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, const void *symbols, int symbols_wrap, int symbols_size, uint32_t code_prefix, int n_prefix, int flags) { int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2, symbol; uint32_t code; VLC_TYPE (*table)[2]; table_size = 1 << table_nb_bits; table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC); #ifdef DEBUG_VLC av_log(NULL,AV_LOG_DEBUG,"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 (!symbols) symbol = i; else GET_DATA(symbol, symbols, i, symbols_wrap, symbols_size); #if defined(DEBUG_VLC) && 0 av_log(NULL,AV_LOG_DEBUG,"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(flags & INIT_VLC_LE) code_prefix2= code & (n_prefix>=32 ? 0xffffffff : (1 << n_prefix)-1); else code_prefix2= code >> n; if (n > 0 && code_prefix2 == 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++) { if(flags & INIT_VLC_LE) j = (code >> n_prefix) + (k<<n); #ifdef DEBUG_VLC av_log(NULL, AV_LOG_DEBUG, "%4x: code=%d n=%d\n", j, i, n); #endif if (table[j][1] /*bits*/ != 0) { av_log(NULL, AV_LOG_ERROR, "incorrect codes\n"); return -1; } table[j][1] = n; //bits table[j][0] = symbol; j++; } } else { n -= table_nb_bits; j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1); #ifdef DEBUG_VLC av_log(NULL,AV_LOG_DEBUG,"%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, symbols, symbols_wrap, symbols_size, (flags & INIT_VLC_LE) ? (code_prefix | (i << n_prefix)) : ((code_prefix << table_nb_bits) | i), n_prefix + table_nb_bits, flags); 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; }