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author | dimitri <dimitri@afe2bf4a-e733-0410-8a33-86f594647bc7> | 2008-01-16 19:20:21 (GMT) |
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committer | dimitri <dimitri@afe2bf4a-e733-0410-8a33-86f594647bc7> | 2008-01-16 19:20:21 (GMT) |
commit | 8dab665567c9dffaa3f5fea198fc2110d536594d (patch) | |
tree | 78bac4e928b25e139605aceefa82537f378d8af0 /libpng/trees.c | |
parent | d3461a1c31f008345d784dc3e819047bc5265c30 (diff) | |
download | Doxygen-8dab665567c9dffaa3f5fea198fc2110d536594d.zip Doxygen-8dab665567c9dffaa3f5fea198fc2110d536594d.tar.gz Doxygen-8dab665567c9dffaa3f5fea198fc2110d536594d.tar.bz2 |
Release-1.5.4
Diffstat (limited to 'libpng/trees.c')
-rw-r--r-- | libpng/trees.c | 247 |
1 files changed, 131 insertions, 116 deletions
diff --git a/libpng/trees.c b/libpng/trees.c index 6125d6b..395e4e1 100644 --- a/libpng/trees.c +++ b/libpng/trees.c @@ -1,6 +1,6 @@ /* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995-2002 Jean-loup Gailly - * For conditions of distribution and use, see copyright notice in zlib.h + * Copyright (C) 1995-2005 Jean-loup Gailly + * For conditions of distribution and use, see copyright notice in zlib.h */ /* @@ -189,7 +189,10 @@ local void gen_trees_header OF((void)); #ifdef DEBUG local void send_bits OF((deflate_state *s, int value, int length)); -local void send_bits(deflate_state s, int value, int length) +local void send_bits(s, value, length) + deflate_state *s; + int value; /* value to send */ + int length; /* number of bits */ { Tracevv((stderr," l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); @@ -227,13 +230,12 @@ local void send_bits(deflate_state s, int value, int length) #endif /* DEBUG */ -#define MAX(a,b) (a >= b ? a : b) /* the arguments must not have side effects */ /* =========================================================================== * Initialize the various 'constant' tables. */ -local void tr_static_init(void) +local void tr_static_init() { #if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; @@ -332,42 +334,42 @@ void gen_trees_header() Assert (header != NULL, "Can't open trees.h"); fprintf(header, - "/* header created automatically with -DGEN_TREES_H */\n\n"); + "/* header created automatically with -DGEN_TREES_H */\n\n"); fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n"); for (i = 0; i < L_CODES+2; i++) { - fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code, - static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5)); + fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code, + static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5)); } fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n"); for (i = 0; i < D_CODES; i++) { - fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code, - static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5)); + fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code, + static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5)); } fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n"); for (i = 0; i < DIST_CODE_LEN; i++) { - fprintf(header, "%2u%s", _dist_code[i], - SEPARATOR(i, DIST_CODE_LEN-1, 20)); + fprintf(header, "%2u%s", _dist_code[i], + SEPARATOR(i, DIST_CODE_LEN-1, 20)); } fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n"); for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) { - fprintf(header, "%2u%s", _length_code[i], - SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); + fprintf(header, "%2u%s", _length_code[i], + SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); } fprintf(header, "local const int base_length[LENGTH_CODES] = {\n"); for (i = 0; i < LENGTH_CODES; i++) { - fprintf(header, "%1u%s", base_length[i], - SEPARATOR(i, LENGTH_CODES-1, 20)); + fprintf(header, "%1u%s", base_length[i], + SEPARATOR(i, LENGTH_CODES-1, 20)); } fprintf(header, "local const int base_dist[D_CODES] = {\n"); for (i = 0; i < D_CODES; i++) { - fprintf(header, "%5u%s", base_dist[i], - SEPARATOR(i, D_CODES-1, 10)); + fprintf(header, "%5u%s", base_dist[i], + SEPARATOR(i, D_CODES-1, 10)); } fclose(header); @@ -377,7 +379,8 @@ void gen_trees_header() /* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ -void _tr_init(deflate_state *s) +void _tr_init(s) + deflate_state *s; { tr_static_init(); @@ -405,7 +408,8 @@ void _tr_init(deflate_state *s) /* =========================================================================== * Initialize a new block. */ -local void init_block(deflate_state *s) +local void init_block(s) + deflate_state *s; { int n; /* iterates over tree elements */ @@ -448,10 +452,10 @@ local void init_block(deflate_state *s) * when the heap property is re-established (each father smaller than its * two sons). */ -local void pqdownheap(deflate_state *s, ct_data *tree, int k) - - /* the tree to restore */ - /* node to move down */ +local void pqdownheap(s, tree, k) + deflate_state *s; + ct_data *tree; /* the tree to restore */ + int k; /* node to move down */ { int v = s->heap[k]; int j = k << 1; /* left son of k */ @@ -483,9 +487,9 @@ local void pqdownheap(deflate_state *s, ct_data *tree, int k) * The length opt_len is updated; static_len is also updated if stree is * not null. */ -local void gen_bitlen(deflate_state *s, tree_desc *desc) - - /* the tree descriptor */ +local void gen_bitlen(s, desc) + deflate_state *s; + tree_desc *desc; /* the tree descriptor */ { ct_data *tree = desc->dyn_tree; int max_code = desc->max_code; @@ -551,7 +555,7 @@ local void gen_bitlen(deflate_state *s, tree_desc *desc) while (n != 0) { m = s->heap[--h]; if (m > max_code) continue; - if (tree[m].Len != (unsigned) bits) { + if ((unsigned) tree[m].Len != (unsigned) bits) { Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); s->opt_len += ((long)bits - (long)tree[m].Len) *(long)tree[m].Freq; @@ -570,10 +574,10 @@ local void gen_bitlen(deflate_state *s, tree_desc *desc) * OUT assertion: the field code is set for all tree elements of non * zero code length. */ -local void gen_codes (ct_data *tree, int max_code, ushf *bl_count) - /* the tree to decorate */ - /* largest code with non zero frequency */ - /* number of codes at each bit length */ +local void gen_codes (tree, max_code, bl_count) + ct_data *tree; /* the tree to decorate */ + int max_code; /* largest code with non zero frequency */ + ushf *bl_count; /* number of codes at each bit length */ { ush next_code[MAX_BITS+1]; /* next code value for each bit length */ ush code = 0; /* running code value */ @@ -612,9 +616,9 @@ local void gen_codes (ct_data *tree, int max_code, ushf *bl_count) * and corresponding code. The length opt_len is updated; static_len is * also updated if stree is not null. The field max_code is set. */ -local void build_tree(deflate_state *s, tree_desc *desc) - - /* the tree descriptor */ +local void build_tree(s, desc) + deflate_state *s; + tree_desc *desc; /* the tree descriptor */ { ct_data *tree = desc->dyn_tree; const ct_data *stree = desc->stat_desc->static_tree; @@ -670,7 +674,8 @@ local void build_tree(deflate_state *s, tree_desc *desc) /* Create a new node father of n and m */ tree[node].Freq = tree[n].Freq + tree[m].Freq; - s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); + s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ? + s->depth[n] : s->depth[m]) + 1); tree[n].Dad = tree[m].Dad = (ush)node; #ifdef DUMP_BL_TREE if (tree == s->bl_tree) { @@ -699,10 +704,10 @@ local void build_tree(deflate_state *s, tree_desc *desc) * Scan a literal or distance tree to determine the frequencies of the codes * in the bit length tree. */ -local void scan_tree (deflate_state *s, ct_data *tree, int max_code) - - /* the tree to be scanned */ - /* and its largest code of non zero frequency */ +local void scan_tree (s, tree, max_code) + deflate_state *s; + ct_data *tree; /* the tree to be scanned */ + int max_code; /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -744,10 +749,10 @@ local void scan_tree (deflate_state *s, ct_data *tree, int max_code) * Send a literal or distance tree in compressed form, using the codes in * bl_tree. */ -local void send_tree (deflate_state *s, ct_data *tree, int max_code) - - /* the tree to be scanned */ - /* and its largest code of non zero frequency */ +local void send_tree (s, tree, max_code) + deflate_state *s; + ct_data *tree; /* the tree to be scanned */ + int max_code; /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -795,7 +800,8 @@ local void send_tree (deflate_state *s, ct_data *tree, int max_code) * Construct the Huffman tree for the bit lengths and return the index in * bl_order of the last bit length code to send. */ -local int build_bl_tree(deflate_state *s) +local int build_bl_tree(s) + deflate_state *s; { int max_blindex; /* index of last bit length code of non zero freq */ @@ -829,9 +835,9 @@ local int build_bl_tree(deflate_state *s) * lengths of the bit length codes, the literal tree and the distance tree. * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. */ -local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) - - /* number of codes for each tree */ +local void send_all_trees(s, lcodes, dcodes, blcodes) + deflate_state *s; + int lcodes, dcodes, blcodes; /* number of codes for each tree */ { int rank; /* index in bl_order */ @@ -858,11 +864,11 @@ local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) /* =========================================================================== * Send a stored block */ -void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) - - /* input block */ - /* length of input block */ - /* true if this is the last block for a file */ +void _tr_stored_block(s, buf, stored_len, eof) + deflate_state *s; + charf *buf; /* input block */ + ulg stored_len; /* length of input block */ + int eof; /* true if this is the last block for a file */ { send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ #ifdef DEBUG @@ -883,7 +889,8 @@ void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) * To simplify the code, we assume the worst case of last real code encoded * on one bit only. */ -void _tr_align(deflate_state *s) +void _tr_align(s) + deflate_state *s; { send_bits(s, STATIC_TREES<<1, 3); send_code(s, END_BLOCK, static_ltree); @@ -911,11 +918,11 @@ void _tr_align(deflate_state *s) * Determine the best encoding for the current block: dynamic trees, static * trees or store, and output the encoded block to the zip file. */ -void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) - - /* input block, or NULL if too old */ - /* length of input block */ - /* true if this is the last block for a file */ +void _tr_flush_block(s, buf, stored_len, eof) + deflate_state *s; + charf *buf; /* input block, or NULL if too old */ + ulg stored_len; /* length of input block */ + int eof; /* true if this is the last block for a file */ { ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ int max_blindex = 0; /* index of last bit length code of non zero freq */ @@ -923,39 +930,40 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) /* Build the Huffman trees unless a stored block is forced */ if (s->level > 0) { - /* Check if the file is ascii or binary */ - if (s->data_type == Z_UNKNOWN) set_data_type(s); + /* Check if the file is binary or text */ + if (stored_len > 0 && s->strm->data_type == Z_UNKNOWN) + set_data_type(s); - /* Construct the literal and distance trees */ - build_tree(s, (tree_desc *)(&(s->l_desc))); - Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, - s->static_len)); + /* Construct the literal and distance trees */ + build_tree(s, (tree_desc *)(&(s->l_desc))); + Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, + s->static_len)); - build_tree(s, (tree_desc *)(&(s->d_desc))); - Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, - s->static_len)); - /* At this point, opt_len and static_len are the total bit lengths of - * the compressed block data, excluding the tree representations. - */ + build_tree(s, (tree_desc *)(&(s->d_desc))); + Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, + s->static_len)); + /* At this point, opt_len and static_len are the total bit lengths of + * the compressed block data, excluding the tree representations. + */ - /* Build the bit length tree for the above two trees, and get the index - * in bl_order of the last bit length code to send. - */ - max_blindex = build_bl_tree(s); + /* Build the bit length tree for the above two trees, and get the index + * in bl_order of the last bit length code to send. + */ + max_blindex = build_bl_tree(s); - /* Determine the best encoding. Compute first the block length in bytes*/ - opt_lenb = (s->opt_len+3+7)>>3; - static_lenb = (s->static_len+3+7)>>3; + /* Determine the best encoding. Compute the block lengths in bytes. */ + opt_lenb = (s->opt_len+3+7)>>3; + static_lenb = (s->static_len+3+7)>>3; - Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", - opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, - s->last_lit)); + Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", + opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, + s->last_lit)); - if (static_lenb <= opt_lenb) opt_lenb = static_lenb; + if (static_lenb <= opt_lenb) opt_lenb = static_lenb; } else { Assert(buf != (char*)0, "lost buf"); - opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ + opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ } #ifdef FORCE_STORED @@ -975,7 +983,7 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) #ifdef FORCE_STATIC } else if (static_lenb >= 0) { /* force static trees */ #else - } else if (static_lenb == opt_lenb) { + } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) { #endif send_bits(s, (STATIC_TREES<<1)+eof, 3); compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); @@ -1011,10 +1019,10 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. */ -int _tr_tally (deflate_state *s, unsigned int dist, unsigned int lc) - - /* distance of matched string */ - /* match length-MIN_MATCH or unmatched char (if dist==0) */ +int _tr_tally (s, dist, lc) + deflate_state *s; + unsigned dist; /* distance of matched string */ + unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ { s->d_buf[s->last_lit] = (ush)dist; s->l_buf[s->last_lit++] = (uch)lc; @@ -1061,10 +1069,10 @@ int _tr_tally (deflate_state *s, unsigned int dist, unsigned int lc) /* =========================================================================== * Send the block data compressed using the given Huffman trees */ -local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) - - /* literal tree */ - /* distance tree */ +local void compress_block(s, ltree, dtree) + deflate_state *s; + ct_data *ltree; /* literal tree */ + ct_data *dtree; /* distance tree */ { unsigned dist; /* distance of matched string */ int lc; /* match length or unmatched char (if dist == 0) */ @@ -1100,7 +1108,8 @@ local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) } /* literal or match pair ? */ /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ - Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); + Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx, + "pendingBuf overflow"); } while (lx < s->last_lit); @@ -1109,20 +1118,24 @@ local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) } /* =========================================================================== - * Set the data type to ASCII or BINARY, using a crude approximation: - * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. - * IN assertion: the fields freq of dyn_ltree are set and the total of all - * frequencies does not exceed 64K (to fit in an int on 16 bit machines). + * Set the data type to BINARY or TEXT, using a crude approximation: + * set it to Z_TEXT if all symbols are either printable characters (33 to 255) + * or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise. + * IN assertion: the fields Freq of dyn_ltree are set. */ -local void set_data_type(deflate_state *s) +local void set_data_type(s) + deflate_state *s; { - int n = 0; - unsigned ascii_freq = 0; - unsigned bin_freq = 0; - while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; - while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; - while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; - s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); + int n; + + for (n = 0; n < 9; n++) + if (s->dyn_ltree[n].Freq != 0) + break; + if (n == 9) + for (n = 14; n < 32; n++) + if (s->dyn_ltree[n].Freq != 0) + break; + s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY; } /* =========================================================================== @@ -1130,9 +1143,9 @@ local void set_data_type(deflate_state *s) * method would use a table) * IN assertion: 1 <= len <= 15 */ -local unsigned bi_reverse(unsigned int code, int len) - /* the value to invert */ - /* its bit length */ +local unsigned bi_reverse(code, len) + unsigned code; /* the value to invert */ + int len; /* its bit length */ { register unsigned res = 0; do { @@ -1145,7 +1158,8 @@ local unsigned bi_reverse(unsigned int code, int len) /* =========================================================================== * Flush the bit buffer, keeping at most 7 bits in it. */ -local void bi_flush(deflate_state *s) +local void bi_flush(s) + deflate_state *s; { if (s->bi_valid == 16) { put_short(s, s->bi_buf); @@ -1161,7 +1175,8 @@ local void bi_flush(deflate_state *s) /* =========================================================================== * Flush the bit buffer and align the output on a byte boundary */ -local void bi_windup(deflate_state *s) +local void bi_windup(s) + deflate_state *s; { if (s->bi_valid > 8) { put_short(s, s->bi_buf); @@ -1179,17 +1194,17 @@ local void bi_windup(deflate_state *s) * Copy a stored block, storing first the length and its * one's complement if requested. */ -local void copy_block(deflate_state *s, charf *buf, unsigned int len, int header) - - /* the input data */ - /* its length */ - /* true if block header must be written */ +local void copy_block(s, buf, len, header) + deflate_state *s; + charf *buf; /* the input data */ + unsigned len; /* its length */ + int header; /* true if block header must be written */ { bi_windup(s); /* align on byte boundary */ s->last_eob_len = 8; /* enough lookahead for inflate */ if (header) { - put_short(s, (ush)len); + put_short(s, (ush)len); put_short(s, (ush)~len); #ifdef DEBUG s->bits_sent += 2*16; |