lzx_compress.c: adjust parameters for slightly stronger compression

[wimlib] / src / lzx_compress.c

diff --git a/src/lzx_compress.c b/src/lzx_compress.c
index 36e27dbed6c2ecdda17b4206e3d8a75c0b299ceb..47d8bf0be9714e7fe1a9a1f846d6f1cf9f92cff7 100644 (file)
--- a/src/lzx_compress.c
+++ b/src/lzx_compress.c
@@ -1585,8 +1585,7 @@ lzx_find_min_cost_path(struct lzx_compressor * const restrict c,
                 * of coding the literal is integrated into the queue update
                 * code below.  */
                literal = *in_next++;
-               cost = cur_node->cost +
-                      c->costs.main[lzx_main_symbol_for_literal(literal)];
+               cost = cur_node->cost + c->costs.main[literal];
 
                /* Advance to the next position.  */
                cur_node++;
@@ -1626,13 +1625,13 @@ lzx_find_min_cost_path(struct lzx_compressor * const restrict c,
 static void
 lzx_compute_match_costs(struct lzx_compressor *c)
 {
-       unsigned num_offset_slots = lzx_get_num_offset_slots(c->window_order);
+       unsigned num_offset_slots = (c->num_main_syms - LZX_NUM_CHARS) / LZX_NUM_LEN_HEADERS;
        struct lzx_costs *costs = &c->costs;
 
        for (unsigned offset_slot = 0; offset_slot < num_offset_slots; offset_slot++) {
 
                u32 extra_cost = (u32)lzx_extra_offset_bits[offset_slot] * LZX_BIT_COST;
-               unsigned main_symbol = lzx_main_symbol_for_match(offset_slot, 0);
+               unsigned main_symbol = LZX_NUM_CHARS + (offset_slot * LZX_NUM_LEN_HEADERS);
                unsigned i;
 
        #if LZX_CONSIDER_ALIGNED_COSTS
@@ -2258,8 +2257,8 @@ lzx_create_compressor(size_t max_bufsize, unsigned compression_level,
                        c->impl = lzx_compress_lazy_16;
                else
                        c->impl = lzx_compress_lazy_32;
-               c->max_search_depth = (36 * compression_level) / 20;
-               c->nice_match_length = (72 * compression_level) / 20;
+               c->max_search_depth = (60 * compression_level) / 20;
+               c->nice_match_length = (80 * compression_level) / 20;
 
                /* lzx_compress_lazy() needs max_search_depth >= 2 because it
                 * halves the max_search_depth when attempting a lazy match, and
@@ -2278,7 +2277,7 @@ lzx_create_compressor(size_t max_bufsize, unsigned compression_level,
                /* Scale nice_match_length and max_search_depth with the
                 * compression level.  */
                c->max_search_depth = (24 * compression_level) / 50;
-               c->nice_match_length = (32 * compression_level) / 50;
+               c->nice_match_length = (48 * compression_level) / 50;
 
                /* Set a number of optimization passes appropriate for the
                 * compression level.  */
@@ -2339,7 +2338,7 @@ lzx_compress(const void *restrict in, size_t in_nbytes,
        else
                memcpy(c->in_buffer, in, in_nbytes);
        c->in_nbytes = in_nbytes;
-       lzx_do_e8_preprocessing(c->in_buffer, in_nbytes);
+       lzx_preprocess(c->in_buffer, in_nbytes);
 
        /* Initially, the previous Huffman codeword lengths are all zeroes.  */
        c->codes_index = 0;
@@ -2354,7 +2353,7 @@ lzx_compress(const void *restrict in, size_t in_nbytes,
        /* Flush the output bitstream and return the compressed size or 0.  */
        result = lzx_flush_output(&os);
        if (!result && c->destructive)
-               lzx_undo_e8_preprocessing(c->in_buffer, c->in_nbytes);
+               lzx_postprocess(c->in_buffer, c->in_nbytes);
        return result;
 }