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Diffstat (limited to 'apps/plugins/imageviewer/jpeg/jpeg_decoder.c')
-rw-r--r-- | apps/plugins/imageviewer/jpeg/jpeg_decoder.c | 1538 |
1 files changed, 1538 insertions, 0 deletions
diff --git a/apps/plugins/imageviewer/jpeg/jpeg_decoder.c b/apps/plugins/imageviewer/jpeg/jpeg_decoder.c new file mode 100644 index 0000000000..c90bff87a4 --- /dev/null +++ b/apps/plugins/imageviewer/jpeg/jpeg_decoder.c | |||
@@ -0,0 +1,1538 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * JPEG image viewer | ||
11 | * (This is a real mess if it has to be coded in one single C file) | ||
12 | * | ||
13 | * File scrolling addition (C) 2005 Alexander Spyridakis | ||
14 | * Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon | ||
15 | * Heavily borrowed from the IJG implementation (C) Thomas G. Lane | ||
16 | * Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding JPEGclub.org | ||
17 | * | ||
18 | * This program is free software; you can redistribute it and/or | ||
19 | * modify it under the terms of the GNU General Public License | ||
20 | * as published by the Free Software Foundation; either version 2 | ||
21 | * of the License, or (at your option) any later version. | ||
22 | * | ||
23 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
24 | * KIND, either express or implied. | ||
25 | * | ||
26 | ****************************************************************************/ | ||
27 | |||
28 | #include "plugin.h" | ||
29 | |||
30 | #include "jpeg_decoder.h" | ||
31 | |||
32 | /* for portability of below JPEG code */ | ||
33 | #define MEMSET(p,v,c) rb->memset(p,v,c) | ||
34 | #define MEMCPY(d,s,c) rb->memcpy(d,s,c) | ||
35 | #define INLINE static inline | ||
36 | #define ENDIAN_SWAP16(n) n /* only for poor little endian machines */ | ||
37 | |||
38 | /**************** begin JPEG code ********************/ | ||
39 | |||
40 | INLINE unsigned range_limit(int value) | ||
41 | { | ||
42 | #if CONFIG_CPU == SH7034 | ||
43 | unsigned tmp; | ||
44 | asm ( /* Note: Uses knowledge that only low byte of result is used */ | ||
45 | "mov #-128,%[t] \n" | ||
46 | "sub %[t],%[v] \n" /* value -= -128; equals value += 128; */ | ||
47 | "extu.b %[v],%[t] \n" | ||
48 | "cmp/eq %[v],%[t] \n" /* low byte == whole number ? */ | ||
49 | "bt 1f \n" /* yes: no overflow */ | ||
50 | "cmp/pz %[v] \n" /* overflow: positive? */ | ||
51 | "subc %[v],%[v] \n" /* %[r] now either 0 or 0xffffffff */ | ||
52 | "1: \n" | ||
53 | : /* outputs */ | ||
54 | [v]"+r"(value), | ||
55 | [t]"=&r"(tmp) | ||
56 | ); | ||
57 | return value; | ||
58 | #elif defined(CPU_COLDFIRE) | ||
59 | asm ( /* Note: Uses knowledge that only the low byte of the result is used */ | ||
60 | "add.l #128,%[v] \n" /* value += 128; */ | ||
61 | "cmp.l #255,%[v] \n" /* overflow? */ | ||
62 | "bls.b 1f \n" /* no: return value */ | ||
63 | "spl.b %[v] \n" /* yes: set low byte to appropriate boundary */ | ||
64 | "1: \n" | ||
65 | : /* outputs */ | ||
66 | [v]"+d"(value) | ||
67 | ); | ||
68 | return value; | ||
69 | #elif defined(CPU_ARM) | ||
70 | asm ( /* Note: Uses knowledge that only the low byte of the result is used */ | ||
71 | "add %[v], %[v], #128 \n" /* value += 128 */ | ||
72 | "cmp %[v], #255 \n" /* out of range 0..255? */ | ||
73 | "mvnhi %[v], %[v], asr #31 \n" /* yes: set all bits to ~(sign_bit) */ | ||
74 | : /* outputs */ | ||
75 | [v]"+r"(value) | ||
76 | ); | ||
77 | return value; | ||
78 | #else | ||
79 | value += 128; | ||
80 | |||
81 | if ((unsigned)value <= 255) | ||
82 | return value; | ||
83 | |||
84 | if (value < 0) | ||
85 | return 0; | ||
86 | |||
87 | return 255; | ||
88 | #endif | ||
89 | } | ||
90 | |||
91 | /* IDCT implementation */ | ||
92 | |||
93 | |||
94 | #define CONST_BITS 13 | ||
95 | #define PASS1_BITS 2 | ||
96 | |||
97 | |||
98 | /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus | ||
99 | * causing a lot of useless floating-point operations at run time. | ||
100 | * To get around this we use the following pre-calculated constants. | ||
101 | * If you change CONST_BITS you may want to add appropriate values. | ||
102 | * (With a reasonable C compiler, you can just rely on the FIX() macro...) | ||
103 | */ | ||
104 | #define FIX_0_298631336 2446 /* FIX(0.298631336) */ | ||
105 | #define FIX_0_390180644 3196 /* FIX(0.390180644) */ | ||
106 | #define FIX_0_541196100 4433 /* FIX(0.541196100) */ | ||
107 | #define FIX_0_765366865 6270 /* FIX(0.765366865) */ | ||
108 | #define FIX_0_899976223 7373 /* FIX(0.899976223) */ | ||
109 | #define FIX_1_175875602 9633 /* FIX(1.175875602) */ | ||
110 | #define FIX_1_501321110 12299 /* FIX(1.501321110) */ | ||
111 | #define FIX_1_847759065 15137 /* FIX(1.847759065) */ | ||
112 | #define FIX_1_961570560 16069 /* FIX(1.961570560) */ | ||
113 | #define FIX_2_053119869 16819 /* FIX(2.053119869) */ | ||
114 | #define FIX_2_562915447 20995 /* FIX(2.562915447) */ | ||
115 | #define FIX_3_072711026 25172 /* FIX(3.072711026) */ | ||
116 | |||
117 | |||
118 | |||
119 | /* Multiply an long variable by an long constant to yield an long result. | ||
120 | * For 8-bit samples with the recommended scaling, all the variable | ||
121 | * and constant values involved are no more than 16 bits wide, so a | ||
122 | * 16x16->32 bit multiply can be used instead of a full 32x32 multiply. | ||
123 | * For 12-bit samples, a full 32-bit multiplication will be needed. | ||
124 | */ | ||
125 | #define MULTIPLY16(var,const) (((short) (var)) * ((short) (const))) | ||
126 | |||
127 | |||
128 | /* Dequantize a coefficient by multiplying it by the multiplier-table | ||
129 | * entry; produce an int result. In this module, both inputs and result | ||
130 | * are 16 bits or less, so either int or short multiply will work. | ||
131 | */ | ||
132 | /* #define DEQUANTIZE(coef,quantval) (((int) (coef)) * (quantval)) */ | ||
133 | #define DEQUANTIZE MULTIPLY16 | ||
134 | |||
135 | /* Descale and correctly round an int value that's scaled by N bits. | ||
136 | * We assume RIGHT_SHIFT rounds towards minus infinity, so adding | ||
137 | * the fudge factor is correct for either sign of X. | ||
138 | */ | ||
139 | #define DESCALE(x,n) (((x) + (1l << ((n)-1))) >> (n)) | ||
140 | |||
141 | |||
142 | |||
143 | /* | ||
144 | * Perform dequantization and inverse DCT on one block of coefficients, | ||
145 | * producing a reduced-size 1x1 output block. | ||
146 | */ | ||
147 | void idct1x1(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line) | ||
148 | { | ||
149 | (void)skip_line; /* unused */ | ||
150 | *p_byte = range_limit(inptr[0] * quantptr[0] >> 3); | ||
151 | } | ||
152 | |||
153 | |||
154 | |||
155 | /* | ||
156 | * Perform dequantization and inverse DCT on one block of coefficients, | ||
157 | * producing a reduced-size 2x2 output block. | ||
158 | */ | ||
159 | void idct2x2(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line) | ||
160 | { | ||
161 | int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5; | ||
162 | unsigned char* outptr; | ||
163 | |||
164 | /* Pass 1: process columns from input, store into work array. */ | ||
165 | |||
166 | /* Column 0 */ | ||
167 | tmp4 = DEQUANTIZE(inptr[8*0], quantptr[8*0]); | ||
168 | tmp5 = DEQUANTIZE(inptr[8*1], quantptr[8*1]); | ||
169 | |||
170 | tmp0 = tmp4 + tmp5; | ||
171 | tmp2 = tmp4 - tmp5; | ||
172 | |||
173 | /* Column 1 */ | ||
174 | tmp4 = DEQUANTIZE(inptr[8*0+1], quantptr[8*0+1]); | ||
175 | tmp5 = DEQUANTIZE(inptr[8*1+1], quantptr[8*1+1]); | ||
176 | |||
177 | tmp1 = tmp4 + tmp5; | ||
178 | tmp3 = tmp4 - tmp5; | ||
179 | |||
180 | /* Pass 2: process 2 rows, store into output array. */ | ||
181 | |||
182 | /* Row 0 */ | ||
183 | outptr = p_byte; | ||
184 | |||
185 | outptr[0] = range_limit((int) DESCALE(tmp0 + tmp1, 3)); | ||
186 | outptr[1] = range_limit((int) DESCALE(tmp0 - tmp1, 3)); | ||
187 | |||
188 | /* Row 1 */ | ||
189 | outptr = p_byte + skip_line; | ||
190 | |||
191 | outptr[0] = range_limit((int) DESCALE(tmp2 + tmp3, 3)); | ||
192 | outptr[1] = range_limit((int) DESCALE(tmp2 - tmp3, 3)); | ||
193 | } | ||
194 | |||
195 | |||
196 | |||
197 | /* | ||
198 | * Perform dequantization and inverse DCT on one block of coefficients, | ||
199 | * producing a reduced-size 4x4 output block. | ||
200 | */ | ||
201 | void idct4x4(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line) | ||
202 | { | ||
203 | int tmp0, tmp2, tmp10, tmp12; | ||
204 | int z1, z2, z3; | ||
205 | int * wsptr; | ||
206 | unsigned char* outptr; | ||
207 | int ctr; | ||
208 | int workspace[4*4]; /* buffers data between passes */ | ||
209 | |||
210 | /* Pass 1: process columns from input, store into work array. */ | ||
211 | |||
212 | wsptr = workspace; | ||
213 | for (ctr = 0; ctr < 4; ctr++, inptr++, quantptr++, wsptr++) | ||
214 | { | ||
215 | /* Even part */ | ||
216 | |||
217 | tmp0 = DEQUANTIZE(inptr[8*0], quantptr[8*0]); | ||
218 | tmp2 = DEQUANTIZE(inptr[8*2], quantptr[8*2]); | ||
219 | |||
220 | tmp10 = (tmp0 + tmp2) << PASS1_BITS; | ||
221 | tmp12 = (tmp0 - tmp2) << PASS1_BITS; | ||
222 | |||
223 | /* Odd part */ | ||
224 | /* Same rotation as in the even part of the 8x8 LL&M IDCT */ | ||
225 | |||
226 | z2 = DEQUANTIZE(inptr[8*1], quantptr[8*1]); | ||
227 | z3 = DEQUANTIZE(inptr[8*3], quantptr[8*3]); | ||
228 | |||
229 | z1 = MULTIPLY16(z2 + z3, FIX_0_541196100); | ||
230 | tmp0 = DESCALE(z1 + MULTIPLY16(z3, - FIX_1_847759065), CONST_BITS-PASS1_BITS); | ||
231 | tmp2 = DESCALE(z1 + MULTIPLY16(z2, FIX_0_765366865), CONST_BITS-PASS1_BITS); | ||
232 | |||
233 | /* Final output stage */ | ||
234 | |||
235 | wsptr[4*0] = (int) (tmp10 + tmp2); | ||
236 | wsptr[4*3] = (int) (tmp10 - tmp2); | ||
237 | wsptr[4*1] = (int) (tmp12 + tmp0); | ||
238 | wsptr[4*2] = (int) (tmp12 - tmp0); | ||
239 | } | ||
240 | |||
241 | /* Pass 2: process 4 rows from work array, store into output array. */ | ||
242 | |||
243 | wsptr = workspace; | ||
244 | for (ctr = 0; ctr < 4; ctr++) | ||
245 | { | ||
246 | outptr = p_byte + (ctr*skip_line); | ||
247 | /* Even part */ | ||
248 | |||
249 | tmp0 = (int) wsptr[0]; | ||
250 | tmp2 = (int) wsptr[2]; | ||
251 | |||
252 | tmp10 = (tmp0 + tmp2) << CONST_BITS; | ||
253 | tmp12 = (tmp0 - tmp2) << CONST_BITS; | ||
254 | |||
255 | /* Odd part */ | ||
256 | /* Same rotation as in the even part of the 8x8 LL&M IDCT */ | ||
257 | |||
258 | z2 = (int) wsptr[1]; | ||
259 | z3 = (int) wsptr[3]; | ||
260 | |||
261 | z1 = MULTIPLY16(z2 + z3, FIX_0_541196100); | ||
262 | tmp0 = z1 + MULTIPLY16(z3, - FIX_1_847759065); | ||
263 | tmp2 = z1 + MULTIPLY16(z2, FIX_0_765366865); | ||
264 | |||
265 | /* Final output stage */ | ||
266 | |||
267 | outptr[0] = range_limit((int) DESCALE(tmp10 + tmp2, | ||
268 | CONST_BITS+PASS1_BITS+3)); | ||
269 | outptr[3] = range_limit((int) DESCALE(tmp10 - tmp2, | ||
270 | CONST_BITS+PASS1_BITS+3)); | ||
271 | outptr[1] = range_limit((int) DESCALE(tmp12 + tmp0, | ||
272 | CONST_BITS+PASS1_BITS+3)); | ||
273 | outptr[2] = range_limit((int) DESCALE(tmp12 - tmp0, | ||
274 | CONST_BITS+PASS1_BITS+3)); | ||
275 | |||
276 | wsptr += 4; /* advance pointer to next row */ | ||
277 | } | ||
278 | } | ||
279 | |||
280 | |||
281 | |||
282 | /* | ||
283 | * Perform dequantization and inverse DCT on one block of coefficients. | ||
284 | */ | ||
285 | void idct8x8(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line) | ||
286 | { | ||
287 | long tmp0, tmp1, tmp2, tmp3; | ||
288 | long tmp10, tmp11, tmp12, tmp13; | ||
289 | long z1, z2, z3, z4, z5; | ||
290 | int * wsptr; | ||
291 | unsigned char* outptr; | ||
292 | int ctr; | ||
293 | int workspace[64]; /* buffers data between passes */ | ||
294 | |||
295 | /* Pass 1: process columns from input, store into work array. */ | ||
296 | /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ | ||
297 | /* furthermore, we scale the results by 2**PASS1_BITS. */ | ||
298 | |||
299 | wsptr = workspace; | ||
300 | for (ctr = 8; ctr > 0; ctr--) | ||
301 | { | ||
302 | /* Due to quantization, we will usually find that many of the input | ||
303 | * coefficients are zero, especially the AC terms. We can exploit this | ||
304 | * by short-circuiting the IDCT calculation for any column in which all | ||
305 | * the AC terms are zero. In that case each output is equal to the | ||
306 | * DC coefficient (with scale factor as needed). | ||
307 | * With typical images and quantization tables, half or more of the | ||
308 | * column DCT calculations can be simplified this way. | ||
309 | */ | ||
310 | |||
311 | if ((inptr[8*1] | inptr[8*2] | inptr[8*3] | ||
312 | | inptr[8*4] | inptr[8*5] | inptr[8*6] | inptr[8*7]) == 0) | ||
313 | { | ||
314 | /* AC terms all zero */ | ||
315 | int dcval = DEQUANTIZE(inptr[8*0], quantptr[8*0]) << PASS1_BITS; | ||
316 | |||
317 | wsptr[8*0] = wsptr[8*1] = wsptr[8*2] = wsptr[8*3] = wsptr[8*4] | ||
318 | = wsptr[8*5] = wsptr[8*6] = wsptr[8*7] = dcval; | ||
319 | inptr++; /* advance pointers to next column */ | ||
320 | quantptr++; | ||
321 | wsptr++; | ||
322 | continue; | ||
323 | } | ||
324 | |||
325 | /* Even part: reverse the even part of the forward DCT. */ | ||
326 | /* The rotator is sqrt(2)*c(-6). */ | ||
327 | |||
328 | z2 = DEQUANTIZE(inptr[8*2], quantptr[8*2]); | ||
329 | z3 = DEQUANTIZE(inptr[8*6], quantptr[8*6]); | ||
330 | |||
331 | z1 = MULTIPLY16(z2 + z3, FIX_0_541196100); | ||
332 | tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065); | ||
333 | tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865); | ||
334 | |||
335 | z2 = DEQUANTIZE(inptr[8*0], quantptr[8*0]); | ||
336 | z3 = DEQUANTIZE(inptr[8*4], quantptr[8*4]); | ||
337 | |||
338 | tmp0 = (z2 + z3) << CONST_BITS; | ||
339 | tmp1 = (z2 - z3) << CONST_BITS; | ||
340 | |||
341 | tmp10 = tmp0 + tmp3; | ||
342 | tmp13 = tmp0 - tmp3; | ||
343 | tmp11 = tmp1 + tmp2; | ||
344 | tmp12 = tmp1 - tmp2; | ||
345 | |||
346 | /* Odd part per figure 8; the matrix is unitary and hence its | ||
347 | transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */ | ||
348 | |||
349 | tmp0 = DEQUANTIZE(inptr[8*7], quantptr[8*7]); | ||
350 | tmp1 = DEQUANTIZE(inptr[8*5], quantptr[8*5]); | ||
351 | tmp2 = DEQUANTIZE(inptr[8*3], quantptr[8*3]); | ||
352 | tmp3 = DEQUANTIZE(inptr[8*1], quantptr[8*1]); | ||
353 | |||
354 | z1 = tmp0 + tmp3; | ||
355 | z2 = tmp1 + tmp2; | ||
356 | z3 = tmp0 + tmp2; | ||
357 | z4 = tmp1 + tmp3; | ||
358 | z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */ | ||
359 | |||
360 | tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ | ||
361 | tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ | ||
362 | tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ | ||
363 | tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ | ||
364 | z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ | ||
365 | z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ | ||
366 | z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ | ||
367 | z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ | ||
368 | |||
369 | z3 += z5; | ||
370 | z4 += z5; | ||
371 | |||
372 | tmp0 += z1 + z3; | ||
373 | tmp1 += z2 + z4; | ||
374 | tmp2 += z2 + z3; | ||
375 | tmp3 += z1 + z4; | ||
376 | |||
377 | /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ | ||
378 | |||
379 | wsptr[8*0] = (int) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS); | ||
380 | wsptr[8*7] = (int) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS); | ||
381 | wsptr[8*1] = (int) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS); | ||
382 | wsptr[8*6] = (int) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS); | ||
383 | wsptr[8*2] = (int) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS); | ||
384 | wsptr[8*5] = (int) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS); | ||
385 | wsptr[8*3] = (int) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS); | ||
386 | wsptr[8*4] = (int) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS); | ||
387 | |||
388 | inptr++; /* advance pointers to next column */ | ||
389 | quantptr++; | ||
390 | wsptr++; | ||
391 | } | ||
392 | |||
393 | /* Pass 2: process rows from work array, store into output array. */ | ||
394 | /* Note that we must descale the results by a factor of 8 == 2**3, */ | ||
395 | /* and also undo the PASS1_BITS scaling. */ | ||
396 | |||
397 | wsptr = workspace; | ||
398 | for (ctr = 0; ctr < 8; ctr++) | ||
399 | { | ||
400 | outptr = p_byte + (ctr*skip_line); | ||
401 | /* Rows of zeroes can be exploited in the same way as we did with columns. | ||
402 | * However, the column calculation has created many nonzero AC terms, so | ||
403 | * the simplification applies less often (typically 5% to 10% of the time). | ||
404 | * On machines with very fast multiplication, it's possible that the | ||
405 | * test takes more time than it's worth. In that case this section | ||
406 | * may be commented out. | ||
407 | */ | ||
408 | |||
409 | #ifndef NO_ZERO_ROW_TEST | ||
410 | if ((wsptr[1] | wsptr[2] | wsptr[3] | ||
411 | | wsptr[4] | wsptr[5] | wsptr[6] | wsptr[7]) == 0) | ||
412 | { | ||
413 | /* AC terms all zero */ | ||
414 | unsigned char dcval = range_limit((int) DESCALE((long) wsptr[0], | ||
415 | PASS1_BITS+3)); | ||
416 | |||
417 | outptr[0] = dcval; | ||
418 | outptr[1] = dcval; | ||
419 | outptr[2] = dcval; | ||
420 | outptr[3] = dcval; | ||
421 | outptr[4] = dcval; | ||
422 | outptr[5] = dcval; | ||
423 | outptr[6] = dcval; | ||
424 | outptr[7] = dcval; | ||
425 | |||
426 | wsptr += 8; /* advance pointer to next row */ | ||
427 | continue; | ||
428 | } | ||
429 | #endif | ||
430 | |||
431 | /* Even part: reverse the even part of the forward DCT. */ | ||
432 | /* The rotator is sqrt(2)*c(-6). */ | ||
433 | |||
434 | z2 = (long) wsptr[2]; | ||
435 | z3 = (long) wsptr[6]; | ||
436 | |||
437 | z1 = MULTIPLY16(z2 + z3, FIX_0_541196100); | ||
438 | tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065); | ||
439 | tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865); | ||
440 | |||
441 | tmp0 = ((long) wsptr[0] + (long) wsptr[4]) << CONST_BITS; | ||
442 | tmp1 = ((long) wsptr[0] - (long) wsptr[4]) << CONST_BITS; | ||
443 | |||
444 | tmp10 = tmp0 + tmp3; | ||
445 | tmp13 = tmp0 - tmp3; | ||
446 | tmp11 = tmp1 + tmp2; | ||
447 | tmp12 = tmp1 - tmp2; | ||
448 | |||
449 | /* Odd part per figure 8; the matrix is unitary and hence its | ||
450 | * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */ | ||
451 | |||
452 | tmp0 = (long) wsptr[7]; | ||
453 | tmp1 = (long) wsptr[5]; | ||
454 | tmp2 = (long) wsptr[3]; | ||
455 | tmp3 = (long) wsptr[1]; | ||
456 | |||
457 | z1 = tmp0 + tmp3; | ||
458 | z2 = tmp1 + tmp2; | ||
459 | z3 = tmp0 + tmp2; | ||
460 | z4 = tmp1 + tmp3; | ||
461 | z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */ | ||
462 | |||
463 | tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ | ||
464 | tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ | ||
465 | tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ | ||
466 | tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ | ||
467 | z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ | ||
468 | z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ | ||
469 | z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ | ||
470 | z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ | ||
471 | |||
472 | z3 += z5; | ||
473 | z4 += z5; | ||
474 | |||
475 | tmp0 += z1 + z3; | ||
476 | tmp1 += z2 + z4; | ||
477 | tmp2 += z2 + z3; | ||
478 | tmp3 += z1 + z4; | ||
479 | |||
480 | /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ | ||
481 | |||
482 | outptr[0] = range_limit((int) DESCALE(tmp10 + tmp3, | ||
483 | CONST_BITS+PASS1_BITS+3)); | ||
484 | outptr[7] = range_limit((int) DESCALE(tmp10 - tmp3, | ||
485 | CONST_BITS+PASS1_BITS+3)); | ||
486 | outptr[1] = range_limit((int) DESCALE(tmp11 + tmp2, | ||
487 | CONST_BITS+PASS1_BITS+3)); | ||
488 | outptr[6] = range_limit((int) DESCALE(tmp11 - tmp2, | ||
489 | CONST_BITS+PASS1_BITS+3)); | ||
490 | outptr[2] = range_limit((int) DESCALE(tmp12 + tmp1, | ||
491 | CONST_BITS+PASS1_BITS+3)); | ||
492 | outptr[5] = range_limit((int) DESCALE(tmp12 - tmp1, | ||
493 | CONST_BITS+PASS1_BITS+3)); | ||
494 | outptr[3] = range_limit((int) DESCALE(tmp13 + tmp0, | ||
495 | CONST_BITS+PASS1_BITS+3)); | ||
496 | outptr[4] = range_limit((int) DESCALE(tmp13 - tmp0, | ||
497 | CONST_BITS+PASS1_BITS+3)); | ||
498 | |||
499 | wsptr += 8; /* advance pointer to next row */ | ||
500 | } | ||
501 | } | ||
502 | |||
503 | |||
504 | |||
505 | /* JPEG decoder implementation */ | ||
506 | |||
507 | /* Preprocess the JPEG JFIF file */ | ||
508 | int process_markers(unsigned char* p_src, long size, struct jpeg* p_jpeg) | ||
509 | { | ||
510 | unsigned char* p_bytes = p_src; | ||
511 | int marker_size; /* variable length of marker segment */ | ||
512 | int i, j, n; | ||
513 | int ret = 0; /* returned flags */ | ||
514 | |||
515 | p_jpeg->p_entropy_end = p_src + size; | ||
516 | |||
517 | while (p_src < p_bytes + size) | ||
518 | { | ||
519 | if (*p_src++ != 0xFF) /* no marker? */ | ||
520 | { | ||
521 | p_src--; /* it's image data, put it back */ | ||
522 | p_jpeg->p_entropy_data = p_src; | ||
523 | break; /* exit marker processing */ | ||
524 | } | ||
525 | |||
526 | switch (*p_src++) | ||
527 | { | ||
528 | case 0xFF: /* Fill byte */ | ||
529 | ret |= FILL_FF; | ||
530 | case 0x00: /* Zero stuffed byte - entropy data */ | ||
531 | p_src--; /* put it back */ | ||
532 | continue; | ||
533 | |||
534 | case 0xC0: /* SOF Huff - Baseline DCT */ | ||
535 | { | ||
536 | ret |= SOF0; | ||
537 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
538 | marker_size |= *p_src++; /* Lowbyte */ | ||
539 | n = *p_src++; /* sample precision (= 8 or 12) */ | ||
540 | if (n != 8) | ||
541 | { | ||
542 | return(-1); /* Unsupported sample precision */ | ||
543 | } | ||
544 | p_jpeg->y_size = *p_src++ << 8; /* Highbyte */ | ||
545 | p_jpeg->y_size |= *p_src++; /* Lowbyte */ | ||
546 | p_jpeg->x_size = *p_src++ << 8; /* Highbyte */ | ||
547 | p_jpeg->x_size |= *p_src++; /* Lowbyte */ | ||
548 | |||
549 | n = (marker_size-2-6)/3; | ||
550 | if (*p_src++ != n || (n != 1 && n != 3)) | ||
551 | { | ||
552 | return(-2); /* Unsupported SOF0 component specification */ | ||
553 | } | ||
554 | for (i=0; i<n; i++) | ||
555 | { | ||
556 | p_jpeg->frameheader[i].ID = *p_src++; /* Component info */ | ||
557 | p_jpeg->frameheader[i].horizontal_sampling = *p_src >> 4; | ||
558 | p_jpeg->frameheader[i].vertical_sampling = *p_src++ & 0x0F; | ||
559 | p_jpeg->frameheader[i].quanttable_select = *p_src++; | ||
560 | if (p_jpeg->frameheader[i].horizontal_sampling > 2 | ||
561 | || p_jpeg->frameheader[i].vertical_sampling > 2) | ||
562 | return -3; /* Unsupported SOF0 subsampling */ | ||
563 | } | ||
564 | p_jpeg->blocks = n; | ||
565 | } | ||
566 | break; | ||
567 | |||
568 | case 0xC1: /* SOF Huff - Extended sequential DCT*/ | ||
569 | case 0xC2: /* SOF Huff - Progressive DCT*/ | ||
570 | case 0xC3: /* SOF Huff - Spatial (sequential) lossless*/ | ||
571 | case 0xC5: /* SOF Huff - Differential sequential DCT*/ | ||
572 | case 0xC6: /* SOF Huff - Differential progressive DCT*/ | ||
573 | case 0xC7: /* SOF Huff - Differential spatial*/ | ||
574 | case 0xC8: /* SOF Arith - Reserved for JPEG extensions*/ | ||
575 | case 0xC9: /* SOF Arith - Extended sequential DCT*/ | ||
576 | case 0xCA: /* SOF Arith - Progressive DCT*/ | ||
577 | case 0xCB: /* SOF Arith - Spatial (sequential) lossless*/ | ||
578 | case 0xCD: /* SOF Arith - Differential sequential DCT*/ | ||
579 | case 0xCE: /* SOF Arith - Differential progressive DCT*/ | ||
580 | case 0xCF: /* SOF Arith - Differential spatial*/ | ||
581 | { | ||
582 | return (-4); /* other DCT model than baseline not implemented */ | ||
583 | } | ||
584 | |||
585 | case 0xC4: /* Define Huffman Table(s) */ | ||
586 | { | ||
587 | unsigned char* p_temp; | ||
588 | |||
589 | ret |= DHT; | ||
590 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
591 | marker_size |= *p_src++; /* Lowbyte */ | ||
592 | |||
593 | p_temp = p_src; | ||
594 | while (p_src < p_temp+marker_size-2-17) /* another table */ | ||
595 | { | ||
596 | int sum = 0; | ||
597 | i = *p_src & 0x0F; /* table index */ | ||
598 | if (i > 1) | ||
599 | { | ||
600 | return (-5); /* Huffman table index out of range */ | ||
601 | } | ||
602 | else if (*p_src++ & 0xF0) /* AC table */ | ||
603 | { | ||
604 | for (j=0; j<16; j++) | ||
605 | { | ||
606 | sum += *p_src; | ||
607 | p_jpeg->hufftable[i].huffmancodes_ac[j] = *p_src++; | ||
608 | } | ||
609 | if(16 + sum > AC_LEN) | ||
610 | return -10; /* longer than allowed */ | ||
611 | |||
612 | for (; j < 16 + sum; j++) | ||
613 | p_jpeg->hufftable[i].huffmancodes_ac[j] = *p_src++; | ||
614 | } | ||
615 | else /* DC table */ | ||
616 | { | ||
617 | for (j=0; j<16; j++) | ||
618 | { | ||
619 | sum += *p_src; | ||
620 | p_jpeg->hufftable[i].huffmancodes_dc[j] = *p_src++; | ||
621 | } | ||
622 | if(16 + sum > DC_LEN) | ||
623 | return -11; /* longer than allowed */ | ||
624 | |||
625 | for (; j < 16 + sum; j++) | ||
626 | p_jpeg->hufftable[i].huffmancodes_dc[j] = *p_src++; | ||
627 | } | ||
628 | } /* while */ | ||
629 | p_src = p_temp+marker_size - 2; /* skip possible residue */ | ||
630 | } | ||
631 | break; | ||
632 | |||
633 | case 0xCC: /* Define Arithmetic coding conditioning(s) */ | ||
634 | return(-6); /* Arithmetic coding not supported */ | ||
635 | |||
636 | case 0xD8: /* Start of Image */ | ||
637 | case 0xD9: /* End of Image */ | ||
638 | case 0x01: /* for temp private use arith code */ | ||
639 | break; /* skip parameterless marker */ | ||
640 | |||
641 | |||
642 | case 0xDA: /* Start of Scan */ | ||
643 | { | ||
644 | ret |= SOS; | ||
645 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
646 | marker_size |= *p_src++; /* Lowbyte */ | ||
647 | |||
648 | n = (marker_size-2-1-3)/2; | ||
649 | if (*p_src++ != n || (n != 1 && n != 3)) | ||
650 | { | ||
651 | return (-7); /* Unsupported SOS component specification */ | ||
652 | } | ||
653 | for (i=0; i<n; i++) | ||
654 | { | ||
655 | p_jpeg->scanheader[i].ID = *p_src++; | ||
656 | p_jpeg->scanheader[i].DC_select = *p_src >> 4; | ||
657 | p_jpeg->scanheader[i].AC_select = *p_src++ & 0x0F; | ||
658 | } | ||
659 | p_src += 3; /* skip spectral information */ | ||
660 | } | ||
661 | break; | ||
662 | |||
663 | case 0xDB: /* Define quantization Table(s) */ | ||
664 | { | ||
665 | ret |= DQT; | ||
666 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
667 | marker_size |= *p_src++; /* Lowbyte */ | ||
668 | n = (marker_size-2)/(QUANT_TABLE_LENGTH+1); /* # of tables */ | ||
669 | for (i=0; i<n; i++) | ||
670 | { | ||
671 | int id = *p_src++; /* ID */ | ||
672 | if (id >= 4) | ||
673 | { | ||
674 | return (-8); /* Unsupported quantization table */ | ||
675 | } | ||
676 | /* Read Quantisation table: */ | ||
677 | for (j=0; j<QUANT_TABLE_LENGTH; j++) | ||
678 | p_jpeg->quanttable[id][j] = *p_src++; | ||
679 | } | ||
680 | } | ||
681 | break; | ||
682 | |||
683 | case 0xDD: /* Define Restart Interval */ | ||
684 | { | ||
685 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
686 | marker_size |= *p_src++; /* Lowbyte */ | ||
687 | p_jpeg->restart_interval = *p_src++ << 8; /* Highbyte */ | ||
688 | p_jpeg->restart_interval |= *p_src++; /* Lowbyte */ | ||
689 | p_src += marker_size-4; /* skip segment */ | ||
690 | } | ||
691 | break; | ||
692 | |||
693 | case 0xDC: /* Define Number of Lines */ | ||
694 | case 0xDE: /* Define Hierarchical progression */ | ||
695 | case 0xDF: /* Expand Reference Component(s) */ | ||
696 | case 0xE0: /* Application Field 0*/ | ||
697 | case 0xE1: /* Application Field 1*/ | ||
698 | case 0xE2: /* Application Field 2*/ | ||
699 | case 0xE3: /* Application Field 3*/ | ||
700 | case 0xE4: /* Application Field 4*/ | ||
701 | case 0xE5: /* Application Field 5*/ | ||
702 | case 0xE6: /* Application Field 6*/ | ||
703 | case 0xE7: /* Application Field 7*/ | ||
704 | case 0xE8: /* Application Field 8*/ | ||
705 | case 0xE9: /* Application Field 9*/ | ||
706 | case 0xEA: /* Application Field 10*/ | ||
707 | case 0xEB: /* Application Field 11*/ | ||
708 | case 0xEC: /* Application Field 12*/ | ||
709 | case 0xED: /* Application Field 13*/ | ||
710 | case 0xEE: /* Application Field 14*/ | ||
711 | case 0xEF: /* Application Field 15*/ | ||
712 | case 0xFE: /* Comment */ | ||
713 | { | ||
714 | marker_size = *p_src++ << 8; /* Highbyte */ | ||
715 | marker_size |= *p_src++; /* Lowbyte */ | ||
716 | p_src += marker_size-2; /* skip segment */ | ||
717 | } | ||
718 | break; | ||
719 | |||
720 | case 0xF0: /* Reserved for JPEG extensions */ | ||
721 | case 0xF1: /* Reserved for JPEG extensions */ | ||
722 | case 0xF2: /* Reserved for JPEG extensions */ | ||
723 | case 0xF3: /* Reserved for JPEG extensions */ | ||
724 | case 0xF4: /* Reserved for JPEG extensions */ | ||
725 | case 0xF5: /* Reserved for JPEG extensions */ | ||
726 | case 0xF6: /* Reserved for JPEG extensions */ | ||
727 | case 0xF7: /* Reserved for JPEG extensions */ | ||
728 | case 0xF8: /* Reserved for JPEG extensions */ | ||
729 | case 0xF9: /* Reserved for JPEG extensions */ | ||
730 | case 0xFA: /* Reserved for JPEG extensions */ | ||
731 | case 0xFB: /* Reserved for JPEG extensions */ | ||
732 | case 0xFC: /* Reserved for JPEG extensions */ | ||
733 | case 0xFD: /* Reserved for JPEG extensions */ | ||
734 | case 0x02: /* Reserved */ | ||
735 | default: | ||
736 | return (-9); /* Unknown marker */ | ||
737 | } /* switch */ | ||
738 | } /* while */ | ||
739 | |||
740 | return (ret); /* return flags with seen markers */ | ||
741 | } | ||
742 | |||
743 | |||
744 | void default_huff_tbl(struct jpeg* p_jpeg) | ||
745 | { | ||
746 | static const struct huffman_table luma_table = | ||
747 | { | ||
748 | { | ||
749 | 0x00,0x01,0x05,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,0x00, | ||
750 | 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B | ||
751 | }, | ||
752 | { | ||
753 | 0x00,0x02,0x01,0x03,0x03,0x02,0x04,0x03,0x05,0x05,0x04,0x04,0x00,0x00,0x01,0x7D, | ||
754 | 0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07, | ||
755 | 0x22,0x71,0x14,0x32,0x81,0x91,0xA1,0x08,0x23,0x42,0xB1,0xC1,0x15,0x52,0xD1,0xF0, | ||
756 | 0x24,0x33,0x62,0x72,0x82,0x09,0x0A,0x16,0x17,0x18,0x19,0x1A,0x25,0x26,0x27,0x28, | ||
757 | 0x29,0x2A,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49, | ||
758 | 0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,0x69, | ||
759 | 0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x83,0x84,0x85,0x86,0x87,0x88,0x89, | ||
760 | 0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7, | ||
761 | 0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,0xC3,0xC4,0xC5, | ||
762 | 0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xE1,0xE2, | ||
763 | 0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8, | ||
764 | 0xF9,0xFA | ||
765 | } | ||
766 | }; | ||
767 | |||
768 | static const struct huffman_table chroma_table = | ||
769 | { | ||
770 | { | ||
771 | 0x00,0x03,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00, | ||
772 | 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B | ||
773 | }, | ||
774 | { | ||
775 | 0x00,0x02,0x01,0x02,0x04,0x04,0x03,0x04,0x07,0x05,0x04,0x04,0x00,0x01,0x02,0x77, | ||
776 | 0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71, | ||
777 | 0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,0xA1,0xB1,0xC1,0x09,0x23,0x33,0x52,0xF0, | ||
778 | 0x15,0x62,0x72,0xD1,0x0A,0x16,0x24,0x34,0xE1,0x25,0xF1,0x17,0x18,0x19,0x1A,0x26, | ||
779 | 0x27,0x28,0x29,0x2A,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48, | ||
780 | 0x49,0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68, | ||
781 | 0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x82,0x83,0x84,0x85,0x86,0x87, | ||
782 | 0x88,0x89,0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5, | ||
783 | 0xA6,0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,0xC3, | ||
784 | 0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA, | ||
785 | 0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8, | ||
786 | 0xF9,0xFA | ||
787 | } | ||
788 | }; | ||
789 | |||
790 | MEMCPY(&p_jpeg->hufftable[0], &luma_table, sizeof(luma_table)); | ||
791 | MEMCPY(&p_jpeg->hufftable[1], &chroma_table, sizeof(chroma_table)); | ||
792 | |||
793 | return; | ||
794 | } | ||
795 | |||
796 | /* Compute the derived values for a Huffman table */ | ||
797 | void fix_huff_tbl(int* htbl, struct derived_tbl* dtbl) | ||
798 | { | ||
799 | int p, i, l, si; | ||
800 | int lookbits, ctr; | ||
801 | char huffsize[257]; | ||
802 | unsigned int huffcode[257]; | ||
803 | unsigned int code; | ||
804 | |||
805 | dtbl->pub = htbl; /* fill in back link */ | ||
806 | |||
807 | /* Figure C.1: make table of Huffman code length for each symbol */ | ||
808 | /* Note that this is in code-length order. */ | ||
809 | |||
810 | p = 0; | ||
811 | for (l = 1; l <= 16; l++) | ||
812 | { /* all possible code length */ | ||
813 | for (i = 1; i <= (int) htbl[l-1]; i++) /* all codes per length */ | ||
814 | huffsize[p++] = (char) l; | ||
815 | } | ||
816 | huffsize[p] = 0; | ||
817 | |||
818 | /* Figure C.2: generate the codes themselves */ | ||
819 | /* Note that this is in code-length order. */ | ||
820 | |||
821 | code = 0; | ||
822 | si = huffsize[0]; | ||
823 | p = 0; | ||
824 | while (huffsize[p]) | ||
825 | { | ||
826 | while (((int) huffsize[p]) == si) | ||
827 | { | ||
828 | huffcode[p++] = code; | ||
829 | code++; | ||
830 | } | ||
831 | code <<= 1; | ||
832 | si++; | ||
833 | } | ||
834 | |||
835 | /* Figure F.15: generate decoding tables for bit-sequential decoding */ | ||
836 | |||
837 | p = 0; | ||
838 | for (l = 1; l <= 16; l++) | ||
839 | { | ||
840 | if (htbl[l-1]) | ||
841 | { | ||
842 | dtbl->valptr[l] = p; /* huffval[] index of 1st symbol of code length l */ | ||
843 | dtbl->mincode[l] = huffcode[p]; /* minimum code of length l */ | ||
844 | p += htbl[l-1]; | ||
845 | dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */ | ||
846 | } | ||
847 | else | ||
848 | { | ||
849 | dtbl->maxcode[l] = -1; /* -1 if no codes of this length */ | ||
850 | } | ||
851 | } | ||
852 | dtbl->maxcode[17] = 0xFFFFFL; /* ensures huff_DECODE terminates */ | ||
853 | |||
854 | /* Compute lookahead tables to speed up decoding. | ||
855 | * First we set all the table entries to 0, indicating "too long"; | ||
856 | * then we iterate through the Huffman codes that are short enough and | ||
857 | * fill in all the entries that correspond to bit sequences starting | ||
858 | * with that code. | ||
859 | */ | ||
860 | |||
861 | MEMSET(dtbl->look_nbits, 0, sizeof(dtbl->look_nbits)); | ||
862 | |||
863 | p = 0; | ||
864 | for (l = 1; l <= HUFF_LOOKAHEAD; l++) | ||
865 | { | ||
866 | for (i = 1; i <= (int) htbl[l-1]; i++, p++) | ||
867 | { | ||
868 | /* l = current code's length, p = its index in huffcode[] & huffval[]. */ | ||
869 | /* Generate left-justified code followed by all possible bit sequences */ | ||
870 | lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l); | ||
871 | for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) | ||
872 | { | ||
873 | dtbl->look_nbits[lookbits] = l; | ||
874 | dtbl->look_sym[lookbits] = htbl[16+p]; | ||
875 | lookbits++; | ||
876 | } | ||
877 | } | ||
878 | } | ||
879 | } | ||
880 | |||
881 | |||
882 | /* zag[i] is the natural-order position of the i'th element of zigzag order. | ||
883 | * If the incoming data is corrupted, decode_mcu could attempt to | ||
884 | * reference values beyond the end of the array. To avoid a wild store, | ||
885 | * we put some extra zeroes after the real entries. | ||
886 | */ | ||
887 | static const int zag[] = | ||
888 | { | ||
889 | 0, 1, 8, 16, 9, 2, 3, 10, | ||
890 | 17, 24, 32, 25, 18, 11, 4, 5, | ||
891 | 12, 19, 26, 33, 40, 48, 41, 34, | ||
892 | 27, 20, 13, 6, 7, 14, 21, 28, | ||
893 | 35, 42, 49, 56, 57, 50, 43, 36, | ||
894 | 29, 22, 15, 23, 30, 37, 44, 51, | ||
895 | 58, 59, 52, 45, 38, 31, 39, 46, | ||
896 | 53, 60, 61, 54, 47, 55, 62, 63, | ||
897 | 0, 0, 0, 0, 0, 0, 0, 0, /* extra entries in case k>63 below */ | ||
898 | 0, 0, 0, 0, 0, 0, 0, 0 | ||
899 | }; | ||
900 | |||
901 | void build_lut(struct jpeg* p_jpeg) | ||
902 | { | ||
903 | int i; | ||
904 | fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_dc, | ||
905 | &p_jpeg->dc_derived_tbls[0]); | ||
906 | fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_ac, | ||
907 | &p_jpeg->ac_derived_tbls[0]); | ||
908 | fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_dc, | ||
909 | &p_jpeg->dc_derived_tbls[1]); | ||
910 | fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_ac, | ||
911 | &p_jpeg->ac_derived_tbls[1]); | ||
912 | |||
913 | /* build the dequantization tables for the IDCT (De-ZiZagged) */ | ||
914 | for (i=0; i<64; i++) | ||
915 | { | ||
916 | p_jpeg->qt_idct[0][zag[i]] = p_jpeg->quanttable[0][i]; | ||
917 | p_jpeg->qt_idct[1][zag[i]] = p_jpeg->quanttable[1][i]; | ||
918 | } | ||
919 | |||
920 | for (i=0; i<4; i++) | ||
921 | p_jpeg->store_pos[i] = i; /* default ordering */ | ||
922 | |||
923 | /* assignments for the decoding of blocks */ | ||
924 | if (p_jpeg->frameheader[0].horizontal_sampling == 2 | ||
925 | && p_jpeg->frameheader[0].vertical_sampling == 1) | ||
926 | { /* 4:2:2 */ | ||
927 | p_jpeg->blocks = 4; | ||
928 | p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16; | ||
929 | p_jpeg->x_phys = p_jpeg->x_mbl * 16; | ||
930 | p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8; | ||
931 | p_jpeg->y_phys = p_jpeg->y_mbl * 8; | ||
932 | p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */ | ||
933 | p_jpeg->mcu_membership[1] = 0; | ||
934 | p_jpeg->mcu_membership[2] = 1; | ||
935 | p_jpeg->mcu_membership[3] = 2; | ||
936 | p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */ | ||
937 | p_jpeg->tab_membership[1] = 0; | ||
938 | p_jpeg->tab_membership[2] = 1; | ||
939 | p_jpeg->tab_membership[3] = 1; | ||
940 | p_jpeg->subsample_x[0] = 1; | ||
941 | p_jpeg->subsample_x[1] = 2; | ||
942 | p_jpeg->subsample_x[2] = 2; | ||
943 | p_jpeg->subsample_y[0] = 1; | ||
944 | p_jpeg->subsample_y[1] = 1; | ||
945 | p_jpeg->subsample_y[2] = 1; | ||
946 | } | ||
947 | if (p_jpeg->frameheader[0].horizontal_sampling == 1 | ||
948 | && p_jpeg->frameheader[0].vertical_sampling == 2) | ||
949 | { /* 4:2:2 vertically subsampled */ | ||
950 | p_jpeg->store_pos[1] = 2; /* block positions are mirrored */ | ||
951 | p_jpeg->store_pos[2] = 1; | ||
952 | p_jpeg->blocks = 4; | ||
953 | p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8; | ||
954 | p_jpeg->x_phys = p_jpeg->x_mbl * 8; | ||
955 | p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16; | ||
956 | p_jpeg->y_phys = p_jpeg->y_mbl * 16; | ||
957 | p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */ | ||
958 | p_jpeg->mcu_membership[1] = 0; | ||
959 | p_jpeg->mcu_membership[2] = 1; | ||
960 | p_jpeg->mcu_membership[3] = 2; | ||
961 | p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */ | ||
962 | p_jpeg->tab_membership[1] = 0; | ||
963 | p_jpeg->tab_membership[2] = 1; | ||
964 | p_jpeg->tab_membership[3] = 1; | ||
965 | p_jpeg->subsample_x[0] = 1; | ||
966 | p_jpeg->subsample_x[1] = 1; | ||
967 | p_jpeg->subsample_x[2] = 1; | ||
968 | p_jpeg->subsample_y[0] = 1; | ||
969 | p_jpeg->subsample_y[1] = 2; | ||
970 | p_jpeg->subsample_y[2] = 2; | ||
971 | } | ||
972 | else if (p_jpeg->frameheader[0].horizontal_sampling == 2 | ||
973 | && p_jpeg->frameheader[0].vertical_sampling == 2) | ||
974 | { /* 4:2:0 */ | ||
975 | p_jpeg->blocks = 6; | ||
976 | p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16; | ||
977 | p_jpeg->x_phys = p_jpeg->x_mbl * 16; | ||
978 | p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16; | ||
979 | p_jpeg->y_phys = p_jpeg->y_mbl * 16; | ||
980 | p_jpeg->mcu_membership[0] = 0; | ||
981 | p_jpeg->mcu_membership[1] = 0; | ||
982 | p_jpeg->mcu_membership[2] = 0; | ||
983 | p_jpeg->mcu_membership[3] = 0; | ||
984 | p_jpeg->mcu_membership[4] = 1; | ||
985 | p_jpeg->mcu_membership[5] = 2; | ||
986 | p_jpeg->tab_membership[0] = 0; | ||
987 | p_jpeg->tab_membership[1] = 0; | ||
988 | p_jpeg->tab_membership[2] = 0; | ||
989 | p_jpeg->tab_membership[3] = 0; | ||
990 | p_jpeg->tab_membership[4] = 1; | ||
991 | p_jpeg->tab_membership[5] = 1; | ||
992 | p_jpeg->subsample_x[0] = 1; | ||
993 | p_jpeg->subsample_x[1] = 2; | ||
994 | p_jpeg->subsample_x[2] = 2; | ||
995 | p_jpeg->subsample_y[0] = 1; | ||
996 | p_jpeg->subsample_y[1] = 2; | ||
997 | p_jpeg->subsample_y[2] = 2; | ||
998 | } | ||
999 | else if (p_jpeg->frameheader[0].horizontal_sampling == 1 | ||
1000 | && p_jpeg->frameheader[0].vertical_sampling == 1) | ||
1001 | { /* 4:4:4 */ | ||
1002 | /* don't overwrite p_jpeg->blocks */ | ||
1003 | p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8; | ||
1004 | p_jpeg->x_phys = p_jpeg->x_mbl * 8; | ||
1005 | p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8; | ||
1006 | p_jpeg->y_phys = p_jpeg->y_mbl * 8; | ||
1007 | p_jpeg->mcu_membership[0] = 0; | ||
1008 | p_jpeg->mcu_membership[1] = 1; | ||
1009 | p_jpeg->mcu_membership[2] = 2; | ||
1010 | p_jpeg->tab_membership[0] = 0; | ||
1011 | p_jpeg->tab_membership[1] = 1; | ||
1012 | p_jpeg->tab_membership[2] = 1; | ||
1013 | p_jpeg->subsample_x[0] = 1; | ||
1014 | p_jpeg->subsample_x[1] = 1; | ||
1015 | p_jpeg->subsample_x[2] = 1; | ||
1016 | p_jpeg->subsample_y[0] = 1; | ||
1017 | p_jpeg->subsample_y[1] = 1; | ||
1018 | p_jpeg->subsample_y[2] = 1; | ||
1019 | } | ||
1020 | else | ||
1021 | { | ||
1022 | /* error */ | ||
1023 | } | ||
1024 | |||
1025 | } | ||
1026 | |||
1027 | |||
1028 | /* | ||
1029 | * These functions/macros provide the in-line portion of bit fetching. | ||
1030 | * Use check_bit_buffer to ensure there are N bits in get_buffer | ||
1031 | * before using get_bits, peek_bits, or drop_bits. | ||
1032 | * check_bit_buffer(state,n,action); | ||
1033 | * Ensure there are N bits in get_buffer; if suspend, take action. | ||
1034 | * val = get_bits(n); | ||
1035 | * Fetch next N bits. | ||
1036 | * val = peek_bits(n); | ||
1037 | * Fetch next N bits without removing them from the buffer. | ||
1038 | * drop_bits(n); | ||
1039 | * Discard next N bits. | ||
1040 | * The value N should be a simple variable, not an expression, because it | ||
1041 | * is evaluated multiple times. | ||
1042 | */ | ||
1043 | |||
1044 | INLINE void check_bit_buffer(struct bitstream* pb, int nbits) | ||
1045 | { | ||
1046 | if (pb->bits_left < nbits) | ||
1047 | { /* nbits is <= 16, so I can always refill 2 bytes in this case */ | ||
1048 | unsigned char byte; | ||
1049 | |||
1050 | byte = *pb->next_input_byte++; | ||
1051 | if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */ | ||
1052 | { /* simplification: just skip the (one-byte) marker code */ | ||
1053 | pb->next_input_byte++; | ||
1054 | } | ||
1055 | pb->get_buffer = (pb->get_buffer << 8) | byte; | ||
1056 | |||
1057 | byte = *pb->next_input_byte++; | ||
1058 | if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */ | ||
1059 | { /* simplification: just skip the (one-byte) marker code */ | ||
1060 | pb->next_input_byte++; | ||
1061 | } | ||
1062 | pb->get_buffer = (pb->get_buffer << 8) | byte; | ||
1063 | |||
1064 | pb->bits_left += 16; | ||
1065 | } | ||
1066 | } | ||
1067 | |||
1068 | INLINE int get_bits(struct bitstream* pb, int nbits) | ||
1069 | { | ||
1070 | return ((int) (pb->get_buffer >> (pb->bits_left -= nbits))) & (BIT_N(nbits)-1); | ||
1071 | } | ||
1072 | |||
1073 | INLINE int peek_bits(struct bitstream* pb, int nbits) | ||
1074 | { | ||
1075 | return ((int) (pb->get_buffer >> (pb->bits_left - nbits))) & (BIT_N(nbits)-1); | ||
1076 | } | ||
1077 | |||
1078 | INLINE void drop_bits(struct bitstream* pb, int nbits) | ||
1079 | { | ||
1080 | pb->bits_left -= nbits; | ||
1081 | } | ||
1082 | |||
1083 | /* re-synchronize to entropy data (skip restart marker) */ | ||
1084 | void search_restart(struct bitstream* pb) | ||
1085 | { | ||
1086 | pb->next_input_byte--; /* we may have overread it, taking 2 bytes */ | ||
1087 | /* search for a non-byte-padding marker, has to be RSTm or EOS */ | ||
1088 | while (pb->next_input_byte < pb->input_end && | ||
1089 | (pb->next_input_byte[-2] != 0xFF || pb->next_input_byte[-1] == 0x00)) | ||
1090 | { | ||
1091 | pb->next_input_byte++; | ||
1092 | } | ||
1093 | pb->bits_left = 0; | ||
1094 | } | ||
1095 | |||
1096 | /* Figure F.12: extend sign bit. */ | ||
1097 | #define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x)) | ||
1098 | |||
1099 | static const int extend_test[16] = /* entry n is 2**(n-1) */ | ||
1100 | { | ||
1101 | 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, | ||
1102 | 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 | ||
1103 | }; | ||
1104 | |||
1105 | static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */ | ||
1106 | { | ||
1107 | 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1, | ||
1108 | ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1, | ||
1109 | ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1, | ||
1110 | ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 | ||
1111 | }; | ||
1112 | |||
1113 | /* Decode a single value */ | ||
1114 | INLINE int huff_decode_dc(struct bitstream* bs, struct derived_tbl* tbl) | ||
1115 | { | ||
1116 | int nb, look, s, r; | ||
1117 | |||
1118 | check_bit_buffer(bs, HUFF_LOOKAHEAD); | ||
1119 | look = peek_bits(bs, HUFF_LOOKAHEAD); | ||
1120 | if ((nb = tbl->look_nbits[look]) != 0) | ||
1121 | { | ||
1122 | drop_bits(bs, nb); | ||
1123 | s = tbl->look_sym[look]; | ||
1124 | check_bit_buffer(bs, s); | ||
1125 | r = get_bits(bs, s); | ||
1126 | s = HUFF_EXTEND(r, s); | ||
1127 | } | ||
1128 | else | ||
1129 | { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */ | ||
1130 | long code; | ||
1131 | nb=HUFF_LOOKAHEAD+1; | ||
1132 | check_bit_buffer(bs, nb); | ||
1133 | code = get_bits(bs, nb); | ||
1134 | while (code > tbl->maxcode[nb]) | ||
1135 | { | ||
1136 | code <<= 1; | ||
1137 | check_bit_buffer(bs, 1); | ||
1138 | code |= get_bits(bs, 1); | ||
1139 | nb++; | ||
1140 | } | ||
1141 | if (nb > 16) /* error in Huffman */ | ||
1142 | { | ||
1143 | s=0; /* fake a zero, this is most safe */ | ||
1144 | } | ||
1145 | else | ||
1146 | { | ||
1147 | s = tbl->pub[16 + tbl->valptr[nb] + ((int) (code - tbl->mincode[nb])) ]; | ||
1148 | check_bit_buffer(bs, s); | ||
1149 | r = get_bits(bs, s); | ||
1150 | s = HUFF_EXTEND(r, s); | ||
1151 | } | ||
1152 | } /* end slow decode */ | ||
1153 | return s; | ||
1154 | } | ||
1155 | |||
1156 | INLINE int huff_decode_ac(struct bitstream* bs, struct derived_tbl* tbl) | ||
1157 | { | ||
1158 | int nb, look, s; | ||
1159 | |||
1160 | check_bit_buffer(bs, HUFF_LOOKAHEAD); | ||
1161 | look = peek_bits(bs, HUFF_LOOKAHEAD); | ||
1162 | if ((nb = tbl->look_nbits[look]) != 0) | ||
1163 | { | ||
1164 | drop_bits(bs, nb); | ||
1165 | s = tbl->look_sym[look]; | ||
1166 | } | ||
1167 | else | ||
1168 | { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */ | ||
1169 | long code; | ||
1170 | nb=HUFF_LOOKAHEAD+1; | ||
1171 | check_bit_buffer(bs, nb); | ||
1172 | code = get_bits(bs, nb); | ||
1173 | while (code > tbl->maxcode[nb]) | ||
1174 | { | ||
1175 | code <<= 1; | ||
1176 | check_bit_buffer(bs, 1); | ||
1177 | code |= get_bits(bs, 1); | ||
1178 | nb++; | ||
1179 | } | ||
1180 | if (nb > 16) /* error in Huffman */ | ||
1181 | { | ||
1182 | s=0; /* fake a zero, this is most safe */ | ||
1183 | } | ||
1184 | else | ||
1185 | { | ||
1186 | s = tbl->pub[16 + tbl->valptr[nb] + ((int) (code - tbl->mincode[nb])) ]; | ||
1187 | } | ||
1188 | } /* end slow decode */ | ||
1189 | return s; | ||
1190 | } | ||
1191 | |||
1192 | |||
1193 | #ifdef HAVE_LCD_COLOR | ||
1194 | |||
1195 | /* JPEG decoder variant for YUV decoding, into 3 different planes */ | ||
1196 | /* Note: it keeps the original color subsampling, even if resized. */ | ||
1197 | int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[3], | ||
1198 | int downscale, void (*pf_progress)(int current, int total)) | ||
1199 | { | ||
1200 | struct bitstream bs; /* bitstream "object" */ | ||
1201 | int block[64]; /* decoded DCT coefficients */ | ||
1202 | |||
1203 | int width, height; | ||
1204 | int skip_line[3]; /* bytes from one line to the next (skip_line) */ | ||
1205 | int skip_strip[3], skip_mcu[3]; /* bytes to next DCT row / column */ | ||
1206 | |||
1207 | int i, x, y; /* loop counter */ | ||
1208 | |||
1209 | unsigned char* p_line[3] = {p_pixel[0], p_pixel[1], p_pixel[2]}; | ||
1210 | unsigned char* p_byte[3]; /* bitmap pointer */ | ||
1211 | |||
1212 | void (*pf_idct)(unsigned char*, int*, int*, int); /* selected IDCT */ | ||
1213 | int k_need; /* AC coefficients needed up to here */ | ||
1214 | int zero_need; /* init the block with this many zeros */ | ||
1215 | |||
1216 | int last_dc_val[3] = {0, 0, 0}; /* or 128 for chroma? */ | ||
1217 | int store_offs[4]; /* memory offsets: order of Y11 Y12 Y21 Y22 U V */ | ||
1218 | int restart = p_jpeg->restart_interval; /* MCUs until restart marker */ | ||
1219 | |||
1220 | /* pick the IDCT we want, determine how to work with coefs */ | ||
1221 | if (downscale == 1) | ||
1222 | { | ||
1223 | pf_idct = idct8x8; | ||
1224 | k_need = 64; /* all */ | ||
1225 | zero_need = 63; /* all */ | ||
1226 | } | ||
1227 | else if (downscale == 2) | ||
1228 | { | ||
1229 | pf_idct = idct4x4; | ||
1230 | k_need = 25; /* this far in zig-zag to cover 4*4 */ | ||
1231 | zero_need = 27; /* clear this far in linear order */ | ||
1232 | } | ||
1233 | else if (downscale == 4) | ||
1234 | { | ||
1235 | pf_idct = idct2x2; | ||
1236 | k_need = 5; /* this far in zig-zag to cover 2*2 */ | ||
1237 | zero_need = 9; /* clear this far in linear order */ | ||
1238 | } | ||
1239 | else if (downscale == 8) | ||
1240 | { | ||
1241 | pf_idct = idct1x1; | ||
1242 | k_need = 0; /* no AC, not needed */ | ||
1243 | zero_need = 0; /* no AC, not needed */ | ||
1244 | } | ||
1245 | else return -1; /* not supported */ | ||
1246 | |||
1247 | /* init bitstream, fake a restart to make it start */ | ||
1248 | bs.next_input_byte = p_jpeg->p_entropy_data; | ||
1249 | bs.bits_left = 0; | ||
1250 | bs.input_end = p_jpeg->p_entropy_end; | ||
1251 | |||
1252 | width = p_jpeg->x_phys / downscale; | ||
1253 | height = p_jpeg->y_phys / downscale; | ||
1254 | for (i=0; i<3; i++) /* calculate some strides */ | ||
1255 | { | ||
1256 | skip_line[i] = width / p_jpeg->subsample_x[i]; | ||
1257 | skip_strip[i] = skip_line[i] | ||
1258 | * (height / p_jpeg->y_mbl) / p_jpeg->subsample_y[i]; | ||
1259 | skip_mcu[i] = width/p_jpeg->x_mbl / p_jpeg->subsample_x[i]; | ||
1260 | } | ||
1261 | |||
1262 | /* prepare offsets about where to store the different blocks */ | ||
1263 | store_offs[p_jpeg->store_pos[0]] = 0; | ||
1264 | store_offs[p_jpeg->store_pos[1]] = 8 / downscale; /* to the right */ | ||
1265 | store_offs[p_jpeg->store_pos[2]] = width * 8 / downscale; /* below */ | ||
1266 | store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2]; /* r+b */ | ||
1267 | |||
1268 | for(y=0; y<p_jpeg->y_mbl && bs.next_input_byte <= bs.input_end; y++) | ||
1269 | { | ||
1270 | for (i=0; i<3; i++) /* scan line init */ | ||
1271 | { | ||
1272 | p_byte[i] = p_line[i]; | ||
1273 | p_line[i] += skip_strip[i]; | ||
1274 | } | ||
1275 | for (x=0; x<p_jpeg->x_mbl; x++) | ||
1276 | { | ||
1277 | int blkn; | ||
1278 | |||
1279 | /* Outer loop handles each block in the MCU */ | ||
1280 | for (blkn = 0; blkn < p_jpeg->blocks; blkn++) | ||
1281 | { /* Decode a single block's worth of coefficients */ | ||
1282 | int k = 1; /* coefficient index */ | ||
1283 | int s, r; /* huffman values */ | ||
1284 | int ci = p_jpeg->mcu_membership[blkn]; /* component index */ | ||
1285 | int ti = p_jpeg->tab_membership[blkn]; /* table index */ | ||
1286 | struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti]; | ||
1287 | struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti]; | ||
1288 | |||
1289 | /* Section F.2.2.1: decode the DC coefficient difference */ | ||
1290 | s = huff_decode_dc(&bs, dctbl); | ||
1291 | |||
1292 | last_dc_val[ci] += s; | ||
1293 | block[0] = last_dc_val[ci]; /* output it (assumes zag[0] = 0) */ | ||
1294 | |||
1295 | /* coefficient buffer must be cleared */ | ||
1296 | MEMSET(block+1, 0, zero_need*sizeof(block[0])); | ||
1297 | |||
1298 | /* Section F.2.2.2: decode the AC coefficients */ | ||
1299 | for (; k < k_need; k++) | ||
1300 | { | ||
1301 | s = huff_decode_ac(&bs, actbl); | ||
1302 | r = s >> 4; | ||
1303 | s &= 15; | ||
1304 | |||
1305 | if (s) | ||
1306 | { | ||
1307 | k += r; | ||
1308 | check_bit_buffer(&bs, s); | ||
1309 | r = get_bits(&bs, s); | ||
1310 | block[zag[k]] = HUFF_EXTEND(r, s); | ||
1311 | } | ||
1312 | else | ||
1313 | { | ||
1314 | if (r != 15) | ||
1315 | { | ||
1316 | k = 64; | ||
1317 | break; | ||
1318 | } | ||
1319 | k += r; | ||
1320 | } | ||
1321 | } /* for k */ | ||
1322 | /* In this path we just discard the values */ | ||
1323 | for (; k < 64; k++) | ||
1324 | { | ||
1325 | s = huff_decode_ac(&bs, actbl); | ||
1326 | r = s >> 4; | ||
1327 | s &= 15; | ||
1328 | |||
1329 | if (s) | ||
1330 | { | ||
1331 | k += r; | ||
1332 | check_bit_buffer(&bs, s); | ||
1333 | drop_bits(&bs, s); | ||
1334 | } | ||
1335 | else | ||
1336 | { | ||
1337 | if (r != 15) | ||
1338 | break; | ||
1339 | k += r; | ||
1340 | } | ||
1341 | } /* for k */ | ||
1342 | |||
1343 | if (ci == 0) | ||
1344 | { /* Y component needs to bother about block store */ | ||
1345 | pf_idct(p_byte[0]+store_offs[blkn], block, | ||
1346 | p_jpeg->qt_idct[ti], skip_line[0]); | ||
1347 | } | ||
1348 | else | ||
1349 | { /* chroma */ | ||
1350 | pf_idct(p_byte[ci], block, p_jpeg->qt_idct[ti], | ||
1351 | skip_line[ci]); | ||
1352 | } | ||
1353 | } /* for blkn */ | ||
1354 | p_byte[0] += skip_mcu[0]; /* unrolled for (i=0; i<3; i++) loop */ | ||
1355 | p_byte[1] += skip_mcu[1]; | ||
1356 | p_byte[2] += skip_mcu[2]; | ||
1357 | if (p_jpeg->restart_interval && --restart == 0) | ||
1358 | { /* if a restart marker is due: */ | ||
1359 | restart = p_jpeg->restart_interval; /* count again */ | ||
1360 | search_restart(&bs); /* align the bitstream */ | ||
1361 | last_dc_val[0] = last_dc_val[1] = | ||
1362 | last_dc_val[2] = 0; /* reset decoder */ | ||
1363 | } | ||
1364 | } /* for x */ | ||
1365 | if (pf_progress != NULL) | ||
1366 | pf_progress(y, p_jpeg->y_mbl-1); /* notify about decoding progress */ | ||
1367 | } /* for y */ | ||
1368 | |||
1369 | return 0; /* success */ | ||
1370 | } | ||
1371 | #else /* !HAVE_LCD_COLOR */ | ||
1372 | |||
1373 | /* a JPEG decoder specialized in decoding only the luminance (b&w) */ | ||
1374 | int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[1], int downscale, | ||
1375 | void (*pf_progress)(int current, int total)) | ||
1376 | { | ||
1377 | struct bitstream bs; /* bitstream "object" */ | ||
1378 | int block[64]; /* decoded DCT coefficients */ | ||
1379 | |||
1380 | int width, height; | ||
1381 | int skip_line; /* bytes from one line to the next (skip_line) */ | ||
1382 | int skip_strip, skip_mcu; /* bytes to next DCT row / column */ | ||
1383 | |||
1384 | int x, y; /* loop counter */ | ||
1385 | |||
1386 | unsigned char* p_line = p_pixel[0]; | ||
1387 | unsigned char* p_byte; /* bitmap pointer */ | ||
1388 | |||
1389 | void (*pf_idct)(unsigned char*, int*, int*, int); /* selected IDCT */ | ||
1390 | int k_need; /* AC coefficients needed up to here */ | ||
1391 | int zero_need; /* init the block with this many zeros */ | ||
1392 | |||
1393 | int last_dc_val = 0; | ||
1394 | int store_offs[4]; /* memory offsets: order of Y11 Y12 Y21 Y22 U V */ | ||
1395 | int restart = p_jpeg->restart_interval; /* MCUs until restart marker */ | ||
1396 | |||
1397 | /* pick the IDCT we want, determine how to work with coefs */ | ||
1398 | if (downscale == 1) | ||
1399 | { | ||
1400 | pf_idct = idct8x8; | ||
1401 | k_need = 64; /* all */ | ||
1402 | zero_need = 63; /* all */ | ||
1403 | } | ||
1404 | else if (downscale == 2) | ||
1405 | { | ||
1406 | pf_idct = idct4x4; | ||
1407 | k_need = 25; /* this far in zig-zag to cover 4*4 */ | ||
1408 | zero_need = 27; /* clear this far in linear order */ | ||
1409 | } | ||
1410 | else if (downscale == 4) | ||
1411 | { | ||
1412 | pf_idct = idct2x2; | ||
1413 | k_need = 5; /* this far in zig-zag to cover 2*2 */ | ||
1414 | zero_need = 9; /* clear this far in linear order */ | ||
1415 | } | ||
1416 | else if (downscale == 8) | ||
1417 | { | ||
1418 | pf_idct = idct1x1; | ||
1419 | k_need = 0; /* no AC, not needed */ | ||
1420 | zero_need = 0; /* no AC, not needed */ | ||
1421 | } | ||
1422 | else return -1; /* not supported */ | ||
1423 | |||
1424 | /* init bitstream, fake a restart to make it start */ | ||
1425 | bs.next_input_byte = p_jpeg->p_entropy_data; | ||
1426 | bs.bits_left = 0; | ||
1427 | bs.input_end = p_jpeg->p_entropy_end; | ||
1428 | |||
1429 | width = p_jpeg->x_phys / downscale; | ||
1430 | height = p_jpeg->y_phys / downscale; | ||
1431 | skip_line = width; | ||
1432 | skip_strip = skip_line * (height / p_jpeg->y_mbl); | ||
1433 | skip_mcu = (width/p_jpeg->x_mbl); | ||
1434 | |||
1435 | /* prepare offsets about where to store the different blocks */ | ||
1436 | store_offs[p_jpeg->store_pos[0]] = 0; | ||
1437 | store_offs[p_jpeg->store_pos[1]] = 8 / downscale; /* to the right */ | ||
1438 | store_offs[p_jpeg->store_pos[2]] = width * 8 / downscale; /* below */ | ||
1439 | store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2]; /* r+b */ | ||
1440 | |||
1441 | for(y=0; y<p_jpeg->y_mbl && bs.next_input_byte <= bs.input_end; y++) | ||
1442 | { | ||
1443 | p_byte = p_line; | ||
1444 | p_line += skip_strip; | ||
1445 | for (x=0; x<p_jpeg->x_mbl; x++) | ||
1446 | { | ||
1447 | int blkn; | ||
1448 | |||
1449 | /* Outer loop handles each block in the MCU */ | ||
1450 | for (blkn = 0; blkn < p_jpeg->blocks; blkn++) | ||
1451 | { /* Decode a single block's worth of coefficients */ | ||
1452 | int k = 1; /* coefficient index */ | ||
1453 | int s, r; /* huffman values */ | ||
1454 | int ci = p_jpeg->mcu_membership[blkn]; /* component index */ | ||
1455 | int ti = p_jpeg->tab_membership[blkn]; /* table index */ | ||
1456 | struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti]; | ||
1457 | struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti]; | ||
1458 | |||
1459 | /* Section F.2.2.1: decode the DC coefficient difference */ | ||
1460 | s = huff_decode_dc(&bs, dctbl); | ||
1461 | |||
1462 | if (ci == 0) /* only for Y component */ | ||
1463 | { | ||
1464 | last_dc_val += s; | ||
1465 | block[0] = last_dc_val; /* output it (assumes zag[0] = 0) */ | ||
1466 | |||
1467 | /* coefficient buffer must be cleared */ | ||
1468 | MEMSET(block+1, 0, zero_need*sizeof(block[0])); | ||
1469 | |||
1470 | /* Section F.2.2.2: decode the AC coefficients */ | ||
1471 | for (; k < k_need; k++) | ||
1472 | { | ||
1473 | s = huff_decode_ac(&bs, actbl); | ||
1474 | r = s >> 4; | ||
1475 | s &= 15; | ||
1476 | |||
1477 | if (s) | ||
1478 | { | ||
1479 | k += r; | ||
1480 | check_bit_buffer(&bs, s); | ||
1481 | r = get_bits(&bs, s); | ||
1482 | block[zag[k]] = HUFF_EXTEND(r, s); | ||
1483 | } | ||
1484 | else | ||
1485 | { | ||
1486 | if (r != 15) | ||
1487 | { | ||
1488 | k = 64; | ||
1489 | break; | ||
1490 | } | ||
1491 | k += r; | ||
1492 | } | ||
1493 | } /* for k */ | ||
1494 | } | ||
1495 | /* In this path we just discard the values */ | ||
1496 | for (; k < 64; k++) | ||
1497 | { | ||
1498 | s = huff_decode_ac(&bs, actbl); | ||
1499 | r = s >> 4; | ||
1500 | s &= 15; | ||
1501 | |||
1502 | if (s) | ||
1503 | { | ||
1504 | k += r; | ||
1505 | check_bit_buffer(&bs, s); | ||
1506 | drop_bits(&bs, s); | ||
1507 | } | ||
1508 | else | ||
1509 | { | ||
1510 | if (r != 15) | ||
1511 | break; | ||
1512 | k += r; | ||
1513 | } | ||
1514 | } /* for k */ | ||
1515 | |||
1516 | if (ci == 0) | ||
1517 | { /* only for Y component */ | ||
1518 | pf_idct(p_byte+store_offs[blkn], block, p_jpeg->qt_idct[ti], | ||
1519 | skip_line); | ||
1520 | } | ||
1521 | } /* for blkn */ | ||
1522 | p_byte += skip_mcu; | ||
1523 | if (p_jpeg->restart_interval && --restart == 0) | ||
1524 | { /* if a restart marker is due: */ | ||
1525 | restart = p_jpeg->restart_interval; /* count again */ | ||
1526 | search_restart(&bs); /* align the bitstream */ | ||
1527 | last_dc_val = 0; /* reset decoder */ | ||
1528 | } | ||
1529 | } /* for x */ | ||
1530 | if (pf_progress != NULL) | ||
1531 | pf_progress(y, p_jpeg->y_mbl-1); /* notify about decoding progress */ | ||
1532 | } /* for y */ | ||
1533 | |||
1534 | return 0; /* success */ | ||
1535 | } | ||
1536 | #endif /* !HAVE_LCD_COLOR */ | ||
1537 | |||
1538 | /**************** end JPEG code ********************/ | ||