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ffmpeg/libavcodec/golomb.h

332 lines
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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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