+++ /dev/null
-/*
- * Common bit i/o utils
- * Copyright (c) 2000, 2001 Fabrice Bellard.
- *
- * 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 init_put_bits(PutBitContext *s,
- uint8_t *buffer, int buffer_size,
- void *opaque,
- void (*write_data)(void *, uint8_t *, int))
-{
- s->buf = buffer;
- s->buf_end = s->buf + buffer_size;
- s->data_out_size = 0;
- if(write_data!=NULL)
- {
- fprintf(stderr, "write Data callback is not supported\n");
- }
-#ifdef ALT_BITSTREAM_WRITER
- s->index=0;
- ((uint32_t*)(s->buf))[0]=0;
-// memset(buffer, 0, buffer_size);
-#else
- s->buf_ptr = s->buf;
- s->bit_left=32;
- s->bit_buf=0;
-#endif
-}
-
-#ifdef CONFIG_ENCODERS
-
-/* return the number of bits output */
-int64_t get_bit_count(PutBitContext *s)
-{
-#ifdef ALT_BITSTREAM_WRITER
- return s->data_out_size * 8 + s->index;
-#else
- return (s->buf_ptr - s->buf + s->data_out_size) * 8 + 32 - (int64_t)s->bit_left;
-#endif
-}
-
-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
-}
-
-#endif //CONFIG_ENCODERS
-
-/* pad the end of the output stream with zeros */
-void flush_put_bits(PutBitContext *s)
-{
-#ifdef ALT_BITSTREAM_WRITER
- align_put_bits(s);
-#else
- s->bit_buf<<= s->bit_left;
- while (s->bit_left < 32) {
- /* XXX: should test end of buffer */
- *s->buf_ptr++=s->bit_buf >> 24;
- s->bit_buf<<=8;
- s->bit_left+=8;
- }
- s->bit_left=32;
- s->bit_buf=0;
-#endif
-}
-
-#ifdef CONFIG_ENCODERS
-
-void put_string(PutBitContext * pbc, char *s)
-{
- while(*s){
- put_bits(pbc, 8, *s);
- s++;
- }
- put_bits(pbc, 8, 0);
-}
-
-/* bit input functions */
-
-#endif //CONFIG_ENCODERS
-
-/**
- * init GetBitContext.
- * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
- * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
- * @param bit_size the size of the buffer in bits
- */
-void init_get_bits(GetBitContext *s,
- const uint8_t *buffer, int bit_size)
-{
- const int buffer_size= (bit_size+7)>>3;
-
- s->buffer= buffer;
- s->size_in_bits= bit_size;
- s->buffer_end= buffer + buffer_size;
-#ifdef ALT_BITSTREAM_READER
- s->index=0;
-#elif defined LIBMPEG2_BITSTREAM_READER
-#ifdef LIBMPEG2_BITSTREAM_READER_HACK
- if ((int)buffer&1) {
- /* word alignment */
- s->cache = (*buffer++)<<24;
- s->buffer_ptr = buffer;
- s->bit_count = 16-8;
- } else
-#endif
- {
- s->buffer_ptr = buffer;
- s->bit_count = 16;
- s->cache = 0;
- }
-#elif defined A32_BITSTREAM_READER
- s->buffer_ptr = (uint32_t*)buffer;
- s->bit_count = 32;
- s->cache0 = 0;
- s->cache1 = 0;
-#endif
- {
- OPEN_READER(re, s)
- UPDATE_CACHE(re, s)
- UPDATE_CACHE(re, s)
- CLOSE_READER(re, s)
- }
-#ifdef A32_BITSTREAM_READER
- s->cache1 = 0;
-#endif
-}
-
-/**
- * reads 0-32 bits.
- */
-unsigned int get_bits_long(GetBitContext *s, int n){
- if(n<=17) return get_bits(s, n);
- else{
- int ret= get_bits(s, 16) << (n-16);
- return ret | get_bits(s, n-16);
- }
-}
-
-/**
- * shows 0-32 bits.
- */
-unsigned int show_bits_long(GetBitContext *s, int n){
- if(n<=17) return show_bits(s, n);
- else{
- GetBitContext gb= *s;
- int ret= get_bits_long(s, n);
- *s= gb;
- return ret;
- }
-}
-
-void align_get_bits(GetBitContext *s)
-{
- int n= (-get_bits_count(s)) & 7;
- if(n) skip_bits(s, n);
-}
-
-int check_marker(GetBitContext *s, const char *msg)
-{
- int bit= get_bits1(s);
- if(!bit) printf("Marker bit missing %s\n", msg);
-
- return bit;
-}
-
-/* VLC decoding */
-
-//#define DEBUG_VLC
-
-#define GET_DATA(v, table, i, wrap, size) \
-{\
- const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
- switch(size) {\
- case 1:\
- v = *(const uint8_t *)ptr;\
- break;\
- case 2:\
- v = *(const uint16_t *)ptr;\
- break;\
- default:\
- v = *(const uint32_t *)ptr;\
- break;\
- }\
-}
-
-
-static int alloc_table(VLC *vlc, int size)
-{
- int index;
- index = vlc->table_size;
- vlc->table_size += size;
- if (vlc->table_size > vlc->table_allocated) {
- vlc->table_allocated += (1 << vlc->bits);
- vlc->table = av_realloc(vlc->table,
- sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
- if (!vlc->table)
- return -1;
- }
- return index;
-}
-
-static int build_table(VLC *vlc, int table_nb_bits,
- int nb_codes,
- const void *bits, int bits_wrap, int bits_size,
- const void *codes, int codes_wrap, int codes_size,
- uint32_t code_prefix, int n_prefix)
-{
- int i, j, k, n, table_size, table_index, nb, n1, index;
- uint32_t code;
- VLC_TYPE (*table)[2];
-
- table_size = 1 << table_nb_bits;
- table_index = alloc_table(vlc, table_size);
-#ifdef DEBUG_VLC
- printf("new table index=%d size=%d code_prefix=%x n=%d\n",
- table_index, table_size, code_prefix, n_prefix);
-#endif
- if (table_index < 0)
- return -1;
- table = &vlc->table[table_index];
-
- for(i=0;i<table_size;i++) {
- table[i][1] = 0; //bits
- table[i][0] = -1; //codes
- }
-
- /* first pass: map codes and compute auxillary table sizes */
- for(i=0;i<nb_codes;i++) {
- GET_DATA(n, bits, i, bits_wrap, bits_size);
- GET_DATA(code, codes, i, codes_wrap, codes_size);
- /* we accept tables with holes */
- if (n <= 0)
- continue;
-#if defined(DEBUG_VLC) && 0
- printf("i=%d n=%d code=0x%x\n", i, n, code);
-#endif
- /* if code matches the prefix, it is in the table */
- n -= n_prefix;
- if (n > 0 && (code >> n) == code_prefix) {
- if (n <= table_nb_bits) {
- /* no need to add another table */
- j = (code << (table_nb_bits - n)) & (table_size - 1);
- nb = 1 << (table_nb_bits - n);
- for(k=0;k<nb;k++) {
-#ifdef DEBUG_VLC
- printf("%4x: code=%d n=%d\n",
- j, i, n);
-#endif
- if (table[j][1] /*bits*/ != 0) {
- fprintf(stderr, "incorrect codes\n");
- av_abort();
- }
- table[j][1] = n; //bits
- table[j][0] = i; //code
- j++;
- }
- } else {
- n -= table_nb_bits;
- j = (code >> n) & ((1 << table_nb_bits) - 1);
-#ifdef DEBUG_VLC
- printf("%4x: n=%d (subtable)\n",
- j, n);
-#endif
- /* compute table size */
- n1 = -table[j][1]; //bits
- if (n > n1)
- n1 = n;
- table[j][1] = -n1; //bits
- }
- }
- }
-
- /* second pass : fill auxillary tables recursively */
- for(i=0;i<table_size;i++) {
- n = table[i][1]; //bits
- if (n < 0) {
- n = -n;
- if (n > table_nb_bits) {
- n = table_nb_bits;
- table[i][1] = -n; //bits
- }
- index = build_table(vlc, n, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- (code_prefix << table_nb_bits) | i,
- n_prefix + table_nb_bits);
- if (index < 0)
- return -1;
- /* note: realloc has been done, so reload tables */
- table = &vlc->table[table_index];
- table[i][0] = index; //code
- }
- }
- return table_index;
-}
-
-
-/* Build VLC decoding tables suitable for use with get_vlc().
-
- 'nb_bits' set thee decoding table size (2^nb_bits) entries. The
- bigger it is, the faster is the decoding. But it should not be too
- big to save memory and L1 cache. '9' is a good compromise.
-
- 'nb_codes' : number of vlcs codes
-
- 'bits' : table which gives the size (in bits) of each vlc code.
-
- 'codes' : table which gives the bit pattern of of each vlc code.
-
- 'xxx_wrap' : give the number of bytes between each entry of the
- 'bits' or 'codes' tables.
-
- 'xxx_size' : gives the number of bytes of each entry of the 'bits'
- or 'codes' tables.
-
- 'wrap' and 'size' allows to use any memory configuration and types
- (byte/word/long) to store the 'bits' and 'codes' tables.
-*/
-int init_vlc(VLC *vlc, int nb_bits, int nb_codes,
- const void *bits, int bits_wrap, int bits_size,
- const void *codes, int codes_wrap, int codes_size)
-{
- vlc->bits = nb_bits;
- vlc->table = NULL;
- vlc->table_allocated = 0;
- vlc->table_size = 0;
-#ifdef DEBUG_VLC
- printf("build table nb_codes=%d\n", nb_codes);
-#endif
-
- if (build_table(vlc, nb_bits, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- 0, 0) < 0) {
- av_free(vlc->table);
- return -1;
- }
- return 0;
-}
-
-
-void free_vlc(VLC *vlc)
-{
- av_free(vlc->table);
-}
-
-int64_t ff_gcd(int64_t a, int64_t b){
- if(b) return ff_gcd(b, a%b);
- else return a;
-}
-
-void ff_float2fraction(int *nom_arg, int *denom_arg, double f, int max){
- double best_diff=1E10, diff;
- int best_denom=1, best_nom=1;
- int nom, denom, gcd;
-
- //brute force here, perhaps we should try continued fractions if we need large max ...
- for(denom=1; denom<=max; denom++){
- nom= (int)(f*denom + 0.5);
- if(nom<=0 || nom>max) continue;
-
- diff= ABS( f - (double)nom / (double)denom );
- if(diff < best_diff){
- best_diff= diff;
- best_nom= nom;
- best_denom= denom;
- }
- }
-
- gcd= ff_gcd(best_nom, best_denom);
- best_nom /= gcd;
- best_denom /= gcd;
-
- *nom_arg= best_nom;
- *denom_arg= best_denom;
-}
projects / synfig.git / blobdiff