scummvm/image/codecs/indeo/vlc.cpp
2021-12-26 18:48:43 +01:00

336 lines
9.9 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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/>.
*
*/
/* VLC code
*
* Original copyright note: * Intel Indeo 4 (IV41, IV42, etc.) video decoder for ffmpeg
* written, produced, and directed by Alan Smithee
*/
#include "image/codecs/indeo/vlc.h"
#include "image/codecs/indeo/mem.h"
#include "common/textconsole.h"
#include "common/util.h"
namespace Image {
namespace Indeo {
/**
* Quicksort
* This sort is fast, and fully inplace but not stable and it is possible
* to construct input that requires O(n^2) time but this is very unlikely to
* happen with non constructed input.
*/
#define AV_QSORT(p, num, type, cmp) do {\
void *stack[64][2];\
int sp = 1;\
stack[0][0] = p;\
stack[0][1] = (p)+(num)-1;\
while(sp){\
type *start = (type *)stack[--sp][0];\
type *end = (type *)stack[ sp][1];\
while (start < end) {\
if (start < end-1) {\
int checksort = 0;\
type *right = end - 2;\
type *left = start + 1;\
type *mid = start + ((end - start) >> 1);\
if(cmp(start, end) > 0) {\
if(cmp( end, mid) > 0) SWAP(*start, *mid);\
else SWAP(*start, *end);\
} else {\
if(cmp(start, mid) > 0) SWAP(*start, *mid);\
else checksort = 1;\
}\
if (cmp(mid, end) > 0) { \
SWAP(*mid, *end);\
checksort = 0;\
}\
if(start == end - 2) break;\
SWAP(end[-1], *mid);\
while (left <= right) {\
while (left<=right && cmp(left, end - 1) < 0)\
left++;\
while (left<=right && cmp(right, end - 1) > 0)\
right--;\
if (left <= right) {\
SWAP(*left, *right);\
left++;\
right--;\
}\
}\
SWAP(end[-1], *left);\
if(checksort && (mid == left - 1 || mid == left)){\
mid= start;\
while(mid<end && cmp(mid, mid+1) <= 0)\
mid++;\
if(mid==end)\
break;\
}\
if (end - left < left - start){\
stack[sp ][0] = start;\
stack[sp++][1] = right;\
start = left + 1;\
} else {\
stack[sp ][0] = left+1;\
stack[sp++][1] = end;\
end = right;\
}\
} else {\
if (cmp(start, end) > 0)\
SWAP(*start, *end);\
break;\
}\
}\
}\
} while (0)
#define COPY(condition)\
for (i = 0; i < nbCodes; i++) { \
buf[j].bits = getData(p_bits, i, bitsWrap, bitsSize); \
if (!(condition)) \
continue; \
if (buf[j].bits > (3 * nbBits) || buf[j].bits > 32) { \
warning("Too long VLC (%d) in init_vlc", buf[j].bits); \
if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
free(buf); \
return -1; \
} \
buf[j].code = getData(codes, i, codesWrap, codesSize); \
if (buf[j].code >= (1LL << buf[j].bits)) { \
warning("Invalid code %x for %d in init_vlc", buf[j].code, i); \
if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
free(buf); \
return -1; \
} \
if (flags & INIT_VLC_LE) \
buf[j].code = bitswap32(buf[j].code); \
else \
buf[j].code <<= 32 - buf[j].bits; \
if (symbols) \
buf[j].symbol = getData(symbols, i, symbolsWrap, symbolsSize); \
else \
buf[j].symbol = i; \
j++; \
}
/*------------------------------------------------------------------------*/
VLC::VLC() : _bits(0), _tableSize(0), _tableAllocated(0), _table(nullptr) {
}
int VLC::init_vlc(int nbBits, int nbCodes, const void *bits, int bitsWrap, int bitsSize,
const void *codes, int codesWrap, int codesSize, int flags) {
return init_vlc(nbBits, nbCodes, bits, bitsWrap, bitsSize, codes, codesWrap,
codesSize, nullptr, 0, 0, flags);
}
int VLC::init_vlc(int nbBits, int nbCodes, const void *p_bits, int bitsWrap,
int bitsSize, const void *codes, int codesWrap, int codesSize,
const void *symbols, int symbolsWrap, int symbolsSize, int flags) {
VLCcode *buf;
int i, j, ret;
VLCcode localbuf[1500]; // the maximum currently needed is 1296 by rv34
VLC localvlc, *vlc;
vlc = this;
vlc->_bits = nbBits;
if (flags & INIT_VLC_USE_NEW_STATIC) {
assert((nbCodes + 1) <= (int)FF_ARRAY_ELEMS(localbuf));
buf = localbuf;
localvlc = *this;
vlc = &localvlc;
vlc->_tableSize = 0;
} else {
vlc->_table = NULL;
vlc->_tableAllocated = 0;
vlc->_tableSize = 0;
buf = (VLCcode *)malloc((nbCodes + 1) * sizeof(VLCcode));
assert(buf);
}
assert(symbolsSize <= 2 || !symbols);
j = 0;
COPY(buf[j].bits > nbBits);
// qsort is the slowest part of init_vlc, and could probably be improved or avoided
AV_QSORT(buf, j, VLCcode, compareVlcSpec);
COPY(buf[j].bits && buf[j].bits <= nbBits);
nbCodes = j;
ret = vlc->buildTable(nbBits, nbCodes, buf, flags);
if (flags & INIT_VLC_USE_NEW_STATIC) {
if (vlc->_tableSize != vlc->_tableAllocated)
warning("needed %d had %d", vlc->_tableSize, vlc->_tableAllocated);
assert(ret >= 0);
*this = *vlc;
} else {
free(buf);
if (ret < 0) {
avFreeP(&vlc->_table);
return -1;
}
}
return 0;
}
void VLC::freeVlc() {
free(_table);
}
int VLC::compareVlcSpec(const void *a, const void *b) {
const VLCcode *sa = (const VLCcode *)a, *sb = (const VLCcode *)b;
return (sa->code >> 1) - (sb->code >> 1);
}
int VLC::buildTable(int tableNbBits, int nbCodes,
VLCcode *codes, int flags) {
VLC *vlc = this;
int tableSize, tableIndex, index, codePrefix, symbol, subtableBits;
int i, j, k, n, nb, inc;
uint32 code;
VLC_TYPE (*table)[2];
tableSize = 1 << tableNbBits;
if (tableNbBits > 30)
return -1;
tableIndex = allocTable(tableSize, flags & INIT_VLC_USE_NEW_STATIC);
//warning("new table index=%d size=%d", tableIndex, tableSize);
if (tableIndex < 0)
return tableIndex;
table = &vlc->_table[tableIndex];
// first pass: map codes and compute auxiliary table sizes
for (i = 0; i < nbCodes; i++) {
n = codes[i].bits;
code = codes[i].code;
symbol = codes[i].symbol;
//warning("i=%d n=%d code=0x%x", i, n, code);
if (n <= tableNbBits) {
// no need to add another table
j = code >> (32 - tableNbBits);
nb = 1 << (tableNbBits - n);
inc = 1;
if (flags & INIT_VLC_LE) {
j = bitswap32(code);
inc = 1 << n;
}
for (k = 0; k < nb; k++) {
int bits = table[j][1];
//warning("%4x: code=%d n=%d", j, i, n);
if (bits != 0 && bits != n) {
warning("incorrect codes");
return -1;
}
table[j][1] = n; //bits
table[j][0] = symbol;
j += inc;
}
} else {
// fill auxiliary table recursively
n -= tableNbBits;
codePrefix = code >> (32 - tableNbBits);
subtableBits = n;
codes[i].bits = n;
codes[i].code = code << tableNbBits;
for (k = i + 1; k < nbCodes; k++) {
n = codes[k].bits - tableNbBits;
if (n <= 0)
break;
code = codes[k].code;
if (code >> (32 - tableNbBits) != (uint)codePrefix)
break;
codes[k].bits = n;
codes[k].code = code << tableNbBits;
subtableBits = MAX(subtableBits, n);
}
subtableBits = MIN(subtableBits, tableNbBits);
j = (flags & INIT_VLC_LE) ? bitswap32(codePrefix) >> (32 - tableNbBits) : codePrefix;
table[j][1] = -subtableBits;
//warning("%4x: n=%d (subtable)", j, codes[i].bits + tableNbBits);
index = vlc->buildTable(subtableBits, k - i, codes + i, flags);
if (index < 0)
return index;
// note: realloc has been done, so reload tables
table = (VLC_TYPE (*)[2])&vlc->_table[tableIndex];
table[j][0] = index; //code
i = k - 1;
}
}
for (i = 0; i < tableSize; i++) {
if (table[i][1] == 0) //bits
table[i][0] = -1; //codes
}
return tableIndex;
}
int VLC::allocTable(int size, int useStatic) {
VLC *vlc = this;
int index = vlc->_tableSize;
vlc->_tableSize += size;
if (vlc->_tableSize > vlc->_tableAllocated) {
// cannot do anything, init_vlc() is used with too little memory
assert(!useStatic);
vlc->_tableAllocated += (1 << vlc->_bits);
vlc->_table = (int16(*)[2])avReallocF(vlc->_table, vlc->_tableAllocated, sizeof(VLC_TYPE) * 2);
if (!vlc->_table) {
vlc->_tableAllocated = 0;
vlc->_tableSize = 0;
return -2;
}
memset(vlc->_table + vlc->_tableAllocated - (1 << vlc->_bits), 0, sizeof(VLC_TYPE) * 2 << vlc->_bits);
}
return index;
}
uint VLC::getData(const void *table, uint idx, uint wrap, uint size) {
const uint8 *ptr = (const uint8 *)table + idx * wrap;
switch(size) {
case 1:
return *(const uint8 *)ptr;
case 2:
return *(const uint16 *)ptr;
default:
return *(const uint32 *)ptr;
}
}
} // End of namespace Indeo
} // End of namespace Image