vrshoot
annotate libs/libjpeg/jchuff.h @ 0:b2f14e535253
initial commit
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sat, 01 Feb 2014 19:58:19 +0200 |
| parents | |
| children |
| rev | line source |
|---|---|
| nuclear@0 | 1 /* |
| nuclear@0 | 2 * jchuff.h |
| nuclear@0 | 3 * |
| nuclear@0 | 4 * Copyright (C) 1991-1997, Thomas G. Lane. |
| nuclear@0 | 5 * This file is part of the Independent JPEG Group's software. |
| nuclear@0 | 6 * For conditions of distribution and use, see the accompanying README file. |
| nuclear@0 | 7 * |
| nuclear@0 | 8 * This file contains declarations for Huffman entropy encoding routines |
| nuclear@0 | 9 * that are shared between the sequential encoder (jchuff.c) and the |
| nuclear@0 | 10 * progressive encoder (jcphuff.c). No other modules need to see these. |
| nuclear@0 | 11 */ |
| nuclear@0 | 12 |
| nuclear@0 | 13 /* The legal range of a DCT coefficient is |
| nuclear@0 | 14 * -1024 .. +1023 for 8-bit data; |
| nuclear@0 | 15 * -16384 .. +16383 for 12-bit data. |
| nuclear@0 | 16 * Hence the magnitude should always fit in 10 or 14 bits respectively. |
| nuclear@0 | 17 */ |
| nuclear@0 | 18 |
| nuclear@0 | 19 #if BITS_IN_JSAMPLE == 8 |
| nuclear@0 | 20 #define MAX_COEF_BITS 10 |
| nuclear@0 | 21 #else |
| nuclear@0 | 22 #define MAX_COEF_BITS 14 |
| nuclear@0 | 23 #endif |
| nuclear@0 | 24 |
| nuclear@0 | 25 /* Derived data constructed for each Huffman table */ |
| nuclear@0 | 26 |
| nuclear@0 | 27 typedef struct { |
| nuclear@0 | 28 unsigned int ehufco[256]; /* code for each symbol */ |
| nuclear@0 | 29 char ehufsi[256]; /* length of code for each symbol */ |
| nuclear@0 | 30 /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */ |
| nuclear@0 | 31 } c_derived_tbl; |
| nuclear@0 | 32 |
| nuclear@0 | 33 /* Short forms of external names for systems with brain-damaged linkers. */ |
| nuclear@0 | 34 |
| nuclear@0 | 35 #ifdef NEED_SHORT_EXTERNAL_NAMES |
| nuclear@0 | 36 #define jpeg_make_c_derived_tbl jMkCDerived |
| nuclear@0 | 37 #define jpeg_gen_optimal_table jGenOptTbl |
| nuclear@0 | 38 #endif /* NEED_SHORT_EXTERNAL_NAMES */ |
| nuclear@0 | 39 |
| nuclear@0 | 40 /* Expand a Huffman table definition into the derived format */ |
| nuclear@0 | 41 EXTERN(void) jpeg_make_c_derived_tbl |
| nuclear@0 | 42 JPP((j_compress_ptr cinfo, boolean isDC, int tblno, |
| nuclear@0 | 43 c_derived_tbl ** pdtbl)); |
| nuclear@0 | 44 |
| nuclear@0 | 45 /* Generate an optimal table definition given the specified counts */ |
| nuclear@0 | 46 EXTERN(void) jpeg_gen_optimal_table |
| nuclear@0 | 47 JPP((j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[])); |