diff options
Diffstat (limited to '')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jchuff.c | 1576 |
1 files changed, 1576 insertions, 0 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jchuff.c b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jchuff.c new file mode 100644 index 0000000..4cbab43 --- /dev/null +++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jchuff.c | |||
@@ -0,0 +1,1576 @@ | |||
1 | /* | ||
2 | * jchuff.c | ||
3 | * | ||
4 | * Copyright (C) 1991-1997, Thomas G. Lane. | ||
5 | * Modified 2006-2009 by Guido Vollbeding. | ||
6 | * This file is part of the Independent JPEG Group's software. | ||
7 | * For conditions of distribution and use, see the accompanying README file. | ||
8 | * | ||
9 | * This file contains Huffman entropy encoding routines. | ||
10 | * Both sequential and progressive modes are supported in this single module. | ||
11 | * | ||
12 | * Much of the complexity here has to do with supporting output suspension. | ||
13 | * If the data destination module demands suspension, we want to be able to | ||
14 | * back up to the start of the current MCU. To do this, we copy state | ||
15 | * variables into local working storage, and update them back to the | ||
16 | * permanent JPEG objects only upon successful completion of an MCU. | ||
17 | * | ||
18 | * We do not support output suspension for the progressive JPEG mode, since | ||
19 | * the library currently does not allow multiple-scan files to be written | ||
20 | * with output suspension. | ||
21 | */ | ||
22 | |||
23 | #define JPEG_INTERNALS | ||
24 | #include "jinclude.h" | ||
25 | #include "jpeglib.h" | ||
26 | |||
27 | |||
28 | /* The legal range of a DCT coefficient is | ||
29 | * -1024 .. +1023 for 8-bit data; | ||
30 | * -16384 .. +16383 for 12-bit data. | ||
31 | * Hence the magnitude should always fit in 10 or 14 bits respectively. | ||
32 | */ | ||
33 | |||
34 | #if BITS_IN_JSAMPLE == 8 | ||
35 | #define MAX_COEF_BITS 10 | ||
36 | #else | ||
37 | #define MAX_COEF_BITS 14 | ||
38 | #endif | ||
39 | |||
40 | /* Derived data constructed for each Huffman table */ | ||
41 | |||
42 | typedef struct { | ||
43 | unsigned int ehufco[256]; /* code for each symbol */ | ||
44 | char ehufsi[256]; /* length of code for each symbol */ | ||
45 | /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */ | ||
46 | } c_derived_tbl; | ||
47 | |||
48 | |||
49 | /* Expanded entropy encoder object for Huffman encoding. | ||
50 | * | ||
51 | * The savable_state subrecord contains fields that change within an MCU, | ||
52 | * but must not be updated permanently until we complete the MCU. | ||
53 | */ | ||
54 | |||
55 | typedef struct { | ||
56 | INT32 put_buffer; /* current bit-accumulation buffer */ | ||
57 | int put_bits; /* # of bits now in it */ | ||
58 | int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ | ||
59 | } savable_state; | ||
60 | |||
61 | /* This macro is to work around compilers with missing or broken | ||
62 | * structure assignment. You'll need to fix this code if you have | ||
63 | * such a compiler and you change MAX_COMPS_IN_SCAN. | ||
64 | */ | ||
65 | |||
66 | #ifndef NO_STRUCT_ASSIGN | ||
67 | #define ASSIGN_STATE(dest,src) ((dest) = (src)) | ||
68 | #else | ||
69 | #if MAX_COMPS_IN_SCAN == 4 | ||
70 | #define ASSIGN_STATE(dest,src) \ | ||
71 | ((dest).put_buffer = (src).put_buffer, \ | ||
72 | (dest).put_bits = (src).put_bits, \ | ||
73 | (dest).last_dc_val[0] = (src).last_dc_val[0], \ | ||
74 | (dest).last_dc_val[1] = (src).last_dc_val[1], \ | ||
75 | (dest).last_dc_val[2] = (src).last_dc_val[2], \ | ||
76 | (dest).last_dc_val[3] = (src).last_dc_val[3]) | ||
77 | #endif | ||
78 | #endif | ||
79 | |||
80 | |||
81 | typedef struct { | ||
82 | struct jpeg_entropy_encoder pub; /* public fields */ | ||
83 | |||
84 | savable_state saved; /* Bit buffer & DC state at start of MCU */ | ||
85 | |||
86 | /* These fields are NOT loaded into local working state. */ | ||
87 | unsigned int restarts_to_go; /* MCUs left in this restart interval */ | ||
88 | int next_restart_num; /* next restart number to write (0-7) */ | ||
89 | |||
90 | /* Pointers to derived tables (these workspaces have image lifespan) */ | ||
91 | c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS]; | ||
92 | c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS]; | ||
93 | |||
94 | /* Statistics tables for optimization */ | ||
95 | long * dc_count_ptrs[NUM_HUFF_TBLS]; | ||
96 | long * ac_count_ptrs[NUM_HUFF_TBLS]; | ||
97 | |||
98 | /* Following fields used only in progressive mode */ | ||
99 | |||
100 | /* Mode flag: TRUE for optimization, FALSE for actual data output */ | ||
101 | boolean gather_statistics; | ||
102 | |||
103 | /* next_output_byte/free_in_buffer are local copies of cinfo->dest fields. | ||
104 | */ | ||
105 | JOCTET * next_output_byte; /* => next byte to write in buffer */ | ||
106 | size_t free_in_buffer; /* # of byte spaces remaining in buffer */ | ||
107 | j_compress_ptr cinfo; /* link to cinfo (needed for dump_buffer) */ | ||
108 | |||
109 | /* Coding status for AC components */ | ||
110 | int ac_tbl_no; /* the table number of the single component */ | ||
111 | unsigned int EOBRUN; /* run length of EOBs */ | ||
112 | unsigned int BE; /* # of buffered correction bits before MCU */ | ||
113 | char * bit_buffer; /* buffer for correction bits (1 per char) */ | ||
114 | /* packing correction bits tightly would save some space but cost time... */ | ||
115 | } huff_entropy_encoder; | ||
116 | |||
117 | typedef huff_entropy_encoder * huff_entropy_ptr; | ||
118 | |||
119 | /* Working state while writing an MCU (sequential mode). | ||
120 | * This struct contains all the fields that are needed by subroutines. | ||
121 | */ | ||
122 | |||
123 | typedef struct { | ||
124 | JOCTET * next_output_byte; /* => next byte to write in buffer */ | ||
125 | size_t free_in_buffer; /* # of byte spaces remaining in buffer */ | ||
126 | savable_state cur; /* Current bit buffer & DC state */ | ||
127 | j_compress_ptr cinfo; /* dump_buffer needs access to this */ | ||
128 | } working_state; | ||
129 | |||
130 | /* MAX_CORR_BITS is the number of bits the AC refinement correction-bit | ||
131 | * buffer can hold. Larger sizes may slightly improve compression, but | ||
132 | * 1000 is already well into the realm of overkill. | ||
133 | * The minimum safe size is 64 bits. | ||
134 | */ | ||
135 | |||
136 | #define MAX_CORR_BITS 1000 /* Max # of correction bits I can buffer */ | ||
137 | |||
138 | /* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. | ||
139 | * We assume that int right shift is unsigned if INT32 right shift is, | ||
140 | * which should be safe. | ||
141 | */ | ||
142 | |||
143 | #ifdef RIGHT_SHIFT_IS_UNSIGNED | ||
144 | #define ISHIFT_TEMPS int ishift_temp; | ||
145 | #define IRIGHT_SHIFT(x,shft) \ | ||
146 | ((ishift_temp = (x)) < 0 ? \ | ||
147 | (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ | ||
148 | (ishift_temp >> (shft))) | ||
149 | #else | ||
150 | #define ISHIFT_TEMPS | ||
151 | #define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) | ||
152 | #endif | ||
153 | |||
154 | |||
155 | /* | ||
156 | * Compute the derived values for a Huffman table. | ||
157 | * This routine also performs some validation checks on the table. | ||
158 | */ | ||
159 | |||
160 | LOCAL(void) | ||
161 | jpeg_make_c_derived_tbl (j_compress_ptr cinfo, boolean isDC, int tblno, | ||
162 | c_derived_tbl ** pdtbl) | ||
163 | { | ||
164 | JHUFF_TBL *htbl; | ||
165 | c_derived_tbl *dtbl; | ||
166 | int p, i, l, lastp, si, maxsymbol; | ||
167 | char huffsize[257]; | ||
168 | unsigned int huffcode[257]; | ||
169 | unsigned int code; | ||
170 | |||
171 | /* Note that huffsize[] and huffcode[] are filled in code-length order, | ||
172 | * paralleling the order of the symbols themselves in htbl->huffval[]. | ||
173 | */ | ||
174 | |||
175 | /* Find the input Huffman table */ | ||
176 | if (tblno < 0 || tblno >= NUM_HUFF_TBLS) | ||
177 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); | ||
178 | htbl = | ||
179 | isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno]; | ||
180 | if (htbl == NULL) | ||
181 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); | ||
182 | |||
183 | /* Allocate a workspace if we haven't already done so. */ | ||
184 | if (*pdtbl == NULL) | ||
185 | *pdtbl = (c_derived_tbl *) | ||
186 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | ||
187 | SIZEOF(c_derived_tbl)); | ||
188 | dtbl = *pdtbl; | ||
189 | |||
190 | /* Figure C.1: make table of Huffman code length for each symbol */ | ||
191 | |||
192 | p = 0; | ||
193 | for (l = 1; l <= 16; l++) { | ||
194 | i = (int) htbl->bits[l]; | ||
195 | if (i < 0 || p + i > 256) /* protect against table overrun */ | ||
196 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); | ||
197 | while (i--) | ||
198 | huffsize[p++] = (char) l; | ||
199 | } | ||
200 | huffsize[p] = 0; | ||
201 | lastp = p; | ||
202 | |||
203 | /* Figure C.2: generate the codes themselves */ | ||
204 | /* We also validate that the counts represent a legal Huffman code tree. */ | ||
205 | |||
206 | code = 0; | ||
207 | si = huffsize[0]; | ||
208 | p = 0; | ||
209 | while (huffsize[p]) { | ||
210 | while (((int) huffsize[p]) == si) { | ||
211 | huffcode[p++] = code; | ||
212 | code++; | ||
213 | } | ||
214 | /* code is now 1 more than the last code used for codelength si; but | ||
215 | * it must still fit in si bits, since no code is allowed to be all ones. | ||
216 | */ | ||
217 | if (((INT32) code) >= (((INT32) 1) << si)) | ||
218 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); | ||
219 | code <<= 1; | ||
220 | si++; | ||
221 | } | ||
222 | |||
223 | /* Figure C.3: generate encoding tables */ | ||
224 | /* These are code and size indexed by symbol value */ | ||
225 | |||
226 | /* Set all codeless symbols to have code length 0; | ||
227 | * this lets us detect duplicate VAL entries here, and later | ||
228 | * allows emit_bits to detect any attempt to emit such symbols. | ||
229 | */ | ||
230 | MEMZERO(dtbl->ehufsi, SIZEOF(dtbl->ehufsi)); | ||
231 | |||
232 | /* This is also a convenient place to check for out-of-range | ||
233 | * and duplicated VAL entries. We allow 0..255 for AC symbols | ||
234 | * but only 0..15 for DC. (We could constrain them further | ||
235 | * based on data depth and mode, but this seems enough.) | ||
236 | */ | ||
237 | maxsymbol = isDC ? 15 : 255; | ||
238 | |||
239 | for (p = 0; p < lastp; p++) { | ||
240 | i = htbl->huffval[p]; | ||
241 | if (i < 0 || i > maxsymbol || dtbl->ehufsi[i]) | ||
242 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); | ||
243 | dtbl->ehufco[i] = huffcode[p]; | ||
244 | dtbl->ehufsi[i] = huffsize[p]; | ||
245 | } | ||
246 | } | ||
247 | |||
248 | |||
249 | /* Outputting bytes to the file. | ||
250 | * NB: these must be called only when actually outputting, | ||
251 | * that is, entropy->gather_statistics == FALSE. | ||
252 | */ | ||
253 | |||
254 | /* Emit a byte, taking 'action' if must suspend. */ | ||
255 | #define emit_byte_s(state,val,action) \ | ||
256 | { *(state)->next_output_byte++ = (JOCTET) (val); \ | ||
257 | if (--(state)->free_in_buffer == 0) \ | ||
258 | if (! dump_buffer_s(state)) \ | ||
259 | { action; } } | ||
260 | |||
261 | /* Emit a byte */ | ||
262 | #define emit_byte_e(entropy,val) \ | ||
263 | { *(entropy)->next_output_byte++ = (JOCTET) (val); \ | ||
264 | if (--(entropy)->free_in_buffer == 0) \ | ||
265 | dump_buffer_e(entropy); } | ||
266 | |||
267 | |||
268 | LOCAL(boolean) | ||
269 | dump_buffer_s (working_state * state) | ||
270 | /* Empty the output buffer; return TRUE if successful, FALSE if must suspend */ | ||
271 | { | ||
272 | struct jpeg_destination_mgr * dest = state->cinfo->dest; | ||
273 | |||
274 | if (! (*dest->empty_output_buffer) (state->cinfo)) | ||
275 | return FALSE; | ||
276 | /* After a successful buffer dump, must reset buffer pointers */ | ||
277 | state->next_output_byte = dest->next_output_byte; | ||
278 | state->free_in_buffer = dest->free_in_buffer; | ||
279 | return TRUE; | ||
280 | } | ||
281 | |||
282 | |||
283 | LOCAL(void) | ||
284 | dump_buffer_e (huff_entropy_ptr entropy) | ||
285 | /* Empty the output buffer; we do not support suspension in this case. */ | ||
286 | { | ||
287 | struct jpeg_destination_mgr * dest = entropy->cinfo->dest; | ||
288 | |||
289 | if (! (*dest->empty_output_buffer) (entropy->cinfo)) | ||
290 | ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND); | ||
291 | /* After a successful buffer dump, must reset buffer pointers */ | ||
292 | entropy->next_output_byte = dest->next_output_byte; | ||
293 | entropy->free_in_buffer = dest->free_in_buffer; | ||
294 | } | ||
295 | |||
296 | |||
297 | /* Outputting bits to the file */ | ||
298 | |||
299 | /* Only the right 24 bits of put_buffer are used; the valid bits are | ||
300 | * left-justified in this part. At most 16 bits can be passed to emit_bits | ||
301 | * in one call, and we never retain more than 7 bits in put_buffer | ||
302 | * between calls, so 24 bits are sufficient. | ||
303 | */ | ||
304 | |||
305 | INLINE | ||
306 | LOCAL(boolean) | ||
307 | emit_bits_s (working_state * state, unsigned int code, int size) | ||
308 | /* Emit some bits; return TRUE if successful, FALSE if must suspend */ | ||
309 | { | ||
310 | /* This routine is heavily used, so it's worth coding tightly. */ | ||
311 | register INT32 put_buffer = (INT32) code; | ||
312 | register int put_bits = state->cur.put_bits; | ||
313 | |||
314 | /* if size is 0, caller used an invalid Huffman table entry */ | ||
315 | if (size == 0) | ||
316 | ERREXIT(state->cinfo, JERR_HUFF_MISSING_CODE); | ||
317 | |||
318 | put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ | ||
319 | |||
320 | put_bits += size; /* new number of bits in buffer */ | ||
321 | |||
322 | put_buffer <<= 24 - put_bits; /* align incoming bits */ | ||
323 | |||
324 | put_buffer |= state->cur.put_buffer; /* and merge with old buffer contents */ | ||
325 | |||
326 | while (put_bits >= 8) { | ||
327 | int c = (int) ((put_buffer >> 16) & 0xFF); | ||
328 | |||
329 | emit_byte_s(state, c, return FALSE); | ||
330 | if (c == 0xFF) { /* need to stuff a zero byte? */ | ||
331 | emit_byte_s(state, 0, return FALSE); | ||
332 | } | ||
333 | put_buffer <<= 8; | ||
334 | put_bits -= 8; | ||
335 | } | ||
336 | |||
337 | state->cur.put_buffer = put_buffer; /* update state variables */ | ||
338 | state->cur.put_bits = put_bits; | ||
339 | |||
340 | return TRUE; | ||
341 | } | ||
342 | |||
343 | |||
344 | INLINE | ||
345 | LOCAL(void) | ||
346 | emit_bits_e (huff_entropy_ptr entropy, unsigned int code, int size) | ||
347 | /* Emit some bits, unless we are in gather mode */ | ||
348 | { | ||
349 | /* This routine is heavily used, so it's worth coding tightly. */ | ||
350 | register INT32 put_buffer = (INT32) code; | ||
351 | register int put_bits = entropy->saved.put_bits; | ||
352 | |||
353 | /* if size is 0, caller used an invalid Huffman table entry */ | ||
354 | if (size == 0) | ||
355 | ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); | ||
356 | |||
357 | if (entropy->gather_statistics) | ||
358 | return; /* do nothing if we're only getting stats */ | ||
359 | |||
360 | put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ | ||
361 | |||
362 | put_bits += size; /* new number of bits in buffer */ | ||
363 | |||
364 | put_buffer <<= 24 - put_bits; /* align incoming bits */ | ||
365 | |||
366 | /* and merge with old buffer contents */ | ||
367 | put_buffer |= entropy->saved.put_buffer; | ||
368 | |||
369 | while (put_bits >= 8) { | ||
370 | int c = (int) ((put_buffer >> 16) & 0xFF); | ||
371 | |||
372 | emit_byte_e(entropy, c); | ||
373 | if (c == 0xFF) { /* need to stuff a zero byte? */ | ||
374 | emit_byte_e(entropy, 0); | ||
375 | } | ||
376 | put_buffer <<= 8; | ||
377 | put_bits -= 8; | ||
378 | } | ||
379 | |||
380 | entropy->saved.put_buffer = put_buffer; /* update variables */ | ||
381 | entropy->saved.put_bits = put_bits; | ||
382 | } | ||
383 | |||
384 | |||
385 | LOCAL(boolean) | ||
386 | flush_bits_s (working_state * state) | ||
387 | { | ||
388 | if (! emit_bits_s(state, 0x7F, 7)) /* fill any partial byte with ones */ | ||
389 | return FALSE; | ||
390 | state->cur.put_buffer = 0; /* and reset bit-buffer to empty */ | ||
391 | state->cur.put_bits = 0; | ||
392 | return TRUE; | ||
393 | } | ||
394 | |||
395 | |||
396 | LOCAL(void) | ||
397 | flush_bits_e (huff_entropy_ptr entropy) | ||
398 | { | ||
399 | emit_bits_e(entropy, 0x7F, 7); /* fill any partial byte with ones */ | ||
400 | entropy->saved.put_buffer = 0; /* and reset bit-buffer to empty */ | ||
401 | entropy->saved.put_bits = 0; | ||
402 | } | ||
403 | |||
404 | |||
405 | /* | ||
406 | * Emit (or just count) a Huffman symbol. | ||
407 | */ | ||
408 | |||
409 | INLINE | ||
410 | LOCAL(void) | ||
411 | emit_dc_symbol (huff_entropy_ptr entropy, int tbl_no, int symbol) | ||
412 | { | ||
413 | if (entropy->gather_statistics) | ||
414 | entropy->dc_count_ptrs[tbl_no][symbol]++; | ||
415 | else { | ||
416 | c_derived_tbl * tbl = entropy->dc_derived_tbls[tbl_no]; | ||
417 | emit_bits_e(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]); | ||
418 | } | ||
419 | } | ||
420 | |||
421 | |||
422 | INLINE | ||
423 | LOCAL(void) | ||
424 | emit_ac_symbol (huff_entropy_ptr entropy, int tbl_no, int symbol) | ||
425 | { | ||
426 | if (entropy->gather_statistics) | ||
427 | entropy->ac_count_ptrs[tbl_no][symbol]++; | ||
428 | else { | ||
429 | c_derived_tbl * tbl = entropy->ac_derived_tbls[tbl_no]; | ||
430 | emit_bits_e(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]); | ||
431 | } | ||
432 | } | ||
433 | |||
434 | |||
435 | /* | ||
436 | * Emit bits from a correction bit buffer. | ||
437 | */ | ||
438 | |||
439 | LOCAL(void) | ||
440 | emit_buffered_bits (huff_entropy_ptr entropy, char * bufstart, | ||
441 | unsigned int nbits) | ||
442 | { | ||
443 | if (entropy->gather_statistics) | ||
444 | return; /* no real work */ | ||
445 | |||
446 | while (nbits > 0) { | ||
447 | emit_bits_e(entropy, (unsigned int) (*bufstart), 1); | ||
448 | bufstart++; | ||
449 | nbits--; | ||
450 | } | ||
451 | } | ||
452 | |||
453 | |||
454 | /* | ||
455 | * Emit any pending EOBRUN symbol. | ||
456 | */ | ||
457 | |||
458 | LOCAL(void) | ||
459 | emit_eobrun (huff_entropy_ptr entropy) | ||
460 | { | ||
461 | register int temp, nbits; | ||
462 | |||
463 | if (entropy->EOBRUN > 0) { /* if there is any pending EOBRUN */ | ||
464 | temp = entropy->EOBRUN; | ||
465 | nbits = 0; | ||
466 | while ((temp >>= 1)) | ||
467 | nbits++; | ||
468 | /* safety check: shouldn't happen given limited correction-bit buffer */ | ||
469 | if (nbits > 14) | ||
470 | ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); | ||
471 | |||
472 | emit_ac_symbol(entropy, entropy->ac_tbl_no, nbits << 4); | ||
473 | if (nbits) | ||
474 | emit_bits_e(entropy, entropy->EOBRUN, nbits); | ||
475 | |||
476 | entropy->EOBRUN = 0; | ||
477 | |||
478 | /* Emit any buffered correction bits */ | ||
479 | emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE); | ||
480 | entropy->BE = 0; | ||
481 | } | ||
482 | } | ||
483 | |||
484 | |||
485 | /* | ||
486 | * Emit a restart marker & resynchronize predictions. | ||
487 | */ | ||
488 | |||
489 | LOCAL(boolean) | ||
490 | emit_restart_s (working_state * state, int restart_num) | ||
491 | { | ||
492 | int ci; | ||
493 | |||
494 | if (! flush_bits_s(state)) | ||
495 | return FALSE; | ||
496 | |||
497 | emit_byte_s(state, 0xFF, return FALSE); | ||
498 | emit_byte_s(state, JPEG_RST0 + restart_num, return FALSE); | ||
499 | |||
500 | /* Re-initialize DC predictions to 0 */ | ||
501 | for (ci = 0; ci < state->cinfo->comps_in_scan; ci++) | ||
502 | state->cur.last_dc_val[ci] = 0; | ||
503 | |||
504 | /* The restart counter is not updated until we successfully write the MCU. */ | ||
505 | |||
506 | return TRUE; | ||
507 | } | ||
508 | |||
509 | |||
510 | LOCAL(void) | ||
511 | emit_restart_e (huff_entropy_ptr entropy, int restart_num) | ||
512 | { | ||
513 | int ci; | ||
514 | |||
515 | emit_eobrun(entropy); | ||
516 | |||
517 | if (! entropy->gather_statistics) { | ||
518 | flush_bits_e(entropy); | ||
519 | emit_byte_e(entropy, 0xFF); | ||
520 | emit_byte_e(entropy, JPEG_RST0 + restart_num); | ||
521 | } | ||
522 | |||
523 | if (entropy->cinfo->Ss == 0) { | ||
524 | /* Re-initialize DC predictions to 0 */ | ||
525 | for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++) | ||
526 | entropy->saved.last_dc_val[ci] = 0; | ||
527 | } else { | ||
528 | /* Re-initialize all AC-related fields to 0 */ | ||
529 | entropy->EOBRUN = 0; | ||
530 | entropy->BE = 0; | ||
531 | } | ||
532 | } | ||
533 | |||
534 | |||
535 | /* | ||
536 | * MCU encoding for DC initial scan (either spectral selection, | ||
537 | * or first pass of successive approximation). | ||
538 | */ | ||
539 | |||
540 | METHODDEF(boolean) | ||
541 | encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
542 | { | ||
543 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
544 | register int temp, temp2; | ||
545 | register int nbits; | ||
546 | int blkn, ci; | ||
547 | int Al = cinfo->Al; | ||
548 | JBLOCKROW block; | ||
549 | jpeg_component_info * compptr; | ||
550 | ISHIFT_TEMPS | ||
551 | |||
552 | entropy->next_output_byte = cinfo->dest->next_output_byte; | ||
553 | entropy->free_in_buffer = cinfo->dest->free_in_buffer; | ||
554 | |||
555 | /* Emit restart marker if needed */ | ||
556 | if (cinfo->restart_interval) | ||
557 | if (entropy->restarts_to_go == 0) | ||
558 | emit_restart_e(entropy, entropy->next_restart_num); | ||
559 | |||
560 | /* Encode the MCU data blocks */ | ||
561 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { | ||
562 | block = MCU_data[blkn]; | ||
563 | ci = cinfo->MCU_membership[blkn]; | ||
564 | compptr = cinfo->cur_comp_info[ci]; | ||
565 | |||
566 | /* Compute the DC value after the required point transform by Al. | ||
567 | * This is simply an arithmetic right shift. | ||
568 | */ | ||
569 | temp2 = IRIGHT_SHIFT((int) ((*block)[0]), Al); | ||
570 | |||
571 | /* DC differences are figured on the point-transformed values. */ | ||
572 | temp = temp2 - entropy->saved.last_dc_val[ci]; | ||
573 | entropy->saved.last_dc_val[ci] = temp2; | ||
574 | |||
575 | /* Encode the DC coefficient difference per section G.1.2.1 */ | ||
576 | temp2 = temp; | ||
577 | if (temp < 0) { | ||
578 | temp = -temp; /* temp is abs value of input */ | ||
579 | /* For a negative input, want temp2 = bitwise complement of abs(input) */ | ||
580 | /* This code assumes we are on a two's complement machine */ | ||
581 | temp2--; | ||
582 | } | ||
583 | |||
584 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
585 | nbits = 0; | ||
586 | while (temp) { | ||
587 | nbits++; | ||
588 | temp >>= 1; | ||
589 | } | ||
590 | /* Check for out-of-range coefficient values. | ||
591 | * Since we're encoding a difference, the range limit is twice as much. | ||
592 | */ | ||
593 | if (nbits > MAX_COEF_BITS+1) | ||
594 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); | ||
595 | |||
596 | /* Count/emit the Huffman-coded symbol for the number of bits */ | ||
597 | emit_dc_symbol(entropy, compptr->dc_tbl_no, nbits); | ||
598 | |||
599 | /* Emit that number of bits of the value, if positive, */ | ||
600 | /* or the complement of its magnitude, if negative. */ | ||
601 | if (nbits) /* emit_bits rejects calls with size 0 */ | ||
602 | emit_bits_e(entropy, (unsigned int) temp2, nbits); | ||
603 | } | ||
604 | |||
605 | cinfo->dest->next_output_byte = entropy->next_output_byte; | ||
606 | cinfo->dest->free_in_buffer = entropy->free_in_buffer; | ||
607 | |||
608 | /* Update restart-interval state too */ | ||
609 | if (cinfo->restart_interval) { | ||
610 | if (entropy->restarts_to_go == 0) { | ||
611 | entropy->restarts_to_go = cinfo->restart_interval; | ||
612 | entropy->next_restart_num++; | ||
613 | entropy->next_restart_num &= 7; | ||
614 | } | ||
615 | entropy->restarts_to_go--; | ||
616 | } | ||
617 | |||
618 | return TRUE; | ||
619 | } | ||
620 | |||
621 | |||
622 | /* | ||
623 | * MCU encoding for AC initial scan (either spectral selection, | ||
624 | * or first pass of successive approximation). | ||
625 | */ | ||
626 | |||
627 | METHODDEF(boolean) | ||
628 | encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
629 | { | ||
630 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
631 | register int temp, temp2; | ||
632 | register int nbits; | ||
633 | register int r, k; | ||
634 | int Se, Al; | ||
635 | const int * natural_order; | ||
636 | JBLOCKROW block; | ||
637 | |||
638 | entropy->next_output_byte = cinfo->dest->next_output_byte; | ||
639 | entropy->free_in_buffer = cinfo->dest->free_in_buffer; | ||
640 | |||
641 | /* Emit restart marker if needed */ | ||
642 | if (cinfo->restart_interval) | ||
643 | if (entropy->restarts_to_go == 0) | ||
644 | emit_restart_e(entropy, entropy->next_restart_num); | ||
645 | |||
646 | Se = cinfo->Se; | ||
647 | Al = cinfo->Al; | ||
648 | natural_order = cinfo->natural_order; | ||
649 | |||
650 | /* Encode the MCU data block */ | ||
651 | block = MCU_data[0]; | ||
652 | |||
653 | /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */ | ||
654 | |||
655 | r = 0; /* r = run length of zeros */ | ||
656 | |||
657 | for (k = cinfo->Ss; k <= Se; k++) { | ||
658 | if ((temp = (*block)[natural_order[k]]) == 0) { | ||
659 | r++; | ||
660 | continue; | ||
661 | } | ||
662 | /* We must apply the point transform by Al. For AC coefficients this | ||
663 | * is an integer division with rounding towards 0. To do this portably | ||
664 | * in C, we shift after obtaining the absolute value; so the code is | ||
665 | * interwoven with finding the abs value (temp) and output bits (temp2). | ||
666 | */ | ||
667 | if (temp < 0) { | ||
668 | temp = -temp; /* temp is abs value of input */ | ||
669 | temp >>= Al; /* apply the point transform */ | ||
670 | /* For a negative coef, want temp2 = bitwise complement of abs(coef) */ | ||
671 | temp2 = ~temp; | ||
672 | } else { | ||
673 | temp >>= Al; /* apply the point transform */ | ||
674 | temp2 = temp; | ||
675 | } | ||
676 | /* Watch out for case that nonzero coef is zero after point transform */ | ||
677 | if (temp == 0) { | ||
678 | r++; | ||
679 | continue; | ||
680 | } | ||
681 | |||
682 | /* Emit any pending EOBRUN */ | ||
683 | if (entropy->EOBRUN > 0) | ||
684 | emit_eobrun(entropy); | ||
685 | /* if run length > 15, must emit special run-length-16 codes (0xF0) */ | ||
686 | while (r > 15) { | ||
687 | emit_ac_symbol(entropy, entropy->ac_tbl_no, 0xF0); | ||
688 | r -= 16; | ||
689 | } | ||
690 | |||
691 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
692 | nbits = 1; /* there must be at least one 1 bit */ | ||
693 | while ((temp >>= 1)) | ||
694 | nbits++; | ||
695 | /* Check for out-of-range coefficient values */ | ||
696 | if (nbits > MAX_COEF_BITS) | ||
697 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); | ||
698 | |||
699 | /* Count/emit Huffman symbol for run length / number of bits */ | ||
700 | emit_ac_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits); | ||
701 | |||
702 | /* Emit that number of bits of the value, if positive, */ | ||
703 | /* or the complement of its magnitude, if negative. */ | ||
704 | emit_bits_e(entropy, (unsigned int) temp2, nbits); | ||
705 | |||
706 | r = 0; /* reset zero run length */ | ||
707 | } | ||
708 | |||
709 | if (r > 0) { /* If there are trailing zeroes, */ | ||
710 | entropy->EOBRUN++; /* count an EOB */ | ||
711 | if (entropy->EOBRUN == 0x7FFF) | ||
712 | emit_eobrun(entropy); /* force it out to avoid overflow */ | ||
713 | } | ||
714 | |||
715 | cinfo->dest->next_output_byte = entropy->next_output_byte; | ||
716 | cinfo->dest->free_in_buffer = entropy->free_in_buffer; | ||
717 | |||
718 | /* Update restart-interval state too */ | ||
719 | if (cinfo->restart_interval) { | ||
720 | if (entropy->restarts_to_go == 0) { | ||
721 | entropy->restarts_to_go = cinfo->restart_interval; | ||
722 | entropy->next_restart_num++; | ||
723 | entropy->next_restart_num &= 7; | ||
724 | } | ||
725 | entropy->restarts_to_go--; | ||
726 | } | ||
727 | |||
728 | return TRUE; | ||
729 | } | ||
730 | |||
731 | |||
732 | /* | ||
733 | * MCU encoding for DC successive approximation refinement scan. | ||
734 | * Note: we assume such scans can be multi-component, although the spec | ||
735 | * is not very clear on the point. | ||
736 | */ | ||
737 | |||
738 | METHODDEF(boolean) | ||
739 | encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
740 | { | ||
741 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
742 | register int temp; | ||
743 | int blkn; | ||
744 | int Al = cinfo->Al; | ||
745 | JBLOCKROW block; | ||
746 | |||
747 | entropy->next_output_byte = cinfo->dest->next_output_byte; | ||
748 | entropy->free_in_buffer = cinfo->dest->free_in_buffer; | ||
749 | |||
750 | /* Emit restart marker if needed */ | ||
751 | if (cinfo->restart_interval) | ||
752 | if (entropy->restarts_to_go == 0) | ||
753 | emit_restart_e(entropy, entropy->next_restart_num); | ||
754 | |||
755 | /* Encode the MCU data blocks */ | ||
756 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { | ||
757 | block = MCU_data[blkn]; | ||
758 | |||
759 | /* We simply emit the Al'th bit of the DC coefficient value. */ | ||
760 | temp = (*block)[0]; | ||
761 | emit_bits_e(entropy, (unsigned int) (temp >> Al), 1); | ||
762 | } | ||
763 | |||
764 | cinfo->dest->next_output_byte = entropy->next_output_byte; | ||
765 | cinfo->dest->free_in_buffer = entropy->free_in_buffer; | ||
766 | |||
767 | /* Update restart-interval state too */ | ||
768 | if (cinfo->restart_interval) { | ||
769 | if (entropy->restarts_to_go == 0) { | ||
770 | entropy->restarts_to_go = cinfo->restart_interval; | ||
771 | entropy->next_restart_num++; | ||
772 | entropy->next_restart_num &= 7; | ||
773 | } | ||
774 | entropy->restarts_to_go--; | ||
775 | } | ||
776 | |||
777 | return TRUE; | ||
778 | } | ||
779 | |||
780 | |||
781 | /* | ||
782 | * MCU encoding for AC successive approximation refinement scan. | ||
783 | */ | ||
784 | |||
785 | METHODDEF(boolean) | ||
786 | encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
787 | { | ||
788 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
789 | register int temp; | ||
790 | register int r, k; | ||
791 | int EOB; | ||
792 | char *BR_buffer; | ||
793 | unsigned int BR; | ||
794 | int Se, Al; | ||
795 | const int * natural_order; | ||
796 | JBLOCKROW block; | ||
797 | int absvalues[DCTSIZE2]; | ||
798 | |||
799 | entropy->next_output_byte = cinfo->dest->next_output_byte; | ||
800 | entropy->free_in_buffer = cinfo->dest->free_in_buffer; | ||
801 | |||
802 | /* Emit restart marker if needed */ | ||
803 | if (cinfo->restart_interval) | ||
804 | if (entropy->restarts_to_go == 0) | ||
805 | emit_restart_e(entropy, entropy->next_restart_num); | ||
806 | |||
807 | Se = cinfo->Se; | ||
808 | Al = cinfo->Al; | ||
809 | natural_order = cinfo->natural_order; | ||
810 | |||
811 | /* Encode the MCU data block */ | ||
812 | block = MCU_data[0]; | ||
813 | |||
814 | /* It is convenient to make a pre-pass to determine the transformed | ||
815 | * coefficients' absolute values and the EOB position. | ||
816 | */ | ||
817 | EOB = 0; | ||
818 | for (k = cinfo->Ss; k <= Se; k++) { | ||
819 | temp = (*block)[natural_order[k]]; | ||
820 | /* We must apply the point transform by Al. For AC coefficients this | ||
821 | * is an integer division with rounding towards 0. To do this portably | ||
822 | * in C, we shift after obtaining the absolute value. | ||
823 | */ | ||
824 | if (temp < 0) | ||
825 | temp = -temp; /* temp is abs value of input */ | ||
826 | temp >>= Al; /* apply the point transform */ | ||
827 | absvalues[k] = temp; /* save abs value for main pass */ | ||
828 | if (temp == 1) | ||
829 | EOB = k; /* EOB = index of last newly-nonzero coef */ | ||
830 | } | ||
831 | |||
832 | /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */ | ||
833 | |||
834 | r = 0; /* r = run length of zeros */ | ||
835 | BR = 0; /* BR = count of buffered bits added now */ | ||
836 | BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */ | ||
837 | |||
838 | for (k = cinfo->Ss; k <= Se; k++) { | ||
839 | if ((temp = absvalues[k]) == 0) { | ||
840 | r++; | ||
841 | continue; | ||
842 | } | ||
843 | |||
844 | /* Emit any required ZRLs, but not if they can be folded into EOB */ | ||
845 | while (r > 15 && k <= EOB) { | ||
846 | /* emit any pending EOBRUN and the BE correction bits */ | ||
847 | emit_eobrun(entropy); | ||
848 | /* Emit ZRL */ | ||
849 | emit_ac_symbol(entropy, entropy->ac_tbl_no, 0xF0); | ||
850 | r -= 16; | ||
851 | /* Emit buffered correction bits that must be associated with ZRL */ | ||
852 | emit_buffered_bits(entropy, BR_buffer, BR); | ||
853 | BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ | ||
854 | BR = 0; | ||
855 | } | ||
856 | |||
857 | /* If the coef was previously nonzero, it only needs a correction bit. | ||
858 | * NOTE: a straight translation of the spec's figure G.7 would suggest | ||
859 | * that we also need to test r > 15. But if r > 15, we can only get here | ||
860 | * if k > EOB, which implies that this coefficient is not 1. | ||
861 | */ | ||
862 | if (temp > 1) { | ||
863 | /* The correction bit is the next bit of the absolute value. */ | ||
864 | BR_buffer[BR++] = (char) (temp & 1); | ||
865 | continue; | ||
866 | } | ||
867 | |||
868 | /* Emit any pending EOBRUN and the BE correction bits */ | ||
869 | emit_eobrun(entropy); | ||
870 | |||
871 | /* Count/emit Huffman symbol for run length / number of bits */ | ||
872 | emit_ac_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1); | ||
873 | |||
874 | /* Emit output bit for newly-nonzero coef */ | ||
875 | temp = ((*block)[natural_order[k]] < 0) ? 0 : 1; | ||
876 | emit_bits_e(entropy, (unsigned int) temp, 1); | ||
877 | |||
878 | /* Emit buffered correction bits that must be associated with this code */ | ||
879 | emit_buffered_bits(entropy, BR_buffer, BR); | ||
880 | BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ | ||
881 | BR = 0; | ||
882 | r = 0; /* reset zero run length */ | ||
883 | } | ||
884 | |||
885 | if (r > 0 || BR > 0) { /* If there are trailing zeroes, */ | ||
886 | entropy->EOBRUN++; /* count an EOB */ | ||
887 | entropy->BE += BR; /* concat my correction bits to older ones */ | ||
888 | /* We force out the EOB if we risk either: | ||
889 | * 1. overflow of the EOB counter; | ||
890 | * 2. overflow of the correction bit buffer during the next MCU. | ||
891 | */ | ||
892 | if (entropy->EOBRUN == 0x7FFF || entropy->BE > (MAX_CORR_BITS-DCTSIZE2+1)) | ||
893 | emit_eobrun(entropy); | ||
894 | } | ||
895 | |||
896 | cinfo->dest->next_output_byte = entropy->next_output_byte; | ||
897 | cinfo->dest->free_in_buffer = entropy->free_in_buffer; | ||
898 | |||
899 | /* Update restart-interval state too */ | ||
900 | if (cinfo->restart_interval) { | ||
901 | if (entropy->restarts_to_go == 0) { | ||
902 | entropy->restarts_to_go = cinfo->restart_interval; | ||
903 | entropy->next_restart_num++; | ||
904 | entropy->next_restart_num &= 7; | ||
905 | } | ||
906 | entropy->restarts_to_go--; | ||
907 | } | ||
908 | |||
909 | return TRUE; | ||
910 | } | ||
911 | |||
912 | |||
913 | /* Encode a single block's worth of coefficients */ | ||
914 | |||
915 | LOCAL(boolean) | ||
916 | encode_one_block (working_state * state, JCOEFPTR block, int last_dc_val, | ||
917 | c_derived_tbl *dctbl, c_derived_tbl *actbl) | ||
918 | { | ||
919 | register int temp, temp2; | ||
920 | register int nbits; | ||
921 | register int k, r, i; | ||
922 | int Se = state->cinfo->lim_Se; | ||
923 | const int * natural_order = state->cinfo->natural_order; | ||
924 | |||
925 | /* Encode the DC coefficient difference per section F.1.2.1 */ | ||
926 | |||
927 | temp = temp2 = block[0] - last_dc_val; | ||
928 | |||
929 | if (temp < 0) { | ||
930 | temp = -temp; /* temp is abs value of input */ | ||
931 | /* For a negative input, want temp2 = bitwise complement of abs(input) */ | ||
932 | /* This code assumes we are on a two's complement machine */ | ||
933 | temp2--; | ||
934 | } | ||
935 | |||
936 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
937 | nbits = 0; | ||
938 | while (temp) { | ||
939 | nbits++; | ||
940 | temp >>= 1; | ||
941 | } | ||
942 | /* Check for out-of-range coefficient values. | ||
943 | * Since we're encoding a difference, the range limit is twice as much. | ||
944 | */ | ||
945 | if (nbits > MAX_COEF_BITS+1) | ||
946 | ERREXIT(state->cinfo, JERR_BAD_DCT_COEF); | ||
947 | |||
948 | /* Emit the Huffman-coded symbol for the number of bits */ | ||
949 | if (! emit_bits_s(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits])) | ||
950 | return FALSE; | ||
951 | |||
952 | /* Emit that number of bits of the value, if positive, */ | ||
953 | /* or the complement of its magnitude, if negative. */ | ||
954 | if (nbits) /* emit_bits rejects calls with size 0 */ | ||
955 | if (! emit_bits_s(state, (unsigned int) temp2, nbits)) | ||
956 | return FALSE; | ||
957 | |||
958 | /* Encode the AC coefficients per section F.1.2.2 */ | ||
959 | |||
960 | r = 0; /* r = run length of zeros */ | ||
961 | |||
962 | for (k = 1; k <= Se; k++) { | ||
963 | if ((temp = block[natural_order[k]]) == 0) { | ||
964 | r++; | ||
965 | } else { | ||
966 | /* if run length > 15, must emit special run-length-16 codes (0xF0) */ | ||
967 | while (r > 15) { | ||
968 | if (! emit_bits_s(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0])) | ||
969 | return FALSE; | ||
970 | r -= 16; | ||
971 | } | ||
972 | |||
973 | temp2 = temp; | ||
974 | if (temp < 0) { | ||
975 | temp = -temp; /* temp is abs value of input */ | ||
976 | /* This code assumes we are on a two's complement machine */ | ||
977 | temp2--; | ||
978 | } | ||
979 | |||
980 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
981 | nbits = 1; /* there must be at least one 1 bit */ | ||
982 | while ((temp >>= 1)) | ||
983 | nbits++; | ||
984 | /* Check for out-of-range coefficient values */ | ||
985 | if (nbits > MAX_COEF_BITS) | ||
986 | ERREXIT(state->cinfo, JERR_BAD_DCT_COEF); | ||
987 | |||
988 | /* Emit Huffman symbol for run length / number of bits */ | ||
989 | i = (r << 4) + nbits; | ||
990 | if (! emit_bits_s(state, actbl->ehufco[i], actbl->ehufsi[i])) | ||
991 | return FALSE; | ||
992 | |||
993 | /* Emit that number of bits of the value, if positive, */ | ||
994 | /* or the complement of its magnitude, if negative. */ | ||
995 | if (! emit_bits_s(state, (unsigned int) temp2, nbits)) | ||
996 | return FALSE; | ||
997 | |||
998 | r = 0; | ||
999 | } | ||
1000 | } | ||
1001 | |||
1002 | /* If the last coef(s) were zero, emit an end-of-block code */ | ||
1003 | if (r > 0) | ||
1004 | if (! emit_bits_s(state, actbl->ehufco[0], actbl->ehufsi[0])) | ||
1005 | return FALSE; | ||
1006 | |||
1007 | return TRUE; | ||
1008 | } | ||
1009 | |||
1010 | |||
1011 | /* | ||
1012 | * Encode and output one MCU's worth of Huffman-compressed coefficients. | ||
1013 | */ | ||
1014 | |||
1015 | METHODDEF(boolean) | ||
1016 | encode_mcu_huff (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
1017 | { | ||
1018 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
1019 | working_state state; | ||
1020 | int blkn, ci; | ||
1021 | jpeg_component_info * compptr; | ||
1022 | |||
1023 | /* Load up working state */ | ||
1024 | state.next_output_byte = cinfo->dest->next_output_byte; | ||
1025 | state.free_in_buffer = cinfo->dest->free_in_buffer; | ||
1026 | ASSIGN_STATE(state.cur, entropy->saved); | ||
1027 | state.cinfo = cinfo; | ||
1028 | |||
1029 | /* Emit restart marker if needed */ | ||
1030 | if (cinfo->restart_interval) { | ||
1031 | if (entropy->restarts_to_go == 0) | ||
1032 | if (! emit_restart_s(&state, entropy->next_restart_num)) | ||
1033 | return FALSE; | ||
1034 | } | ||
1035 | |||
1036 | /* Encode the MCU data blocks */ | ||
1037 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { | ||
1038 | ci = cinfo->MCU_membership[blkn]; | ||
1039 | compptr = cinfo->cur_comp_info[ci]; | ||
1040 | if (! encode_one_block(&state, | ||
1041 | MCU_data[blkn][0], state.cur.last_dc_val[ci], | ||
1042 | entropy->dc_derived_tbls[compptr->dc_tbl_no], | ||
1043 | entropy->ac_derived_tbls[compptr->ac_tbl_no])) | ||
1044 | return FALSE; | ||
1045 | /* Update last_dc_val */ | ||
1046 | state.cur.last_dc_val[ci] = MCU_data[blkn][0][0]; | ||
1047 | } | ||
1048 | |||
1049 | /* Completed MCU, so update state */ | ||
1050 | cinfo->dest->next_output_byte = state.next_output_byte; | ||
1051 | cinfo->dest->free_in_buffer = state.free_in_buffer; | ||
1052 | ASSIGN_STATE(entropy->saved, state.cur); | ||
1053 | |||
1054 | /* Update restart-interval state too */ | ||
1055 | if (cinfo->restart_interval) { | ||
1056 | if (entropy->restarts_to_go == 0) { | ||
1057 | entropy->restarts_to_go = cinfo->restart_interval; | ||
1058 | entropy->next_restart_num++; | ||
1059 | entropy->next_restart_num &= 7; | ||
1060 | } | ||
1061 | entropy->restarts_to_go--; | ||
1062 | } | ||
1063 | |||
1064 | return TRUE; | ||
1065 | } | ||
1066 | |||
1067 | |||
1068 | /* | ||
1069 | * Finish up at the end of a Huffman-compressed scan. | ||
1070 | */ | ||
1071 | |||
1072 | METHODDEF(void) | ||
1073 | finish_pass_huff (j_compress_ptr cinfo) | ||
1074 | { | ||
1075 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
1076 | working_state state; | ||
1077 | |||
1078 | if (cinfo->progressive_mode) { | ||
1079 | entropy->next_output_byte = cinfo->dest->next_output_byte; | ||
1080 | entropy->free_in_buffer = cinfo->dest->free_in_buffer; | ||
1081 | |||
1082 | /* Flush out any buffered data */ | ||
1083 | emit_eobrun(entropy); | ||
1084 | flush_bits_e(entropy); | ||
1085 | |||
1086 | cinfo->dest->next_output_byte = entropy->next_output_byte; | ||
1087 | cinfo->dest->free_in_buffer = entropy->free_in_buffer; | ||
1088 | } else { | ||
1089 | /* Load up working state ... flush_bits needs it */ | ||
1090 | state.next_output_byte = cinfo->dest->next_output_byte; | ||
1091 | state.free_in_buffer = cinfo->dest->free_in_buffer; | ||
1092 | ASSIGN_STATE(state.cur, entropy->saved); | ||
1093 | state.cinfo = cinfo; | ||
1094 | |||
1095 | /* Flush out the last data */ | ||
1096 | if (! flush_bits_s(&state)) | ||
1097 | ERREXIT(cinfo, JERR_CANT_SUSPEND); | ||
1098 | |||
1099 | /* Update state */ | ||
1100 | cinfo->dest->next_output_byte = state.next_output_byte; | ||
1101 | cinfo->dest->free_in_buffer = state.free_in_buffer; | ||
1102 | ASSIGN_STATE(entropy->saved, state.cur); | ||
1103 | } | ||
1104 | } | ||
1105 | |||
1106 | |||
1107 | /* | ||
1108 | * Huffman coding optimization. | ||
1109 | * | ||
1110 | * We first scan the supplied data and count the number of uses of each symbol | ||
1111 | * that is to be Huffman-coded. (This process MUST agree with the code above.) | ||
1112 | * Then we build a Huffman coding tree for the observed counts. | ||
1113 | * Symbols which are not needed at all for the particular image are not | ||
1114 | * assigned any code, which saves space in the DHT marker as well as in | ||
1115 | * the compressed data. | ||
1116 | */ | ||
1117 | |||
1118 | |||
1119 | /* Process a single block's worth of coefficients */ | ||
1120 | |||
1121 | LOCAL(void) | ||
1122 | htest_one_block (j_compress_ptr cinfo, JCOEFPTR block, int last_dc_val, | ||
1123 | long dc_counts[], long ac_counts[]) | ||
1124 | { | ||
1125 | register int temp; | ||
1126 | register int nbits; | ||
1127 | register int k, r; | ||
1128 | int Se = cinfo->lim_Se; | ||
1129 | const int * natural_order = cinfo->natural_order; | ||
1130 | |||
1131 | /* Encode the DC coefficient difference per section F.1.2.1 */ | ||
1132 | |||
1133 | temp = block[0] - last_dc_val; | ||
1134 | if (temp < 0) | ||
1135 | temp = -temp; | ||
1136 | |||
1137 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
1138 | nbits = 0; | ||
1139 | while (temp) { | ||
1140 | nbits++; | ||
1141 | temp >>= 1; | ||
1142 | } | ||
1143 | /* Check for out-of-range coefficient values. | ||
1144 | * Since we're encoding a difference, the range limit is twice as much. | ||
1145 | */ | ||
1146 | if (nbits > MAX_COEF_BITS+1) | ||
1147 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); | ||
1148 | |||
1149 | /* Count the Huffman symbol for the number of bits */ | ||
1150 | dc_counts[nbits]++; | ||
1151 | |||
1152 | /* Encode the AC coefficients per section F.1.2.2 */ | ||
1153 | |||
1154 | r = 0; /* r = run length of zeros */ | ||
1155 | |||
1156 | for (k = 1; k <= Se; k++) { | ||
1157 | if ((temp = block[natural_order[k]]) == 0) { | ||
1158 | r++; | ||
1159 | } else { | ||
1160 | /* if run length > 15, must emit special run-length-16 codes (0xF0) */ | ||
1161 | while (r > 15) { | ||
1162 | ac_counts[0xF0]++; | ||
1163 | r -= 16; | ||
1164 | } | ||
1165 | |||
1166 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
1167 | if (temp < 0) | ||
1168 | temp = -temp; | ||
1169 | |||
1170 | /* Find the number of bits needed for the magnitude of the coefficient */ | ||
1171 | nbits = 1; /* there must be at least one 1 bit */ | ||
1172 | while ((temp >>= 1)) | ||
1173 | nbits++; | ||
1174 | /* Check for out-of-range coefficient values */ | ||
1175 | if (nbits > MAX_COEF_BITS) | ||
1176 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); | ||
1177 | |||
1178 | /* Count Huffman symbol for run length / number of bits */ | ||
1179 | ac_counts[(r << 4) + nbits]++; | ||
1180 | |||
1181 | r = 0; | ||
1182 | } | ||
1183 | } | ||
1184 | |||
1185 | /* If the last coef(s) were zero, emit an end-of-block code */ | ||
1186 | if (r > 0) | ||
1187 | ac_counts[0]++; | ||
1188 | } | ||
1189 | |||
1190 | |||
1191 | /* | ||
1192 | * Trial-encode one MCU's worth of Huffman-compressed coefficients. | ||
1193 | * No data is actually output, so no suspension return is possible. | ||
1194 | */ | ||
1195 | |||
1196 | METHODDEF(boolean) | ||
1197 | encode_mcu_gather (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | ||
1198 | { | ||
1199 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
1200 | int blkn, ci; | ||
1201 | jpeg_component_info * compptr; | ||
1202 | |||
1203 | /* Take care of restart intervals if needed */ | ||
1204 | if (cinfo->restart_interval) { | ||
1205 | if (entropy->restarts_to_go == 0) { | ||
1206 | /* Re-initialize DC predictions to 0 */ | ||
1207 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) | ||
1208 | entropy->saved.last_dc_val[ci] = 0; | ||
1209 | /* Update restart state */ | ||
1210 | entropy->restarts_to_go = cinfo->restart_interval; | ||
1211 | } | ||
1212 | entropy->restarts_to_go--; | ||
1213 | } | ||
1214 | |||
1215 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { | ||
1216 | ci = cinfo->MCU_membership[blkn]; | ||
1217 | compptr = cinfo->cur_comp_info[ci]; | ||
1218 | htest_one_block(cinfo, MCU_data[blkn][0], entropy->saved.last_dc_val[ci], | ||
1219 | entropy->dc_count_ptrs[compptr->dc_tbl_no], | ||
1220 | entropy->ac_count_ptrs[compptr->ac_tbl_no]); | ||
1221 | entropy->saved.last_dc_val[ci] = MCU_data[blkn][0][0]; | ||
1222 | } | ||
1223 | |||
1224 | return TRUE; | ||
1225 | } | ||
1226 | |||
1227 | |||
1228 | /* | ||
1229 | * Generate the best Huffman code table for the given counts, fill htbl. | ||
1230 | * | ||
1231 | * The JPEG standard requires that no symbol be assigned a codeword of all | ||
1232 | * one bits (so that padding bits added at the end of a compressed segment | ||
1233 | * can't look like a valid code). Because of the canonical ordering of | ||
1234 | * codewords, this just means that there must be an unused slot in the | ||
1235 | * longest codeword length category. Section K.2 of the JPEG spec suggests | ||
1236 | * reserving such a slot by pretending that symbol 256 is a valid symbol | ||
1237 | * with count 1. In theory that's not optimal; giving it count zero but | ||
1238 | * including it in the symbol set anyway should give a better Huffman code. | ||
1239 | * But the theoretically better code actually seems to come out worse in | ||
1240 | * practice, because it produces more all-ones bytes (which incur stuffed | ||
1241 | * zero bytes in the final file). In any case the difference is tiny. | ||
1242 | * | ||
1243 | * The JPEG standard requires Huffman codes to be no more than 16 bits long. | ||
1244 | * If some symbols have a very small but nonzero probability, the Huffman tree | ||
1245 | * must be adjusted to meet the code length restriction. We currently use | ||
1246 | * the adjustment method suggested in JPEG section K.2. This method is *not* | ||
1247 | * optimal; it may not choose the best possible limited-length code. But | ||
1248 | * typically only very-low-frequency symbols will be given less-than-optimal | ||
1249 | * lengths, so the code is almost optimal. Experimental comparisons against | ||
1250 | * an optimal limited-length-code algorithm indicate that the difference is | ||
1251 | * microscopic --- usually less than a hundredth of a percent of total size. | ||
1252 | * So the extra complexity of an optimal algorithm doesn't seem worthwhile. | ||
1253 | */ | ||
1254 | |||
1255 | LOCAL(void) | ||
1256 | jpeg_gen_optimal_table (j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[]) | ||
1257 | { | ||
1258 | #define MAX_CLEN 32 /* assumed maximum initial code length */ | ||
1259 | UINT8 bits[MAX_CLEN+1]; /* bits[k] = # of symbols with code length k */ | ||
1260 | int codesize[257]; /* codesize[k] = code length of symbol k */ | ||
1261 | int others[257]; /* next symbol in current branch of tree */ | ||
1262 | int c1, c2; | ||
1263 | int p, i, j; | ||
1264 | long v; | ||
1265 | |||
1266 | /* This algorithm is explained in section K.2 of the JPEG standard */ | ||
1267 | |||
1268 | MEMZERO(bits, SIZEOF(bits)); | ||
1269 | MEMZERO(codesize, SIZEOF(codesize)); | ||
1270 | for (i = 0; i < 257; i++) | ||
1271 | others[i] = -1; /* init links to empty */ | ||
1272 | |||
1273 | freq[256] = 1; /* make sure 256 has a nonzero count */ | ||
1274 | /* Including the pseudo-symbol 256 in the Huffman procedure guarantees | ||
1275 | * that no real symbol is given code-value of all ones, because 256 | ||
1276 | * will be placed last in the largest codeword category. | ||
1277 | */ | ||
1278 | |||
1279 | /* Huffman's basic algorithm to assign optimal code lengths to symbols */ | ||
1280 | |||
1281 | for (;;) { | ||
1282 | /* Find the smallest nonzero frequency, set c1 = its symbol */ | ||
1283 | /* In case of ties, take the larger symbol number */ | ||
1284 | c1 = -1; | ||
1285 | v = 1000000000L; | ||
1286 | for (i = 0; i <= 256; i++) { | ||
1287 | if (freq[i] && freq[i] <= v) { | ||
1288 | v = freq[i]; | ||
1289 | c1 = i; | ||
1290 | } | ||
1291 | } | ||
1292 | |||
1293 | /* Find the next smallest nonzero frequency, set c2 = its symbol */ | ||
1294 | /* In case of ties, take the larger symbol number */ | ||
1295 | c2 = -1; | ||
1296 | v = 1000000000L; | ||
1297 | for (i = 0; i <= 256; i++) { | ||
1298 | if (freq[i] && freq[i] <= v && i != c1) { | ||
1299 | v = freq[i]; | ||
1300 | c2 = i; | ||
1301 | } | ||
1302 | } | ||
1303 | |||
1304 | /* Done if we've merged everything into one frequency */ | ||
1305 | if (c2 < 0) | ||
1306 | break; | ||
1307 | |||
1308 | /* Else merge the two counts/trees */ | ||
1309 | freq[c1] += freq[c2]; | ||
1310 | freq[c2] = 0; | ||
1311 | |||
1312 | /* Increment the codesize of everything in c1's tree branch */ | ||
1313 | codesize[c1]++; | ||
1314 | while (others[c1] >= 0) { | ||
1315 | c1 = others[c1]; | ||
1316 | codesize[c1]++; | ||
1317 | } | ||
1318 | |||
1319 | others[c1] = c2; /* chain c2 onto c1's tree branch */ | ||
1320 | |||
1321 | /* Increment the codesize of everything in c2's tree branch */ | ||
1322 | codesize[c2]++; | ||
1323 | while (others[c2] >= 0) { | ||
1324 | c2 = others[c2]; | ||
1325 | codesize[c2]++; | ||
1326 | } | ||
1327 | } | ||
1328 | |||
1329 | /* Now count the number of symbols of each code length */ | ||
1330 | for (i = 0; i <= 256; i++) { | ||
1331 | if (codesize[i]) { | ||
1332 | /* The JPEG standard seems to think that this can't happen, */ | ||
1333 | /* but I'm paranoid... */ | ||
1334 | if (codesize[i] > MAX_CLEN) | ||
1335 | ERREXIT(cinfo, JERR_HUFF_CLEN_OVERFLOW); | ||
1336 | |||
1337 | bits[codesize[i]]++; | ||
1338 | } | ||
1339 | } | ||
1340 | |||
1341 | /* JPEG doesn't allow symbols with code lengths over 16 bits, so if the pure | ||
1342 | * Huffman procedure assigned any such lengths, we must adjust the coding. | ||
1343 | * Here is what the JPEG spec says about how this next bit works: | ||
1344 | * Since symbols are paired for the longest Huffman code, the symbols are | ||
1345 | * removed from this length category two at a time. The prefix for the pair | ||
1346 | * (which is one bit shorter) is allocated to one of the pair; then, | ||
1347 | * skipping the BITS entry for that prefix length, a code word from the next | ||
1348 | * shortest nonzero BITS entry is converted into a prefix for two code words | ||
1349 | * one bit longer. | ||
1350 | */ | ||
1351 | |||
1352 | for (i = MAX_CLEN; i > 16; i--) { | ||
1353 | while (bits[i] > 0) { | ||
1354 | j = i - 2; /* find length of new prefix to be used */ | ||
1355 | while (bits[j] == 0) | ||
1356 | j--; | ||
1357 | |||
1358 | bits[i] -= 2; /* remove two symbols */ | ||
1359 | bits[i-1]++; /* one goes in this length */ | ||
1360 | bits[j+1] += 2; /* two new symbols in this length */ | ||
1361 | bits[j]--; /* symbol of this length is now a prefix */ | ||
1362 | } | ||
1363 | } | ||
1364 | |||
1365 | /* Remove the count for the pseudo-symbol 256 from the largest codelength */ | ||
1366 | while (bits[i] == 0) /* find largest codelength still in use */ | ||
1367 | i--; | ||
1368 | bits[i]--; | ||
1369 | |||
1370 | /* Return final symbol counts (only for lengths 0..16) */ | ||
1371 | MEMCOPY(htbl->bits, bits, SIZEOF(htbl->bits)); | ||
1372 | |||
1373 | /* Return a list of the symbols sorted by code length */ | ||
1374 | /* It's not real clear to me why we don't need to consider the codelength | ||
1375 | * changes made above, but the JPEG spec seems to think this works. | ||
1376 | */ | ||
1377 | p = 0; | ||
1378 | for (i = 1; i <= MAX_CLEN; i++) { | ||
1379 | for (j = 0; j <= 255; j++) { | ||
1380 | if (codesize[j] == i) { | ||
1381 | htbl->huffval[p] = (UINT8) j; | ||
1382 | p++; | ||
1383 | } | ||
1384 | } | ||
1385 | } | ||
1386 | |||
1387 | /* Set sent_table FALSE so updated table will be written to JPEG file. */ | ||
1388 | htbl->sent_table = FALSE; | ||
1389 | } | ||
1390 | |||
1391 | |||
1392 | /* | ||
1393 | * Finish up a statistics-gathering pass and create the new Huffman tables. | ||
1394 | */ | ||
1395 | |||
1396 | METHODDEF(void) | ||
1397 | finish_pass_gather (j_compress_ptr cinfo) | ||
1398 | { | ||
1399 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
1400 | int ci, tbl; | ||
1401 | jpeg_component_info * compptr; | ||
1402 | JHUFF_TBL **htblptr; | ||
1403 | boolean did_dc[NUM_HUFF_TBLS]; | ||
1404 | boolean did_ac[NUM_HUFF_TBLS]; | ||
1405 | |||
1406 | /* It's important not to apply jpeg_gen_optimal_table more than once | ||
1407 | * per table, because it clobbers the input frequency counts! | ||
1408 | */ | ||
1409 | if (cinfo->progressive_mode) | ||
1410 | /* Flush out buffered data (all we care about is counting the EOB symbol) */ | ||
1411 | emit_eobrun(entropy); | ||
1412 | |||
1413 | MEMZERO(did_dc, SIZEOF(did_dc)); | ||
1414 | MEMZERO(did_ac, SIZEOF(did_ac)); | ||
1415 | |||
1416 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | ||
1417 | compptr = cinfo->cur_comp_info[ci]; | ||
1418 | /* DC needs no table for refinement scan */ | ||
1419 | if (cinfo->Ss == 0 && cinfo->Ah == 0) { | ||
1420 | tbl = compptr->dc_tbl_no; | ||
1421 | if (! did_dc[tbl]) { | ||
1422 | htblptr = & cinfo->dc_huff_tbl_ptrs[tbl]; | ||
1423 | if (*htblptr == NULL) | ||
1424 | *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); | ||
1425 | jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[tbl]); | ||
1426 | did_dc[tbl] = TRUE; | ||
1427 | } | ||
1428 | } | ||
1429 | /* AC needs no table when not present */ | ||
1430 | if (cinfo->Se) { | ||
1431 | tbl = compptr->ac_tbl_no; | ||
1432 | if (! did_ac[tbl]) { | ||
1433 | htblptr = & cinfo->ac_huff_tbl_ptrs[tbl]; | ||
1434 | if (*htblptr == NULL) | ||
1435 | *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); | ||
1436 | jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[tbl]); | ||
1437 | did_ac[tbl] = TRUE; | ||
1438 | } | ||
1439 | } | ||
1440 | } | ||
1441 | } | ||
1442 | |||
1443 | |||
1444 | /* | ||
1445 | * Initialize for a Huffman-compressed scan. | ||
1446 | * If gather_statistics is TRUE, we do not output anything during the scan, | ||
1447 | * just count the Huffman symbols used and generate Huffman code tables. | ||
1448 | */ | ||
1449 | |||
1450 | METHODDEF(void) | ||
1451 | start_pass_huff (j_compress_ptr cinfo, boolean gather_statistics) | ||
1452 | { | ||
1453 | huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; | ||
1454 | int ci, tbl; | ||
1455 | jpeg_component_info * compptr; | ||
1456 | |||
1457 | if (gather_statistics) | ||
1458 | entropy->pub.finish_pass = finish_pass_gather; | ||
1459 | else | ||
1460 | entropy->pub.finish_pass = finish_pass_huff; | ||
1461 | |||
1462 | if (cinfo->progressive_mode) { | ||
1463 | entropy->cinfo = cinfo; | ||
1464 | entropy->gather_statistics = gather_statistics; | ||
1465 | |||
1466 | /* We assume jcmaster.c already validated the scan parameters. */ | ||
1467 | |||
1468 | /* Select execution routine */ | ||
1469 | if (cinfo->Ah == 0) { | ||
1470 | if (cinfo->Ss == 0) | ||
1471 | entropy->pub.encode_mcu = encode_mcu_DC_first; | ||
1472 | else | ||
1473 | entropy->pub.encode_mcu = encode_mcu_AC_first; | ||
1474 | } else { | ||
1475 | if (cinfo->Ss == 0) | ||
1476 | entropy->pub.encode_mcu = encode_mcu_DC_refine; | ||
1477 | else { | ||
1478 | entropy->pub.encode_mcu = encode_mcu_AC_refine; | ||
1479 | /* AC refinement needs a correction bit buffer */ | ||
1480 | if (entropy->bit_buffer == NULL) | ||
1481 | entropy->bit_buffer = (char *) | ||
1482 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | ||
1483 | MAX_CORR_BITS * SIZEOF(char)); | ||
1484 | } | ||
1485 | } | ||
1486 | |||
1487 | /* Initialize AC stuff */ | ||
1488 | entropy->ac_tbl_no = cinfo->cur_comp_info[0]->ac_tbl_no; | ||
1489 | entropy->EOBRUN = 0; | ||
1490 | entropy->BE = 0; | ||
1491 | } else { | ||
1492 | if (gather_statistics) | ||
1493 | entropy->pub.encode_mcu = encode_mcu_gather; | ||
1494 | else | ||
1495 | entropy->pub.encode_mcu = encode_mcu_huff; | ||
1496 | } | ||
1497 | |||
1498 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | ||
1499 | compptr = cinfo->cur_comp_info[ci]; | ||
1500 | /* DC needs no table for refinement scan */ | ||
1501 | if (cinfo->Ss == 0 && cinfo->Ah == 0) { | ||
1502 | tbl = compptr->dc_tbl_no; | ||
1503 | if (gather_statistics) { | ||
1504 | /* Check for invalid table index */ | ||
1505 | /* (make_c_derived_tbl does this in the other path) */ | ||
1506 | if (tbl < 0 || tbl >= NUM_HUFF_TBLS) | ||
1507 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl); | ||
1508 | /* Allocate and zero the statistics tables */ | ||
1509 | /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */ | ||
1510 | if (entropy->dc_count_ptrs[tbl] == NULL) | ||
1511 | entropy->dc_count_ptrs[tbl] = (long *) | ||
1512 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | ||
1513 | 257 * SIZEOF(long)); | ||
1514 | MEMZERO(entropy->dc_count_ptrs[tbl], 257 * SIZEOF(long)); | ||
1515 | } else { | ||
1516 | /* Compute derived values for Huffman tables */ | ||
1517 | /* We may do this more than once for a table, but it's not expensive */ | ||
1518 | jpeg_make_c_derived_tbl(cinfo, TRUE, tbl, | ||
1519 | & entropy->dc_derived_tbls[tbl]); | ||
1520 | } | ||
1521 | /* Initialize DC predictions to 0 */ | ||
1522 | entropy->saved.last_dc_val[ci] = 0; | ||
1523 | } | ||
1524 | /* AC needs no table when not present */ | ||
1525 | if (cinfo->Se) { | ||
1526 | tbl = compptr->ac_tbl_no; | ||
1527 | if (gather_statistics) { | ||
1528 | if (tbl < 0 || tbl >= NUM_HUFF_TBLS) | ||
1529 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl); | ||
1530 | if (entropy->ac_count_ptrs[tbl] == NULL) | ||
1531 | entropy->ac_count_ptrs[tbl] = (long *) | ||
1532 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | ||
1533 | 257 * SIZEOF(long)); | ||
1534 | MEMZERO(entropy->ac_count_ptrs[tbl], 257 * SIZEOF(long)); | ||
1535 | } else { | ||
1536 | jpeg_make_c_derived_tbl(cinfo, FALSE, tbl, | ||
1537 | & entropy->ac_derived_tbls[tbl]); | ||
1538 | } | ||
1539 | } | ||
1540 | } | ||
1541 | |||
1542 | /* Initialize bit buffer to empty */ | ||
1543 | entropy->saved.put_buffer = 0; | ||
1544 | entropy->saved.put_bits = 0; | ||
1545 | |||
1546 | /* Initialize restart stuff */ | ||
1547 | entropy->restarts_to_go = cinfo->restart_interval; | ||
1548 | entropy->next_restart_num = 0; | ||
1549 | } | ||
1550 | |||
1551 | |||
1552 | /* | ||
1553 | * Module initialization routine for Huffman entropy encoding. | ||
1554 | */ | ||
1555 | |||
1556 | GLOBAL(void) | ||
1557 | jinit_huff_encoder (j_compress_ptr cinfo) | ||
1558 | { | ||
1559 | huff_entropy_ptr entropy; | ||
1560 | int i; | ||
1561 | |||
1562 | entropy = (huff_entropy_ptr) | ||
1563 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | ||
1564 | SIZEOF(huff_entropy_encoder)); | ||
1565 | cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; | ||
1566 | entropy->pub.start_pass = start_pass_huff; | ||
1567 | |||
1568 | /* Mark tables unallocated */ | ||
1569 | for (i = 0; i < NUM_HUFF_TBLS; i++) { | ||
1570 | entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; | ||
1571 | entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL; | ||
1572 | } | ||
1573 | |||
1574 | if (cinfo->progressive_mode) | ||
1575 | entropy->bit_buffer = NULL; /* needed only in AC refinement scan */ | ||
1576 | } | ||