/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/* JOrbis
* Copyright (C) 2000 ymnk, JCraft,Inc.
*
* Written by: 2000 ymnk<ymnk@jcraft.com>
*
* Many thanks to
* Monty <monty@xiph.org> and
* The XIPHOPHORUS Company http://www.xiph.org/ .
* JOrbis has been based on their awesome works, Vorbis codec.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License
* as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package com.jcraft.jorbis;
import com.jcraft.jogg.Buffer;
class StaticCodeBook {
int dim; // codebook dimensions (elements per vector)
int entries; // codebook entries
int[] lengthlist; // codeword lengths in bits
// mapping
int maptype; // 0=none
// 1=implicitly populated values from map column
// 2=listed arbitrary values
// The below does a linear, single monotonic sequence mapping.
int q_min; // packed 32 bit float; quant value 0 maps to minval
int q_delta; // packed 32 bit float; val 1 - val 0 == delta
int q_quant; // bits: 0 < quant <= 16
int q_sequencep; // bitflag
// additional information for log (dB) mapping; the linear mapping
// is assumed to actually be values in dB. encodebias is used to
// assign an error weight to 0 dB. We have two additional flags:
// zeroflag indicates if entry zero is to represent -Inf dB; negflag
// indicates if we're to represent negative linear values in a
// mirror of the positive mapping.
int[] quantlist; // map == 1: (int)(entries/dim) element column map
// map == 2: list of dim*entries quantized entry vals
StaticCodeBook() {
}
int pack(Buffer opb) {
int i;
boolean ordered = false;
opb.write(0x564342, 24);
opb.write(dim, 16);
opb.write(entries, 24);
// pack the codewords. There are two packings; length ordered and
// length random. Decide between the two now.
for (i = 1; i < entries; i++) {
if (lengthlist[i] < lengthlist[i - 1])
break;
}
if (i == entries)
ordered = true;
if (ordered) {
// length ordered. We only need to say how many codewords of
// each length. The actual codewords are generated
// deterministically
int count = 0;
opb.write(1, 1); // ordered
opb.write(lengthlist[0] - 1, 5); // 1 to 32
for (i = 1; i < entries; i++) {
int _this = lengthlist[i];
int _last = lengthlist[i - 1];
if (_this > _last) {
for (int j = _last; j < _this; j++) {
opb.write(i - count, Util.ilog(entries - count));
count = i;
}
}
}
opb.write(i - count, Util.ilog(entries - count));
} else {
// length random. Again, we don't code the codeword itself, just
// the length. This time, though, we have to encode each length
opb.write(0, 1); // unordered
// algortihmic mapping has use for 'unused entries', which we tag
// here. The algorithmic mapping happens as usual, but the unused
// entry has no codeword.
for (i = 0; i < entries; i++) {
if (lengthlist[i] == 0)
break;
}
if (i == entries) {
opb.write(0, 1); // no unused entries
for (i = 0; i < entries; i++) {
opb.write(lengthlist[i] - 1, 5);
}
} else {
opb.write(1, 1); // we have unused entries; thus we tag
for (i = 0; i < entries; i++) {
if (lengthlist[i] == 0) {
opb.write(0, 1);
} else {
opb.write(1, 1);
opb.write(lengthlist[i] - 1, 5);
}
}
}
}
// is the entry number the desired return value, or do we have a
// mapping? If we have a mapping, what type?
opb.write(maptype, 4);
switch (maptype) {
case 0:
// no mapping
break;
case 1:
case 2:
// implicitly populated value mapping
// explicitly populated value mapping
if (quantlist == null) {
// no quantlist? error
return (-1);
}
// values that define the dequantization
opb.write(q_min, 32);
opb.write(q_delta, 32);
opb.write(q_quant - 1, 4);
opb.write(q_sequencep, 1);
{
int quantvals = 0;
switch (maptype) {
case 1:
// a single column of (c->entries/c->dim) quantized values for
// building a full value list algorithmically (square lattice)
quantvals = maptype1_quantvals();
break;
case 2:
// every value (c->entries*c->dim total) specified explicitly
quantvals = entries * dim;
break;
}
// quantized values
for (i = 0; i < quantvals; i++) {
opb.write(Math.abs(quantlist[i]), q_quant);
}
}
break;
default:
// error case; we don't have any other map types now
return (-1);
}
return (0);
}
// unpacks a codebook from the packet buffer into the codebook struct,
// readies the codebook auxiliary structures for decode
int unpack(Buffer opb) {
int i;
//memset(s,0,sizeof(static_codebook));
// make sure alignment is correct
if (opb.read(24) != 0x564342) {
// goto _eofout;
clear();
return (-1);
}
// first the basic parameters
dim = opb.read(16);
entries = opb.read(24);
if (entries == -1) {
// goto _eofout;
clear();
return (-1);
}
// codeword ordering.... length ordered or unordered?
switch (opb.read(1)) {
case 0:
// unordered
lengthlist = new int[entries];
// allocated but unused entries?
if (opb.read(1) != 0) {
// yes, unused entries
for (i = 0; i < entries; i++) {
if (opb.read(1) != 0) {
int num = opb.read(5);
if (num == -1) {
// goto _eofout;
clear();
return (-1);
}
lengthlist[i] = num + 1;
} else {
lengthlist[i] = 0;
}
}
} else {
// all entries used; no tagging
for (i = 0; i < entries; i++) {
int num = opb.read(5);
if (num == -1) {
// goto _eofout;
clear();
return (-1);
}
lengthlist[i] = num + 1;
}
}
break;
case 1:
// ordered
{
int length = opb.read(5) + 1;
lengthlist = new int[entries];
for (i = 0; i < entries;) {
int num = opb.read(Util.ilog(entries - i));
if (num == -1) {
// goto _eofout;
clear();
return (-1);
}
for (int j = 0; j < num; j++, i++) {
lengthlist[i] = length;
}
length++;
}
}
break;
default:
// EOF
return (-1);
}
// Do we have a mapping to unpack?
switch ((maptype = opb.read(4))) {
case 0:
// no mapping
break;
case 1:
case 2:
// implicitly populated value mapping
// explicitly populated value mapping
q_min = opb.read(32);
q_delta = opb.read(32);
q_quant = opb.read(4) + 1;
q_sequencep = opb.read(1);
{
int quantvals = 0;
switch (maptype) {
case 1:
quantvals = maptype1_quantvals();
break;
case 2:
quantvals = entries * dim;
break;
}
// quantized values
quantlist = new int[quantvals];
for (i = 0; i < quantvals; i++) {
quantlist[i] = opb.read(q_quant);
}
if (quantlist[quantvals - 1] == -1) {
// goto _eofout;
clear();
return (-1);
}
}
break;
default:
// goto _eofout;
clear();
return (-1);
}
// all set
return (0);
// _errout:
// _eofout:
// vorbis_staticbook_clear(s);
// return(-1);
}
// there might be a straightforward one-line way to do the below
// that's portable and totally safe against roundoff, but I haven't
// thought of it. Therefore, we opt on the side of caution
private int maptype1_quantvals() {
int vals = (int) (Math.floor(Math.pow(entries, 1. / dim)));
// the above *should* be reliable, but we'll not assume that FP is
// ever reliable when bitstream sync is at stake; verify via integer
// means that vals really is the greatest value of dim for which
// vals^b->bim <= b->entries
// treat the above as an initial guess
while (true) {
int acc = 1;
int acc1 = 1;
for (int i = 0; i < dim; i++) {
acc *= vals;
acc1 *= vals + 1;
}
if (acc <= entries && acc1 > entries) {
return (vals);
} else {
if (acc > entries) {
vals--;
} else {
vals++;
}
}
}
}
void clear() {
}
// unpack the quantized list of values for encode/decode
// we need to deal with two map types: in map type 1, the values are
// generated algorithmically (each column of the vector counts through
// the values in the quant vector). in map type 2, all the values came
// in in an explicit list. Both value lists must be unpacked
float[] unquantize() {
if (maptype == 1 || maptype == 2) {
int quantvals;
float mindel = float32_unpack(q_min);
float delta = float32_unpack(q_delta);
float[] r = new float[entries * dim];
// maptype 1 and 2 both use a quantized value vector, but
// different sizes
switch (maptype) {
case 1:
// most of the time, entries%dimensions == 0, but we need to be
// well defined. We define that the possible vales at each
// scalar is values == entries/dim. If entries%dim != 0, we'll
// have 'too few' values (values*dim<entries), which means that
// we'll have 'left over' entries; left over entries use zeroed
// values (and are wasted). So don't generate codebooks like that
quantvals = maptype1_quantvals();
for (int j = 0; j < entries; j++) {
float last = 0.f;
int indexdiv = 1;
for (int k = 0; k < dim; k++) {
int index = (j / indexdiv) % quantvals;
float val = quantlist[index];
val = Math.abs(val) * delta + mindel + last;
if (q_sequencep != 0)
last = val;
r[j * dim + k] = val;
indexdiv *= quantvals;
}
}
break;
case 2:
for (int j = 0; j < entries; j++) {
float last = 0.f;
for (int k = 0; k < dim; k++) {
float val = quantlist[j * dim + k];
//if((j*dim+k)==0){System.err.println(" | 0 -> "+val+" | ");}
val = Math.abs(val) * delta + mindel + last;
if (q_sequencep != 0)
last = val;
r[j * dim + k] = val;
//if((j*dim+k)==0){System.err.println(" $ r[0] -> "+r[0]+" | ");}
}
}
//System.err.println("\nr[0]="+r[0]);
}
return (r);
}
return (null);
}
// 32 bit float (not IEEE; nonnormalized mantissa +
// biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm
// Why not IEEE? It's just not that important here.
static final int VQ_FEXP = 10;
static final int VQ_FMAN = 21;
static final int VQ_FEXP_BIAS = 768; // bias toward values smaller than 1.
// doesn't currently guard under/overflow
static long float32_pack(float val) {
int sign = 0;
int exp;
int mant;
if (val < 0) {
sign = 0x80000000;
val = -val;
}
exp = (int) Math.floor(Math.log(val) / Math.log(2));
mant = (int) Math.rint(Math.pow(val, (VQ_FMAN - 1) - exp));
exp = (exp + VQ_FEXP_BIAS) << VQ_FMAN;
return (sign | exp | mant);
}
static float float32_unpack(int val) {
float mant = val & 0x1fffff;
float exp = (val & 0x7fe00000) >>> VQ_FMAN;
if ((val & 0x80000000) != 0)
mant = -mant;
return (ldexp(mant, ((int) exp) - (VQ_FMAN - 1) - VQ_FEXP_BIAS));
}
static float ldexp(float foo, int e) {
return (float) (foo * Math.pow(2, e));
}
}