Displaying 20 results from an estimated 700 matches similar to: "Floor1 header decoding"
2003 Feb 13
1
Bug in vorbis documentation
I've been tinkering (not very seriously) with writing a vorbis (and ogg)
decoder from scratch using only the documentation. I've got as far as
starting to decoding floor 1 without any problems. However, there's a
problem in the floor 1 header decode. Specifically:
22) [floor1_values] = [floor1_values] + [floor1_class_dimensions] element
[i]
hould probably be:
22) [floor1_values] =
2002 Aug 02
2
More spec notes
A few more notes on the specs -- I just spent a few minutes and did up
floor 1 header decode. Short and sweet, but still important.
Monty, please read these and my several earliers -- I'm trying to
improve and validate the spec for your codec, and though I understand
you were taking a break before, a reply would be appreciated. Note
(again, if you read my other emails) that if you help me get
2009 Aug 21
1
Floor1 encode/decode and FLOOR1_fromdB_LOOKUP
Hello,
I have two questions concerning floor1 encoding/decoding. First I'll ask
about the FLOOR1_fromdB_LOOKUP table: what is it's purpose? Is it to convert
the amplitude differences between [floor1_Y] values to a dB scale? And, if
I'm right with that, here comes the 2nd question: when render_line0 is used
to encode floor1, then floor1_inverse2 must be used in decode (in order to
2009 Nov 08
1
Floor1 X axis frequency units?
Hello,
I was printing some Floor1 X values from a test audio file, and the values
that I've obtained look mostly like the following:
[23,33,46,65,79,93,111,130,158,186,220,260,312,372,464,556,750,1024] => For
long blocks
[8,16,33,70,128] => For short blocks
Obviously they are not in Hz, so, could someone please tell me what is the
unit used? In the specs it's said that the Floor1
2001 Aug 16
2
bug in rc2: floor1.c
Hello,
There is a bug in the current version of vorbis/lib/floor1.c.
The line that says:-
qsort(sortpointer,n,sizeof(int),icomp);
should be:-
qsort(sortpointer,n,sizeof(int *),icomp);
But somebody probably fixed that already. :)
Also, I'd like to know how I can encode a file using the channel
coupling modes. oggenc doesn't have an option for that yet.
Greetings,
2009 Nov 11
1
Floor1 doubts...
Hello,
I've read in a thread from this mailing list (
http://lists.xiph.org/pipermail/vorbis-dev/2009-September/020019.html) that
the usage of FLOOR1_fromdB_LOOKUP table is to convert Floor1 values from a
dB scale to a linear scale. In a dB scale, given a reference value, the
other dB values are obtained from it, normally dB_value = 10log(p1/p0),
where p0 is the reference value. Supposing p0
2009 Sep 16
0
How floor1 modifications may affect final (de)coded samples?
Hello,
I've been "playing" a little with the floor1 encoding, and my game has posed
me a question. I've been modifying (just curiosity) manually, and randomly
(not too great modifications), the quantized [floor1_Y] values, just before
coding them with the codebooks. As, if I'm not wrong, the [floor1_Y]
obtained are then removed to get the residue vectors for each channel, I
2009 May 31
0
Bit allocation dependetnt on masking threshold and floor1 inverse dB lookup table
Hi,
We are two students doing project with Vorbis audio compression for our B.Sc
studies.
We have two questions:
Our first question related to the floor1 inverse dB lookup table.
As we understood the floor values encoded as offset integers (Y) from 1 to
256 and then used as index in the floor1_inverse_dB_table to get an
encoded value. This value (denoted as X) is inverse of linear frequency so
2001 Oct 12
2
FLOOR_fromdB_LOOKUP
Hello,
You know, I always worry about the precision
and the float constants... and there is a large
lookup table in the floor1.c ... and I figure out
a way to keep the code size and speed, but
to improve the precision at this lookup table.
(the difference is small, but audible)
Here is the modifications in the floor1.c:
tatic unsigned long FLOOR_fromdB_LOOKUP[256]={
2002 Aug 13
1
Specification documents
Hi everyone,
after having an extensive look at the reference decoder as well as the
specification documents, I'd like to point out what I think to be some
minor omissions/flaws in the latter, and suggestions for correcting them.
---
#1:
in vorbis-spec-floor1.html, packet decode:
Between 14) and 15) a crucial step is missing. Please insert:
14a) [cval] >>= [cbits]
----
#2:
in
2013 Jul 26
0
[LLVMdev] floor
Here is a test case:
extern double floor(double);
extern double floor_(double);
double x = 1.5;
double y, y_;
void foo() {
double y = floor(x);
double y_ = floor_(x);
}
If I compile this for Mips16, it calls the proper helper function for
floor_ but not for floor, because the signature for floor in callee info
is wrong. Args[0] = void RetTy = void
2003 Mar 25
1
problems with beta4 encoder
Hi,
Am trying to run beta4 encoder on a Sun machine. Want to compare floor0
and floor1. Do not have autoconf and automake.
Got the encoder to compile with a simple makefile. The only define i am
using is NO_FLOAT_MATH_LIB.
The encoded file when played(winamp) gives out plain noise. Am i
missing any other flags/defs?
-Cathy
<p>---------------------------------
Do you Yahoo!?
Yahoo!
2014 Mar 20
2
BARK implementation (or specification) error
Hi,
In the course of some work which I describe below, I have found a very significant difference between the BARK function described in the Vorbis specification and its implementation in libvorbis.
In the specificationhttp://xiph.org/vorbis/doc/Vorbis_I_spec.pdf
bark(x) = 13.1arctan(.00074x) + 2.24arctan(.0000000185x**2 + .0001x)
In the libvorbis code
2003 Aug 08
3
where to get vorbis files with all configuration the spec support
Hi
According to vorbis I spec, there are several configurations. There are 2
formats of floor, 3 formats of residue and 3 look up types of VQ codebook,
etc. I think to get all kinds of vorbis file with these configurations but
what I have got from network only support some of the formats (Ex. floor1,
residue 1 & 2, VQ lookup type0 & 1). I downloaded several freeware vorbis
encoder
2002 Jul 08
1
Divide by zero in accumulate_fit
Hi,
Lately, my oggenc builds (from CVS) haven't been running correctly. In a few
debugging sessions, I've found that I'm getting a divide by zero exception.
The exception happens in accumulate_fit (floor1.c), line 455:
int weight=nb*info->twofitweight/na;
Here is the call stack:
accumulate_fit
floot1_fit
mapping0_forward
vorbis_analysis
oe_encode
main
The
2005 Mar 05
2
Vorbis I specification errata
Hi!
While implementing a Vorbis I decoder, I have found a few errors in the
specification. After making the following changes everything works as
advertised, thank you!
Errata:
1.)
In section 7.2.2 Floor1 header decode (on a side not wouldn't 7.2.2.1 be the
logical number here, looking at the overall structure of the document?),
step 21 element element ([j] + [floor1_values]) should
2003 Nov 08
1
Compiling problems libvorbis 2.0
Hi Guys,
I want to compile libvorbis, but I get this error message if I made a make.
I use Sun Solaris 9 on a UltraSPARC Server and gcc 3.3
can anyone help me, please?
<p>Best Thanks
Daniel
Here the message output from compiling.
-----------------------------------------
/usr/ccs/bin/ld -G -z defs -h libvorbis.so.0 -o .libs/libvorbis.so.0.3.0
mdct.lo smallft.lo block.lo envelope.lo
2005 Sep 25
3
several questions
VorbisHi
Any help is appreciate.
I have two questions.
First, I looked into the vorbis-?-specific and was confused by the floor1 algorithm.
I think at last the aim is to derive the piecewise curve with the list X and Y,then when encodering ,why not
use the selected point orderly to get the curve ? In other words, the specific use the list of [0,128,64,32,96,16,48,80] ,
why can not use
2002 Oct 15
5
Specification change requests
Hi,
as Conrad suggested, I've made a complete list of all points in the
specification, which I beleive are errors, or where the explanation
is unclear, contains unneccessary steps and so on.
I hope someone has time to look through the points and if and when
accepting or rejecting them be so very kind and inform me about it.
I will also once again try to work through the residue
2013 Jul 26
2
[LLVMdev] floor
I'm getting some problems because it seems that the compiler is treating
"floor" differently from other math library functions like "sin".
The Args and RetVal have the parameter and return types marked as void.
For mips16, it's important that I be able to know the original signature
for floating point functions.
In some cases, need to create calls to helper