Displaying 20 results from an estimated 6000 matches similar to: "After Code book"
2004 Feb 19
1
read codebook function
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
2004 Feb 18
1
OggVorbis "tutorial" file
Hi,
I would like to ask if someone couldhelp me. I am writing a decoder for ogg-vorbis. I am not using the libvorbis because we want a code using our memory functions and I am going to rip some of the decoder functionality as we want only to use mono, 44.100, 96-160kbs sound files. We want to write the fastest and cleanest code possible even using assembler functions where possible.
I have
2008 Sep 02
1
How can I minimize the memory use in Tremor?
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
2005 Sep 13
1
Clarification on code books usage.
Dear All,
As i have understood it , the Huffman codebook uses a huffman code
present in the bitstream ( lets us say it is decoding a floor 1 Y value
using the specifed codebook number ) to walk through the huffman code
book tree till it hits a leaf node which is nothing but the entry number.
If we consider our floor 1 Y value example , this entry number is
directly being used as the Y value.
2000 Nov 17
1
Floor codebooks vs. Residue codebooks
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
2006 Feb 20
3
Huge VQ codebooks
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
2001 Oct 18
4
libvorbisrtp-0.1
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
2009 Jul 14
2
Fixing ogg vorbis corruption caused by bad metadata
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
2001 Apr 26
1
From LAME mailing list
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
2003 Jun 13
2
Trouble decoding number of codebooks
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 :
2003 Feb 11
1
Update on Vorbis RTP I-D
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
2005 Aug 08
3
Reg. getting codewords from codelengths
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
1999 Nov 11
1
VQ codebook sanity check (please help)
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
2004 Mar 19
2
Packet questions
Sorry the basic questions but first of all, what are the packet used afterall?? seems that only pages are important
if i have a segment table like the one listed above means that i have 4 packets and each value is its size???
199 195 200 207
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2004 May 18
2
encode example
Hi,
I am testing the encoder example and I have a question about it... How can I encode a mono file in 22050 and 44100?
I've changed the init values to:
ret=vorbis_encode_init_vbr(&vi,1,22050,.5) ;
and in the loop:
// uninterleave samples
for(i=0;i<bytes/2;i++)
{
buffer[0][i]=((readbuffer[i*2+1]<<8)|(0x00ff&(int)readbuffer[i*2]))/32768.f;
}
..
1995 Nov 14
1
Vorbis Codebooks
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
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Ogg project
2004 May 07
2
Samples inside a packet
Hi,
Just to confirm:
for blockSizes of 256 and 2048 (0 and 1 respectively) the number of sample inside this audio packet will be acording to table below:
LastWind ThisWin Samples
0 0 128
0 1 576
1 0 576
1 1 1024
Correct??
thanks a lot.
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2005 Oct 14
2
Steganographic extension to Speex
Hello kind developers,
I am planning on creating a steganographic extension for speex/CELP.
Since speex/CELP is lossy, there should be quite many bits that one
can use for hiding data.
I'm familiar with the principles of CELP (two filter loops, one for
pitch, the other for formants, let the raw speech frame run through
those filter loops, take residue signal, map it on a codebook entry,
2004 Feb 05
1
Psychoacoustic model
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
2006 Sep 08
1
Question regarding Speex
Hi,
I have some questions regarding Speex. please reply as soon as
possible.
where are the two filter loops applied to the raw signal?
where is the residue (innovation) signal calculated?
where is the innovation mapped on a codebook entry (key)?
which bits of a transmitted frame are the two filters, which are codebook
keys?
Is the codebook from the beginning on static (so already known by