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authorAndrew Mahone <andrew.mahone@gmail.com>2009-05-01 23:24:23 +0000
committerAndrew Mahone <andrew.mahone@gmail.com>2009-05-01 23:24:23 +0000
commit60d420938372477226184fb9012de7f6b4ea2d83 (patch)
tree086926f469d87635a483bfff55ea50898bdd0e1c /apps/recorder/jpeg_load.c
parentb22516f995ef4a448251b883b0737d4aa0abdb84 (diff)
downloadrockbox-60d420938372477226184fb9012de7f6b4ea2d83.tar.gz
rockbox-60d420938372477226184fb9012de7f6b4ea2d83.zip
Add core JPEG reader, adapted from the JPEG plugin's decoder, with some changes to prevent include conflicts between the two decoders.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20836 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/recorder/jpeg_load.c')
-rw-r--r--apps/recorder/jpeg_load.c2012
1 files changed, 2012 insertions, 0 deletions
diff --git a/apps/recorder/jpeg_load.c b/apps/recorder/jpeg_load.c
new file mode 100644
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+++ b/apps/recorder/jpeg_load.c
@@ -0,0 +1,2012 @@
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* Copyright (C) 2009 Andrew Mahone fractional decode, split IDCT - 16-point
14* IDCT based on IJG jpeg-7 pre-release
15* File scrolling addition (C) 2005 Alexander Spyridakis
16* Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
17* Heavily borrowed from the IJG implementation (C) Thomas G. Lane
18* Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding JPEGclub.org
19*
20* This program is free software; you can redistribute it and/or
21* modify it under the terms of the GNU General Public License
22* as published by the Free Software Foundation; either version 2
23* of the License, or (at your option) any later version.
24*
25* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
26* KIND, either express or implied.
27*
28****************************************************************************/
29
30#include "plugin.h"
31#include "debug.h"
32#include "jpeg_load.h"
33/*#define JPEG_BS_DEBUG*/
34/* for portability of below JPEG code */
35#define MEMSET(p,v,c) memset(p,v,c)
36#define MEMCPY(d,s,c) memcpy(d,s,c)
37#define INLINE static inline
38#define ENDIAN_SWAP16(n) n /* only for poor little endian machines */
39
40/**************** begin JPEG code ********************/
41
42#ifdef HAVE_LCD_COLOR
43typedef struct uint8_rgb jpeg_pix_t;
44#else
45typedef uint8_t jpeg_pix_t;
46#endif
47#define JPEG_PIX_SZ (sizeof(jpeg_pix_t))
48
49/* This can't be in jpeg_load.h because plugin.h includes it, and it conflicts
50 * with the definition in jpeg_decoder.h
51 */
52struct jpeg
53{
54 int fd;
55 int buf_left;
56 unsigned char *buf_index;
57 unsigned long int bitbuf;
58 int bitbuf_bits;
59 int marker_ind;
60 int marker_val;
61 unsigned char marker;
62 int x_size, y_size; /* size of image (can be less than block boundary) */
63 int x_phys, y_phys; /* physical size, block aligned */
64 int x_mbl; /* x dimension of MBL */
65 int y_mbl; /* y dimension of MBL */
66 int blocks; /* blocks per MB */
67 int restart_interval; /* number of MCUs between RSTm markers */
68 int restart; /* blocks until next restart marker */
69 int mcu_row; /* current row relative to first row of this row of MCUs */
70 unsigned char *out_ptr; /* pointer to current row to output */
71 int cur_row; /* current row relative to top of image */
72 int set_rows;
73 int store_pos[4]; /* for Y block ordering */
74#ifdef HAVE_LCD_COLOR
75 int last_dc_val[3];
76#else
77 int last_dc_val;
78#endif
79 int h_scale[2]; /* horizontal scalefactor = (2**N) / 8 */
80 int v_scale[2]; /* same as above, for vertical direction */
81 int k_need[3]; /* per component zig-zag index of last needed coefficient */
82 int zero_need[3]; /* per compenent number of coefficients to zero */
83 jpeg_pix_t *img_buf;
84
85 int quanttable[4][QUANT_TABLE_LENGTH]; /* raw quantization tables 0-3 */
86
87 struct huffman_table hufftable[2]; /* Huffman tables */
88 struct derived_tbl dc_derived_tbls[2]; /* Huffman-LUTs */
89 struct derived_tbl ac_derived_tbls[2];
90
91 struct frame_component frameheader[3]; /* Component descriptor */
92 struct scan_component scanheader[3]; /* currently not used */
93
94 int mcu_membership[6]; /* info per block */
95 int tab_membership[6];
96 int subsample_x[3]; /* info per component */
97 int subsample_y[3];
98 unsigned char buf[JPEG_READ_BUF_SIZE];
99 struct img_part part;
100};
101
102INLINE unsigned range_limit(int value)
103{
104#if CONFIG_CPU == SH7034
105 unsigned tmp;
106 asm ( /* Note: Uses knowledge that only low byte of result is used */
107 "mov #-128,%[t] \n"
108 "sub %[t],%[v] \n" /* value -= -128; equals value += 128; */
109 "extu.b %[v],%[t] \n"
110 "cmp/eq %[v],%[t] \n" /* low byte == whole number ? */
111 "bt 1f \n" /* yes: no overflow */
112 "cmp/pz %[v] \n" /* overflow: positive? */
113 "subc %[v],%[v] \n" /* %[r] now either 0 or 0xffffffff */
114 "1: \n"
115 : /* outputs */
116 [v]"+r"(value),
117 [t]"=&r"(tmp)
118 );
119 return value;
120#elif defined(CPU_COLDFIRE)
121 /* Note: Uses knowledge that only the low byte of the result is used */
122 asm (
123 "add.l #128,%[v] \n" /* value += 128; */
124 "cmp.l #255,%[v] \n" /* overflow? */
125 "bls.b 1f \n" /* no: return value */
126 /* yes: set low byte to appropriate boundary */
127 "spl.b %[v] \n"
128 "1: \n"
129 : /* outputs */
130 [v]"+d"(value)
131 );
132 return value;
133#elif defined(CPU_ARM)
134 /* Note: Uses knowledge that only the low byte of the result is used */
135 asm (
136 "add %[v], %[v], #128 \n" /* value += 128 */
137 "cmp %[v], #255 \n" /* out of range 0..255? */
138 "mvnhi %[v], %[v], asr #31 \n" /* yes: set all bits to ~(sign_bit) */
139 : /* outputs */
140 [v]"+r"(value)
141 );
142 return value;
143#else
144 value += 128;
145
146 if ((unsigned)value <= 255)
147 return value;
148
149 if (value < 0)
150 return 0;
151
152 return 255;
153#endif
154}
155
156static inline int clamp_component(int x)
157{
158 if ((unsigned)x > 255)
159 x = x < 0 ? 0 : 255;
160 return x;
161}
162
163/* IDCT implementation */
164
165
166#define CONST_BITS 13
167#define PASS1_BITS 2
168
169
170/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
171* causing a lot of useless floating-point operations at run time.
172* To get around this we use the following pre-calculated constants.
173* If you change CONST_BITS you may want to add appropriate values.
174* (With a reasonable C compiler, you can just rely on the FIX() macro...)
175*/
176#define FIX_0_298631336 2446 /* FIX(0.298631336) */
177#define FIX_0_390180644 3196 /* FIX(0.390180644) */
178#define FIX_0_541196100 4433 /* FIX(0.541196100) */
179#define FIX_0_765366865 6270 /* FIX(0.765366865) */
180#define FIX_0_899976223 7373 /* FIX(0.899976223) */
181#define FIX_1_175875602 9633 /* FIX(1.175875602) */
182#define FIX_1_501321110 12299 /* FIX(1.501321110) */
183#define FIX_1_847759065 15137 /* FIX(1.847759065) */
184#define FIX_1_961570560 16069 /* FIX(1.961570560) */
185#define FIX_2_053119869 16819 /* FIX(2.053119869) */
186#define FIX_2_562915447 20995 /* FIX(2.562915447) */
187#define FIX_3_072711026 25172 /* FIX(3.072711026) */
188
189
190
191/* Multiply an long variable by an long constant to yield an long result.
192* For 8-bit samples with the recommended scaling, all the variable
193* and constant values involved are no more than 16 bits wide, so a
194* 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
195* For 12-bit samples, a full 32-bit multiplication will be needed.
196*/
197#define MULTIPLY16(var,const) (((short) (var)) * ((short) (const)))
198
199#define MULTIPLY(var1, var2) ((var1) * (var2))
200
201/*
202 * Macros for handling fixed-point arithmetic; these are used by many
203 * but not all of the DCT/IDCT modules.
204 *
205 * All values are expected to be of type INT32.
206 * Fractional constants are scaled left by CONST_BITS bits.
207 * CONST_BITS is defined within each module using these macros,
208 * and may differ from one module to the next.
209 */
210#define ONE ((long)1)
211#define CONST_SCALE (ONE << CONST_BITS)
212
213/* Convert a positive real constant to an integer scaled by CONST_SCALE.
214 * Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
215 * thus causing a lot of useless floating-point operations at run time.
216 */
217#define FIX(x) ((long) ((x) * CONST_SCALE + 0.5))
218#define RIGHT_SHIFT(x,shft) ((x) >> (shft))
219
220/* Descale and correctly round an int value that's scaled by N bits.
221* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
222* the fudge factor is correct for either sign of X.
223*/
224#define DESCALE(x,n) (((x) + (1l << ((n)-1))) >> (n))
225
226#define DS_OUT ((CONST_BITS)+(PASS1_BITS)+3)
227
228/*
229 * Conversion of full 0-255 range YCrCb to RGB:
230 * |R| |1.000000 -0.000001 1.402000| |Y'|
231 * |G| = |1.000000 -0.334136 -0.714136| |Pb|
232 * |B| |1.000000 1.772000 0.000000| |Pr|
233 * Scaled (yields s15-bit output):
234 * |R| |128 0 179| |Y |
235 * |G| = |128 -43 -91| |Cb - 128|
236 * |B| |128 227 0| |Cr - 128|
237 */
238#define YFAC 128
239#define RVFAC 179
240#define GUFAC (-43)
241#define GVFAC (-91)
242#define BUFAC 227
243#define COMPONENT_SHIFT 15
244
245/* horizontal-pass 1-point IDCT */
246static void idct1h(int *ws, unsigned char *out, int rows, int rowstep)
247{
248 int row;
249 for (row = 0; row < rows; row++)
250 {
251 *out = range_limit((int) DESCALE(*ws, DS_OUT));
252 out += rowstep;
253 ws += 8;
254 }
255}
256
257/* vertical-pass 2-point IDCT */
258static void idct2v(int *ws, int cols)
259{
260 int col;
261 for (col = 0; col < cols; col++)
262 {
263 int tmp1 = ws[0];
264 int tmp2 = ws[8];
265 ws[0] = tmp1 + tmp2;
266 ws[8] = tmp1 - tmp2;
267 ws++;
268 }
269}
270
271/* horizontal-pass 2-point IDCT */
272static void idct2h(int *ws, unsigned char *out, int rows, int rowstep)
273{
274 int row;
275 for (row = 0; row < rows; row++)
276 {
277 int tmp1 = ws[0] + (ONE << (DS_OUT - 1));
278 int tmp2 = ws[1];
279 out[JPEG_PIX_SZ*0] = range_limit((int) RIGHT_SHIFT(tmp1 + tmp2,
280 DS_OUT));
281 out[JPEG_PIX_SZ*1] = range_limit((int) RIGHT_SHIFT(tmp1 - tmp2,
282 DS_OUT));
283 out += rowstep;
284 ws += 8;
285 }
286}
287
288/* vertical-pass 4-point IDCT */
289static void idct4v(int *ws, int cols)
290{
291 int tmp0, tmp2, tmp10, tmp12;
292 int z1, z2, z3;
293 int col;
294 for (col = 0; col < cols; col++, ws++)
295 {
296 /* Even part */
297
298 tmp0 = ws[8*0];
299 tmp2 = ws[8*2];
300
301 tmp10 = (tmp0 + tmp2) << PASS1_BITS;
302 tmp12 = (tmp0 - tmp2) << PASS1_BITS;
303
304 /* Odd part */
305 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
306
307 z2 = ws[8*1];
308 z3 = ws[8*3];
309
310 z1 = MULTIPLY16(z2 + z3, FIX_0_541196100) +
311 (ONE << (CONST_BITS - PASS1_BITS - 1));
312 tmp0 = RIGHT_SHIFT(z1 + MULTIPLY16(z3, - FIX_1_847759065),
313 CONST_BITS-PASS1_BITS);
314 tmp2 = RIGHT_SHIFT(z1 + MULTIPLY16(z2, FIX_0_765366865),
315 CONST_BITS-PASS1_BITS);
316
317 /* Final output stage */
318
319 ws[8*0] = (int) (tmp10 + tmp2);
320 ws[8*3] = (int) (tmp10 - tmp2);
321 ws[8*1] = (int) (tmp12 + tmp0);
322 ws[8*2] = (int) (tmp12 - tmp0);
323 }
324}
325
326/* horizontal-pass 4-point IDCT */
327static void idct4h(int *ws, unsigned char *out, int rows, int rowstep)
328{
329 int tmp0, tmp2, tmp10, tmp12;
330 int z1, z2, z3;
331 int row;
332 for (row = 0; row < rows; row++, out += rowstep, ws += 8)
333 {
334 /* Even part */
335
336 tmp0 = (int) ws[0] + (ONE << (PASS1_BITS + 2));
337 tmp2 = (int) ws[2];
338
339 tmp10 = (tmp0 + tmp2) << CONST_BITS;
340 tmp12 = (tmp0 - tmp2) << CONST_BITS;
341
342 /* Odd part */
343 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
344
345 z2 = (int) ws[1];
346 z3 = (int) ws[3];
347
348 z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
349 tmp0 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
350 tmp2 = z1 + MULTIPLY16(z2, FIX_0_765366865);
351
352 /* Final output stage */
353
354 out[JPEG_PIX_SZ*0] = range_limit((int) RIGHT_SHIFT(tmp10 + tmp2,
355 DS_OUT));
356 out[JPEG_PIX_SZ*3] = range_limit((int) RIGHT_SHIFT(tmp10 - tmp2,
357 DS_OUT));
358 out[JPEG_PIX_SZ*1] = range_limit((int) RIGHT_SHIFT(tmp12 + tmp0,
359 DS_OUT));
360 out[JPEG_PIX_SZ*2] = range_limit((int) RIGHT_SHIFT(tmp12 - tmp0,
361 DS_OUT));
362 }
363}
364
365/* vertical-pass 8-point IDCT */
366static void idct8v(int *ws, int cols)
367{
368 long tmp0, tmp1, tmp2, tmp3;
369 long tmp10, tmp11, tmp12, tmp13;
370 long z1, z2, z3, z4, z5;
371 int col;
372 for (col = 0; col < cols; col++, ws++)
373 {
374 /* Due to quantization, we will usually find that many of the input
375 * coefficients are zero, especially the AC terms. We can exploit this
376 * by short-circuiting the IDCT calculation for any column in which all
377 * the AC terms are zero. In that case each output is equal to the
378 * DC coefficient (with scale factor as needed).
379 * With typical images and quantization tables, half or more of the
380 * column DCT calculations can be simplified this way.
381 */
382 if ((ws[8*1] | ws[8*2] | ws[8*3]
383 | ws[8*4] | ws[8*5] | ws[8*6] | ws[8*7]) == 0)
384 {
385 /* AC terms all zero */
386 int dcval = ws[8*0] << PASS1_BITS;
387
388 ws[8*0] = ws[8*1] = ws[8*2] = ws[8*3] = ws[8*4]
389 = ws[8*5] = ws[8*6] = ws[8*7] = dcval;
390 continue;
391 }
392
393 /* Even part: reverse the even part of the forward DCT. */
394 /* The rotator is sqrt(2)*c(-6). */
395
396 z2 = ws[8*2];
397 z3 = ws[8*6];
398
399 z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
400 tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
401 tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865);
402
403 z2 = ws[8*0] << CONST_BITS;
404 z2 += ONE << (CONST_BITS - PASS1_BITS - 1);
405 z3 = ws[8*4] << CONST_BITS;
406
407 tmp0 = (z2 + z3);
408 tmp1 = (z2 - z3);
409
410 tmp10 = tmp0 + tmp3;
411 tmp13 = tmp0 - tmp3;
412 tmp11 = tmp1 + tmp2;
413 tmp12 = tmp1 - tmp2;
414
415 /* Odd part per figure 8; the matrix is unitary and hence its
416 transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */
417
418 tmp0 = ws[8*7];
419 tmp1 = ws[8*5];
420 tmp2 = ws[8*3];
421 tmp3 = ws[8*1];
422
423 z1 = tmp0 + tmp3;
424 z2 = tmp1 + tmp2;
425 z3 = tmp0 + tmp2;
426 z4 = tmp1 + tmp3;
427 z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
428
429 tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
430 tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
431 tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
432 tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
433 z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
434 z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
435 z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
436 z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
437
438 z3 += z5;
439 z4 += z5;
440
441 tmp0 += z1 + z3;
442 tmp1 += z2 + z4;
443 tmp2 += z2 + z3;
444 tmp3 += z1 + z4;
445
446 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
447
448 ws[8*0] = (int) RIGHT_SHIFT(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
449 ws[8*7] = (int) RIGHT_SHIFT(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
450 ws[8*1] = (int) RIGHT_SHIFT(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
451 ws[8*6] = (int) RIGHT_SHIFT(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
452 ws[8*2] = (int) RIGHT_SHIFT(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
453 ws[8*5] = (int) RIGHT_SHIFT(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
454 ws[8*3] = (int) RIGHT_SHIFT(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
455 ws[8*4] = (int) RIGHT_SHIFT(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
456 }
457}
458
459/* horizontal-pass 8-point IDCT */
460static void idct8h(int *ws, unsigned char *out, int rows, int rowstep)
461{
462 long tmp0, tmp1, tmp2, tmp3;
463 long tmp10, tmp11, tmp12, tmp13;
464 long z1, z2, z3, z4, z5;
465 int row;
466 for (row = 0; row < rows; row++, out += rowstep, ws += 8)
467 {
468 /* Rows of zeroes can be exploited in the same way as we did with
469 * columns. However, the column calculation has created many nonzero AC
470 * terms, so the simplification applies less often (typically 5% to 10%
471 * of the time). On machines with very fast multiplication, it's
472 * possible that the test takes more time than it's worth. In that
473 * case this section may be commented out.
474 */
475
476#ifndef NO_ZERO_ROW_TEST
477 if ((ws[1] | ws[2] | ws[3]
478 | ws[4] | ws[5] | ws[6] | ws[7]) == 0)
479 {
480 /* AC terms all zero */
481 unsigned char dcval = range_limit((int) DESCALE((long) ws[0],
482 PASS1_BITS+3));
483
484 out[JPEG_PIX_SZ*0] = dcval;
485 out[JPEG_PIX_SZ*1] = dcval;
486 out[JPEG_PIX_SZ*2] = dcval;
487 out[JPEG_PIX_SZ*3] = dcval;
488 out[JPEG_PIX_SZ*4] = dcval;
489 out[JPEG_PIX_SZ*5] = dcval;
490 out[JPEG_PIX_SZ*6] = dcval;
491 out[JPEG_PIX_SZ*7] = dcval;
492 continue;
493 }
494#endif
495
496 /* Even part: reverse the even part of the forward DCT. */
497 /* The rotator is sqrt(2)*c(-6). */
498
499 z2 = (long) ws[2];
500 z3 = (long) ws[6];
501
502 z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
503 tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
504 tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865);
505
506 z4 = (long) ws[0] + (ONE << (PASS1_BITS + 2));
507 z4 <<= CONST_BITS;
508 z5 = (long) ws[4] << CONST_BITS;
509 tmp0 = z4 + z5;
510 tmp1 = z4 - z5;
511
512 tmp10 = tmp0 + tmp3;
513 tmp13 = tmp0 - tmp3;
514 tmp11 = tmp1 + tmp2;
515 tmp12 = tmp1 - tmp2;
516
517 /* Odd part per figure 8; the matrix is unitary and hence its
518 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */
519
520 tmp0 = (long) ws[7];
521 tmp1 = (long) ws[5];
522 tmp2 = (long) ws[3];
523 tmp3 = (long) ws[1];
524
525 z1 = tmp0 + tmp3;
526 z2 = tmp1 + tmp2;
527 z3 = tmp0 + tmp2;
528 z4 = tmp1 + tmp3;
529 z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
530
531 tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
532 tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
533 tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
534 tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
535 z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
536 z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
537 z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
538 z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
539
540 z3 += z5;
541 z4 += z5;
542
543 tmp0 += z1 + z3;
544 tmp1 += z2 + z4;
545 tmp2 += z2 + z3;
546 tmp3 += z1 + z4;
547
548 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
549
550 out[JPEG_PIX_SZ*0] = range_limit((int) RIGHT_SHIFT(tmp10 + tmp3,
551 DS_OUT));
552 out[JPEG_PIX_SZ*7] = range_limit((int) RIGHT_SHIFT(tmp10 - tmp3,
553 DS_OUT));
554 out[JPEG_PIX_SZ*1] = range_limit((int) RIGHT_SHIFT(tmp11 + tmp2,
555 DS_OUT));
556 out[JPEG_PIX_SZ*6] = range_limit((int) RIGHT_SHIFT(tmp11 - tmp2,
557 DS_OUT));
558 out[JPEG_PIX_SZ*2] = range_limit((int) RIGHT_SHIFT(tmp12 + tmp1,
559 DS_OUT));
560 out[JPEG_PIX_SZ*5] = range_limit((int) RIGHT_SHIFT(tmp12 - tmp1,
561 DS_OUT));
562 out[JPEG_PIX_SZ*3] = range_limit((int) RIGHT_SHIFT(tmp13 + tmp0,
563 DS_OUT));
564 out[JPEG_PIX_SZ*4] = range_limit((int) RIGHT_SHIFT(tmp13 - tmp0,
565 DS_OUT));
566 }
567}
568
569/* vertical-pass 16-point IDCT */
570static void idct16v(int *ws, int cols)
571{
572 long tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13;
573 long tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27;
574 long z1, z2, z3, z4;
575 int col;
576 for (col = 0; col < cols; col++, ws++)
577 {
578 /* Even part */
579
580 tmp0 = ws[8*0] << CONST_BITS;
581 /* Add fudge factor here for final descale. */
582 tmp0 += 1 << (CONST_BITS-PASS1_BITS-1);
583
584 z1 = ws[8*4];
585 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */
586 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */
587
588 tmp10 = tmp0 + tmp1;
589 tmp11 = tmp0 - tmp1;
590 tmp12 = tmp0 + tmp2;
591 tmp13 = tmp0 - tmp2;
592
593 z1 = ws[8*2];
594 z2 = ws[8*6];
595 z3 = z1 - z2;
596 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */
597 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */
598
599 /* (c6+c2)[16] = (c3+c1)[8] */
600 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447);
601 /* (c6-c14)[16] = (c3-c7)[8] */
602 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223);
603 /* (c2-c10)[16] = (c1-c5)[8] */
604 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887));
605 /* (c10-c14)[16] = (c5-c7)[8] */
606 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579));
607
608 tmp20 = tmp10 + tmp0;
609 tmp27 = tmp10 - tmp0;
610 tmp21 = tmp12 + tmp1;
611 tmp26 = tmp12 - tmp1;
612 tmp22 = tmp13 + tmp2;
613 tmp25 = tmp13 - tmp2;
614 tmp23 = tmp11 + tmp3;
615 tmp24 = tmp11 - tmp3;
616
617 /* Odd part */
618
619 z1 = ws[8*1];
620 z2 = ws[8*3];
621 z3 = ws[8*5];
622 z4 = ws[8*7];
623
624 tmp11 = z1 + z3;
625
626 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */
627 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */
628 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */
629 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */
630 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */
631 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */
632 tmp0 = tmp1 + tmp2 + tmp3 -
633 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */
634 tmp13 = tmp10 + tmp11 + tmp12 -
635 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */
636 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */
637 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */
638 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */
639 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */
640 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */
641 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */
642 z2 += z4;
643 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */
644 tmp1 += z1;
645 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */
646 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */
647 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */
648 tmp12 += z2;
649 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */
650 tmp2 += z2;
651 tmp3 += z2;
652 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */
653 tmp10 += z2;
654 tmp11 += z2;
655
656 /* Final output stage */
657 ws[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp0, CONST_BITS-PASS1_BITS);
658 ws[8*15] = (int) RIGHT_SHIFT(tmp20 - tmp0, CONST_BITS-PASS1_BITS);
659 ws[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp1, CONST_BITS-PASS1_BITS);
660 ws[8*14] = (int) RIGHT_SHIFT(tmp21 - tmp1, CONST_BITS-PASS1_BITS);
661 ws[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp2, CONST_BITS-PASS1_BITS);
662 ws[8*13] = (int) RIGHT_SHIFT(tmp22 - tmp2, CONST_BITS-PASS1_BITS);
663 ws[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp3, CONST_BITS-PASS1_BITS);
664 ws[8*12] = (int) RIGHT_SHIFT(tmp23 - tmp3, CONST_BITS-PASS1_BITS);
665 ws[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp10, CONST_BITS-PASS1_BITS);
666 ws[8*11] = (int) RIGHT_SHIFT(tmp24 - tmp10, CONST_BITS-PASS1_BITS);
667 ws[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp11, CONST_BITS-PASS1_BITS);
668 ws[8*10] = (int) RIGHT_SHIFT(tmp25 - tmp11, CONST_BITS-PASS1_BITS);
669 ws[8*6] = (int) RIGHT_SHIFT(tmp26 + tmp12, CONST_BITS-PASS1_BITS);
670 ws[8*9] = (int) RIGHT_SHIFT(tmp26 - tmp12, CONST_BITS-PASS1_BITS);
671 ws[8*7] = (int) RIGHT_SHIFT(tmp27 + tmp13, CONST_BITS-PASS1_BITS);
672 ws[8*8] = (int) RIGHT_SHIFT(tmp27 - tmp13, CONST_BITS-PASS1_BITS);
673 }
674}
675
676/* horizontal-pass 16-point IDCT */
677static void idct16h(int *ws, unsigned char *out, int rows, int rowstep)
678{
679 long tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13;
680 long tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27;
681 long z1, z2, z3, z4;
682 int row;
683 for (row = 0; row < rows; row++, out += rowstep, ws += 8)
684 {
685 /* Even part */
686
687 /* Add fudge factor here for final descale. */
688 tmp0 = (long) ws[0] + (ONE << (PASS1_BITS+2));
689 tmp0 <<= CONST_BITS;
690
691 z1 = (long) ws[4];
692 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */
693 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */
694
695 tmp10 = tmp0 + tmp1;
696 tmp11 = tmp0 - tmp1;
697 tmp12 = tmp0 + tmp2;
698 tmp13 = tmp0 - tmp2;
699
700 z1 = (long) ws[2];
701 z2 = (long) ws[6];
702 z3 = z1 - z2;
703 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */
704 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */
705
706 /* (c6+c2)[16] = (c3+c1)[8] */
707 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447);
708 /* (c6-c14)[16] = (c3-c7)[8] */
709 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223);
710 /* (c2-c10)[16] = (c1-c5)[8] */
711 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887));
712 /* (c10-c14)[16] = (c5-c7)[8] */
713 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579));
714
715 tmp20 = tmp10 + tmp0;
716 tmp27 = tmp10 - tmp0;
717 tmp21 = tmp12 + tmp1;
718 tmp26 = tmp12 - tmp1;
719 tmp22 = tmp13 + tmp2;
720 tmp25 = tmp13 - tmp2;
721 tmp23 = tmp11 + tmp3;
722 tmp24 = tmp11 - tmp3;
723
724 /* Odd part */
725
726 z1 = (long) ws[1];
727 z2 = (long) ws[3];
728 z3 = (long) ws[5];
729 z4 = (long) ws[7];
730
731 tmp11 = z1 + z3;
732
733 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */
734 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */
735 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */
736 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */
737 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */
738 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */
739 tmp0 = tmp1 + tmp2 + tmp3 -
740 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */
741 tmp13 = tmp10 + tmp11 + tmp12 -
742 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */
743 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */
744 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */
745 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */
746 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */
747 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */
748 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */
749 z2 += z4;
750 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */
751 tmp1 += z1;
752 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */
753 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */
754 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */
755 tmp12 += z2;
756 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */
757 tmp2 += z2;
758 tmp3 += z2;
759 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */
760 tmp10 += z2;
761 tmp11 += z2;
762
763 /* Final output stage */
764
765 out[JPEG_PIX_SZ*0] = range_limit((int) RIGHT_SHIFT(tmp20 + tmp0,
766 DS_OUT));
767 out[JPEG_PIX_SZ*15] = range_limit((int) RIGHT_SHIFT(tmp20 - tmp0,
768 DS_OUT));
769 out[JPEG_PIX_SZ*1] = range_limit((int) RIGHT_SHIFT(tmp21 + tmp1,
770 DS_OUT));
771 out[JPEG_PIX_SZ*14] = range_limit((int) RIGHT_SHIFT(tmp21 - tmp1,
772 DS_OUT));
773 out[JPEG_PIX_SZ*2] = range_limit((int) RIGHT_SHIFT(tmp22 + tmp2,
774 DS_OUT));
775 out[JPEG_PIX_SZ*13] = range_limit((int) RIGHT_SHIFT(tmp22 - tmp2,
776 DS_OUT));
777 out[JPEG_PIX_SZ*3] = range_limit((int) RIGHT_SHIFT(tmp23 + tmp3,
778 DS_OUT));
779 out[JPEG_PIX_SZ*12] = range_limit((int) RIGHT_SHIFT(tmp23 - tmp3,
780 DS_OUT));
781 out[JPEG_PIX_SZ*4] = range_limit((int) RIGHT_SHIFT(tmp24 + tmp10,
782 DS_OUT));
783 out[JPEG_PIX_SZ*11] = range_limit((int) RIGHT_SHIFT(tmp24 - tmp10,
784 DS_OUT));
785 out[JPEG_PIX_SZ*5] = range_limit((int) RIGHT_SHIFT(tmp25 + tmp11,
786 DS_OUT));
787 out[JPEG_PIX_SZ*10] = range_limit((int) RIGHT_SHIFT(tmp25 - tmp11,
788 DS_OUT));
789 out[JPEG_PIX_SZ*6] = range_limit((int) RIGHT_SHIFT(tmp26 + tmp12,
790 DS_OUT));
791 out[JPEG_PIX_SZ*9] = range_limit((int) RIGHT_SHIFT(tmp26 - tmp12,
792 DS_OUT));
793 out[JPEG_PIX_SZ*7] = range_limit((int) RIGHT_SHIFT(tmp27 + tmp13,
794 DS_OUT));
795 out[JPEG_PIX_SZ*8] = range_limit((int) RIGHT_SHIFT(tmp27 - tmp13,
796 DS_OUT));
797 }
798}
799
800struct idct_entry {
801 int v_scale;
802 int h_scale;
803 void (*v_idct)(int *ws, int cols);
804 void (*h_idct)(int *ws, unsigned char *out, int rows, int rowstep);
805};
806
807struct idct_entry idct_tbl[] = {
808 { PASS1_BITS, CONST_BITS, NULL, idct1h },
809 { PASS1_BITS, CONST_BITS, idct2v, idct2h },
810 { 0, 0, idct4v, idct4h },
811 { 0, 0, idct8v, idct8h },
812 { 0, 0, idct16v, idct16h },
813};
814
815/* JPEG decoder implementation */
816
817INLINE void fill_buf(struct jpeg* p_jpeg)
818{
819 p_jpeg->buf_left = read(p_jpeg->fd, p_jpeg->buf, JPEG_READ_BUF_SIZE);
820 p_jpeg->buf_index = p_jpeg->buf;
821}
822
823static unsigned char *getc(struct jpeg* p_jpeg)
824{
825 if (p_jpeg->buf_left < 1)
826 fill_buf(p_jpeg);
827 if (p_jpeg->buf_left < 1)
828 return NULL;
829 p_jpeg->buf_left--;
830 return p_jpeg->buf_index++;
831}
832
833INLINE bool skip_bytes_seek(struct jpeg* p_jpeg)
834{
835 if (lseek(p_jpeg->fd, -p_jpeg->buf_left, SEEK_CUR) < 0)
836 return false;
837 p_jpeg->buf_left = 0;
838 return true;
839}
840
841static bool skip_bytes(struct jpeg* p_jpeg, int count)
842{
843 p_jpeg->buf_left -= count;
844 p_jpeg->buf_index += count;
845 return p_jpeg->buf_left >= 0 || skip_bytes_seek(p_jpeg);
846}
847
848#define e_skip_bytes(jpeg, count) \
849do {\
850 if (!skip_bytes((jpeg),(count))) \
851 return -1; \
852} while (0)
853
854#define e_getc(jpeg, code) \
855({ \
856 unsigned char *c; \
857 if (!(c = getc(jpeg))) \
858 return (code); \
859 *c; \
860})
861
862#define d_getc(jpeg, def) \
863({ \
864 unsigned char *cp = getc(jpeg); \
865 unsigned char c = cp ? *cp : (def); \
866 c; \
867})
868
869static void putc(struct jpeg* p_jpeg)
870{
871 p_jpeg->buf_left++;
872 p_jpeg->buf_index--;
873}
874
875/* Preprocess the JPEG JFIF file */
876static int process_markers(struct jpeg* p_jpeg)
877{
878 unsigned char c;
879 int marker_size; /* variable length of marker segment */
880 int i, j, n;
881 int ret = 0; /* returned flags */
882
883 while ((c = e_getc(p_jpeg, -1)))
884 {
885 if (c != 0xFF) /* no marker? */
886 {
887 putc(p_jpeg);
888 break; /* exit marker processing */
889 }
890
891 c = e_getc(p_jpeg, -1);
892 switch (c)
893 {
894 case 0xFF: /* Fill byte */
895 ret |= FILL_FF;
896 case 0x00: /* Zero stuffed byte - entropy data */
897 putc(p_jpeg);
898 continue;
899
900 case 0xC0: /* SOF Huff - Baseline DCT */
901 {
902 ret |= SOF0;
903 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
904 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
905 n = e_getc(p_jpeg, -1); /* sample precision (= 8 or 12) */
906 if (n != 8)
907 {
908 return(-1); /* Unsupported sample precision */
909 }
910 p_jpeg->y_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
911 p_jpeg->y_size |= e_getc(p_jpeg, -1); /* Lowbyte */
912 p_jpeg->x_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
913 p_jpeg->x_size |= e_getc(p_jpeg, -1); /* Lowbyte */
914
915 n = (marker_size-2-6)/3;
916 if (e_getc(p_jpeg, -1) != n || (n != 1 && n != 3))
917 {
918 return(-2); /* Unsupported SOF0 component specification */
919 }
920 for (i=0; i<n; i++)
921 {
922 /* Component info */
923 p_jpeg->frameheader[i].ID = e_getc(p_jpeg, -1);
924 p_jpeg->frameheader[i].horizontal_sampling =
925 (c = e_getc(p_jpeg, -1)) >> 4;
926 p_jpeg->frameheader[i].vertical_sampling = c & 0x0F;
927 p_jpeg->frameheader[i].quanttable_select =
928 e_getc(p_jpeg, -1);
929 if (p_jpeg->frameheader[i].horizontal_sampling > 2
930 || p_jpeg->frameheader[i].vertical_sampling > 2)
931 return -3; /* Unsupported SOF0 subsampling */
932 }
933 p_jpeg->blocks = n;
934 }
935 break;
936
937 case 0xC1: /* SOF Huff - Extended sequential DCT*/
938 case 0xC2: /* SOF Huff - Progressive DCT*/
939 case 0xC3: /* SOF Huff - Spatial (sequential) lossless*/
940 case 0xC5: /* SOF Huff - Differential sequential DCT*/
941 case 0xC6: /* SOF Huff - Differential progressive DCT*/
942 case 0xC7: /* SOF Huff - Differential spatial*/
943 case 0xC8: /* SOF Arith - Reserved for JPEG extensions*/
944 case 0xC9: /* SOF Arith - Extended sequential DCT*/
945 case 0xCA: /* SOF Arith - Progressive DCT*/
946 case 0xCB: /* SOF Arith - Spatial (sequential) lossless*/
947 case 0xCD: /* SOF Arith - Differential sequential DCT*/
948 case 0xCE: /* SOF Arith - Differential progressive DCT*/
949 case 0xCF: /* SOF Arith - Differential spatial*/
950 {
951 return (-4); /* other DCT model than baseline not implemented */
952 }
953
954 case 0xC4: /* Define Huffman Table(s) */
955 {
956 ret |= DHT;
957 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
958 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
959 marker_size -= 2;
960
961 while (marker_size > 17) /* another table */
962 {
963 c = e_getc(p_jpeg, -1);
964 marker_size--;
965 int sum = 0;
966 i = c & 0x0F; /* table index */
967 if (i > 1)
968 {
969 return (-5); /* Huffman table index out of range */
970 } else {
971 if (c & 0xF0) /* AC table */
972 {
973 for (j=0; j<16; j++)
974 {
975 p_jpeg->hufftable[i].huffmancodes_ac[j] =
976 (c = e_getc(p_jpeg, -1));
977 sum += c;
978 marker_size -= 1;
979 }
980 if(16 + sum > AC_LEN)
981 return -10; /* longer than allowed */
982
983 for (; j < 16 + sum; j++)
984 {
985 p_jpeg->hufftable[i].huffmancodes_ac[j] =
986 e_getc(p_jpeg, -1);
987 marker_size--;
988 }
989 }
990 else /* DC table */
991 {
992 for (j=0; j<16; j++)
993 {
994 p_jpeg->hufftable[i].huffmancodes_dc[j] =
995 (c = e_getc(p_jpeg, -1));
996 sum += c;
997 marker_size--;
998 }
999 if(16 + sum > DC_LEN)
1000 return -11; /* longer than allowed */
1001
1002 for (; j < 16 + sum; j++)
1003 {
1004 p_jpeg->hufftable[i].huffmancodes_dc[j] =
1005 e_getc(p_jpeg, -1);
1006 marker_size--;
1007 }
1008 }
1009 }
1010 } /* while */
1011 e_skip_bytes(p_jpeg, marker_size);
1012 }
1013 break;
1014
1015 case 0xCC: /* Define Arithmetic coding conditioning(s) */
1016 return(-6); /* Arithmetic coding not supported */
1017
1018 case 0xD8: /* Start of Image */
1019 case 0xD9: /* End of Image */
1020 case 0x01: /* for temp private use arith code */
1021 break; /* skip parameterless marker */
1022
1023
1024 case 0xDA: /* Start of Scan */
1025 {
1026 ret |= SOS;
1027 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
1028 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
1029 marker_size -= 2;
1030
1031 n = (marker_size-1-3)/2;
1032 if (e_getc(p_jpeg, -1) != n || (n != 1 && n != 3))
1033 {
1034 return (-7); /* Unsupported SOS component specification */
1035 }
1036 marker_size--;
1037 for (i=0; i<n; i++)
1038 {
1039 p_jpeg->scanheader[i].ID = e_getc(p_jpeg, -1);
1040 p_jpeg->scanheader[i].DC_select = (c = e_getc(p_jpeg, -1))
1041 >> 4;
1042 p_jpeg->scanheader[i].AC_select = c & 0x0F;
1043 marker_size -= 2;
1044 }
1045 /* skip spectral information */
1046 e_skip_bytes(p_jpeg, marker_size);
1047 }
1048 break;
1049
1050 case 0xDB: /* Define quantization Table(s) */
1051 {
1052 ret |= DQT;
1053 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
1054 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
1055 marker_size -= 2;
1056
1057 n = (marker_size)/(QUANT_TABLE_LENGTH+1); /* # of tables */
1058 for (i=0; i<n; i++)
1059 {
1060 int id = e_getc(p_jpeg, -1); /* ID */
1061 marker_size--;
1062 if (id >= 4)
1063 {
1064 return (-8); /* Unsupported quantization table */
1065 }
1066 /* Read Quantisation table: */
1067 for (j=0; j<QUANT_TABLE_LENGTH; j++)
1068 {
1069 p_jpeg->quanttable[id][j] = e_getc(p_jpeg, -1);
1070 marker_size--;
1071 }
1072 }
1073 e_skip_bytes(p_jpeg, marker_size);
1074 }
1075 break;
1076
1077 case 0xDD: /* Define Restart Interval */
1078 {
1079 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
1080 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
1081 marker_size -= 4;
1082 /* Highbyte */
1083 p_jpeg->restart_interval = e_getc(p_jpeg, -1) << 8;
1084 p_jpeg->restart_interval |= e_getc(p_jpeg, -1); /* Lowbyte */
1085 e_skip_bytes(p_jpeg, marker_size); /* skip segment */
1086 }
1087 break;
1088
1089 case 0xDC: /* Define Number of Lines */
1090 case 0xDE: /* Define Hierarchical progression */
1091 case 0xDF: /* Expand Reference Component(s) */
1092 case 0xE0: /* Application Field 0*/
1093 case 0xE1: /* Application Field 1*/
1094 case 0xE2: /* Application Field 2*/
1095 case 0xE3: /* Application Field 3*/
1096 case 0xE4: /* Application Field 4*/
1097 case 0xE5: /* Application Field 5*/
1098 case 0xE6: /* Application Field 6*/
1099 case 0xE7: /* Application Field 7*/
1100 case 0xE8: /* Application Field 8*/
1101 case 0xE9: /* Application Field 9*/
1102 case 0xEA: /* Application Field 10*/
1103 case 0xEB: /* Application Field 11*/
1104 case 0xEC: /* Application Field 12*/
1105 case 0xED: /* Application Field 13*/
1106 case 0xEE: /* Application Field 14*/
1107 case 0xEF: /* Application Field 15*/
1108 case 0xFE: /* Comment */
1109 {
1110 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
1111 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
1112 marker_size -= 2;
1113 e_skip_bytes(p_jpeg, marker_size); /* skip segment */
1114 }
1115 break;
1116
1117 case 0xF0: /* Reserved for JPEG extensions */
1118 case 0xF1: /* Reserved for JPEG extensions */
1119 case 0xF2: /* Reserved for JPEG extensions */
1120 case 0xF3: /* Reserved for JPEG extensions */
1121 case 0xF4: /* Reserved for JPEG extensions */
1122 case 0xF5: /* Reserved for JPEG extensions */
1123 case 0xF6: /* Reserved for JPEG extensions */
1124 case 0xF7: /* Reserved for JPEG extensions */
1125 case 0xF8: /* Reserved for JPEG extensions */
1126 case 0xF9: /* Reserved for JPEG extensions */
1127 case 0xFA: /* Reserved for JPEG extensions */
1128 case 0xFB: /* Reserved for JPEG extensions */
1129 case 0xFC: /* Reserved for JPEG extensions */
1130 case 0xFD: /* Reserved for JPEG extensions */
1131 case 0x02: /* Reserved */
1132 default:
1133 return (-9); /* Unknown marker */
1134 } /* switch */
1135 } /* while */
1136
1137 return (ret); /* return flags with seen markers */
1138}
1139
1140static const struct huffman_table luma_table =
1141{
1142 {
1143 0x00,0x01,0x05,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,0x00,
1144 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B
1145 },
1146 {
1147 0x00,0x02,0x01,0x03,0x03,0x02,0x04,0x03,0x05,0x05,0x04,0x04,0x00,0x00,
1148 0x01,0x7D,0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,
1149 0x13,0x51,0x61,0x07,0x22,0x71,0x14,0x32,0x81,0x91,0xA1,0x08,0x23,0x42,
1150 0xB1,0xC1,0x15,0x52,0xD1,0xF0,0x24,0x33,0x62,0x72,0x82,0x09,0x0A,0x16,
1151 0x17,0x18,0x19,0x1A,0x25,0x26,0x27,0x28,0x29,0x2A,0x34,0x35,0x36,0x37,
1152 0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x53,0x54,0x55,
1153 0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x73,
1154 0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x83,0x84,0x85,0x86,0x87,0x88,0x89,
1155 0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,
1156 0xA6,0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,
1157 0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,
1158 0xD7,0xD8,0xD9,0xDA,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,
1159 0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA
1160 }
1161};
1162
1163static const struct huffman_table chroma_table =
1164{
1165 {
1166 0x00,0x03,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,
1167 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B
1168 },
1169 {
1170 0x00,0x02,0x01,0x02,0x04,0x04,0x03,0x04,0x07,0x05,0x04,0x04,0x00,0x01,
1171 0x02,0x77,0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,
1172 0x51,0x07,0x61,0x71,0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,0xA1,0xB1,
1173 0xC1,0x09,0x23,0x33,0x52,0xF0,0x15,0x62,0x72,0xD1,0x0A,0x16,0x24,0x34,
1174 0xE1,0x25,0xF1,0x17,0x18,0x19,0x1A,0x26,0x27,0x28,0x29,0x2A,0x35,0x36,
1175 0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x53,0x54,
1176 0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,
1177 0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x82,0x83,0x84,0x85,0x86,0x87,
1178 0x88,0x89,0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,
1179 0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,
1180 0xB9,0xBA,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,
1181 0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,
1182 0xEA,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA
1183 }
1184};
1185
1186static void default_huff_tbl(struct jpeg* p_jpeg)
1187{
1188
1189 MEMCPY(&p_jpeg->hufftable[0], &luma_table, sizeof(luma_table));
1190 MEMCPY(&p_jpeg->hufftable[1], &chroma_table, sizeof(chroma_table));
1191
1192 return;
1193}
1194
1195/* Compute the derived values for a Huffman table */
1196static void fix_huff_tbl(int* htbl, struct derived_tbl* dtbl)
1197{
1198 int p, i, l, si;
1199 int lookbits, ctr;
1200 char huffsize[257];
1201 unsigned int huffcode[257];
1202 unsigned int code;
1203
1204 dtbl->pub = htbl; /* fill in back link */
1205
1206 /* Figure C.1: make table of Huffman code length for each symbol */
1207 /* Note that this is in code-length order. */
1208
1209 p = 0;
1210 for (l = 1; l <= 16; l++)
1211 { /* all possible code length */
1212 for (i = 1; i <= (int) htbl[l-1]; i++) /* all codes per length */
1213 huffsize[p++] = (char) l;
1214 }
1215 huffsize[p] = 0;
1216
1217 /* Figure C.2: generate the codes themselves */
1218 /* Note that this is in code-length order. */
1219
1220 code = 0;
1221 si = huffsize[0];
1222 p = 0;
1223 while (huffsize[p])
1224 {
1225 while (((int) huffsize[p]) == si)
1226 {
1227 huffcode[p++] = code;
1228 code++;
1229 }
1230 code <<= 1;
1231 si++;
1232 }
1233
1234 /* Figure F.15: generate decoding tables for bit-sequential decoding */
1235
1236 p = 0;
1237 for (l = 1; l <= 16; l++)
1238 {
1239 if (htbl[l-1])
1240 {
1241 /* huffval[] index of 1st symbol of code length l */
1242 dtbl->valptr[l] = p;
1243 dtbl->mincode[l] = huffcode[p]; /* minimum code of length l */
1244 p += htbl[l-1];
1245 dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
1246 }
1247 else
1248 {
1249 dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
1250 }
1251 }
1252 dtbl->maxcode[17] = 0xFFFFFL; /* ensures huff_DECODE terminates */
1253
1254 /* Compute lookahead tables to speed up decoding.
1255 * First we set all the table entries to 0, indicating "too long";
1256 * then we iterate through the Huffman codes that are short enough and
1257 * fill in all the entries that correspond to bit sequences starting
1258 * with that code.
1259 */
1260
1261 MEMSET(dtbl->look_nbits, 0, sizeof(dtbl->look_nbits));
1262
1263 p = 0;
1264 for (l = 1; l <= HUFF_LOOKAHEAD; l++)
1265 {
1266 for (i = 1; i <= (int) htbl[l-1]; i++, p++)
1267 {
1268 /* l = current code's length, p = its index in huffcode[] &
1269 * huffval[]. Generate left-justified code followed by all possible
1270 * bit sequences
1271 */
1272 lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
1273 for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--)
1274 {
1275 dtbl->look_nbits[lookbits] = l;
1276 dtbl->look_sym[lookbits] = htbl[16+p];
1277 lookbits++;
1278 }
1279 }
1280 }
1281}
1282
1283
1284/* zag[i] is the natural-order position of the i'th element of zigzag order.
1285 * If the incoming data is corrupted, decode_mcu could attempt to
1286 * reference values beyond the end of the array. To avoid a wild store,
1287 * we put some extra zeroes after the real entries.
1288 */
1289static const unsigned char zag[] =
1290{
1291 0, 1, 8, 16, 9, 2, 3, 10,
1292 17, 24, 32, 25, 18, 11, 4, 5,
1293 12, 19, 26, 33, 40, 48, 41, 34,
1294 27, 20, 13, 6, 7, 14, 21, 28,
1295 35, 42, 49, 56, 57, 50, 43, 36,
1296 29, 22, 15, 23, 30, 37, 44, 51,
1297 58, 59, 52, 45, 38, 31, 39, 46,
1298 53, 60, 61, 54, 47, 55, 62, 63,
1299 0, 0, 0, 0, 0, 0, 0, 0, /* extra entries in case k>63 below */
1300 0, 0, 0, 0, 0, 0, 0, 0
1301};
1302
1303/* zig[i] is the the zig-zag order position of the i'th element of natural
1304 * order, reading left-to-right then top-to-bottom.
1305 */
1306static const unsigned char zig[] =
1307{
1308 0, 1, 5, 6, 14, 15, 27, 28,
1309 2, 4, 7, 13, 16, 26, 29, 42,
1310 3, 8, 12, 17, 25, 30, 41, 43,
1311 9, 11, 18, 24, 31, 40, 44, 53,
1312 10, 19, 23, 32, 39, 45, 52, 54,
1313 20, 22, 33, 38, 46, 51, 55, 60,
1314 21, 34, 37, 47, 50, 56, 59, 61,
1315 35, 36, 48, 49, 57, 58, 62, 63
1316};
1317
1318/* Reformat some image header data so that the decoder can use it properly. */
1319INLINE void fix_headers(struct jpeg* p_jpeg)
1320{
1321 int i;
1322
1323 for (i=0; i<4; i++)
1324 p_jpeg->store_pos[i] = i; /* default ordering */
1325
1326 /* assignments for the decoding of blocks */
1327 if (p_jpeg->frameheader[0].horizontal_sampling == 2
1328 && p_jpeg->frameheader[0].vertical_sampling == 1)
1329 { /* 4:2:2 */
1330 p_jpeg->blocks = 4;
1331 p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16;
1332 p_jpeg->x_phys = p_jpeg->x_mbl * 16;
1333 p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
1334 p_jpeg->y_phys = p_jpeg->y_mbl * 8;
1335 p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
1336 p_jpeg->mcu_membership[1] = 0;
1337 p_jpeg->mcu_membership[2] = 1;
1338 p_jpeg->mcu_membership[3] = 2;
1339 p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
1340 p_jpeg->tab_membership[1] = 0;
1341 p_jpeg->tab_membership[2] = 1;
1342 p_jpeg->tab_membership[3] = 1;
1343 p_jpeg->subsample_x[0] = 1;
1344 p_jpeg->subsample_x[1] = 2;
1345 p_jpeg->subsample_x[2] = 2;
1346 p_jpeg->subsample_y[0] = 1;
1347 p_jpeg->subsample_y[1] = 1;
1348 p_jpeg->subsample_y[2] = 1;
1349 }
1350 if (p_jpeg->frameheader[0].horizontal_sampling == 1
1351 && p_jpeg->frameheader[0].vertical_sampling == 2)
1352 { /* 4:2:2 vertically subsampled */
1353 p_jpeg->store_pos[1] = 2; /* block positions are mirrored */
1354 p_jpeg->store_pos[2] = 1;
1355 p_jpeg->blocks = 4;
1356 p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8;
1357 p_jpeg->x_phys = p_jpeg->x_mbl * 8;
1358 p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16;
1359 p_jpeg->y_phys = p_jpeg->y_mbl * 16;
1360 p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
1361 p_jpeg->mcu_membership[1] = 0;
1362 p_jpeg->mcu_membership[2] = 1;
1363 p_jpeg->mcu_membership[3] = 2;
1364 p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
1365 p_jpeg->tab_membership[1] = 0;
1366 p_jpeg->tab_membership[2] = 1;
1367 p_jpeg->tab_membership[3] = 1;
1368 p_jpeg->subsample_x[0] = 1;
1369 p_jpeg->subsample_x[1] = 1;
1370 p_jpeg->subsample_x[2] = 1;
1371 p_jpeg->subsample_y[0] = 1;
1372 p_jpeg->subsample_y[1] = 2;
1373 p_jpeg->subsample_y[2] = 2;
1374 }
1375 else if (p_jpeg->frameheader[0].horizontal_sampling == 2
1376 && p_jpeg->frameheader[0].vertical_sampling == 2)
1377 { /* 4:2:0 */
1378 p_jpeg->blocks = 6;
1379 p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16;
1380 p_jpeg->x_phys = p_jpeg->x_mbl * 16;
1381 p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16;
1382 p_jpeg->y_phys = p_jpeg->y_mbl * 16;
1383 p_jpeg->mcu_membership[0] = 0;
1384 p_jpeg->mcu_membership[1] = 0;
1385 p_jpeg->mcu_membership[2] = 0;
1386 p_jpeg->mcu_membership[3] = 0;
1387 p_jpeg->mcu_membership[4] = 1;
1388 p_jpeg->mcu_membership[5] = 2;
1389 p_jpeg->tab_membership[0] = 0;
1390 p_jpeg->tab_membership[1] = 0;
1391 p_jpeg->tab_membership[2] = 0;
1392 p_jpeg->tab_membership[3] = 0;
1393 p_jpeg->tab_membership[4] = 1;
1394 p_jpeg->tab_membership[5] = 1;
1395 p_jpeg->subsample_x[0] = 1;
1396 p_jpeg->subsample_x[1] = 2;
1397 p_jpeg->subsample_x[2] = 2;
1398 p_jpeg->subsample_y[0] = 1;
1399 p_jpeg->subsample_y[1] = 2;
1400 p_jpeg->subsample_y[2] = 2;
1401 }
1402 else if (p_jpeg->frameheader[0].horizontal_sampling == 1
1403 && p_jpeg->frameheader[0].vertical_sampling == 1)
1404 { /* 4:4:4 */
1405 /* don't overwrite p_jpeg->blocks */
1406 p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8;
1407 p_jpeg->x_phys = p_jpeg->x_mbl * 8;
1408 p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
1409 p_jpeg->y_phys = p_jpeg->y_mbl * 8;
1410 p_jpeg->mcu_membership[0] = 0;
1411 p_jpeg->mcu_membership[1] = 1;
1412 p_jpeg->mcu_membership[2] = 2;
1413 p_jpeg->tab_membership[0] = 0;
1414 p_jpeg->tab_membership[1] = 1;
1415 p_jpeg->tab_membership[2] = 1;
1416 p_jpeg->subsample_x[0] = 1;
1417 p_jpeg->subsample_x[1] = 1;
1418 p_jpeg->subsample_x[2] = 1;
1419 p_jpeg->subsample_y[0] = 1;
1420 p_jpeg->subsample_y[1] = 1;
1421 p_jpeg->subsample_y[2] = 1;
1422 }
1423 else
1424 {
1425 /* error */
1426 }
1427
1428}
1429
1430INLINE void fix_huff_tables(struct jpeg *p_jpeg)
1431{
1432 fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_dc,
1433 &p_jpeg->dc_derived_tbls[0]);
1434 fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_ac,
1435 &p_jpeg->ac_derived_tbls[0]);
1436 fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_dc,
1437 &p_jpeg->dc_derived_tbls[1]);
1438 fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_ac,
1439 &p_jpeg->ac_derived_tbls[1]);
1440}
1441
1442/* Because some of the IDCT routines never multiply by any constants, and
1443 * therefore do not produce shifted output, we add the shift into the
1444 * quantization table when one of these IDCT routines is used, rather than
1445 * have the IDCT shift each value it processes.
1446 */
1447INLINE void fix_quant_tables(struct jpeg *p_jpeg)
1448{
1449 int shift, i, x, y, a;
1450 for (i = 0; i < 2; i++)
1451 {
1452 shift = idct_tbl[p_jpeg->v_scale[i]].v_scale +
1453 idct_tbl[p_jpeg->h_scale[i]].h_scale;
1454 if (shift)
1455 {
1456 a = 0;
1457 for (y = 0; y < 1 << p_jpeg->h_scale[i]; y++)
1458 {
1459 for (x = 0; x < 1 << p_jpeg->v_scale[i]; x++)
1460 p_jpeg->quanttable[i][zig[a+x]] <<= shift;
1461 a += 8;
1462 }
1463 }
1464 }
1465}
1466
1467/*
1468* These functions/macros provide the in-line portion of bit fetching.
1469* Use check_bit_buffer to ensure there are N bits in get_buffer
1470* before using get_bits, peek_bits, or drop_bits.
1471* check_bit_buffer(state,n,action);
1472* Ensure there are N bits in get_buffer; if suspend, take action.
1473* val = get_bits(n);
1474* Fetch next N bits.
1475* val = peek_bits(n);
1476* Fetch next N bits without removing them from the buffer.
1477* drop_bits(n);
1478* Discard next N bits.
1479* The value N should be a simple variable, not an expression, because it
1480* is evaluated multiple times.
1481*/
1482
1483static void fill_bit_buffer(struct jpeg* p_jpeg)
1484{
1485 unsigned char byte, marker;
1486
1487 if (p_jpeg->marker_val)
1488 p_jpeg->marker_ind += 16;
1489 byte = d_getc(p_jpeg, 0);
1490 if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */
1491 { /* simplification: just skip the (one-byte) marker code */
1492 marker = d_getc(p_jpeg, 0);
1493 if ((marker & ~7) == 0xD0)
1494 {
1495 p_jpeg->marker_val = marker;
1496 p_jpeg->marker_ind = 8;
1497 }
1498 }
1499 p_jpeg->bitbuf = (p_jpeg->bitbuf << 8) | byte;
1500
1501 byte = d_getc(p_jpeg, 0);
1502 if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */
1503 { /* simplification: just skip the (one-byte) marker code */
1504 marker = d_getc(p_jpeg, 0);
1505 if ((marker & ~7) == 0xD0)
1506 {
1507 p_jpeg->marker_val = marker;
1508 p_jpeg->marker_ind = 0;
1509 }
1510 }
1511 p_jpeg->bitbuf = (p_jpeg->bitbuf << 8) | byte;
1512 p_jpeg->bitbuf_bits += 16;
1513#ifdef JPEG_BS_DEBUG
1514 DEBUGF("read in: %X\n", p_jpeg->bitbuf & 0xFFFF);
1515#endif
1516}
1517
1518INLINE void check_bit_buffer(struct jpeg *p_jpeg, int nbits)
1519{
1520 if (nbits > p_jpeg->bitbuf_bits)
1521 fill_bit_buffer(p_jpeg);
1522}
1523
1524INLINE int get_bits(struct jpeg *p_jpeg, int nbits)
1525{
1526#ifdef JPEG_BS_DEBUG
1527 if (nbits > p_jpeg->bitbuf_bits)
1528 DEBUGF("bitbuffer underrun\n");
1529 int mask = 1 << (p_jpeg->bitbuf_bits - 1);
1530 int i;
1531 DEBUGF("get %d bits: ", nbits);
1532 for (i = 0; i < nbits; i++)
1533 DEBUGF("%d",!!(p_jpeg->bitbuf & (mask >>= 1)));
1534 DEBUGF("\n");
1535#endif
1536 return ((int) (p_jpeg->bitbuf >> (p_jpeg->bitbuf_bits -= nbits))) &
1537 ((1<<nbits)-1);
1538}
1539
1540INLINE int peek_bits(struct jpeg *p_jpeg, int nbits)
1541{
1542#ifdef JPEG_BS_DEBUG
1543 int mask = 1 << (p_jpeg->bitbuf_bits - 1);
1544 int i;
1545 DEBUGF("peek %d bits: ", nbits);
1546 for (i = 0; i < nbits; i++)
1547 DEBUGF("%d",!!(p_jpeg->bitbuf & (mask >>= 1)));
1548 DEBUGF("\n");
1549#endif
1550 return ((int) (p_jpeg->bitbuf >> (p_jpeg->bitbuf_bits - nbits))) &
1551 ((1<<nbits)-1);
1552}
1553
1554INLINE void drop_bits(struct jpeg *p_jpeg, int nbits)
1555{
1556#ifdef JPEG_BS_DEBUG
1557 int mask = 1 << (p_jpeg->bitbuf_bits - 1);
1558 int i;
1559 DEBUGF("drop %d bits: ", nbits);
1560 for (i = 0; i < nbits; i++)
1561 DEBUGF("%d",!!(p_jpeg->bitbuf & (mask >>= 1)));
1562 DEBUGF("\n");
1563#endif
1564 p_jpeg->bitbuf_bits -= nbits;
1565}
1566
1567/* re-synchronize to entropy data (skip restart marker) */
1568static void search_restart(struct jpeg *p_jpeg)
1569{
1570 if (p_jpeg->marker_val)
1571 {
1572 p_jpeg->marker_val = 0;
1573 p_jpeg->bitbuf_bits = p_jpeg->marker_ind;
1574 p_jpeg->marker_ind = 0;
1575 return;
1576 }
1577 unsigned char byte;
1578 p_jpeg->bitbuf_bits = 0;
1579 while ((byte = d_getc(p_jpeg, 0xFF)))
1580 {
1581 if (byte == 0xff)
1582 {
1583 byte = d_getc(p_jpeg, 0xD0);
1584 if ((byte & ~7) == 0xD0)
1585 {
1586 return;
1587 }
1588 else
1589 putc(p_jpeg);
1590 }
1591 }
1592}
1593
1594/* Figure F.12: extend sign bit. */
1595#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
1596
1597static const int extend_test[16] = /* entry n is 2**(n-1) */
1598{
1599 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
1600 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000
1601};
1602
1603static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
1604{
1605 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
1606 ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
1607 ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
1608 ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1
1609};
1610
1611/* Decode a single value */
1612INLINE int huff_decode_dc(struct jpeg *p_jpeg, struct derived_tbl* tbl)
1613{
1614 int nb, look, s, r;
1615
1616 check_bit_buffer(p_jpeg, HUFF_LOOKAHEAD);
1617 look = peek_bits(p_jpeg, HUFF_LOOKAHEAD);
1618 if ((nb = tbl->look_nbits[look]) != 0)
1619 {
1620 drop_bits(p_jpeg, nb);
1621 s = tbl->look_sym[look];
1622 check_bit_buffer(p_jpeg, s);
1623 r = get_bits(p_jpeg, s);
1624 s = HUFF_EXTEND(r, s);
1625 }
1626 else
1627 { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */
1628 long code;
1629 nb=HUFF_LOOKAHEAD+1;
1630 check_bit_buffer(p_jpeg, nb);
1631 code = get_bits(p_jpeg, nb);
1632 while (code > tbl->maxcode[nb])
1633 {
1634 code <<= 1;
1635 check_bit_buffer(p_jpeg, 1);
1636 code |= get_bits(p_jpeg, 1);
1637 nb++;
1638 }
1639 if (nb > 16) /* error in Huffman */
1640 {
1641 s=0; /* fake a zero, this is most safe */
1642 }
1643 else
1644 {
1645 s = tbl->pub[16 + tbl->valptr[nb] +
1646 ((int) (code - tbl->mincode[nb]))];
1647 check_bit_buffer(p_jpeg, s);
1648 r = get_bits(p_jpeg, s);
1649 s = HUFF_EXTEND(r, s);
1650 }
1651 } /* end slow decode */
1652 return s;
1653}
1654
1655INLINE int huff_decode_ac(struct jpeg *p_jpeg, struct derived_tbl* tbl)
1656{
1657 int nb, look, s;
1658
1659 check_bit_buffer(p_jpeg, HUFF_LOOKAHEAD);
1660 look = peek_bits(p_jpeg, HUFF_LOOKAHEAD);
1661 if ((nb = tbl->look_nbits[look]) != 0)
1662 {
1663 drop_bits(p_jpeg, nb);
1664 s = tbl->look_sym[look];
1665 }
1666 else
1667 { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */
1668 long code;
1669 nb=HUFF_LOOKAHEAD+1;
1670 check_bit_buffer(p_jpeg, nb);
1671 code = get_bits(p_jpeg, nb);
1672 while (code > tbl->maxcode[nb])
1673 {
1674 code <<= 1;
1675 check_bit_buffer(p_jpeg, 1);
1676 code |= get_bits(p_jpeg, 1);
1677 nb++;
1678 }
1679 if (nb > 16) /* error in Huffman */
1680 {
1681 s=0; /* fake a zero, this is most safe */
1682 }
1683 else
1684 {
1685 s = tbl->pub[16 + tbl->valptr[nb] +
1686 ((int) (code - tbl->mincode[nb]))];
1687 }
1688 } /* end slow decode */
1689 return s;
1690}
1691
1692struct img_part *store_row_jpeg(void *jpeg_args)
1693{
1694 struct jpeg *p_jpeg = (struct jpeg*) jpeg_args;
1695 unsigned int width = p_jpeg->x_mbl << p_jpeg->h_scale[1];
1696 unsigned int b_width = width * JPEG_PIX_SZ;
1697 int height = 1U << p_jpeg->v_scale[1];
1698 int x;
1699 if (!p_jpeg->mcu_row) /* Need to decode a new row of MCUs */
1700 {
1701 p_jpeg->out_ptr = (unsigned char *)p_jpeg->img_buf;
1702 int store_offs[4];
1703 int mcu_offset = JPEG_PIX_SZ << p_jpeg->h_scale[1];
1704 unsigned char *out = p_jpeg->out_ptr;
1705 store_offs[p_jpeg->store_pos[0]] = 0;
1706 store_offs[p_jpeg->store_pos[1]] = JPEG_PIX_SZ << p_jpeg->h_scale[0];
1707 store_offs[p_jpeg->store_pos[2]] = b_width << p_jpeg->v_scale[0];
1708 store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2];
1709
1710 int block[128]; /* decoded DCT coefficients */
1711 for (x = 0; x < p_jpeg->x_mbl; x++)
1712 {
1713 int blkn;
1714 for (blkn = 0; blkn < p_jpeg->blocks; blkn++)
1715 {
1716 int k = 1; /* coefficient index */
1717 int s, r; /* huffman values */
1718 int ci = p_jpeg->mcu_membership[blkn]; /* component index */
1719 int ti = p_jpeg->tab_membership[blkn]; /* table index */
1720 struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti];
1721 struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti];
1722
1723 /* Section F.2.2.1: decode the DC coefficient difference */
1724 s = huff_decode_dc(p_jpeg, dctbl);
1725
1726#ifndef HAVE_LCD_COLOR
1727 if (!ci)
1728#endif
1729 {
1730#ifdef HAVE_LCD_COLOR
1731 p_jpeg->last_dc_val[ci] += s;
1732 /* output it (assumes zag[0] = 0) */
1733 block[0] = p_jpeg->last_dc_val[ci] *
1734 p_jpeg->quanttable[!!ci][0];
1735#else
1736 p_jpeg->last_dc_val += s;
1737 /* output it (assumes zag[0] = 0) */
1738 block[0] = p_jpeg->last_dc_val *
1739 p_jpeg->quanttable[!!ci][0];
1740#endif
1741 /* coefficient buffer must be cleared */
1742 MEMSET(block+1, 0, p_jpeg->zero_need[!!ci] * sizeof(int));
1743 /* Section F.2.2.2: decode the AC coefficients */
1744 for (; k < p_jpeg->k_need[!!ci]; k++)
1745 {
1746 s = huff_decode_ac(p_jpeg, actbl);
1747 r = s >> 4;
1748 s &= 15;
1749 if (s)
1750 {
1751 k += r;
1752 check_bit_buffer(p_jpeg, s);
1753 r = get_bits(p_jpeg, s);
1754 r = HUFF_EXTEND(r, s);
1755 int a = zag[k];
1756 if (a <= zag[p_jpeg->k_need[!!ci]] && (a & 7) <=
1757 (zag[p_jpeg->k_need[!!ci]] & 7))
1758 {
1759 r *= p_jpeg->quanttable[!!ci][k];
1760 block[zag[k]] = r ;
1761 }
1762 }
1763 else
1764 {
1765 if (r != 15)
1766 {
1767 k = 64;
1768 break;
1769 }
1770 k += r;
1771 }
1772 } /* for k */
1773 }
1774 for (; k < 64; k++)
1775 {
1776 s = huff_decode_ac(p_jpeg, actbl);
1777 r = s >> 4;
1778 s &= 15;
1779
1780 if (s)
1781 {
1782 k += r;
1783 check_bit_buffer(p_jpeg, s);
1784 drop_bits(p_jpeg, s);
1785 }
1786 else
1787 {
1788 if (r != 15)
1789 break;
1790 k += r;
1791 }
1792 } /* for k */
1793#ifndef HAVE_LCD_COLOR
1794 if (!ci)
1795#endif
1796 {
1797 unsigned char si = !!ci;
1798 int idct_cols = 1 << MIN(p_jpeg->h_scale[si], 3);
1799 int idct_rows = 1 << p_jpeg->v_scale[si];
1800 unsigned char *b_out = out + (ci ? ci : store_offs[blkn]);
1801 if (idct_tbl[p_jpeg->v_scale[si]].v_idct)
1802 idct_tbl[p_jpeg->v_scale[si]].v_idct(block, idct_cols);
1803 idct_tbl[p_jpeg->h_scale[si]].h_idct(block, b_out,
1804 idct_rows, b_width);
1805 }
1806 } /* for blkn */
1807 /* don't starve other threads while an MCU row decodes */
1808 yield();
1809#ifdef HAVE_LCD_COLOR
1810 unsigned int xp;
1811 int yp;
1812 unsigned char *row = out;
1813 if (p_jpeg->blocks > 1) {
1814 for (yp = 0; yp < height; yp++, row += b_width)
1815 {
1816 unsigned char *px = row;
1817 for (xp = 0; xp < 1U << p_jpeg->h_scale[1];
1818 xp++, px += JPEG_PIX_SZ)
1819 {
1820 int y, u, v, rv, guv, bu;
1821 y = px[0] * YFAC + (YFAC >> 1);
1822 u = px[1] - 128;
1823 v = px[2] - 128;
1824 rv = RVFAC * v;
1825 guv = GUFAC * u + GVFAC * v;
1826 bu = BUFAC * u;
1827 struct uint8_rgb *rgb = (struct uint8_rgb *)px;
1828 rgb->red = clamp_component((y + rv) / YFAC);
1829 rgb->green = clamp_component((y + guv) / YFAC);
1830 rgb->blue = clamp_component((y + bu) / YFAC);
1831 }
1832 }
1833 } else {
1834 for (yp = 0; yp < height; yp++, row += b_width)
1835 {
1836 unsigned char *px = row;
1837 for (xp = 0; xp < 1U << p_jpeg->h_scale[1];
1838 xp++, px += JPEG_PIX_SZ)
1839 {
1840 px[1] = px[2] = px[0];
1841 }
1842 }
1843 }
1844#endif
1845 out += mcu_offset;
1846 if (p_jpeg->restart_interval && --p_jpeg->restart == 0)
1847 { /* if a restart marker is due: */
1848 p_jpeg->restart = p_jpeg->restart_interval; /* count again */
1849 search_restart(p_jpeg); /* align the bitstream */
1850#ifdef HAVE_LCD_COLOR
1851 p_jpeg->last_dc_val[0] = p_jpeg->last_dc_val[1] =
1852 p_jpeg->last_dc_val[2] = 0; /* reset decoder */
1853#else
1854 p_jpeg->last_dc_val = 0;
1855#endif
1856 }
1857 }
1858 } /* if !p_jpeg->mcu_row */
1859 p_jpeg->mcu_row = (p_jpeg->mcu_row + 1) & (height - 1);
1860 p_jpeg->part.len = width;
1861 p_jpeg->part.buf = (jpeg_pix_t *)p_jpeg->out_ptr;
1862 p_jpeg->out_ptr += b_width;
1863 return &(p_jpeg->part);
1864}
1865
1866/******************************************************************************
1867 * read_jpeg_file()
1868 *
1869 * Reads a JPEG file and puts the data in rockbox format in *bitmap.
1870 *
1871 *****************************************************************************/
1872int read_jpeg_file(const char* filename,
1873 struct bitmap *bm,
1874 int maxsize,
1875 int format,
1876 const struct custom_format *cformat)
1877{
1878 int fd, ret;
1879 fd = open(filename, O_RDONLY);
1880
1881 /* Exit if file opening failed */
1882 if (fd < 0) {
1883 DEBUGF("read_jpeg_file: can't open '%s', rc: %d\n", filename, fd);
1884 return fd * 10 - 1;
1885 }
1886
1887 ret = read_jpeg_fd(fd, bm, maxsize, format, cformat);
1888 close(fd);
1889 return ret;
1890}
1891
1892static int calc_scale(int in_size, int out_size, int subsample)
1893{
1894 int scale = 0;
1895 out_size <<= 3;
1896 for (scale = 0; scale < 5 - subsample; scale++)
1897 {
1898 if (out_size <= in_size)
1899 break;
1900 else
1901 in_size <<= 1;
1902 }
1903 return scale;
1904}
1905
1906int read_jpeg_fd(int fd,
1907 struct bitmap *bm,
1908 int maxsize,
1909 int format,
1910 const struct custom_format *cformat)
1911{
1912 bool resize = false, dither = false;
1913 struct rowset rset;
1914 struct dim src_dim;
1915 struct jpeg *p_jpeg = (struct jpeg*)bm->data;
1916 int tmp_size = maxsize;
1917 int status;
1918 int bm_size;
1919 ALIGN_BUFFER(p_jpeg, tmp_size, sizeof(int));
1920 /* not enough memory for our struct jpeg */
1921 if ((size_t)tmp_size < sizeof(struct jpeg))
1922 return -1;
1923
1924 memset(p_jpeg, 0, sizeof(struct jpeg));
1925 p_jpeg->fd = fd;
1926 status = process_markers(p_jpeg);
1927 if (status < 0)
1928 return status;
1929 if ((status & (DQT | SOF0)) != (DQT | SOF0))
1930 return -(status * 16);
1931 if (!(status & DHT)) /* if no Huffman table present: */
1932 default_huff_tbl(p_jpeg); /* use default */
1933 fix_headers(p_jpeg); /* derive Huffman and other lookup-tables */
1934 src_dim.width = p_jpeg->x_size;
1935 src_dim.height = p_jpeg->y_size;
1936 if (format & FORMAT_RESIZE)
1937 resize = true;
1938 if (format & FORMAT_DITHER)
1939 dither = true;
1940 if (resize) {
1941 struct dim resize_dim = {
1942 .width = bm->width,
1943 .height = bm->height,
1944 };
1945 if (format & FORMAT_KEEP_ASPECT)
1946 recalc_dimension(&resize_dim, &src_dim);
1947 bm->width = resize_dim.width;
1948 bm->height = resize_dim.height;
1949 if (bm->width == src_dim.width && bm->height == src_dim.height)
1950 resize = false;
1951 } else {
1952 bm->width = p_jpeg->x_size;
1953 bm->height = p_jpeg->y_size;
1954 }
1955 p_jpeg->h_scale[0] = calc_scale(p_jpeg->x_size, bm->width,
1956 p_jpeg->frameheader[0].horizontal_sampling);
1957 p_jpeg->v_scale[0] = calc_scale(p_jpeg->y_size, bm->height,
1958 p_jpeg->frameheader[0].vertical_sampling);
1959 p_jpeg->h_scale[1] = p_jpeg->h_scale[0] +
1960 p_jpeg->frameheader[0].horizontal_sampling - 1;
1961 p_jpeg->v_scale[1] = p_jpeg->v_scale[0] +
1962 p_jpeg->frameheader[0].vertical_sampling - 1;
1963 fix_quant_tables(p_jpeg);
1964 int decode_w = (1 << MIN(p_jpeg->h_scale[0],3)) - 1;
1965 int decode_h = (1 << MIN(p_jpeg->v_scale[0],3)) - 1;
1966 src_dim.width = (p_jpeg->x_size << p_jpeg->h_scale[0]) >> 3;
1967 src_dim.height = (p_jpeg->y_size << p_jpeg->v_scale[0]) >> 3;
1968 p_jpeg->zero_need[0] = (decode_h << 3) + decode_w;
1969 p_jpeg->k_need[0] = zig[p_jpeg->zero_need[0]];
1970 decode_w = (1 << MIN(p_jpeg->h_scale[1],3)) - 1;
1971 decode_h = (1 << MIN(p_jpeg->v_scale[1],3)) - 1;
1972 p_jpeg->zero_need[1] = p_jpeg->zero_need[2] = (decode_h << 3) + decode_w;
1973 p_jpeg->k_need[1] = p_jpeg->k_need[2] = zig[p_jpeg->zero_need[1]];
1974 if (cformat)
1975 bm_size = cformat->get_size(bm);
1976 else
1977 bm_size = BM_SIZE(bm->width,bm->height,FORMAT_NATIVE,false);
1978 if (bm_size > maxsize)
1979 return -1;
1980 char *buf_start = (char *)bm->data + bm_size;
1981 char *buf_end = (char *)bm->data + maxsize;
1982 maxsize = buf_end - buf_start;
1983 ALIGN_BUFFER(buf_start, maxsize, sizeof(uint32_t));
1984 if (maxsize < (int)sizeof(struct jpeg))
1985 return -1;
1986 memmove(buf_start, p_jpeg, sizeof(struct jpeg));
1987 p_jpeg = (struct jpeg *)buf_start;
1988 fix_huff_tables(p_jpeg);
1989 buf_start += sizeof(struct jpeg);
1990 maxsize = buf_end - buf_start;
1991 int decode_buf_size = (p_jpeg->x_mbl << p_jpeg->h_scale[1])
1992 << p_jpeg->v_scale[1];
1993 decode_buf_size *= JPEG_PIX_SZ;
1994 p_jpeg->img_buf = (jpeg_pix_t *)buf_start;
1995 if (buf_end - buf_start < decode_buf_size)
1996 return -1;
1997 buf_start += decode_buf_size;
1998 maxsize = buf_end - buf_start;
1999 memset(p_jpeg->img_buf, 0, decode_buf_size);
2000 p_jpeg->mcu_row = 0;
2001 p_jpeg->restart = p_jpeg->restart_interval;
2002 rset.rowstart = 0;
2003 rset.rowstop = bm->height;
2004 rset.rowstep = 1;
2005 if (resize_on_load(bm, dither, &src_dim, &rset, buf_start, maxsize, cformat,
2006 store_row_jpeg, p_jpeg))
2007 return bm_size;
2008 else
2009 return 0;
2010}
2011
2012/**************** end JPEG code ********************/
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-23 20:25:11 +0000