/decoder_example ...so this means you MUST edit it them to suit your system. For example, I specify my rtenc3 to multicast just on eth1 (to avoid pissing off my cable supplier on

Hi all, Apologies in advance, this email is quite long. I've prepared an updated Vorbis RTP Internet Draft, which is a continuation of draft-moffitt-vorbis-rtp-00.txt which can be found below. If this new draft gets the ok I'd like to submit this to the AVT WG later this week. There are a number of changes over the original I-D, notably the changing of the M bit function in the RTP

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, 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

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

Monty Montgomery wrote, on 7/14/2009 1:44 AM: > On Tue, Jul 14, 2009 at 1:41 AM, Erik de Castro > Lopo<mle+la at mega-nerd.com> wrote: >> Monty Montgomery wrote: >> >>> Yes. Without the first three packets (which hold all the codec >>> settings and all the instruction how to handle the subsequent packets) >>> the rest of the stream is gibberish.

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, Below is the Vorbis RTP Internet Draft as sent to the AVT working group of the IETF. Comments and feedback is still welcomed from the Vorbis community. Cheers Phil ---------------------------8<-----------------8<------------------------ Network Working Group Phil Kerr Internet-Draft The Ogg Vorbis January 07, 2003 Community / OpenDrama

Comments? ---------------------------------------- "Mark Taylor" <mt@sulaco.org> wrote: [...] > This is related to one minor objection I have to vector quantization > based codecs like Vorbis and the MPEG4 VQ codec: they do not compute > the quantization noise during the encoding process. The choice of > codebooks (use a big codebook: low quantization noise, use a

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 everyone, I have got some questions about Speex, I am sorry if my questions are too newbie: 1. For the LP analysis, did Speex use the AR (Autoregressive) model or the ARMA model? 2. Am I right to say that Speex use a multistage VQ (since I believe Speex employs two or more VQ consecutively - based on the manual it says that Speex uses dynamically selectable codebooks (linear

2009/6/18 Adam Rosi-Kessel <adam at rosi-kessel.org>: > On Thu, Jun 18, 2009 at 11:12:30PM +0900, Conrad Parker wrote: >> yow, that's pretty badly corrupted, the vorbis codebooks (usually the >> third packet) is completely gone. It looks like you'd need to throw >> away the first 16 packets, start with fresh headers, and copy in the >> rest of the data

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

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