aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c
diff options
context:
space:
mode:
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c')
-rw-r--r--libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c3082
1 files changed, 1541 insertions, 1541 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c
index 9694117..06f92fe 100644
--- a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c
+++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jdhuff.c
@@ -1,1541 +1,1541 @@
1/* 1/*
2 * jdhuff.c 2 * jdhuff.c
3 * 3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane. 4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 2006-2009 by Guido Vollbeding. 5 * Modified 2006-2009 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software. 6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file. 7 * For conditions of distribution and use, see the accompanying README file.
8 * 8 *
9 * This file contains Huffman entropy decoding routines. 9 * This file contains Huffman entropy decoding routines.
10 * Both sequential and progressive modes are supported in this single module. 10 * Both sequential and progressive modes are supported in this single module.
11 * 11 *
12 * Much of the complexity here has to do with supporting input suspension. 12 * Much of the complexity here has to do with supporting input suspension.
13 * If the data source module demands suspension, we want to be able to back 13 * If the data source module demands suspension, we want to be able to back
14 * up to the start of the current MCU. To do this, we copy state variables 14 * up to the start of the current MCU. To do this, we copy state variables
15 * into local working storage, and update them back to the permanent 15 * into local working storage, and update them back to the permanent
16 * storage only upon successful completion of an MCU. 16 * storage only upon successful completion of an MCU.
17 */ 17 */
18 18
19#define JPEG_INTERNALS 19#define JPEG_INTERNALS
20#include "jinclude.h" 20#include "jinclude.h"
21#include "jpeglib.h" 21#include "jpeglib.h"
22 22
23 23
24/* Derived data constructed for each Huffman table */ 24/* Derived data constructed for each Huffman table */
25 25
26#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */ 26#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */
27 27
28typedef struct { 28typedef struct {
29 /* Basic tables: (element [0] of each array is unused) */ 29 /* Basic tables: (element [0] of each array is unused) */
30 INT32 maxcode[18]; /* largest code of length k (-1 if none) */ 30 INT32 maxcode[18]; /* largest code of length k (-1 if none) */
31 /* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */ 31 /* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */
32 INT32 valoffset[17]; /* huffval[] offset for codes of length k */ 32 INT32 valoffset[17]; /* huffval[] offset for codes of length k */
33 /* valoffset[k] = huffval[] index of 1st symbol of code length k, less 33 /* valoffset[k] = huffval[] index of 1st symbol of code length k, less
34 * the smallest code of length k; so given a code of length k, the 34 * the smallest code of length k; so given a code of length k, the
35 * corresponding symbol is huffval[code + valoffset[k]] 35 * corresponding symbol is huffval[code + valoffset[k]]
36 */ 36 */
37 37
38 /* Link to public Huffman table (needed only in jpeg_huff_decode) */ 38 /* Link to public Huffman table (needed only in jpeg_huff_decode) */
39 JHUFF_TBL *pub; 39 JHUFF_TBL *pub;
40 40
41 /* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of 41 /* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of
42 * the input data stream. If the next Huffman code is no more 42 * the input data stream. If the next Huffman code is no more
43 * than HUFF_LOOKAHEAD bits long, we can obtain its length and 43 * than HUFF_LOOKAHEAD bits long, we can obtain its length and
44 * the corresponding symbol directly from these tables. 44 * the corresponding symbol directly from these tables.
45 */ 45 */
46 int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */ 46 int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */
47 UINT8 look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */ 47 UINT8 look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */
48} d_derived_tbl; 48} d_derived_tbl;
49 49
50 50
51/* 51/*
52 * Fetching the next N bits from the input stream is a time-critical operation 52 * Fetching the next N bits from the input stream is a time-critical operation
53 * for the Huffman decoders. We implement it with a combination of inline 53 * for the Huffman decoders. We implement it with a combination of inline
54 * macros and out-of-line subroutines. Note that N (the number of bits 54 * macros and out-of-line subroutines. Note that N (the number of bits
55 * demanded at one time) never exceeds 15 for JPEG use. 55 * demanded at one time) never exceeds 15 for JPEG use.
56 * 56 *
57 * We read source bytes into get_buffer and dole out bits as needed. 57 * We read source bytes into get_buffer and dole out bits as needed.
58 * If get_buffer already contains enough bits, they are fetched in-line 58 * If get_buffer already contains enough bits, they are fetched in-line
59 * by the macros CHECK_BIT_BUFFER and GET_BITS. When there aren't enough 59 * by the macros CHECK_BIT_BUFFER and GET_BITS. When there aren't enough
60 * bits, jpeg_fill_bit_buffer is called; it will attempt to fill get_buffer 60 * bits, jpeg_fill_bit_buffer is called; it will attempt to fill get_buffer
61 * as full as possible (not just to the number of bits needed; this 61 * as full as possible (not just to the number of bits needed; this
62 * prefetching reduces the overhead cost of calling jpeg_fill_bit_buffer). 62 * prefetching reduces the overhead cost of calling jpeg_fill_bit_buffer).
63 * Note that jpeg_fill_bit_buffer may return FALSE to indicate suspension. 63 * Note that jpeg_fill_bit_buffer may return FALSE to indicate suspension.
64 * On TRUE return, jpeg_fill_bit_buffer guarantees that get_buffer contains 64 * On TRUE return, jpeg_fill_bit_buffer guarantees that get_buffer contains
65 * at least the requested number of bits --- dummy zeroes are inserted if 65 * at least the requested number of bits --- dummy zeroes are inserted if
66 * necessary. 66 * necessary.
67 */ 67 */
68 68
69typedef INT32 bit_buf_type; /* type of bit-extraction buffer */ 69typedef INT32 bit_buf_type; /* type of bit-extraction buffer */
70#define BIT_BUF_SIZE 32 /* size of buffer in bits */ 70#define BIT_BUF_SIZE 32 /* size of buffer in bits */
71 71
72/* If long is > 32 bits on your machine, and shifting/masking longs is 72/* If long is > 32 bits on your machine, and shifting/masking longs is
73 * reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE 73 * reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE
74 * appropriately should be a win. Unfortunately we can't define the size 74 * appropriately should be a win. Unfortunately we can't define the size
75 * with something like #define BIT_BUF_SIZE (sizeof(bit_buf_type)*8) 75 * with something like #define BIT_BUF_SIZE (sizeof(bit_buf_type)*8)
76 * because not all machines measure sizeof in 8-bit bytes. 76 * because not all machines measure sizeof in 8-bit bytes.
77 */ 77 */
78 78
79typedef struct { /* Bitreading state saved across MCUs */ 79typedef struct { /* Bitreading state saved across MCUs */
80 bit_buf_type get_buffer; /* current bit-extraction buffer */ 80 bit_buf_type get_buffer; /* current bit-extraction buffer */
81 int bits_left; /* # of unused bits in it */ 81 int bits_left; /* # of unused bits in it */
82} bitread_perm_state; 82} bitread_perm_state;
83 83
84typedef struct { /* Bitreading working state within an MCU */ 84typedef struct { /* Bitreading working state within an MCU */
85 /* Current data source location */ 85 /* Current data source location */
86 /* We need a copy, rather than munging the original, in case of suspension */ 86 /* We need a copy, rather than munging the original, in case of suspension */
87 const JOCTET * next_input_byte; /* => next byte to read from source */ 87 const JOCTET * next_input_byte; /* => next byte to read from source */
88 size_t bytes_in_buffer; /* # of bytes remaining in source buffer */ 88 size_t bytes_in_buffer; /* # of bytes remaining in source buffer */
89 /* Bit input buffer --- note these values are kept in register variables, 89 /* Bit input buffer --- note these values are kept in register variables,
90 * not in this struct, inside the inner loops. 90 * not in this struct, inside the inner loops.
91 */ 91 */
92 bit_buf_type get_buffer; /* current bit-extraction buffer */ 92 bit_buf_type get_buffer; /* current bit-extraction buffer */
93 int bits_left; /* # of unused bits in it */ 93 int bits_left; /* # of unused bits in it */
94 /* Pointer needed by jpeg_fill_bit_buffer. */ 94 /* Pointer needed by jpeg_fill_bit_buffer. */
95 j_decompress_ptr cinfo; /* back link to decompress master record */ 95 j_decompress_ptr cinfo; /* back link to decompress master record */
96} bitread_working_state; 96} bitread_working_state;
97 97
98/* Macros to declare and load/save bitread local variables. */ 98/* Macros to declare and load/save bitread local variables. */
99#define BITREAD_STATE_VARS \ 99#define BITREAD_STATE_VARS \
100 register bit_buf_type get_buffer; \ 100 register bit_buf_type get_buffer; \
101 register int bits_left; \ 101 register int bits_left; \
102 bitread_working_state br_state 102 bitread_working_state br_state
103 103
104#define BITREAD_LOAD_STATE(cinfop,permstate) \ 104#define BITREAD_LOAD_STATE(cinfop,permstate) \
105 br_state.cinfo = cinfop; \ 105 br_state.cinfo = cinfop; \
106 br_state.next_input_byte = cinfop->src->next_input_byte; \ 106 br_state.next_input_byte = cinfop->src->next_input_byte; \
107 br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \ 107 br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \
108 get_buffer = permstate.get_buffer; \ 108 get_buffer = permstate.get_buffer; \
109 bits_left = permstate.bits_left; 109 bits_left = permstate.bits_left;
110 110
111#define BITREAD_SAVE_STATE(cinfop,permstate) \ 111#define BITREAD_SAVE_STATE(cinfop,permstate) \
112 cinfop->src->next_input_byte = br_state.next_input_byte; \ 112 cinfop->src->next_input_byte = br_state.next_input_byte; \
113 cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \ 113 cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \
114 permstate.get_buffer = get_buffer; \ 114 permstate.get_buffer = get_buffer; \
115 permstate.bits_left = bits_left 115 permstate.bits_left = bits_left
116 116
117/* 117/*
118 * These macros provide the in-line portion of bit fetching. 118 * These macros provide the in-line portion of bit fetching.
119 * Use CHECK_BIT_BUFFER to ensure there are N bits in get_buffer 119 * Use CHECK_BIT_BUFFER to ensure there are N bits in get_buffer
120 * before using GET_BITS, PEEK_BITS, or DROP_BITS. 120 * before using GET_BITS, PEEK_BITS, or DROP_BITS.
121 * The variables get_buffer and bits_left are assumed to be locals, 121 * The variables get_buffer and bits_left are assumed to be locals,
122 * but the state struct might not be (jpeg_huff_decode needs this). 122 * but the state struct might not be (jpeg_huff_decode needs this).
123 * CHECK_BIT_BUFFER(state,n,action); 123 * CHECK_BIT_BUFFER(state,n,action);
124 * Ensure there are N bits in get_buffer; if suspend, take action. 124 * Ensure there are N bits in get_buffer; if suspend, take action.
125 * val = GET_BITS(n); 125 * val = GET_BITS(n);
126 * Fetch next N bits. 126 * Fetch next N bits.
127 * val = PEEK_BITS(n); 127 * val = PEEK_BITS(n);
128 * Fetch next N bits without removing them from the buffer. 128 * Fetch next N bits without removing them from the buffer.
129 * DROP_BITS(n); 129 * DROP_BITS(n);
130 * Discard next N bits. 130 * Discard next N bits.
131 * The value N should be a simple variable, not an expression, because it 131 * The value N should be a simple variable, not an expression, because it
132 * is evaluated multiple times. 132 * is evaluated multiple times.
133 */ 133 */
134 134
135#define CHECK_BIT_BUFFER(state,nbits,action) \ 135#define CHECK_BIT_BUFFER(state,nbits,action) \
136 { if (bits_left < (nbits)) { \ 136 { if (bits_left < (nbits)) { \
137 if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \ 137 if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \
138 { action; } \ 138 { action; } \
139 get_buffer = (state).get_buffer; bits_left = (state).bits_left; } } 139 get_buffer = (state).get_buffer; bits_left = (state).bits_left; } }
140 140
141#define GET_BITS(nbits) \ 141#define GET_BITS(nbits) \
142 (((int) (get_buffer >> (bits_left -= (nbits)))) & BIT_MASK(nbits)) 142 (((int) (get_buffer >> (bits_left -= (nbits)))) & BIT_MASK(nbits))
143 143
144#define PEEK_BITS(nbits) \ 144#define PEEK_BITS(nbits) \
145 (((int) (get_buffer >> (bits_left - (nbits)))) & BIT_MASK(nbits)) 145 (((int) (get_buffer >> (bits_left - (nbits)))) & BIT_MASK(nbits))
146 146
147#define DROP_BITS(nbits) \ 147#define DROP_BITS(nbits) \
148 (bits_left -= (nbits)) 148 (bits_left -= (nbits))
149 149
150 150
151/* 151/*
152 * Code for extracting next Huffman-coded symbol from input bit stream. 152 * Code for extracting next Huffman-coded symbol from input bit stream.
153 * Again, this is time-critical and we make the main paths be macros. 153 * Again, this is time-critical and we make the main paths be macros.
154 * 154 *
155 * We use a lookahead table to process codes of up to HUFF_LOOKAHEAD bits 155 * We use a lookahead table to process codes of up to HUFF_LOOKAHEAD bits
156 * without looping. Usually, more than 95% of the Huffman codes will be 8 156 * without looping. Usually, more than 95% of the Huffman codes will be 8
157 * or fewer bits long. The few overlength codes are handled with a loop, 157 * or fewer bits long. The few overlength codes are handled with a loop,
158 * which need not be inline code. 158 * which need not be inline code.
159 * 159 *
160 * Notes about the HUFF_DECODE macro: 160 * Notes about the HUFF_DECODE macro:
161 * 1. Near the end of the data segment, we may fail to get enough bits 161 * 1. Near the end of the data segment, we may fail to get enough bits
162 * for a lookahead. In that case, we do it the hard way. 162 * for a lookahead. In that case, we do it the hard way.
163 * 2. If the lookahead table contains no entry, the next code must be 163 * 2. If the lookahead table contains no entry, the next code must be
164 * more than HUFF_LOOKAHEAD bits long. 164 * more than HUFF_LOOKAHEAD bits long.
165 * 3. jpeg_huff_decode returns -1 if forced to suspend. 165 * 3. jpeg_huff_decode returns -1 if forced to suspend.
166 */ 166 */
167 167
168#define HUFF_DECODE(result,state,htbl,failaction,slowlabel) \ 168#define HUFF_DECODE(result,state,htbl,failaction,slowlabel) \
169{ register int nb, look; \ 169{ register int nb, look; \
170 if (bits_left < HUFF_LOOKAHEAD) { \ 170 if (bits_left < HUFF_LOOKAHEAD) { \
171 if (! jpeg_fill_bit_buffer(&state,get_buffer,bits_left, 0)) {failaction;} \ 171 if (! jpeg_fill_bit_buffer(&state,get_buffer,bits_left, 0)) {failaction;} \
172 get_buffer = state.get_buffer; bits_left = state.bits_left; \ 172 get_buffer = state.get_buffer; bits_left = state.bits_left; \
173 if (bits_left < HUFF_LOOKAHEAD) { \ 173 if (bits_left < HUFF_LOOKAHEAD) { \
174 nb = 1; goto slowlabel; \ 174 nb = 1; goto slowlabel; \
175 } \ 175 } \
176 } \ 176 } \
177 look = PEEK_BITS(HUFF_LOOKAHEAD); \ 177 look = PEEK_BITS(HUFF_LOOKAHEAD); \
178 if ((nb = htbl->look_nbits[look]) != 0) { \ 178 if ((nb = htbl->look_nbits[look]) != 0) { \
179 DROP_BITS(nb); \ 179 DROP_BITS(nb); \
180 result = htbl->look_sym[look]; \ 180 result = htbl->look_sym[look]; \
181 } else { \ 181 } else { \
182 nb = HUFF_LOOKAHEAD+1; \ 182 nb = HUFF_LOOKAHEAD+1; \
183slowlabel: \ 183slowlabel: \
184 if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \ 184 if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \
185 { failaction; } \ 185 { failaction; } \
186 get_buffer = state.get_buffer; bits_left = state.bits_left; \ 186 get_buffer = state.get_buffer; bits_left = state.bits_left; \
187 } \ 187 } \
188} 188}
189 189
190 190
191/* 191/*
192 * Expanded entropy decoder object for Huffman decoding. 192 * Expanded entropy decoder object for Huffman decoding.
193 * 193 *
194 * The savable_state subrecord contains fields that change within an MCU, 194 * The savable_state subrecord contains fields that change within an MCU,
195 * but must not be updated permanently until we complete the MCU. 195 * but must not be updated permanently until we complete the MCU.
196 */ 196 */
197 197
198typedef struct { 198typedef struct {
199 unsigned int EOBRUN; /* remaining EOBs in EOBRUN */ 199 unsigned int EOBRUN; /* remaining EOBs in EOBRUN */
200 int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ 200 int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
201} savable_state; 201} savable_state;
202 202
203/* This macro is to work around compilers with missing or broken 203/* This macro is to work around compilers with missing or broken
204 * structure assignment. You'll need to fix this code if you have 204 * structure assignment. You'll need to fix this code if you have
205 * such a compiler and you change MAX_COMPS_IN_SCAN. 205 * such a compiler and you change MAX_COMPS_IN_SCAN.
206 */ 206 */
207 207
208#ifndef NO_STRUCT_ASSIGN 208#ifndef NO_STRUCT_ASSIGN
209#define ASSIGN_STATE(dest,src) ((dest) = (src)) 209#define ASSIGN_STATE(dest,src) ((dest) = (src))
210#else 210#else
211#if MAX_COMPS_IN_SCAN == 4 211#if MAX_COMPS_IN_SCAN == 4
212#define ASSIGN_STATE(dest,src) \ 212#define ASSIGN_STATE(dest,src) \
213 ((dest).EOBRUN = (src).EOBRUN, \ 213 ((dest).EOBRUN = (src).EOBRUN, \
214 (dest).last_dc_val[0] = (src).last_dc_val[0], \ 214 (dest).last_dc_val[0] = (src).last_dc_val[0], \
215 (dest).last_dc_val[1] = (src).last_dc_val[1], \ 215 (dest).last_dc_val[1] = (src).last_dc_val[1], \
216 (dest).last_dc_val[2] = (src).last_dc_val[2], \ 216 (dest).last_dc_val[2] = (src).last_dc_val[2], \
217 (dest).last_dc_val[3] = (src).last_dc_val[3]) 217 (dest).last_dc_val[3] = (src).last_dc_val[3])
218#endif 218#endif
219#endif 219#endif
220 220
221 221
222typedef struct { 222typedef struct {
223 struct jpeg_entropy_decoder pub; /* public fields */ 223 struct jpeg_entropy_decoder pub; /* public fields */
224 224
225 /* These fields are loaded into local variables at start of each MCU. 225 /* These fields are loaded into local variables at start of each MCU.
226 * In case of suspension, we exit WITHOUT updating them. 226 * In case of suspension, we exit WITHOUT updating them.
227 */ 227 */
228 bitread_perm_state bitstate; /* Bit buffer at start of MCU */ 228 bitread_perm_state bitstate; /* Bit buffer at start of MCU */
229 savable_state saved; /* Other state at start of MCU */ 229 savable_state saved; /* Other state at start of MCU */
230 230
231 /* These fields are NOT loaded into local working state. */ 231 /* These fields are NOT loaded into local working state. */
232 boolean insufficient_data; /* set TRUE after emitting warning */ 232 boolean insufficient_data; /* set TRUE after emitting warning */
233 unsigned int restarts_to_go; /* MCUs left in this restart interval */ 233 unsigned int restarts_to_go; /* MCUs left in this restart interval */
234 234
235 /* Following two fields used only in progressive mode */ 235 /* Following two fields used only in progressive mode */
236 236
237 /* Pointers to derived tables (these workspaces have image lifespan) */ 237 /* Pointers to derived tables (these workspaces have image lifespan) */
238 d_derived_tbl * derived_tbls[NUM_HUFF_TBLS]; 238 d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
239 239
240 d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */ 240 d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */
241 241
242 /* Following fields used only in sequential mode */ 242 /* Following fields used only in sequential mode */
243 243
244 /* Pointers to derived tables (these workspaces have image lifespan) */ 244 /* Pointers to derived tables (these workspaces have image lifespan) */
245 d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS]; 245 d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
246 d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS]; 246 d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
247 247
248 /* Precalculated info set up by start_pass for use in decode_mcu: */ 248 /* Precalculated info set up by start_pass for use in decode_mcu: */
249 249
250 /* Pointers to derived tables to be used for each block within an MCU */ 250 /* Pointers to derived tables to be used for each block within an MCU */
251 d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU]; 251 d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
252 d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU]; 252 d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
253 /* Whether we care about the DC and AC coefficient values for each block */ 253 /* Whether we care about the DC and AC coefficient values for each block */
254 int coef_limit[D_MAX_BLOCKS_IN_MCU]; 254 int coef_limit[D_MAX_BLOCKS_IN_MCU];
255} huff_entropy_decoder; 255} huff_entropy_decoder;
256 256
257typedef huff_entropy_decoder * huff_entropy_ptr; 257typedef huff_entropy_decoder * huff_entropy_ptr;
258 258
259 259
260static const int jpeg_zigzag_order[8][8] = { 260static const int jpeg_zigzag_order[8][8] = {
261 { 0, 1, 5, 6, 14, 15, 27, 28 }, 261 { 0, 1, 5, 6, 14, 15, 27, 28 },
262 { 2, 4, 7, 13, 16, 26, 29, 42 }, 262 { 2, 4, 7, 13, 16, 26, 29, 42 },
263 { 3, 8, 12, 17, 25, 30, 41, 43 }, 263 { 3, 8, 12, 17, 25, 30, 41, 43 },
264 { 9, 11, 18, 24, 31, 40, 44, 53 }, 264 { 9, 11, 18, 24, 31, 40, 44, 53 },
265 { 10, 19, 23, 32, 39, 45, 52, 54 }, 265 { 10, 19, 23, 32, 39, 45, 52, 54 },
266 { 20, 22, 33, 38, 46, 51, 55, 60 }, 266 { 20, 22, 33, 38, 46, 51, 55, 60 },
267 { 21, 34, 37, 47, 50, 56, 59, 61 }, 267 { 21, 34, 37, 47, 50, 56, 59, 61 },
268 { 35, 36, 48, 49, 57, 58, 62, 63 } 268 { 35, 36, 48, 49, 57, 58, 62, 63 }
269}; 269};
270 270
271static const int jpeg_zigzag_order7[7][7] = { 271static const int jpeg_zigzag_order7[7][7] = {
272 { 0, 1, 5, 6, 14, 15, 27 }, 272 { 0, 1, 5, 6, 14, 15, 27 },
273 { 2, 4, 7, 13, 16, 26, 28 }, 273 { 2, 4, 7, 13, 16, 26, 28 },
274 { 3, 8, 12, 17, 25, 29, 38 }, 274 { 3, 8, 12, 17, 25, 29, 38 },
275 { 9, 11, 18, 24, 30, 37, 39 }, 275 { 9, 11, 18, 24, 30, 37, 39 },
276 { 10, 19, 23, 31, 36, 40, 45 }, 276 { 10, 19, 23, 31, 36, 40, 45 },
277 { 20, 22, 32, 35, 41, 44, 46 }, 277 { 20, 22, 32, 35, 41, 44, 46 },
278 { 21, 33, 34, 42, 43, 47, 48 } 278 { 21, 33, 34, 42, 43, 47, 48 }
279}; 279};
280 280
281static const int jpeg_zigzag_order6[6][6] = { 281static const int jpeg_zigzag_order6[6][6] = {
282 { 0, 1, 5, 6, 14, 15 }, 282 { 0, 1, 5, 6, 14, 15 },
283 { 2, 4, 7, 13, 16, 25 }, 283 { 2, 4, 7, 13, 16, 25 },
284 { 3, 8, 12, 17, 24, 26 }, 284 { 3, 8, 12, 17, 24, 26 },
285 { 9, 11, 18, 23, 27, 32 }, 285 { 9, 11, 18, 23, 27, 32 },
286 { 10, 19, 22, 28, 31, 33 }, 286 { 10, 19, 22, 28, 31, 33 },
287 { 20, 21, 29, 30, 34, 35 } 287 { 20, 21, 29, 30, 34, 35 }
288}; 288};
289 289
290static const int jpeg_zigzag_order5[5][5] = { 290static const int jpeg_zigzag_order5[5][5] = {
291 { 0, 1, 5, 6, 14 }, 291 { 0, 1, 5, 6, 14 },
292 { 2, 4, 7, 13, 15 }, 292 { 2, 4, 7, 13, 15 },
293 { 3, 8, 12, 16, 21 }, 293 { 3, 8, 12, 16, 21 },
294 { 9, 11, 17, 20, 22 }, 294 { 9, 11, 17, 20, 22 },
295 { 10, 18, 19, 23, 24 } 295 { 10, 18, 19, 23, 24 }
296}; 296};
297 297
298static const int jpeg_zigzag_order4[4][4] = { 298static const int jpeg_zigzag_order4[4][4] = {
299 { 0, 1, 5, 6 }, 299 { 0, 1, 5, 6 },
300 { 2, 4, 7, 12 }, 300 { 2, 4, 7, 12 },
301 { 3, 8, 11, 13 }, 301 { 3, 8, 11, 13 },
302 { 9, 10, 14, 15 } 302 { 9, 10, 14, 15 }
303}; 303};
304 304
305static const int jpeg_zigzag_order3[3][3] = { 305static const int jpeg_zigzag_order3[3][3] = {
306 { 0, 1, 5 }, 306 { 0, 1, 5 },
307 { 2, 4, 6 }, 307 { 2, 4, 6 },
308 { 3, 7, 8 } 308 { 3, 7, 8 }
309}; 309};
310 310
311static const int jpeg_zigzag_order2[2][2] = { 311static const int jpeg_zigzag_order2[2][2] = {
312 { 0, 1 }, 312 { 0, 1 },
313 { 2, 3 } 313 { 2, 3 }
314}; 314};
315 315
316 316
317/* 317/*
318 * Compute the derived values for a Huffman table. 318 * Compute the derived values for a Huffman table.
319 * This routine also performs some validation checks on the table. 319 * This routine also performs some validation checks on the table.
320 */ 320 */
321 321
322LOCAL(void) 322LOCAL(void)
323jpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno, 323jpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno,
324 d_derived_tbl ** pdtbl) 324 d_derived_tbl ** pdtbl)
325{ 325{
326 JHUFF_TBL *htbl; 326 JHUFF_TBL *htbl;
327 d_derived_tbl *dtbl; 327 d_derived_tbl *dtbl;
328 int p, i, l, si, numsymbols; 328 int p, i, l, si, numsymbols;
329 int lookbits, ctr; 329 int lookbits, ctr;
330 char huffsize[257]; 330 char huffsize[257];
331 unsigned int huffcode[257]; 331 unsigned int huffcode[257];
332 unsigned int code; 332 unsigned int code;
333 333
334 /* Note that huffsize[] and huffcode[] are filled in code-length order, 334 /* Note that huffsize[] and huffcode[] are filled in code-length order,
335 * paralleling the order of the symbols themselves in htbl->huffval[]. 335 * paralleling the order of the symbols themselves in htbl->huffval[].
336 */ 336 */
337 337
338 /* Find the input Huffman table */ 338 /* Find the input Huffman table */
339 if (tblno < 0 || tblno >= NUM_HUFF_TBLS) 339 if (tblno < 0 || tblno >= NUM_HUFF_TBLS)
340 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 340 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
341 htbl = 341 htbl =
342 isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno]; 342 isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno];
343 if (htbl == NULL) 343 if (htbl == NULL)
344 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 344 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
345 345
346 /* Allocate a workspace if we haven't already done so. */ 346 /* Allocate a workspace if we haven't already done so. */
347 if (*pdtbl == NULL) 347 if (*pdtbl == NULL)
348 *pdtbl = (d_derived_tbl *) 348 *pdtbl = (d_derived_tbl *)
349 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 349 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
350 SIZEOF(d_derived_tbl)); 350 SIZEOF(d_derived_tbl));
351 dtbl = *pdtbl; 351 dtbl = *pdtbl;
352 dtbl->pub = htbl; /* fill in back link */ 352 dtbl->pub = htbl; /* fill in back link */
353 353
354 /* Figure C.1: make table of Huffman code length for each symbol */ 354 /* Figure C.1: make table of Huffman code length for each symbol */
355 355
356 p = 0; 356 p = 0;
357 for (l = 1; l <= 16; l++) { 357 for (l = 1; l <= 16; l++) {
358 i = (int) htbl->bits[l]; 358 i = (int) htbl->bits[l];
359 if (i < 0 || p + i > 256) /* protect against table overrun */ 359 if (i < 0 || p + i > 256) /* protect against table overrun */
360 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 360 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
361 while (i--) 361 while (i--)
362 huffsize[p++] = (char) l; 362 huffsize[p++] = (char) l;
363 } 363 }
364 huffsize[p] = 0; 364 huffsize[p] = 0;
365 numsymbols = p; 365 numsymbols = p;
366 366
367 /* Figure C.2: generate the codes themselves */ 367 /* Figure C.2: generate the codes themselves */
368 /* We also validate that the counts represent a legal Huffman code tree. */ 368 /* We also validate that the counts represent a legal Huffman code tree. */
369 369
370 code = 0; 370 code = 0;
371 si = huffsize[0]; 371 si = huffsize[0];
372 p = 0; 372 p = 0;
373 while (huffsize[p]) { 373 while (huffsize[p]) {
374 while (((int) huffsize[p]) == si) { 374 while (((int) huffsize[p]) == si) {
375 huffcode[p++] = code; 375 huffcode[p++] = code;
376 code++; 376 code++;
377 } 377 }
378 /* code is now 1 more than the last code used for codelength si; but 378 /* code is now 1 more than the last code used for codelength si; but
379 * it must still fit in si bits, since no code is allowed to be all ones. 379 * it must still fit in si bits, since no code is allowed to be all ones.
380 */ 380 */
381 if (((INT32) code) >= (((INT32) 1) << si)) 381 if (((INT32) code) >= (((INT32) 1) << si))
382 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 382 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
383 code <<= 1; 383 code <<= 1;
384 si++; 384 si++;
385 } 385 }
386 386
387 /* Figure F.15: generate decoding tables for bit-sequential decoding */ 387 /* Figure F.15: generate decoding tables for bit-sequential decoding */
388 388
389 p = 0; 389 p = 0;
390 for (l = 1; l <= 16; l++) { 390 for (l = 1; l <= 16; l++) {
391 if (htbl->bits[l]) { 391 if (htbl->bits[l]) {
392 /* valoffset[l] = huffval[] index of 1st symbol of code length l, 392 /* valoffset[l] = huffval[] index of 1st symbol of code length l,
393 * minus the minimum code of length l 393 * minus the minimum code of length l
394 */ 394 */
395 dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p]; 395 dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p];
396 p += htbl->bits[l]; 396 p += htbl->bits[l];
397 dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */ 397 dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
398 } else { 398 } else {
399 dtbl->maxcode[l] = -1; /* -1 if no codes of this length */ 399 dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
400 } 400 }
401 } 401 }
402 dtbl->maxcode[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */ 402 dtbl->maxcode[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */
403 403
404 /* Compute lookahead tables to speed up decoding. 404 /* Compute lookahead tables to speed up decoding.
405 * First we set all the table entries to 0, indicating "too long"; 405 * First we set all the table entries to 0, indicating "too long";
406 * then we iterate through the Huffman codes that are short enough and 406 * then we iterate through the Huffman codes that are short enough and
407 * fill in all the entries that correspond to bit sequences starting 407 * fill in all the entries that correspond to bit sequences starting
408 * with that code. 408 * with that code.
409 */ 409 */
410 410
411 MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits)); 411 MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits));
412 412
413 p = 0; 413 p = 0;
414 for (l = 1; l <= HUFF_LOOKAHEAD; l++) { 414 for (l = 1; l <= HUFF_LOOKAHEAD; l++) {
415 for (i = 1; i <= (int) htbl->bits[l]; i++, p++) { 415 for (i = 1; i <= (int) htbl->bits[l]; i++, p++) {
416 /* l = current code's length, p = its index in huffcode[] & huffval[]. */ 416 /* l = current code's length, p = its index in huffcode[] & huffval[]. */
417 /* Generate left-justified code followed by all possible bit sequences */ 417 /* Generate left-justified code followed by all possible bit sequences */
418 lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l); 418 lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
419 for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) { 419 for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) {
420 dtbl->look_nbits[lookbits] = l; 420 dtbl->look_nbits[lookbits] = l;
421 dtbl->look_sym[lookbits] = htbl->huffval[p]; 421 dtbl->look_sym[lookbits] = htbl->huffval[p];
422 lookbits++; 422 lookbits++;
423 } 423 }
424 } 424 }
425 } 425 }
426 426
427 /* Validate symbols as being reasonable. 427 /* Validate symbols as being reasonable.
428 * For AC tables, we make no check, but accept all byte values 0..255. 428 * For AC tables, we make no check, but accept all byte values 0..255.
429 * For DC tables, we require the symbols to be in range 0..15. 429 * For DC tables, we require the symbols to be in range 0..15.
430 * (Tighter bounds could be applied depending on the data depth and mode, 430 * (Tighter bounds could be applied depending on the data depth and mode,
431 * but this is sufficient to ensure safe decoding.) 431 * but this is sufficient to ensure safe decoding.)
432 */ 432 */
433 if (isDC) { 433 if (isDC) {
434 for (i = 0; i < numsymbols; i++) { 434 for (i = 0; i < numsymbols; i++) {
435 int sym = htbl->huffval[i]; 435 int sym = htbl->huffval[i];
436 if (sym < 0 || sym > 15) 436 if (sym < 0 || sym > 15)
437 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 437 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
438 } 438 }
439 } 439 }
440} 440}
441 441
442 442
443/* 443/*
444 * Out-of-line code for bit fetching. 444 * Out-of-line code for bit fetching.
445 * Note: current values of get_buffer and bits_left are passed as parameters, 445 * Note: current values of get_buffer and bits_left are passed as parameters,
446 * but are returned in the corresponding fields of the state struct. 446 * but are returned in the corresponding fields of the state struct.
447 * 447 *
448 * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width 448 * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width
449 * of get_buffer to be used. (On machines with wider words, an even larger 449 * of get_buffer to be used. (On machines with wider words, an even larger
450 * buffer could be used.) However, on some machines 32-bit shifts are 450 * buffer could be used.) However, on some machines 32-bit shifts are
451 * quite slow and take time proportional to the number of places shifted. 451 * quite slow and take time proportional to the number of places shifted.
452 * (This is true with most PC compilers, for instance.) In this case it may 452 * (This is true with most PC compilers, for instance.) In this case it may
453 * be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the 453 * be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the
454 * average shift distance at the cost of more calls to jpeg_fill_bit_buffer. 454 * average shift distance at the cost of more calls to jpeg_fill_bit_buffer.
455 */ 455 */
456 456
457#ifdef SLOW_SHIFT_32 457#ifdef SLOW_SHIFT_32
458#define MIN_GET_BITS 15 /* minimum allowable value */ 458#define MIN_GET_BITS 15 /* minimum allowable value */
459#else 459#else
460#define MIN_GET_BITS (BIT_BUF_SIZE-7) 460#define MIN_GET_BITS (BIT_BUF_SIZE-7)
461#endif 461#endif
462 462
463 463
464LOCAL(boolean) 464LOCAL(boolean)
465jpeg_fill_bit_buffer (bitread_working_state * state, 465jpeg_fill_bit_buffer (bitread_working_state * state,
466 register bit_buf_type get_buffer, register int bits_left, 466 register bit_buf_type get_buffer, register int bits_left,
467 int nbits) 467 int nbits)
468/* Load up the bit buffer to a depth of at least nbits */ 468/* Load up the bit buffer to a depth of at least nbits */
469{ 469{
470 /* Copy heavily used state fields into locals (hopefully registers) */ 470 /* Copy heavily used state fields into locals (hopefully registers) */
471 register const JOCTET * next_input_byte = state->next_input_byte; 471 register const JOCTET * next_input_byte = state->next_input_byte;
472 register size_t bytes_in_buffer = state->bytes_in_buffer; 472 register size_t bytes_in_buffer = state->bytes_in_buffer;
473 j_decompress_ptr cinfo = state->cinfo; 473 j_decompress_ptr cinfo = state->cinfo;
474 474
475 /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */ 475 /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */
476 /* (It is assumed that no request will be for more than that many bits.) */ 476 /* (It is assumed that no request will be for more than that many bits.) */
477 /* We fail to do so only if we hit a marker or are forced to suspend. */ 477 /* We fail to do so only if we hit a marker or are forced to suspend. */
478 478
479 if (cinfo->unread_marker == 0) { /* cannot advance past a marker */ 479 if (cinfo->unread_marker == 0) { /* cannot advance past a marker */
480 while (bits_left < MIN_GET_BITS) { 480 while (bits_left < MIN_GET_BITS) {
481 register int c; 481 register int c;
482 482
483 /* Attempt to read a byte */ 483 /* Attempt to read a byte */
484 if (bytes_in_buffer == 0) { 484 if (bytes_in_buffer == 0) {
485 if (! (*cinfo->src->fill_input_buffer) (cinfo)) 485 if (! (*cinfo->src->fill_input_buffer) (cinfo))
486 return FALSE; 486 return FALSE;
487 next_input_byte = cinfo->src->next_input_byte; 487 next_input_byte = cinfo->src->next_input_byte;
488 bytes_in_buffer = cinfo->src->bytes_in_buffer; 488 bytes_in_buffer = cinfo->src->bytes_in_buffer;
489 } 489 }
490 bytes_in_buffer--; 490 bytes_in_buffer--;
491 c = GETJOCTET(*next_input_byte++); 491 c = GETJOCTET(*next_input_byte++);
492 492
493 /* If it's 0xFF, check and discard stuffed zero byte */ 493 /* If it's 0xFF, check and discard stuffed zero byte */
494 if (c == 0xFF) { 494 if (c == 0xFF) {
495 /* Loop here to discard any padding FF's on terminating marker, 495 /* Loop here to discard any padding FF's on terminating marker,
496 * so that we can save a valid unread_marker value. NOTE: we will 496 * so that we can save a valid unread_marker value. NOTE: we will
497 * accept multiple FF's followed by a 0 as meaning a single FF data 497 * accept multiple FF's followed by a 0 as meaning a single FF data
498 * byte. This data pattern is not valid according to the standard. 498 * byte. This data pattern is not valid according to the standard.
499 */ 499 */
500 do { 500 do {
501 if (bytes_in_buffer == 0) { 501 if (bytes_in_buffer == 0) {
502 if (! (*cinfo->src->fill_input_buffer) (cinfo)) 502 if (! (*cinfo->src->fill_input_buffer) (cinfo))
503 return FALSE; 503 return FALSE;
504 next_input_byte = cinfo->src->next_input_byte; 504 next_input_byte = cinfo->src->next_input_byte;
505 bytes_in_buffer = cinfo->src->bytes_in_buffer; 505 bytes_in_buffer = cinfo->src->bytes_in_buffer;
506 } 506 }
507 bytes_in_buffer--; 507 bytes_in_buffer--;
508 c = GETJOCTET(*next_input_byte++); 508 c = GETJOCTET(*next_input_byte++);
509 } while (c == 0xFF); 509 } while (c == 0xFF);
510 510
511 if (c == 0) { 511 if (c == 0) {
512 /* Found FF/00, which represents an FF data byte */ 512 /* Found FF/00, which represents an FF data byte */
513 c = 0xFF; 513 c = 0xFF;
514 } else { 514 } else {
515 /* Oops, it's actually a marker indicating end of compressed data. 515 /* Oops, it's actually a marker indicating end of compressed data.
516 * Save the marker code for later use. 516 * Save the marker code for later use.
517 * Fine point: it might appear that we should save the marker into 517 * Fine point: it might appear that we should save the marker into
518 * bitread working state, not straight into permanent state. But 518 * bitread working state, not straight into permanent state. But
519 * once we have hit a marker, we cannot need to suspend within the 519 * once we have hit a marker, we cannot need to suspend within the
520 * current MCU, because we will read no more bytes from the data 520 * current MCU, because we will read no more bytes from the data
521 * source. So it is OK to update permanent state right away. 521 * source. So it is OK to update permanent state right away.
522 */ 522 */
523 cinfo->unread_marker = c; 523 cinfo->unread_marker = c;
524 /* See if we need to insert some fake zero bits. */ 524 /* See if we need to insert some fake zero bits. */
525 goto no_more_bytes; 525 goto no_more_bytes;
526 } 526 }
527 } 527 }
528 528
529 /* OK, load c into get_buffer */ 529 /* OK, load c into get_buffer */
530 get_buffer = (get_buffer << 8) | c; 530 get_buffer = (get_buffer << 8) | c;
531 bits_left += 8; 531 bits_left += 8;
532 } /* end while */ 532 } /* end while */
533 } else { 533 } else {
534 no_more_bytes: 534 no_more_bytes:
535 /* We get here if we've read the marker that terminates the compressed 535 /* We get here if we've read the marker that terminates the compressed
536 * data segment. There should be enough bits in the buffer register 536 * data segment. There should be enough bits in the buffer register
537 * to satisfy the request; if so, no problem. 537 * to satisfy the request; if so, no problem.
538 */ 538 */
539 if (nbits > bits_left) { 539 if (nbits > bits_left) {
540 /* Uh-oh. Report corrupted data to user and stuff zeroes into 540 /* Uh-oh. Report corrupted data to user and stuff zeroes into
541 * the data stream, so that we can produce some kind of image. 541 * the data stream, so that we can produce some kind of image.
542 * We use a nonvolatile flag to ensure that only one warning message 542 * We use a nonvolatile flag to ensure that only one warning message
543 * appears per data segment. 543 * appears per data segment.
544 */ 544 */
545 if (! ((huff_entropy_ptr) cinfo->entropy)->insufficient_data) { 545 if (! ((huff_entropy_ptr) cinfo->entropy)->insufficient_data) {
546 WARNMS(cinfo, JWRN_HIT_MARKER); 546 WARNMS(cinfo, JWRN_HIT_MARKER);
547 ((huff_entropy_ptr) cinfo->entropy)->insufficient_data = TRUE; 547 ((huff_entropy_ptr) cinfo->entropy)->insufficient_data = TRUE;
548 } 548 }
549 /* Fill the buffer with zero bits */ 549 /* Fill the buffer with zero bits */
550 get_buffer <<= MIN_GET_BITS - bits_left; 550 get_buffer <<= MIN_GET_BITS - bits_left;
551 bits_left = MIN_GET_BITS; 551 bits_left = MIN_GET_BITS;
552 } 552 }
553 } 553 }
554 554
555 /* Unload the local registers */ 555 /* Unload the local registers */
556 state->next_input_byte = next_input_byte; 556 state->next_input_byte = next_input_byte;
557 state->bytes_in_buffer = bytes_in_buffer; 557 state->bytes_in_buffer = bytes_in_buffer;
558 state->get_buffer = get_buffer; 558 state->get_buffer = get_buffer;
559 state->bits_left = bits_left; 559 state->bits_left = bits_left;
560 560
561 return TRUE; 561 return TRUE;
562} 562}
563 563
564 564
565/* 565/*
566 * Figure F.12: extend sign bit. 566 * Figure F.12: extend sign bit.
567 * On some machines, a shift and sub will be faster than a table lookup. 567 * On some machines, a shift and sub will be faster than a table lookup.
568 */ 568 */
569 569
570#ifdef AVOID_TABLES 570#ifdef AVOID_TABLES
571 571
572#define BIT_MASK(nbits) ((1<<(nbits))-1) 572#define BIT_MASK(nbits) ((1<<(nbits))-1)
573#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) - ((1<<(s))-1) : (x)) 573#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) - ((1<<(s))-1) : (x))
574 574
575#else 575#else
576 576
577#define BIT_MASK(nbits) bmask[nbits] 577#define BIT_MASK(nbits) bmask[nbits]
578#define HUFF_EXTEND(x,s) ((x) <= bmask[(s) - 1] ? (x) - bmask[s] : (x)) 578#define HUFF_EXTEND(x,s) ((x) <= bmask[(s) - 1] ? (x) - bmask[s] : (x))
579 579
580static const int bmask[16] = /* bmask[n] is mask for n rightmost bits */ 580static const int bmask[16] = /* bmask[n] is mask for n rightmost bits */
581 { 0, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F, 0x007F, 0x00FF, 581 { 0, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F, 0x007F, 0x00FF,
582 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF }; 582 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF };
583 583
584#endif /* AVOID_TABLES */ 584#endif /* AVOID_TABLES */
585 585
586 586
587/* 587/*
588 * Out-of-line code for Huffman code decoding. 588 * Out-of-line code for Huffman code decoding.
589 */ 589 */
590 590
591LOCAL(int) 591LOCAL(int)
592jpeg_huff_decode (bitread_working_state * state, 592jpeg_huff_decode (bitread_working_state * state,
593 register bit_buf_type get_buffer, register int bits_left, 593 register bit_buf_type get_buffer, register int bits_left,
594 d_derived_tbl * htbl, int min_bits) 594 d_derived_tbl * htbl, int min_bits)
595{ 595{
596 register int l = min_bits; 596 register int l = min_bits;
597 register INT32 code; 597 register INT32 code;
598 598
599 /* HUFF_DECODE has determined that the code is at least min_bits */ 599 /* HUFF_DECODE has determined that the code is at least min_bits */
600 /* bits long, so fetch that many bits in one swoop. */ 600 /* bits long, so fetch that many bits in one swoop. */
601 601
602 CHECK_BIT_BUFFER(*state, l, return -1); 602 CHECK_BIT_BUFFER(*state, l, return -1);
603 code = GET_BITS(l); 603 code = GET_BITS(l);
604 604
605 /* Collect the rest of the Huffman code one bit at a time. */ 605 /* Collect the rest of the Huffman code one bit at a time. */
606 /* This is per Figure F.16 in the JPEG spec. */ 606 /* This is per Figure F.16 in the JPEG spec. */
607 607
608 while (code > htbl->maxcode[l]) { 608 while (code > htbl->maxcode[l]) {
609 code <<= 1; 609 code <<= 1;
610 CHECK_BIT_BUFFER(*state, 1, return -1); 610 CHECK_BIT_BUFFER(*state, 1, return -1);
611 code |= GET_BITS(1); 611 code |= GET_BITS(1);
612 l++; 612 l++;
613 } 613 }
614 614
615 /* Unload the local registers */ 615 /* Unload the local registers */
616 state->get_buffer = get_buffer; 616 state->get_buffer = get_buffer;
617 state->bits_left = bits_left; 617 state->bits_left = bits_left;
618 618
619 /* With garbage input we may reach the sentinel value l = 17. */ 619 /* With garbage input we may reach the sentinel value l = 17. */
620 620
621 if (l > 16) { 621 if (l > 16) {
622 WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE); 622 WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE);
623 return 0; /* fake a zero as the safest result */ 623 return 0; /* fake a zero as the safest result */
624 } 624 }
625 625
626 return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ]; 626 return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ];
627} 627}
628 628
629 629
630/* 630/*
631 * Check for a restart marker & resynchronize decoder. 631 * Check for a restart marker & resynchronize decoder.
632 * Returns FALSE if must suspend. 632 * Returns FALSE if must suspend.
633 */ 633 */
634 634
635LOCAL(boolean) 635LOCAL(boolean)
636process_restart (j_decompress_ptr cinfo) 636process_restart (j_decompress_ptr cinfo)
637{ 637{
638 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 638 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
639 int ci; 639 int ci;
640 640
641 /* Throw away any unused bits remaining in bit buffer; */ 641 /* Throw away any unused bits remaining in bit buffer; */
642 /* include any full bytes in next_marker's count of discarded bytes */ 642 /* include any full bytes in next_marker's count of discarded bytes */
643 cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8; 643 cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
644 entropy->bitstate.bits_left = 0; 644 entropy->bitstate.bits_left = 0;
645 645
646 /* Advance past the RSTn marker */ 646 /* Advance past the RSTn marker */
647 if (! (*cinfo->marker->read_restart_marker) (cinfo)) 647 if (! (*cinfo->marker->read_restart_marker) (cinfo))
648 return FALSE; 648 return FALSE;
649 649
650 /* Re-initialize DC predictions to 0 */ 650 /* Re-initialize DC predictions to 0 */
651 for (ci = 0; ci < cinfo->comps_in_scan; ci++) 651 for (ci = 0; ci < cinfo->comps_in_scan; ci++)
652 entropy->saved.last_dc_val[ci] = 0; 652 entropy->saved.last_dc_val[ci] = 0;
653 /* Re-init EOB run count, too */ 653 /* Re-init EOB run count, too */
654 entropy->saved.EOBRUN = 0; 654 entropy->saved.EOBRUN = 0;
655 655
656 /* Reset restart counter */ 656 /* Reset restart counter */
657 entropy->restarts_to_go = cinfo->restart_interval; 657 entropy->restarts_to_go = cinfo->restart_interval;
658 658
659 /* Reset out-of-data flag, unless read_restart_marker left us smack up 659 /* Reset out-of-data flag, unless read_restart_marker left us smack up
660 * against a marker. In that case we will end up treating the next data 660 * against a marker. In that case we will end up treating the next data
661 * segment as empty, and we can avoid producing bogus output pixels by 661 * segment as empty, and we can avoid producing bogus output pixels by
662 * leaving the flag set. 662 * leaving the flag set.
663 */ 663 */
664 if (cinfo->unread_marker == 0) 664 if (cinfo->unread_marker == 0)
665 entropy->insufficient_data = FALSE; 665 entropy->insufficient_data = FALSE;
666 666
667 return TRUE; 667 return TRUE;
668} 668}
669 669
670 670
671/* 671/*
672 * Huffman MCU decoding. 672 * Huffman MCU decoding.
673 * Each of these routines decodes and returns one MCU's worth of 673 * Each of these routines decodes and returns one MCU's worth of
674 * Huffman-compressed coefficients. 674 * Huffman-compressed coefficients.
675 * The coefficients are reordered from zigzag order into natural array order, 675 * The coefficients are reordered from zigzag order into natural array order,
676 * but are not dequantized. 676 * but are not dequantized.
677 * 677 *
678 * The i'th block of the MCU is stored into the block pointed to by 678 * The i'th block of the MCU is stored into the block pointed to by
679 * MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER. 679 * MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
680 * (Wholesale zeroing is usually a little faster than retail...) 680 * (Wholesale zeroing is usually a little faster than retail...)
681 * 681 *
682 * We return FALSE if data source requested suspension. In that case no 682 * We return FALSE if data source requested suspension. In that case no
683 * changes have been made to permanent state. (Exception: some output 683 * changes have been made to permanent state. (Exception: some output
684 * coefficients may already have been assigned. This is harmless for 684 * coefficients may already have been assigned. This is harmless for
685 * spectral selection, since we'll just re-assign them on the next call. 685 * spectral selection, since we'll just re-assign them on the next call.
686 * Successive approximation AC refinement has to be more careful, however.) 686 * Successive approximation AC refinement has to be more careful, however.)
687 */ 687 */
688 688
689/* 689/*
690 * MCU decoding for DC initial scan (either spectral selection, 690 * MCU decoding for DC initial scan (either spectral selection,
691 * or first pass of successive approximation). 691 * or first pass of successive approximation).
692 */ 692 */
693 693
694METHODDEF(boolean) 694METHODDEF(boolean)
695decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 695decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
696{ 696{
697 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 697 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
698 int Al = cinfo->Al; 698 int Al = cinfo->Al;
699 register int s, r; 699 register int s, r;
700 int blkn, ci; 700 int blkn, ci;
701 JBLOCKROW block; 701 JBLOCKROW block;
702 BITREAD_STATE_VARS; 702 BITREAD_STATE_VARS;
703 savable_state state; 703 savable_state state;
704 d_derived_tbl * tbl; 704 d_derived_tbl * tbl;
705 jpeg_component_info * compptr; 705 jpeg_component_info * compptr;
706 706
707 /* Process restart marker if needed; may have to suspend */ 707 /* Process restart marker if needed; may have to suspend */
708 if (cinfo->restart_interval) { 708 if (cinfo->restart_interval) {
709 if (entropy->restarts_to_go == 0) 709 if (entropy->restarts_to_go == 0)
710 if (! process_restart(cinfo)) 710 if (! process_restart(cinfo))
711 return FALSE; 711 return FALSE;
712 } 712 }
713 713
714 /* If we've run out of data, just leave the MCU set to zeroes. 714 /* If we've run out of data, just leave the MCU set to zeroes.
715 * This way, we return uniform gray for the remainder of the segment. 715 * This way, we return uniform gray for the remainder of the segment.
716 */ 716 */
717 if (! entropy->insufficient_data) { 717 if (! entropy->insufficient_data) {
718 718
719 /* Load up working state */ 719 /* Load up working state */
720 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 720 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
721 ASSIGN_STATE(state, entropy->saved); 721 ASSIGN_STATE(state, entropy->saved);
722 722
723 /* Outer loop handles each block in the MCU */ 723 /* Outer loop handles each block in the MCU */
724 724
725 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 725 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
726 block = MCU_data[blkn]; 726 block = MCU_data[blkn];
727 ci = cinfo->MCU_membership[blkn]; 727 ci = cinfo->MCU_membership[blkn];
728 compptr = cinfo->cur_comp_info[ci]; 728 compptr = cinfo->cur_comp_info[ci];
729 tbl = entropy->derived_tbls[compptr->dc_tbl_no]; 729 tbl = entropy->derived_tbls[compptr->dc_tbl_no];
730 730
731 /* Decode a single block's worth of coefficients */ 731 /* Decode a single block's worth of coefficients */
732 732
733 /* Section F.2.2.1: decode the DC coefficient difference */ 733 /* Section F.2.2.1: decode the DC coefficient difference */
734 HUFF_DECODE(s, br_state, tbl, return FALSE, label1); 734 HUFF_DECODE(s, br_state, tbl, return FALSE, label1);
735 if (s) { 735 if (s) {
736 CHECK_BIT_BUFFER(br_state, s, return FALSE); 736 CHECK_BIT_BUFFER(br_state, s, return FALSE);
737 r = GET_BITS(s); 737 r = GET_BITS(s);
738 s = HUFF_EXTEND(r, s); 738 s = HUFF_EXTEND(r, s);
739 } 739 }
740 740
741 /* Convert DC difference to actual value, update last_dc_val */ 741 /* Convert DC difference to actual value, update last_dc_val */
742 s += state.last_dc_val[ci]; 742 s += state.last_dc_val[ci];
743 state.last_dc_val[ci] = s; 743 state.last_dc_val[ci] = s;
744 /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */ 744 /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */
745 (*block)[0] = (JCOEF) (s << Al); 745 (*block)[0] = (JCOEF) (s << Al);
746 } 746 }
747 747
748 /* Completed MCU, so update state */ 748 /* Completed MCU, so update state */
749 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 749 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
750 ASSIGN_STATE(entropy->saved, state); 750 ASSIGN_STATE(entropy->saved, state);
751 } 751 }
752 752
753 /* Account for restart interval (no-op if not using restarts) */ 753 /* Account for restart interval (no-op if not using restarts) */
754 entropy->restarts_to_go--; 754 entropy->restarts_to_go--;
755 755
756 return TRUE; 756 return TRUE;
757} 757}
758 758
759 759
760/* 760/*
761 * MCU decoding for AC initial scan (either spectral selection, 761 * MCU decoding for AC initial scan (either spectral selection,
762 * or first pass of successive approximation). 762 * or first pass of successive approximation).
763 */ 763 */
764 764
765METHODDEF(boolean) 765METHODDEF(boolean)
766decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 766decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
767{ 767{
768 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 768 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
769 register int s, k, r; 769 register int s, k, r;
770 unsigned int EOBRUN; 770 unsigned int EOBRUN;
771 int Se, Al; 771 int Se, Al;
772 const int * natural_order; 772 const int * natural_order;
773 JBLOCKROW block; 773 JBLOCKROW block;
774 BITREAD_STATE_VARS; 774 BITREAD_STATE_VARS;
775 d_derived_tbl * tbl; 775 d_derived_tbl * tbl;
776 776
777 /* Process restart marker if needed; may have to suspend */ 777 /* Process restart marker if needed; may have to suspend */
778 if (cinfo->restart_interval) { 778 if (cinfo->restart_interval) {
779 if (entropy->restarts_to_go == 0) 779 if (entropy->restarts_to_go == 0)
780 if (! process_restart(cinfo)) 780 if (! process_restart(cinfo))
781 return FALSE; 781 return FALSE;
782 } 782 }
783 783
784 /* If we've run out of data, just leave the MCU set to zeroes. 784 /* If we've run out of data, just leave the MCU set to zeroes.
785 * This way, we return uniform gray for the remainder of the segment. 785 * This way, we return uniform gray for the remainder of the segment.
786 */ 786 */
787 if (! entropy->insufficient_data) { 787 if (! entropy->insufficient_data) {
788 788
789 Se = cinfo->Se; 789 Se = cinfo->Se;
790 Al = cinfo->Al; 790 Al = cinfo->Al;
791 natural_order = cinfo->natural_order; 791 natural_order = cinfo->natural_order;
792 792
793 /* Load up working state. 793 /* Load up working state.
794 * We can avoid loading/saving bitread state if in an EOB run. 794 * We can avoid loading/saving bitread state if in an EOB run.
795 */ 795 */
796 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */ 796 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
797 797
798 /* There is always only one block per MCU */ 798 /* There is always only one block per MCU */
799 799
800 if (EOBRUN > 0) /* if it's a band of zeroes... */ 800 if (EOBRUN > 0) /* if it's a band of zeroes... */
801 EOBRUN--; /* ...process it now (we do nothing) */ 801 EOBRUN--; /* ...process it now (we do nothing) */
802 else { 802 else {
803 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 803 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
804 block = MCU_data[0]; 804 block = MCU_data[0];
805 tbl = entropy->ac_derived_tbl; 805 tbl = entropy->ac_derived_tbl;
806 806
807 for (k = cinfo->Ss; k <= Se; k++) { 807 for (k = cinfo->Ss; k <= Se; k++) {
808 HUFF_DECODE(s, br_state, tbl, return FALSE, label2); 808 HUFF_DECODE(s, br_state, tbl, return FALSE, label2);
809 r = s >> 4; 809 r = s >> 4;
810 s &= 15; 810 s &= 15;
811 if (s) { 811 if (s) {
812 k += r; 812 k += r;
813 CHECK_BIT_BUFFER(br_state, s, return FALSE); 813 CHECK_BIT_BUFFER(br_state, s, return FALSE);
814 r = GET_BITS(s); 814 r = GET_BITS(s);
815 s = HUFF_EXTEND(r, s); 815 s = HUFF_EXTEND(r, s);
816 /* Scale and output coefficient in natural (dezigzagged) order */ 816 /* Scale and output coefficient in natural (dezigzagged) order */
817 (*block)[natural_order[k]] = (JCOEF) (s << Al); 817 (*block)[natural_order[k]] = (JCOEF) (s << Al);
818 } else { 818 } else {
819 if (r == 15) { /* ZRL */ 819 if (r == 15) { /* ZRL */
820 k += 15; /* skip 15 zeroes in band */ 820 k += 15; /* skip 15 zeroes in band */
821 } else { /* EOBr, run length is 2^r + appended bits */ 821 } else { /* EOBr, run length is 2^r + appended bits */
822 EOBRUN = 1 << r; 822 EOBRUN = 1 << r;
823 if (r) { /* EOBr, r > 0 */ 823 if (r) { /* EOBr, r > 0 */
824 CHECK_BIT_BUFFER(br_state, r, return FALSE); 824 CHECK_BIT_BUFFER(br_state, r, return FALSE);
825 r = GET_BITS(r); 825 r = GET_BITS(r);
826 EOBRUN += r; 826 EOBRUN += r;
827 } 827 }
828 EOBRUN--; /* this band is processed at this moment */ 828 EOBRUN--; /* this band is processed at this moment */
829 break; /* force end-of-band */ 829 break; /* force end-of-band */
830 } 830 }
831 } 831 }
832 } 832 }
833 833
834 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 834 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
835 } 835 }
836 836
837 /* Completed MCU, so update state */ 837 /* Completed MCU, so update state */
838 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */ 838 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
839 } 839 }
840 840
841 /* Account for restart interval (no-op if not using restarts) */ 841 /* Account for restart interval (no-op if not using restarts) */
842 entropy->restarts_to_go--; 842 entropy->restarts_to_go--;
843 843
844 return TRUE; 844 return TRUE;
845} 845}
846 846
847 847
848/* 848/*
849 * MCU decoding for DC successive approximation refinement scan. 849 * MCU decoding for DC successive approximation refinement scan.
850 * Note: we assume such scans can be multi-component, although the spec 850 * Note: we assume such scans can be multi-component, although the spec
851 * is not very clear on the point. 851 * is not very clear on the point.
852 */ 852 */
853 853
854METHODDEF(boolean) 854METHODDEF(boolean)
855decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 855decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
856{ 856{
857 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 857 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
858 int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ 858 int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
859 int blkn; 859 int blkn;
860 JBLOCKROW block; 860 JBLOCKROW block;
861 BITREAD_STATE_VARS; 861 BITREAD_STATE_VARS;
862 862
863 /* Process restart marker if needed; may have to suspend */ 863 /* Process restart marker if needed; may have to suspend */
864 if (cinfo->restart_interval) { 864 if (cinfo->restart_interval) {
865 if (entropy->restarts_to_go == 0) 865 if (entropy->restarts_to_go == 0)
866 if (! process_restart(cinfo)) 866 if (! process_restart(cinfo))
867 return FALSE; 867 return FALSE;
868 } 868 }
869 869
870 /* Not worth the cycles to check insufficient_data here, 870 /* Not worth the cycles to check insufficient_data here,
871 * since we will not change the data anyway if we read zeroes. 871 * since we will not change the data anyway if we read zeroes.
872 */ 872 */
873 873
874 /* Load up working state */ 874 /* Load up working state */
875 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 875 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
876 876
877 /* Outer loop handles each block in the MCU */ 877 /* Outer loop handles each block in the MCU */
878 878
879 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 879 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
880 block = MCU_data[blkn]; 880 block = MCU_data[blkn];
881 881
882 /* Encoded data is simply the next bit of the two's-complement DC value */ 882 /* Encoded data is simply the next bit of the two's-complement DC value */
883 CHECK_BIT_BUFFER(br_state, 1, return FALSE); 883 CHECK_BIT_BUFFER(br_state, 1, return FALSE);
884 if (GET_BITS(1)) 884 if (GET_BITS(1))
885 (*block)[0] |= p1; 885 (*block)[0] |= p1;
886 /* Note: since we use |=, repeating the assignment later is safe */ 886 /* Note: since we use |=, repeating the assignment later is safe */
887 } 887 }
888 888
889 /* Completed MCU, so update state */ 889 /* Completed MCU, so update state */
890 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 890 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
891 891
892 /* Account for restart interval (no-op if not using restarts) */ 892 /* Account for restart interval (no-op if not using restarts) */
893 entropy->restarts_to_go--; 893 entropy->restarts_to_go--;
894 894
895 return TRUE; 895 return TRUE;
896} 896}
897 897
898 898
899/* 899/*
900 * MCU decoding for AC successive approximation refinement scan. 900 * MCU decoding for AC successive approximation refinement scan.
901 */ 901 */
902 902
903METHODDEF(boolean) 903METHODDEF(boolean)
904decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 904decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
905{ 905{
906 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 906 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
907 register int s, k, r; 907 register int s, k, r;
908 unsigned int EOBRUN; 908 unsigned int EOBRUN;
909 int Se, p1, m1; 909 int Se, p1, m1;
910 const int * natural_order; 910 const int * natural_order;
911 JBLOCKROW block; 911 JBLOCKROW block;
912 JCOEFPTR thiscoef; 912 JCOEFPTR thiscoef;
913 BITREAD_STATE_VARS; 913 BITREAD_STATE_VARS;
914 d_derived_tbl * tbl; 914 d_derived_tbl * tbl;
915 int num_newnz; 915 int num_newnz;
916 int newnz_pos[DCTSIZE2]; 916 int newnz_pos[DCTSIZE2];
917 917
918 /* Process restart marker if needed; may have to suspend */ 918 /* Process restart marker if needed; may have to suspend */
919 if (cinfo->restart_interval) { 919 if (cinfo->restart_interval) {
920 if (entropy->restarts_to_go == 0) 920 if (entropy->restarts_to_go == 0)
921 if (! process_restart(cinfo)) 921 if (! process_restart(cinfo))
922 return FALSE; 922 return FALSE;
923 } 923 }
924 924
925 /* If we've run out of data, don't modify the MCU. 925 /* If we've run out of data, don't modify the MCU.
926 */ 926 */
927 if (! entropy->insufficient_data) { 927 if (! entropy->insufficient_data) {
928 928
929 Se = cinfo->Se; 929 Se = cinfo->Se;
930 p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ 930 p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
931 m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */ 931 m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */
932 natural_order = cinfo->natural_order; 932 natural_order = cinfo->natural_order;
933 933
934 /* Load up working state */ 934 /* Load up working state */
935 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 935 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
936 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */ 936 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
937 937
938 /* There is always only one block per MCU */ 938 /* There is always only one block per MCU */
939 block = MCU_data[0]; 939 block = MCU_data[0];
940 tbl = entropy->ac_derived_tbl; 940 tbl = entropy->ac_derived_tbl;
941 941
942 /* If we are forced to suspend, we must undo the assignments to any newly 942 /* If we are forced to suspend, we must undo the assignments to any newly
943 * nonzero coefficients in the block, because otherwise we'd get confused 943 * nonzero coefficients in the block, because otherwise we'd get confused
944 * next time about which coefficients were already nonzero. 944 * next time about which coefficients were already nonzero.
945 * But we need not undo addition of bits to already-nonzero coefficients; 945 * But we need not undo addition of bits to already-nonzero coefficients;
946 * instead, we can test the current bit to see if we already did it. 946 * instead, we can test the current bit to see if we already did it.
947 */ 947 */
948 num_newnz = 0; 948 num_newnz = 0;
949 949
950 /* initialize coefficient loop counter to start of band */ 950 /* initialize coefficient loop counter to start of band */
951 k = cinfo->Ss; 951 k = cinfo->Ss;
952 952
953 if (EOBRUN == 0) { 953 if (EOBRUN == 0) {
954 for (; k <= Se; k++) { 954 for (; k <= Se; k++) {
955 HUFF_DECODE(s, br_state, tbl, goto undoit, label3); 955 HUFF_DECODE(s, br_state, tbl, goto undoit, label3);
956 r = s >> 4; 956 r = s >> 4;
957 s &= 15; 957 s &= 15;
958 if (s) { 958 if (s) {
959 if (s != 1) /* size of new coef should always be 1 */ 959 if (s != 1) /* size of new coef should always be 1 */
960 WARNMS(cinfo, JWRN_HUFF_BAD_CODE); 960 WARNMS(cinfo, JWRN_HUFF_BAD_CODE);
961 CHECK_BIT_BUFFER(br_state, 1, goto undoit); 961 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
962 if (GET_BITS(1)) 962 if (GET_BITS(1))
963 s = p1; /* newly nonzero coef is positive */ 963 s = p1; /* newly nonzero coef is positive */
964 else 964 else
965 s = m1; /* newly nonzero coef is negative */ 965 s = m1; /* newly nonzero coef is negative */
966 } else { 966 } else {
967 if (r != 15) { 967 if (r != 15) {
968 EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */ 968 EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */
969 if (r) { 969 if (r) {
970 CHECK_BIT_BUFFER(br_state, r, goto undoit); 970 CHECK_BIT_BUFFER(br_state, r, goto undoit);
971 r = GET_BITS(r); 971 r = GET_BITS(r);
972 EOBRUN += r; 972 EOBRUN += r;
973 } 973 }
974 break; /* rest of block is handled by EOB logic */ 974 break; /* rest of block is handled by EOB logic */
975 } 975 }
976 /* note s = 0 for processing ZRL */ 976 /* note s = 0 for processing ZRL */
977 } 977 }
978 /* Advance over already-nonzero coefs and r still-zero coefs, 978 /* Advance over already-nonzero coefs and r still-zero coefs,
979 * appending correction bits to the nonzeroes. A correction bit is 1 979 * appending correction bits to the nonzeroes. A correction bit is 1
980 * if the absolute value of the coefficient must be increased. 980 * if the absolute value of the coefficient must be increased.
981 */ 981 */
982 do { 982 do {
983 thiscoef = *block + natural_order[k]; 983 thiscoef = *block + natural_order[k];
984 if (*thiscoef != 0) { 984 if (*thiscoef != 0) {
985 CHECK_BIT_BUFFER(br_state, 1, goto undoit); 985 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
986 if (GET_BITS(1)) { 986 if (GET_BITS(1)) {
987 if ((*thiscoef & p1) == 0) { /* do nothing if already set it */ 987 if ((*thiscoef & p1) == 0) { /* do nothing if already set it */
988 if (*thiscoef >= 0) 988 if (*thiscoef >= 0)
989 *thiscoef += p1; 989 *thiscoef += p1;
990 else 990 else
991 *thiscoef += m1; 991 *thiscoef += m1;
992 } 992 }
993 } 993 }
994 } else { 994 } else {
995 if (--r < 0) 995 if (--r < 0)
996 break; /* reached target zero coefficient */ 996 break; /* reached target zero coefficient */
997 } 997 }
998 k++; 998 k++;
999 } while (k <= Se); 999 } while (k <= Se);
1000 if (s) { 1000 if (s) {
1001 int pos = natural_order[k]; 1001 int pos = natural_order[k];
1002 /* Output newly nonzero coefficient */ 1002 /* Output newly nonzero coefficient */
1003 (*block)[pos] = (JCOEF) s; 1003 (*block)[pos] = (JCOEF) s;
1004 /* Remember its position in case we have to suspend */ 1004 /* Remember its position in case we have to suspend */
1005 newnz_pos[num_newnz++] = pos; 1005 newnz_pos[num_newnz++] = pos;
1006 } 1006 }
1007 } 1007 }
1008 } 1008 }
1009 1009
1010 if (EOBRUN > 0) { 1010 if (EOBRUN > 0) {
1011 /* Scan any remaining coefficient positions after the end-of-band 1011 /* Scan any remaining coefficient positions after the end-of-band
1012 * (the last newly nonzero coefficient, if any). Append a correction 1012 * (the last newly nonzero coefficient, if any). Append a correction
1013 * bit to each already-nonzero coefficient. A correction bit is 1 1013 * bit to each already-nonzero coefficient. A correction bit is 1
1014 * if the absolute value of the coefficient must be increased. 1014 * if the absolute value of the coefficient must be increased.
1015 */ 1015 */
1016 for (; k <= Se; k++) { 1016 for (; k <= Se; k++) {
1017 thiscoef = *block + natural_order[k]; 1017 thiscoef = *block + natural_order[k];
1018 if (*thiscoef != 0) { 1018 if (*thiscoef != 0) {
1019 CHECK_BIT_BUFFER(br_state, 1, goto undoit); 1019 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
1020 if (GET_BITS(1)) { 1020 if (GET_BITS(1)) {
1021 if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */ 1021 if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */
1022 if (*thiscoef >= 0) 1022 if (*thiscoef >= 0)
1023 *thiscoef += p1; 1023 *thiscoef += p1;
1024 else 1024 else
1025 *thiscoef += m1; 1025 *thiscoef += m1;
1026 } 1026 }
1027 } 1027 }
1028 } 1028 }
1029 } 1029 }
1030 /* Count one block completed in EOB run */ 1030 /* Count one block completed in EOB run */
1031 EOBRUN--; 1031 EOBRUN--;
1032 } 1032 }
1033 1033
1034 /* Completed MCU, so update state */ 1034 /* Completed MCU, so update state */
1035 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 1035 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
1036 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */ 1036 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
1037 } 1037 }
1038 1038
1039 /* Account for restart interval (no-op if not using restarts) */ 1039 /* Account for restart interval (no-op if not using restarts) */
1040 entropy->restarts_to_go--; 1040 entropy->restarts_to_go--;
1041 1041
1042 return TRUE; 1042 return TRUE;
1043 1043
1044undoit: 1044undoit:
1045 /* Re-zero any output coefficients that we made newly nonzero */ 1045 /* Re-zero any output coefficients that we made newly nonzero */
1046 while (num_newnz > 0) 1046 while (num_newnz > 0)
1047 (*block)[newnz_pos[--num_newnz]] = 0; 1047 (*block)[newnz_pos[--num_newnz]] = 0;
1048 1048
1049 return FALSE; 1049 return FALSE;
1050} 1050}
1051 1051
1052 1052
1053/* 1053/*
1054 * Decode one MCU's worth of Huffman-compressed coefficients, 1054 * Decode one MCU's worth of Huffman-compressed coefficients,
1055 * partial blocks. 1055 * partial blocks.
1056 */ 1056 */
1057 1057
1058METHODDEF(boolean) 1058METHODDEF(boolean)
1059decode_mcu_sub (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 1059decode_mcu_sub (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
1060{ 1060{
1061 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 1061 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
1062 const int * natural_order; 1062 const int * natural_order;
1063 int Se, blkn; 1063 int Se, blkn;
1064 BITREAD_STATE_VARS; 1064 BITREAD_STATE_VARS;
1065 savable_state state; 1065 savable_state state;
1066 1066
1067 /* Process restart marker if needed; may have to suspend */ 1067 /* Process restart marker if needed; may have to suspend */
1068 if (cinfo->restart_interval) { 1068 if (cinfo->restart_interval) {
1069 if (entropy->restarts_to_go == 0) 1069 if (entropy->restarts_to_go == 0)
1070 if (! process_restart(cinfo)) 1070 if (! process_restart(cinfo))
1071 return FALSE; 1071 return FALSE;
1072 } 1072 }
1073 1073
1074 /* If we've run out of data, just leave the MCU set to zeroes. 1074 /* If we've run out of data, just leave the MCU set to zeroes.
1075 * This way, we return uniform gray for the remainder of the segment. 1075 * This way, we return uniform gray for the remainder of the segment.
1076 */ 1076 */
1077 if (! entropy->insufficient_data) { 1077 if (! entropy->insufficient_data) {
1078 1078
1079 natural_order = cinfo->natural_order; 1079 natural_order = cinfo->natural_order;
1080 Se = cinfo->lim_Se; 1080 Se = cinfo->lim_Se;
1081 1081
1082 /* Load up working state */ 1082 /* Load up working state */
1083 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 1083 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
1084 ASSIGN_STATE(state, entropy->saved); 1084 ASSIGN_STATE(state, entropy->saved);
1085 1085
1086 /* Outer loop handles each block in the MCU */ 1086 /* Outer loop handles each block in the MCU */
1087 1087
1088 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 1088 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
1089 JBLOCKROW block = MCU_data[blkn]; 1089 JBLOCKROW block = MCU_data[blkn];
1090 d_derived_tbl * htbl; 1090 d_derived_tbl * htbl;
1091 register int s, k, r; 1091 register int s, k, r;
1092 int coef_limit, ci; 1092 int coef_limit, ci;
1093 1093
1094 /* Decode a single block's worth of coefficients */ 1094 /* Decode a single block's worth of coefficients */
1095 1095
1096 /* Section F.2.2.1: decode the DC coefficient difference */ 1096 /* Section F.2.2.1: decode the DC coefficient difference */
1097 htbl = entropy->dc_cur_tbls[blkn]; 1097 htbl = entropy->dc_cur_tbls[blkn];
1098 HUFF_DECODE(s, br_state, htbl, return FALSE, label1); 1098 HUFF_DECODE(s, br_state, htbl, return FALSE, label1);
1099 1099
1100 htbl = entropy->ac_cur_tbls[blkn]; 1100 htbl = entropy->ac_cur_tbls[blkn];
1101 k = 1; 1101 k = 1;
1102 coef_limit = entropy->coef_limit[blkn]; 1102 coef_limit = entropy->coef_limit[blkn];
1103 if (coef_limit) { 1103 if (coef_limit) {
1104 /* Convert DC difference to actual value, update last_dc_val */ 1104 /* Convert DC difference to actual value, update last_dc_val */
1105 if (s) { 1105 if (s) {
1106 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1106 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1107 r = GET_BITS(s); 1107 r = GET_BITS(s);
1108 s = HUFF_EXTEND(r, s); 1108 s = HUFF_EXTEND(r, s);
1109 } 1109 }
1110 ci = cinfo->MCU_membership[blkn]; 1110 ci = cinfo->MCU_membership[blkn];
1111 s += state.last_dc_val[ci]; 1111 s += state.last_dc_val[ci];
1112 state.last_dc_val[ci] = s; 1112 state.last_dc_val[ci] = s;
1113 /* Output the DC coefficient */ 1113 /* Output the DC coefficient */
1114 (*block)[0] = (JCOEF) s; 1114 (*block)[0] = (JCOEF) s;
1115 1115
1116 /* Section F.2.2.2: decode the AC coefficients */ 1116 /* Section F.2.2.2: decode the AC coefficients */
1117 /* Since zeroes are skipped, output area must be cleared beforehand */ 1117 /* Since zeroes are skipped, output area must be cleared beforehand */
1118 for (; k < coef_limit; k++) { 1118 for (; k < coef_limit; k++) {
1119 HUFF_DECODE(s, br_state, htbl, return FALSE, label2); 1119 HUFF_DECODE(s, br_state, htbl, return FALSE, label2);
1120 1120
1121 r = s >> 4; 1121 r = s >> 4;
1122 s &= 15; 1122 s &= 15;
1123 1123
1124 if (s) { 1124 if (s) {
1125 k += r; 1125 k += r;
1126 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1126 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1127 r = GET_BITS(s); 1127 r = GET_BITS(s);
1128 s = HUFF_EXTEND(r, s); 1128 s = HUFF_EXTEND(r, s);
1129 /* Output coefficient in natural (dezigzagged) order. 1129 /* Output coefficient in natural (dezigzagged) order.
1130 * Note: the extra entries in natural_order[] will save us 1130 * Note: the extra entries in natural_order[] will save us
1131 * if k > Se, which could happen if the data is corrupted. 1131 * if k > Se, which could happen if the data is corrupted.
1132 */ 1132 */
1133 (*block)[natural_order[k]] = (JCOEF) s; 1133 (*block)[natural_order[k]] = (JCOEF) s;
1134 } else { 1134 } else {
1135 if (r != 15) 1135 if (r != 15)
1136 goto EndOfBlock; 1136 goto EndOfBlock;
1137 k += 15; 1137 k += 15;
1138 } 1138 }
1139 } 1139 }
1140 } else { 1140 } else {
1141 if (s) { 1141 if (s) {
1142 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1142 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1143 DROP_BITS(s); 1143 DROP_BITS(s);
1144 } 1144 }
1145 } 1145 }
1146 1146
1147 /* Section F.2.2.2: decode the AC coefficients */ 1147 /* Section F.2.2.2: decode the AC coefficients */
1148 /* In this path we just discard the values */ 1148 /* In this path we just discard the values */
1149 for (; k <= Se; k++) { 1149 for (; k <= Se; k++) {
1150 HUFF_DECODE(s, br_state, htbl, return FALSE, label3); 1150 HUFF_DECODE(s, br_state, htbl, return FALSE, label3);
1151 1151
1152 r = s >> 4; 1152 r = s >> 4;
1153 s &= 15; 1153 s &= 15;
1154 1154
1155 if (s) { 1155 if (s) {
1156 k += r; 1156 k += r;
1157 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1157 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1158 DROP_BITS(s); 1158 DROP_BITS(s);
1159 } else { 1159 } else {
1160 if (r != 15) 1160 if (r != 15)
1161 break; 1161 break;
1162 k += 15; 1162 k += 15;
1163 } 1163 }
1164 } 1164 }
1165 1165
1166 EndOfBlock: ; 1166 EndOfBlock: ;
1167 } 1167 }
1168 1168
1169 /* Completed MCU, so update state */ 1169 /* Completed MCU, so update state */
1170 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 1170 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
1171 ASSIGN_STATE(entropy->saved, state); 1171 ASSIGN_STATE(entropy->saved, state);
1172 } 1172 }
1173 1173
1174 /* Account for restart interval (no-op if not using restarts) */ 1174 /* Account for restart interval (no-op if not using restarts) */
1175 entropy->restarts_to_go--; 1175 entropy->restarts_to_go--;
1176 1176
1177 return TRUE; 1177 return TRUE;
1178} 1178}
1179 1179
1180 1180
1181/* 1181/*
1182 * Decode one MCU's worth of Huffman-compressed coefficients, 1182 * Decode one MCU's worth of Huffman-compressed coefficients,
1183 * full-size blocks. 1183 * full-size blocks.
1184 */ 1184 */
1185 1185
1186METHODDEF(boolean) 1186METHODDEF(boolean)
1187decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 1187decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
1188{ 1188{
1189 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 1189 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
1190 int blkn; 1190 int blkn;
1191 BITREAD_STATE_VARS; 1191 BITREAD_STATE_VARS;
1192 savable_state state; 1192 savable_state state;
1193 1193
1194 /* Process restart marker if needed; may have to suspend */ 1194 /* Process restart marker if needed; may have to suspend */
1195 if (cinfo->restart_interval) { 1195 if (cinfo->restart_interval) {
1196 if (entropy->restarts_to_go == 0) 1196 if (entropy->restarts_to_go == 0)
1197 if (! process_restart(cinfo)) 1197 if (! process_restart(cinfo))
1198 return FALSE; 1198 return FALSE;
1199 } 1199 }
1200 1200
1201 /* If we've run out of data, just leave the MCU set to zeroes. 1201 /* If we've run out of data, just leave the MCU set to zeroes.
1202 * This way, we return uniform gray for the remainder of the segment. 1202 * This way, we return uniform gray for the remainder of the segment.
1203 */ 1203 */
1204 if (! entropy->insufficient_data) { 1204 if (! entropy->insufficient_data) {
1205 1205
1206 /* Load up working state */ 1206 /* Load up working state */
1207 BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 1207 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
1208 ASSIGN_STATE(state, entropy->saved); 1208 ASSIGN_STATE(state, entropy->saved);
1209 1209
1210 /* Outer loop handles each block in the MCU */ 1210 /* Outer loop handles each block in the MCU */
1211 1211
1212 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 1212 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
1213 JBLOCKROW block = MCU_data[blkn]; 1213 JBLOCKROW block = MCU_data[blkn];
1214 d_derived_tbl * htbl; 1214 d_derived_tbl * htbl;
1215 register int s, k, r; 1215 register int s, k, r;
1216 int coef_limit, ci; 1216 int coef_limit, ci;
1217 1217
1218 /* Decode a single block's worth of coefficients */ 1218 /* Decode a single block's worth of coefficients */
1219 1219
1220 /* Section F.2.2.1: decode the DC coefficient difference */ 1220 /* Section F.2.2.1: decode the DC coefficient difference */
1221 htbl = entropy->dc_cur_tbls[blkn]; 1221 htbl = entropy->dc_cur_tbls[blkn];
1222 HUFF_DECODE(s, br_state, htbl, return FALSE, label1); 1222 HUFF_DECODE(s, br_state, htbl, return FALSE, label1);
1223 1223
1224 htbl = entropy->ac_cur_tbls[blkn]; 1224 htbl = entropy->ac_cur_tbls[blkn];
1225 k = 1; 1225 k = 1;
1226 coef_limit = entropy->coef_limit[blkn]; 1226 coef_limit = entropy->coef_limit[blkn];
1227 if (coef_limit) { 1227 if (coef_limit) {
1228 /* Convert DC difference to actual value, update last_dc_val */ 1228 /* Convert DC difference to actual value, update last_dc_val */
1229 if (s) { 1229 if (s) {
1230 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1230 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1231 r = GET_BITS(s); 1231 r = GET_BITS(s);
1232 s = HUFF_EXTEND(r, s); 1232 s = HUFF_EXTEND(r, s);
1233 } 1233 }
1234 ci = cinfo->MCU_membership[blkn]; 1234 ci = cinfo->MCU_membership[blkn];
1235 s += state.last_dc_val[ci]; 1235 s += state.last_dc_val[ci];
1236 state.last_dc_val[ci] = s; 1236 state.last_dc_val[ci] = s;
1237 /* Output the DC coefficient */ 1237 /* Output the DC coefficient */
1238 (*block)[0] = (JCOEF) s; 1238 (*block)[0] = (JCOEF) s;
1239 1239
1240 /* Section F.2.2.2: decode the AC coefficients */ 1240 /* Section F.2.2.2: decode the AC coefficients */
1241 /* Since zeroes are skipped, output area must be cleared beforehand */ 1241 /* Since zeroes are skipped, output area must be cleared beforehand */
1242 for (; k < coef_limit; k++) { 1242 for (; k < coef_limit; k++) {
1243 HUFF_DECODE(s, br_state, htbl, return FALSE, label2); 1243 HUFF_DECODE(s, br_state, htbl, return FALSE, label2);
1244 1244
1245 r = s >> 4; 1245 r = s >> 4;
1246 s &= 15; 1246 s &= 15;
1247 1247
1248 if (s) { 1248 if (s) {
1249 k += r; 1249 k += r;
1250 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1250 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1251 r = GET_BITS(s); 1251 r = GET_BITS(s);
1252 s = HUFF_EXTEND(r, s); 1252 s = HUFF_EXTEND(r, s);
1253 /* Output coefficient in natural (dezigzagged) order. 1253 /* Output coefficient in natural (dezigzagged) order.
1254 * Note: the extra entries in jpeg_natural_order[] will save us 1254 * Note: the extra entries in jpeg_natural_order[] will save us
1255 * if k >= DCTSIZE2, which could happen if the data is corrupted. 1255 * if k >= DCTSIZE2, which could happen if the data is corrupted.
1256 */ 1256 */
1257 (*block)[jpeg_natural_order[k]] = (JCOEF) s; 1257 (*block)[jpeg_natural_order[k]] = (JCOEF) s;
1258 } else { 1258 } else {
1259 if (r != 15) 1259 if (r != 15)
1260 goto EndOfBlock; 1260 goto EndOfBlock;
1261 k += 15; 1261 k += 15;
1262 } 1262 }
1263 } 1263 }
1264 } else { 1264 } else {
1265 if (s) { 1265 if (s) {
1266 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1266 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1267 DROP_BITS(s); 1267 DROP_BITS(s);
1268 } 1268 }
1269 } 1269 }
1270 1270
1271 /* Section F.2.2.2: decode the AC coefficients */ 1271 /* Section F.2.2.2: decode the AC coefficients */
1272 /* In this path we just discard the values */ 1272 /* In this path we just discard the values */
1273 for (; k < DCTSIZE2; k++) { 1273 for (; k < DCTSIZE2; k++) {
1274 HUFF_DECODE(s, br_state, htbl, return FALSE, label3); 1274 HUFF_DECODE(s, br_state, htbl, return FALSE, label3);
1275 1275
1276 r = s >> 4; 1276 r = s >> 4;
1277 s &= 15; 1277 s &= 15;
1278 1278
1279 if (s) { 1279 if (s) {
1280 k += r; 1280 k += r;
1281 CHECK_BIT_BUFFER(br_state, s, return FALSE); 1281 CHECK_BIT_BUFFER(br_state, s, return FALSE);
1282 DROP_BITS(s); 1282 DROP_BITS(s);
1283 } else { 1283 } else {
1284 if (r != 15) 1284 if (r != 15)
1285 break; 1285 break;
1286 k += 15; 1286 k += 15;
1287 } 1287 }
1288 } 1288 }
1289 1289
1290 EndOfBlock: ; 1290 EndOfBlock: ;
1291 } 1291 }
1292 1292
1293 /* Completed MCU, so update state */ 1293 /* Completed MCU, so update state */
1294 BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 1294 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
1295 ASSIGN_STATE(entropy->saved, state); 1295 ASSIGN_STATE(entropy->saved, state);
1296 } 1296 }
1297 1297
1298 /* Account for restart interval (no-op if not using restarts) */ 1298 /* Account for restart interval (no-op if not using restarts) */
1299 entropy->restarts_to_go--; 1299 entropy->restarts_to_go--;
1300 1300
1301 return TRUE; 1301 return TRUE;
1302} 1302}
1303 1303
1304 1304
1305/* 1305/*
1306 * Initialize for a Huffman-compressed scan. 1306 * Initialize for a Huffman-compressed scan.
1307 */ 1307 */
1308 1308
1309METHODDEF(void) 1309METHODDEF(void)
1310start_pass_huff_decoder (j_decompress_ptr cinfo) 1310start_pass_huff_decoder (j_decompress_ptr cinfo)
1311{ 1311{
1312 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 1312 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
1313 int ci, blkn, tbl, i; 1313 int ci, blkn, tbl, i;
1314 jpeg_component_info * compptr; 1314 jpeg_component_info * compptr;
1315 1315
1316 if (cinfo->progressive_mode) { 1316 if (cinfo->progressive_mode) {
1317 /* Validate progressive scan parameters */ 1317 /* Validate progressive scan parameters */
1318 if (cinfo->Ss == 0) { 1318 if (cinfo->Ss == 0) {
1319 if (cinfo->Se != 0) 1319 if (cinfo->Se != 0)
1320 goto bad; 1320 goto bad;
1321 } else { 1321 } else {
1322 /* need not check Ss/Se < 0 since they came from unsigned bytes */ 1322 /* need not check Ss/Se < 0 since they came from unsigned bytes */
1323 if (cinfo->Se < cinfo->Ss || cinfo->Se > cinfo->lim_Se) 1323 if (cinfo->Se < cinfo->Ss || cinfo->Se > cinfo->lim_Se)
1324 goto bad; 1324 goto bad;
1325 /* AC scans may have only one component */ 1325 /* AC scans may have only one component */
1326 if (cinfo->comps_in_scan != 1) 1326 if (cinfo->comps_in_scan != 1)
1327 goto bad; 1327 goto bad;
1328 } 1328 }
1329 if (cinfo->Ah != 0) { 1329 if (cinfo->Ah != 0) {
1330 /* Successive approximation refinement scan: must have Al = Ah-1. */ 1330 /* Successive approximation refinement scan: must have Al = Ah-1. */
1331 if (cinfo->Ah-1 != cinfo->Al) 1331 if (cinfo->Ah-1 != cinfo->Al)
1332 goto bad; 1332 goto bad;
1333 } 1333 }
1334 if (cinfo->Al > 13) { /* need not check for < 0 */ 1334 if (cinfo->Al > 13) { /* need not check for < 0 */
1335 /* Arguably the maximum Al value should be less than 13 for 8-bit precision, 1335 /* Arguably the maximum Al value should be less than 13 for 8-bit precision,
1336 * but the spec doesn't say so, and we try to be liberal about what we 1336 * but the spec doesn't say so, and we try to be liberal about what we
1337 * accept. Note: large Al values could result in out-of-range DC 1337 * accept. Note: large Al values could result in out-of-range DC
1338 * coefficients during early scans, leading to bizarre displays due to 1338 * coefficients during early scans, leading to bizarre displays due to
1339 * overflows in the IDCT math. But we won't crash. 1339 * overflows in the IDCT math. But we won't crash.
1340 */ 1340 */
1341 bad: 1341 bad:
1342 ERREXIT4(cinfo, JERR_BAD_PROGRESSION, 1342 ERREXIT4(cinfo, JERR_BAD_PROGRESSION,
1343 cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al); 1343 cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);
1344 } 1344 }
1345 /* Update progression status, and verify that scan order is legal. 1345 /* Update progression status, and verify that scan order is legal.
1346 * Note that inter-scan inconsistencies are treated as warnings 1346 * Note that inter-scan inconsistencies are treated as warnings
1347 * not fatal errors ... not clear if this is right way to behave. 1347 * not fatal errors ... not clear if this is right way to behave.
1348 */ 1348 */
1349 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 1349 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
1350 int coefi, cindex = cinfo->cur_comp_info[ci]->component_index; 1350 int coefi, cindex = cinfo->cur_comp_info[ci]->component_index;
1351 int *coef_bit_ptr = & cinfo->coef_bits[cindex][0]; 1351 int *coef_bit_ptr = & cinfo->coef_bits[cindex][0];
1352 if (cinfo->Ss && coef_bit_ptr[0] < 0) /* AC without prior DC scan */ 1352 if (cinfo->Ss && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
1353 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0); 1353 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
1354 for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) { 1354 for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
1355 int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi]; 1355 int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
1356 if (cinfo->Ah != expected) 1356 if (cinfo->Ah != expected)
1357 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi); 1357 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
1358 coef_bit_ptr[coefi] = cinfo->Al; 1358 coef_bit_ptr[coefi] = cinfo->Al;
1359 } 1359 }
1360 } 1360 }
1361 1361
1362 /* Select MCU decoding routine */ 1362 /* Select MCU decoding routine */
1363 if (cinfo->Ah == 0) { 1363 if (cinfo->Ah == 0) {
1364 if (cinfo->Ss == 0) 1364 if (cinfo->Ss == 0)
1365 entropy->pub.decode_mcu = decode_mcu_DC_first; 1365 entropy->pub.decode_mcu = decode_mcu_DC_first;
1366 else 1366 else
1367 entropy->pub.decode_mcu = decode_mcu_AC_first; 1367 entropy->pub.decode_mcu = decode_mcu_AC_first;
1368 } else { 1368 } else {
1369 if (cinfo->Ss == 0) 1369 if (cinfo->Ss == 0)
1370 entropy->pub.decode_mcu = decode_mcu_DC_refine; 1370 entropy->pub.decode_mcu = decode_mcu_DC_refine;
1371 else 1371 else
1372 entropy->pub.decode_mcu = decode_mcu_AC_refine; 1372 entropy->pub.decode_mcu = decode_mcu_AC_refine;
1373 } 1373 }
1374 1374
1375 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 1375 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
1376 compptr = cinfo->cur_comp_info[ci]; 1376 compptr = cinfo->cur_comp_info[ci];
1377 /* Make sure requested tables are present, and compute derived tables. 1377 /* Make sure requested tables are present, and compute derived tables.
1378 * We may build same derived table more than once, but it's not expensive. 1378 * We may build same derived table more than once, but it's not expensive.
1379 */ 1379 */
1380 if (cinfo->Ss == 0) { 1380 if (cinfo->Ss == 0) {
1381 if (cinfo->Ah == 0) { /* DC refinement needs no table */ 1381 if (cinfo->Ah == 0) { /* DC refinement needs no table */
1382 tbl = compptr->dc_tbl_no; 1382 tbl = compptr->dc_tbl_no;
1383 jpeg_make_d_derived_tbl(cinfo, TRUE, tbl, 1383 jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,
1384 & entropy->derived_tbls[tbl]); 1384 & entropy->derived_tbls[tbl]);
1385 } 1385 }
1386 } else { 1386 } else {
1387 tbl = compptr->ac_tbl_no; 1387 tbl = compptr->ac_tbl_no;
1388 jpeg_make_d_derived_tbl(cinfo, FALSE, tbl, 1388 jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,
1389 & entropy->derived_tbls[tbl]); 1389 & entropy->derived_tbls[tbl]);
1390 /* remember the single active table */ 1390 /* remember the single active table */
1391 entropy->ac_derived_tbl = entropy->derived_tbls[tbl]; 1391 entropy->ac_derived_tbl = entropy->derived_tbls[tbl];
1392 } 1392 }
1393 /* Initialize DC predictions to 0 */ 1393 /* Initialize DC predictions to 0 */
1394 entropy->saved.last_dc_val[ci] = 0; 1394 entropy->saved.last_dc_val[ci] = 0;
1395 } 1395 }
1396 1396
1397 /* Initialize private state variables */ 1397 /* Initialize private state variables */
1398 entropy->saved.EOBRUN = 0; 1398 entropy->saved.EOBRUN = 0;
1399 } else { 1399 } else {
1400 /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG. 1400 /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG.
1401 * This ought to be an error condition, but we make it a warning because 1401 * This ought to be an error condition, but we make it a warning because
1402 * there are some baseline files out there with all zeroes in these bytes. 1402 * there are some baseline files out there with all zeroes in these bytes.
1403 */ 1403 */
1404 if (cinfo->Ss != 0 || cinfo->Ah != 0 || cinfo->Al != 0 || 1404 if (cinfo->Ss != 0 || cinfo->Ah != 0 || cinfo->Al != 0 ||
1405 ((cinfo->is_baseline || cinfo->Se < DCTSIZE2) && 1405 ((cinfo->is_baseline || cinfo->Se < DCTSIZE2) &&
1406 cinfo->Se != cinfo->lim_Se)) 1406 cinfo->Se != cinfo->lim_Se))
1407 WARNMS(cinfo, JWRN_NOT_SEQUENTIAL); 1407 WARNMS(cinfo, JWRN_NOT_SEQUENTIAL);
1408 1408
1409 /* Select MCU decoding routine */ 1409 /* Select MCU decoding routine */
1410 /* We retain the hard-coded case for full-size blocks. 1410 /* We retain the hard-coded case for full-size blocks.
1411 * This is not necessary, but it appears that this version is slightly 1411 * This is not necessary, but it appears that this version is slightly
1412 * more performant in the given implementation. 1412 * more performant in the given implementation.
1413 * With an improved implementation we would prefer a single optimized 1413 * With an improved implementation we would prefer a single optimized
1414 * function. 1414 * function.
1415 */ 1415 */
1416 if (cinfo->lim_Se != DCTSIZE2-1) 1416 if (cinfo->lim_Se != DCTSIZE2-1)
1417 entropy->pub.decode_mcu = decode_mcu_sub; 1417 entropy->pub.decode_mcu = decode_mcu_sub;
1418 else 1418 else
1419 entropy->pub.decode_mcu = decode_mcu; 1419 entropy->pub.decode_mcu = decode_mcu;
1420 1420
1421 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 1421 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
1422 compptr = cinfo->cur_comp_info[ci]; 1422 compptr = cinfo->cur_comp_info[ci];
1423 /* Compute derived values for Huffman tables */ 1423 /* Compute derived values for Huffman tables */
1424 /* We may do this more than once for a table, but it's not expensive */ 1424 /* We may do this more than once for a table, but it's not expensive */
1425 tbl = compptr->dc_tbl_no; 1425 tbl = compptr->dc_tbl_no;
1426 jpeg_make_d_derived_tbl(cinfo, TRUE, tbl, 1426 jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,
1427 & entropy->dc_derived_tbls[tbl]); 1427 & entropy->dc_derived_tbls[tbl]);
1428 if (cinfo->lim_Se) { /* AC needs no table when not present */ 1428 if (cinfo->lim_Se) { /* AC needs no table when not present */
1429 tbl = compptr->ac_tbl_no; 1429 tbl = compptr->ac_tbl_no;
1430 jpeg_make_d_derived_tbl(cinfo, FALSE, tbl, 1430 jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,
1431 & entropy->ac_derived_tbls[tbl]); 1431 & entropy->ac_derived_tbls[tbl]);
1432 } 1432 }
1433 /* Initialize DC predictions to 0 */ 1433 /* Initialize DC predictions to 0 */
1434 entropy->saved.last_dc_val[ci] = 0; 1434 entropy->saved.last_dc_val[ci] = 0;
1435 } 1435 }
1436 1436
1437 /* Precalculate decoding info for each block in an MCU of this scan */ 1437 /* Precalculate decoding info for each block in an MCU of this scan */
1438 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 1438 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
1439 ci = cinfo->MCU_membership[blkn]; 1439 ci = cinfo->MCU_membership[blkn];
1440 compptr = cinfo->cur_comp_info[ci]; 1440 compptr = cinfo->cur_comp_info[ci];
1441 /* Precalculate which table to use for each block */ 1441 /* Precalculate which table to use for each block */
1442 entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no]; 1442 entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no];
1443 entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no]; 1443 entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no];
1444 /* Decide whether we really care about the coefficient values */ 1444 /* Decide whether we really care about the coefficient values */
1445 if (compptr->component_needed) { 1445 if (compptr->component_needed) {
1446 ci = compptr->DCT_v_scaled_size; 1446 ci = compptr->DCT_v_scaled_size;
1447 i = compptr->DCT_h_scaled_size; 1447 i = compptr->DCT_h_scaled_size;
1448 switch (cinfo->lim_Se) { 1448 switch (cinfo->lim_Se) {
1449 case (1*1-1): 1449 case (1*1-1):
1450 entropy->coef_limit[blkn] = 1; 1450 entropy->coef_limit[blkn] = 1;
1451 break; 1451 break;
1452 case (2*2-1): 1452 case (2*2-1):
1453 if (ci <= 0 || ci > 2) ci = 2; 1453 if (ci <= 0 || ci > 2) ci = 2;
1454 if (i <= 0 || i > 2) i = 2; 1454 if (i <= 0 || i > 2) i = 2;
1455 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order2[ci - 1][i - 1]; 1455 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order2[ci - 1][i - 1];
1456 break; 1456 break;
1457 case (3*3-1): 1457 case (3*3-1):
1458 if (ci <= 0 || ci > 3) ci = 3; 1458 if (ci <= 0 || ci > 3) ci = 3;
1459 if (i <= 0 || i > 3) i = 3; 1459 if (i <= 0 || i > 3) i = 3;
1460 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order3[ci - 1][i - 1]; 1460 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order3[ci - 1][i - 1];
1461 break; 1461 break;
1462 case (4*4-1): 1462 case (4*4-1):
1463 if (ci <= 0 || ci > 4) ci = 4; 1463 if (ci <= 0 || ci > 4) ci = 4;
1464 if (i <= 0 || i > 4) i = 4; 1464 if (i <= 0 || i > 4) i = 4;
1465 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order4[ci - 1][i - 1]; 1465 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order4[ci - 1][i - 1];
1466 break; 1466 break;
1467 case (5*5-1): 1467 case (5*5-1):
1468 if (ci <= 0 || ci > 5) ci = 5; 1468 if (ci <= 0 || ci > 5) ci = 5;
1469 if (i <= 0 || i > 5) i = 5; 1469 if (i <= 0 || i > 5) i = 5;
1470 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order5[ci - 1][i - 1]; 1470 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order5[ci - 1][i - 1];
1471 break; 1471 break;
1472 case (6*6-1): 1472 case (6*6-1):
1473 if (ci <= 0 || ci > 6) ci = 6; 1473 if (ci <= 0 || ci > 6) ci = 6;
1474 if (i <= 0 || i > 6) i = 6; 1474 if (i <= 0 || i > 6) i = 6;
1475 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order6[ci - 1][i - 1]; 1475 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order6[ci - 1][i - 1];
1476 break; 1476 break;
1477 case (7*7-1): 1477 case (7*7-1):
1478 if (ci <= 0 || ci > 7) ci = 7; 1478 if (ci <= 0 || ci > 7) ci = 7;
1479 if (i <= 0 || i > 7) i = 7; 1479 if (i <= 0 || i > 7) i = 7;
1480 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order7[ci - 1][i - 1]; 1480 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order7[ci - 1][i - 1];
1481 break; 1481 break;
1482 default: 1482 default:
1483 if (ci <= 0 || ci > 8) ci = 8; 1483 if (ci <= 0 || ci > 8) ci = 8;
1484 if (i <= 0 || i > 8) i = 8; 1484 if (i <= 0 || i > 8) i = 8;
1485 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order[ci - 1][i - 1]; 1485 entropy->coef_limit[blkn] = 1 + jpeg_zigzag_order[ci - 1][i - 1];
1486 break; 1486 break;
1487 } 1487 }
1488 } else { 1488 } else {
1489 entropy->coef_limit[blkn] = 0; 1489 entropy->coef_limit[blkn] = 0;
1490 } 1490 }
1491 } 1491 }
1492 } 1492 }
1493 1493
1494 /* Initialize bitread state variables */ 1494 /* Initialize bitread state variables */
1495 entropy->bitstate.bits_left = 0; 1495 entropy->bitstate.bits_left = 0;
1496 entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */ 1496 entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
1497 entropy->insufficient_data = FALSE; 1497 entropy->insufficient_data = FALSE;
1498 1498
1499 /* Initialize restart counter */ 1499 /* Initialize restart counter */
1500 entropy->restarts_to_go = cinfo->restart_interval; 1500 entropy->restarts_to_go = cinfo->restart_interval;
1501} 1501}
1502 1502
1503 1503
1504/* 1504/*
1505 * Module initialization routine for Huffman entropy decoding. 1505 * Module initialization routine for Huffman entropy decoding.
1506 */ 1506 */
1507 1507
1508GLOBAL(void) 1508GLOBAL(void)
1509jinit_huff_decoder (j_decompress_ptr cinfo) 1509jinit_huff_decoder (j_decompress_ptr cinfo)
1510{ 1510{
1511 huff_entropy_ptr entropy; 1511 huff_entropy_ptr entropy;
1512 int i; 1512 int i;
1513 1513
1514 entropy = (huff_entropy_ptr) 1514 entropy = (huff_entropy_ptr)
1515 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 1515 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
1516 SIZEOF(huff_entropy_decoder)); 1516 SIZEOF(huff_entropy_decoder));
1517 cinfo->entropy = (struct jpeg_entropy_decoder *) entropy; 1517 cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
1518 entropy->pub.start_pass = start_pass_huff_decoder; 1518 entropy->pub.start_pass = start_pass_huff_decoder;
1519 1519
1520 if (cinfo->progressive_mode) { 1520 if (cinfo->progressive_mode) {
1521 /* Create progression status table */ 1521 /* Create progression status table */
1522 int *coef_bit_ptr, ci; 1522 int *coef_bit_ptr, ci;
1523 cinfo->coef_bits = (int (*)[DCTSIZE2]) 1523 cinfo->coef_bits = (int (*)[DCTSIZE2])
1524 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 1524 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
1525 cinfo->num_components*DCTSIZE2*SIZEOF(int)); 1525 cinfo->num_components*DCTSIZE2*SIZEOF(int));
1526 coef_bit_ptr = & cinfo->coef_bits[0][0]; 1526 coef_bit_ptr = & cinfo->coef_bits[0][0];
1527 for (ci = 0; ci < cinfo->num_components; ci++) 1527 for (ci = 0; ci < cinfo->num_components; ci++)
1528 for (i = 0; i < DCTSIZE2; i++) 1528 for (i = 0; i < DCTSIZE2; i++)
1529 *coef_bit_ptr++ = -1; 1529 *coef_bit_ptr++ = -1;
1530 1530
1531 /* Mark derived tables unallocated */ 1531 /* Mark derived tables unallocated */
1532 for (i = 0; i < NUM_HUFF_TBLS; i++) { 1532 for (i = 0; i < NUM_HUFF_TBLS; i++) {
1533 entropy->derived_tbls[i] = NULL; 1533 entropy->derived_tbls[i] = NULL;
1534 } 1534 }
1535 } else { 1535 } else {
1536 /* Mark tables unallocated */ 1536 /* Mark tables unallocated */
1537 for (i = 0; i < NUM_HUFF_TBLS; i++) { 1537 for (i = 0; i < NUM_HUFF_TBLS; i++) {
1538 entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; 1538 entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
1539 } 1539 }
1540 } 1540 }
1541} 1541}
generated by cgit v1.1 at 2024-10-31 10:00:28 +0000