ref: dcb8dde7e12044abd7b4f9ffea89f2b9ecabd0f9
dir: /libfaac/huff2.c/
/****************************************************************************
Huffman coding
Copyright (C) 2017 Krzysztof Nikiel
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
****************************************************************************/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "coder.h"
#include "huffdata.h"
#include "huff2.h"
#include "bitstream.h"
static int escape(int x, int *code)
{
int preflen = 0;
int base = 32;
if (x >= 8192)
{
fprintf(stderr, "%s(%d): x_quant >= 8192\n", __FILE__, __LINE__);
return 0;
}
*code = 0;
while (base <= x)
{
base <<= 1;
*code <<= 1;
*code |= 1;
preflen++;
}
base >>= 1;
// separator
*code <<= 1;
*code <<= (preflen + 4);
*code |= (x - base);
return (preflen << 1) + 5;
}
static int huffcode(int *qs /* quantized spectrum */,
int len,
int bnum,
CoderInfo *coder)
{
static hcode16_t * const hmap[12] = {0, book01, book02, book03, book04,
book05, book06, book07, book08, book09, book10, book11};
hcode16_t *book;
int cnt;
int bits = 0, blen;
int ofs, *qp;
int data;
int idx;
int datacnt;
if (coder)
datacnt = coder->datacnt;
else
datacnt = 0;
if ((bnum < 1) || (bnum > 11))
{
fprintf(stderr, "%s(%d) book %d out of range\n", __FILE__, __LINE__, bnum);
return -1;
}
book = hmap[bnum];
switch (bnum)
{
case 1:
case 2:
for(ofs = 0; ofs < len; ofs += 4)
{
qp = qs+ofs;
idx = 27 * qp[0] + 9 * qp[1] + 3 * qp[2] + qp[3] + 40;
blen = book[idx].len;
if (coder)
{
data = book[idx].data;
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
break;
case 3:
case 4:
for(ofs = 0; ofs < len; ofs += 4)
{
qp = qs+ofs;
idx = 27 * abs(qp[0]) + 9 * abs(qp[1]) + 3 * abs(qp[2]) + abs(qp[3]);
blen = book[idx].len;
if (!coder)
{
// add sign bits
for(cnt = 0; cnt < 4; cnt++)
if(qp[cnt])
blen++;
}
else
{
data = book[idx].data;
// add sign bits
for(cnt = 0; cnt < 4; cnt++)
{
if(qp[cnt])
{
blen++;
data <<= 1;
if (qp[cnt] < 0)
data |= 1;
}
}
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
break;
case 5:
case 6:
for(ofs = 0; ofs < len; ofs += 2)
{
qp = qs+ofs;
idx = 9 * qp[0] + qp[1] + 40;
blen = book[idx].len;
if (coder)
{
data = book[idx].data;
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
break;
case 7:
case 8:
for(ofs = 0; ofs < len; ofs += 2)
{
qp = qs+ofs;
idx = 8 * abs(qp[0]) + abs(qp[1]);
blen = book[idx].len;
if (!coder)
{
for(cnt = 0; cnt < 2; cnt++)
if(qp[cnt])
blen++;
}
else
{
data = book[idx].data;
for(cnt = 0; cnt < 2; cnt++)
{
if(qp[cnt])
{
blen++;
data <<= 1;
if (qp[cnt] < 0)
data |= 1;
}
}
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
break;
case 9:
case 10:
for(ofs = 0; ofs < len; ofs += 2)
{
qp = qs+ofs;
idx = 13 * abs(qp[0]) + abs(qp[1]);
blen = book[idx].len;
if (!coder)
{
for(cnt = 0; cnt < 2; cnt++)
if(qp[cnt])
blen++;
}
else
{
data = book[idx].data;
for(cnt = 0; cnt < 2; cnt++)
{
if(qp[cnt])
{
blen++;
data <<= 1;
if (qp[cnt] < 0)
data |= 1;
}
}
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
break;
case 11:
for(ofs = 0; ofs < len; ofs += 2)
{
int x0, x1;
qp = qs+ofs;
x0 = abs(qp[0]);
x1 = abs(qp[1]);
if (x0 > 16)
x0 = 16;
if (x1 > 16)
x1 = 16;
idx = 17 * x0 + x1;
blen = book[idx].len;
if (!coder)
{
for(cnt = 0; cnt < 2; cnt++)
if(qp[cnt])
blen++;
}
else
{
data = book[idx].data;
for(cnt = 0; cnt < 2; cnt++)
{
if(qp[cnt])
{
blen++;
data <<= 1;
if (qp[cnt] < 0)
data |= 1;
}
}
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
if (x0 >= 16)
{
blen = escape(abs(qp[0]), &data);
if (coder)
{
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
if (x1 >= 16)
{
blen = escape(abs(qp[1]), &data);
if (coder)
{
coder->s[datacnt].data = data;
coder->s[datacnt++].len = blen;
}
bits += blen;
}
}
break;
}
if (coder)
coder->datacnt = datacnt;
return bits;
}
int huffbook(CoderInfo *coder,
int *qs /* quantized spectrum */,
int len)
{
int cnt;
int maxq = 0;
int bookmin, lenmin;
for (cnt = 0; cnt < len; cnt++)
{
int q = abs(qs[cnt]);
if (maxq < q)
maxq = q;
}
#define BOOKMIN(n)bookmin=n;lenmin=huffcode(qs,len,bookmin,0);if(huffcode(qs,len,bookmin+1,0)<lenmin)bookmin++;
if (maxq < 1)
{
bookmin = ZERO_HCB;
lenmin = 0;
}
else if (maxq < 2)
{
BOOKMIN(1);
}
else if (maxq < 3)
{
BOOKMIN(3);
}
else if (maxq < 5)
{
BOOKMIN(5);
}
else if (maxq < 8)
{
BOOKMIN(7);
}
else if (maxq < 13)
{
BOOKMIN(9);
}
else
{
bookmin = ESC_HCB;
lenmin = huffcode(qs, len, bookmin, 0);
}
coder->book[coder->bandcnt] = bookmin;
if (bookmin > ZERO_HCB)
huffcode(qs, len, bookmin, coder);
return 0;
}
int writebooks(CoderInfo *coder, BitStream *stream, int write)
{
int cnt;
int bookcnt;
int bits = 0;
int previous;
int maxcnt, cntbits;
int group;
int bookbits = 4;
#ifdef DRM
bookbits = 5; /* 5 bits in case of VCB11 */
#endif
if (coder->block_type == ONLY_SHORT_WINDOW){
maxcnt = 7;
cntbits = 3;
} else {
maxcnt = 31;
cntbits = 5;
}
for (group = 0; group < coder->groups.n; group++)
{
int band = group * coder->sfbn;
int book = coder->book[band];
previous = book;
bookcnt = 1;
if (write) {
PutBit(stream, book, bookbits);
}
bits += bookbits;
for (cnt = band + 1; cnt < (band + coder->sfbn); cnt++)
{
book = coder->book[cnt];
#ifdef DRM
/* sect_len is not transmitted in case the codebook for a */
/* section is 11 or in the range of 16 and 31 */
if ((previous == 11) ||
((previous >= 16) && (previous <= 32)))
{
if (write)
PutBit(stream, book, bookbits);
bits += bookbits;
previous = book;
bookcnt=1;
} else
#endif
if (book != previous)
{
if (write) {
PutBit(stream, bookcnt, cntbits);
}
bits += cntbits;
if (bookcnt >= maxcnt)
{
if (write)
PutBit(stream, 0, cntbits);
bits += cntbits;
}
if (write)
PutBit(stream, book, bookbits);
bits += bookbits;
previous = book;
bookcnt = 1;
continue;
}
if (bookcnt >= maxcnt)
{
if (write) {
PutBit(stream, bookcnt, cntbits);
}
bits += cntbits;
bookcnt = 1;
}
else {
bookcnt++;
}
}
#ifdef DRM
if (!((previous == 11) || ((previous >= 16) && (previous <= 32))))
#endif
{
if (write)
PutBit(stream, bookcnt, cntbits);
bits += cntbits;
if (bookcnt >= maxcnt)
{
if (write)
PutBit(stream, 0, cntbits);
bits += cntbits;
}
}
}
return bits;
}
int writesf(CoderInfo *coder, BitStream *stream, int write)
{
int cnt;
int bits = 0;
int diff, length;
int lastsf;
int lastis;
lastsf = coder->global_gain;
lastis = 0;
// fixme: move range check to quantizer
for (cnt = 0; cnt < coder->bandcnt; cnt++)
{
int book = coder->book[cnt];
if ((book == INTENSITY_HCB) || (book== INTENSITY_HCB2))
{
diff = coder->sf[cnt] - lastis;
if (diff > 60)
diff = 60;
if (diff < -60)
diff = -60;
length = book12[60 + diff].len;
bits += length;
lastis += diff;
if (write)
PutBit(stream, book12[60 + diff].data, length);
}
else if (book)
{
diff = coder->sf[cnt] - lastsf;
if (diff > 60)
diff = 60;
if (diff < -60)
diff = -60;
length = book12[60 + diff].len;
bits += length;
lastsf += diff;
if (write)
PutBit(stream, book12[60 + diff].data, length);
}
}
return bits;
}