Changeset 161 for libmpc/branches/r2d/common/huffman.c

Timestamp:

12/18/06 20:52:54 (17 years ago)

Author:

r2d

Message:

• changed entropy coding (all huffman tables are canonical)
• scalefactor range now -6..121, no more clipping
• compression gain is 2.36% on the test file

File:

• libmpc/branches/r2d/common/huffman.c (modified) (3 diffs)

libmpc/branches/r2d/common/huffman.c

@@ -194 +194 @@
  * @param num_symbols
  * @param print_type
- */
-void _Huffman_PrintCodes(huff_sym_t * sym, unsigned int num_symbols, int print_type)
+ * @param offset
+ */
+void _Huffman_PrintCodes(huff_sym_t * sym, unsigned int num_symbols, int print_type, int offset)
 {
         unsigned int total_cnt = 0, total_size = 0, optim_size = 0;
-        int i;
+        int i, packs[4];
 
         switch( print_type ) {
@@ -217 +218 @@
                         printf("{\n     ");
                         for( i = num_symbols - 1; i >= 0; i--) {
-                                printf("{0x%.8x, %u, %u}", sym[i].Code << (32 - sym[i].Bits), sym[i].Bits, sym[i].Symbol);
+                                printf("{0x%.8x, %u, %i}", sym[i].Code << (32 - sym[i].Bits), sym[i].Bits, sym[i].Symbol - offset);
+                                if (i != 0)
+                                        printf(", ");
+                        }
+                        printf("\n}\n");
+                        break;
+                case 4:
+                        qsort(sym, num_symbols, sizeof(huff_sym_t),
+                                  (int (*)(const void *, const void *)) _Huffman_CompBits);
+                        printf("{\n     ");
+                        for( i = num_symbols - 1; i >= 0; i--) {
+                                int symbol =  sym[i].Symbol;
+                                packs[3] = symbol / (offset * offset * offset);
+                                packs[2] = (symbol - packs[3] * offset * offset * offset) / (offset * offset);
+                                packs[1] = (symbol - (packs[3] * offset + packs[2]) * offset * offset) / offset;
+                                packs[0] = symbol - ((packs[3] * offset + packs[2]) * offset + packs[1] * offset);
+                                packs[0] -= offset >> 1;
+                                packs[1] -= offset >> 1;
+                                packs[2] -= offset >> 1;
+                                packs[3] -= offset >> 1;
+                                symbol = ((packs[3] & 15) << 12) | ((packs[2] & 15) << 8) | ((packs[1] & 15) << 4) | (packs[0] & 15);
+                                printf("{0x%.8x, %u, %i}", sym[i].Code << (32 - sym[i].Bits), sym[i].Bits, symbol);
                                 if (i != 0)
                                         printf(", ");
@@ -234 +256 @@
                         for( i = 0; i < num_symbols; i++) {
                                 int k = sym[i].Bits - 1;
-                                printf("%-10u   %-10u   %-10u   ", sym[i].Symbol, sym[i].Count, sym[i].Bits);
+                                printf("%-10i   %-10u   %-10u   ", sym[i].Symbol - offset, sym[i].Count, sym[i].Bits);
                                 for (; k >= 0 ; k--)
                                         printf("%u", (sym[i].Code >> k) & 1 );