Displaying 3 results from an estimated 3 matches for "floor1_final_y".
2002 Aug 13
1
Specification documents
...latter, and suggestions for correcting them.
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#1:
in vorbis-spec-floor1.html, packet decode:
Between 14) and 15) a crucial step is missing. Please insert:
14a) [cval] >>= [cbits]
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#2:
in vorbis-spec-floor1.html, curve computation step #1:
The distinction between [floor1_Y] and [floor1_final_Y] looks invalid.
IIRC the prediction loop works as follows:
At the beginning Y[0] and Y[1] contain the absolute amplitudes (log scale)
at the lower resp. upper X boundaries, and the Y[i] for i>=2 are the
wrapped difference values, which are then progressively replaced by the
predicted absolute am...
2002 Sep 23
2
More errors in the file format specification Was: Test files for decoder implementation
Hi,
I've found some more errors in the file format specification (or
at least points, where the specification and actual libvorbis implementation
mismatch):
- Floor 1 / curve computation / step 1: amplitude value synthesis
21) vector [floor1_final_Y] element [i] =
[predicted] - (([val] - 1) divided by 2 using integer division)
hould be:
21) vector [floor1_final_Y] element [i] =
[predicted] - (([val] + 1) divided by 2 using integer division)
<p>- in the function render_line
11) [ady] = [ady] - [base] * [adx]
hould be:
11) [a...
2002 Oct 15
5
Specification change requests
...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 specification,
as I beleive there are more errors in that part.
Tor
<p>###############
#2002-09-23-001
Floor 1 / curve computation / step 1:
23) vector [floor1_final_Y] element [i] =
[predicted] - ([val] - [lowroom]) - 1
hould be:
23) vector [floor1_final_Y] element [i] =
[predicted] - [val] + [hiroom] - 1
due to floor1.c, line 1019:
val = -1-(val-hiroom);
<p>###############
#2002-09-23-002
Floor 1 / curve computation / step 1:
25) vector [floo...