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ffmpeg/libavcodec/golomb.h
Michael Niedermayer 11e659c203 golomb rice codes 
use gradients instead of prediction errors as context model
store independant quantization tables for each point
merge contexts with opposit sign

Originally committed as revision 1957 to svn://svn.ffmpeg.org/ffmpeg/trunk
2003-06-13 21:31:28 +00:00

332 lines
8.1 KiB
C
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/*
* exp golomb vlc stuff
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* @file golomb.h
* @brief
* exp golomb vlc stuff
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#define INVALID_VLC 0x80000000
extern const uint8_t ff_golomb_vlc_len[512];
extern const uint8_t ff_ue_golomb_vlc_code[512];
extern const int8_t ff_se_golomb_vlc_code[512];
extern const uint8_t ff_ue_golomb_len[256];
extern const uint8_t ff_interleaved_golomb_vlc_len[256];
extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
extern const int8_t ff_interleaved_se_golomb_vlc_code[256];
/**
* read unsigned exp golomb code.
*/
static inline int get_ue_golomb(GetBitContext *gb){
unsigned int buf;
int log;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf=GET_CACHE(re, gb);
if(buf >= (1<<27)){
buf >>= 32 - 9;
LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_ue_golomb_vlc_code[buf];
}else{
log= 2*av_log2(buf) - 31;
buf>>= log;
buf--;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
return buf;
}
}
static inline int svq3_get_ue_golomb(GetBitContext *gb){
uint32_t buf;
int log;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf=GET_CACHE(re, gb);
if(buf&0xAA800000){
buf >>= 32 - 8;
LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_interleaved_ue_golomb_vlc_code[buf];
}else{
buf|=1;
if((buf & 0xAAAAAAAA) == 0)
return INVALID_VLC;
for(log=31; (buf & 0x80000000) == 0; log--){
buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
}
LAST_SKIP_BITS(re, gb, 63 - 2*log);
CLOSE_READER(re, gb);
return ((buf << log) >> log) - 1;
}
}
/**
* read unsigned truncated exp golomb code.
*/
static inline int get_te0_golomb(GetBitContext *gb, int range){
assert(range >= 1);
if(range==1) return 0;
else if(range==2) return get_bits1(gb)^1;
else return get_ue_golomb(gb);
}
/**
* read unsigned truncated exp golomb code.
*/
static inline int get_te_golomb(GetBitContext *gb, int range){
assert(range >= 1);
if(range==2) return get_bits1(gb)^1;
else return get_ue_golomb(gb);
}
/**
* read signed exp golomb code.
*/
static inline int get_se_golomb(GetBitContext *gb){
unsigned int buf;
int log;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf=GET_CACHE(re, gb);
if(buf >= (1<<27)){
buf >>= 32 - 9;
LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_se_golomb_vlc_code[buf];
}else{
log= 2*av_log2(buf) - 31;
buf>>= log;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
if(buf&1) buf= -(buf>>1);
else buf= (buf>>1);
return buf;
}
}
static inline int svq3_get_se_golomb(GetBitContext *gb){
unsigned int buf;
int log;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf=GET_CACHE(re, gb);
if(buf&0xAA800000){
buf >>= 32 - 8;
LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_interleaved_se_golomb_vlc_code[buf];
}else{
buf |=1;
if((buf & 0xAAAAAAAA) == 0)
return INVALID_VLC;
for(log=31; (buf & 0x80000000) == 0; log--){
buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
}
LAST_SKIP_BITS(re, gb, 63 - 2*log);
CLOSE_READER(re, gb);
return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
}
}
/**
* read unsigned golomb rice code.
*/
static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
unsigned int buf;
int log;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf=GET_CACHE(re, gb);
log= av_log2(buf);
//printf("buf:%X log:%d\n", buf, log);
if(log > 31-limit){
buf >>= log - k;
buf += (30-log)<<k;
LAST_SKIP_BITS(re, gb, 32 + k - log);
CLOSE_READER(re, gb);
return buf;
}else if(log == 31-limit){
buf >>= log - esc_len;
buf -= 1<<esc_len;
LAST_SKIP_BITS(re, gb, esc_len + limit + 1);
CLOSE_READER(re, gb);
return buf + 1;
}else
return -1;
}
#ifdef TRACE
static inline int get_ue(GetBitContext *s, char *file, char *func, int line){
int show= show_bits(s, 24);
int pos= get_bits_count(s);
int i= get_ue_golomb(s);
int len= get_bits_count(s) - pos;
int bits= show>>(24-len);
print_bin(bits, len);
printf("%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
return i;
}
static inline int get_se(GetBitContext *s, char *file, char *func, int line){
int show= show_bits(s, 24);
int pos= get_bits_count(s);
int i= get_se_golomb(s);
int len= get_bits_count(s) - pos;
int bits= show>>(24-len);
print_bin(bits, len);
printf("%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
return i;
}
static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){
int show= show_bits(s, 24);
int pos= get_bits_count(s);
int i= get_te0_golomb(s, r);
int len= get_bits_count(s) - pos;
int bits= show>>(24-len);
print_bin(bits, len);
printf("%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
return i;
}
#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#endif
/**
* write unsigned exp golomb code.
*/
static inline void set_ue_golomb(PutBitContext *pb, int i){
int e;
assert(i>=0);
#if 0
if(i=0){
put_bits(pb, 1, 1);
return;
}
#endif
if(i<256)
put_bits(pb, ff_ue_golomb_len[i], i+1);
else{
e= av_log2(i+1);
put_bits(pb, 2*e+1, i+1);
}
}
/**
* write truncated unsigned exp golomb code.
*/
static inline void set_te_golomb(PutBitContext *pb, int i, int range){
assert(range >= 1);
assert(i<=range);
if(range==2) put_bits(pb, 1, i^1);
else set_ue_golomb(pb, i);
}
/**
* write signed exp golomb code.
*/
static inline void set_se_golomb(PutBitContext *pb, int i){
#if 0
if(i<=0) i= -2*i;
else i= 2*i-1;
#elif 1
i= 2*i-1;
if(i<0) i^= -1; //FIXME check if gcc does the right thing
#else
i= 2*i-1;
i^= (i>>31);
#endif
set_ue_golomb(pb, i);
}
/**
* write unsigned golomb rice code.
*/
static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
int e;
assert(i>=0);
e= i>>k;
if(e<limit){
put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
}else{
// printf("set %08X, %d\n", (1<<esc_len) + i - 1, limit + esc_len + 1);
put_bits(pb, limit + esc_len + 1, (1<<esc_len) + i - 1);
// put_bits(pb, 1, limit + 1);
// put_bits(pb, i - 1, esc_len);
}
}
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