mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-26 09:12:33 +00:00
1924f3ce36
Originally committed as revision 1734 to svn://svn.ffmpeg.org/ffmpeg/trunk
216 lines
5.2 KiB
C
216 lines
5.2 KiB
C
/*
|
|
* 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>
|
|
*/
|
|
|
|
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];
|
|
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
}
|
|
|
|
#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);
|
|
}
|