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/*
* Common bit i/o utils
* Copyright (c) 2000, 2001 Fabrice Bellard.
* Copyright (c) 2002-2004 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
*
* alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
*/
/**
* @file common.c
* common internal api.
*/
#include "avcodec.h"
const uint8_t ff_sqrt_tab[128]={
0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,
11,11,11
};
const uint8_t ff_log2_tab[256]={
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};
void align_put_bits(PutBitContext *s)
{
#ifdef ALT_BITSTREAM_WRITER
put_bits(s,( - s->index) & 7,0);
#else
put_bits(s,s->bit_left & 7,0);
#endif
}
int64_t ff_gcd(int64_t a, int64_t b){
if(b) return ff_gcd(b, a%b);
else return a;
}
#ifndef ALT_BITSTREAM_WRITER
void put_bits(PutBitContext *s, int n, unsigned int value)
{
unsigned int bit_buf;
int bit_left;
assert(n == 32 || value < (1U << n));
bit_buf = s->bit_buf;
bit_left = s->bit_left;
/* XXX: optimize */
if (n < bit_left) {
bit_buf = (bit_buf<<n) | value;
bit_left-=n;
} else {
bit_buf<<=bit_left;
bit_buf |= value >> (n - bit_left);
*(uint32_t *)s->buf_ptr = be2me_32(bit_buf);
/*printf("bitbuf = %08x\n", bit_buf);*/
s->buf_ptr+=4;
bit_left+=32 - n;
bit_buf = value;
}
s->bit_buf = bit_buf;
s->bit_left = bit_left;
}
#else
void put_bits(PutBitContext *s, int n, unsigned int value)
{
# ifdef ALIGNED_BITSTREAM_WRITER
int index= s->index;
uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
value<<= 32-n;
ptr[0] |= be2me_32(value>>(index&31));
ptr[1] = be2me_32(value<<(32-(index&31)));
index+= n;
s->index= index;
# else /*ALIGNED_BITSTREAM_WRITER*/
int index= s->index;
uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
ptr[0] |= be2me_32(value<<(32-n-(index&7) ));
ptr[1] = 0;
index+= n;
s->index= index;
# endif /*!ALIGNED_BITSTREAM_WRITER*/
}
#endif
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