1 : /*
2 : * jcparam.c
3 : *
4 : * Copyright (C) 1991-1998, Thomas G. Lane.
5 : * Modified 2003-2008 by Guido Vollbeding.
6 : * Copyright (C) 2009-2011, D. R. Commander.
7 : * This file is part of the Independent JPEG Group's software.
8 : * For conditions of distribution and use, see the accompanying README file.
9 : *
10 : * This file contains optional default-setting code for the JPEG compressor.
11 : * Applications do not have to use this file, but those that don't use it
12 : * must know a lot more about the innards of the JPEG code.
13 : */
14 :
15 : #define JPEG_INTERNALS
16 : #include "jinclude.h"
17 : #include "jpeglib.h"
18 :
19 :
20 : /*
21 : * Quantization table setup routines
22 : */
23 :
24 : GLOBAL(void)
25 12 : jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
26 : const unsigned int *basic_table,
27 : int scale_factor, boolean force_baseline)
28 : /* Define a quantization table equal to the basic_table times
29 : * a scale factor (given as a percentage).
30 : * If force_baseline is TRUE, the computed quantization table entries
31 : * are limited to 1..255 for JPEG baseline compatibility.
32 : */
33 : {
34 : JQUANT_TBL ** qtblptr;
35 : int i;
36 : long temp;
37 :
38 : /* Safety check to ensure start_compress not called yet. */
39 12 : if (cinfo->global_state != CSTATE_START)
40 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
41 :
42 12 : if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
43 0 : ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);
44 :
45 12 : qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];
46 :
47 12 : if (*qtblptr == NULL)
48 6 : *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);
49 :
50 780 : for (i = 0; i < DCTSIZE2; i++) {
51 768 : temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
52 : /* limit the values to the valid range */
53 768 : if (temp <= 0L) temp = 1L;
54 768 : if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
55 768 : if (force_baseline && temp > 255L)
56 0 : temp = 255L; /* limit to baseline range if requested */
57 768 : (*qtblptr)->quantval[i] = (UINT16) temp;
58 : }
59 :
60 : /* Initialize sent_table FALSE so table will be written to JPEG file. */
61 12 : (*qtblptr)->sent_table = FALSE;
62 12 : }
63 :
64 :
65 : /* These are the sample quantization tables given in JPEG spec section K.1.
66 : * The spec says that the values given produce "good" quality, and
67 : * when divided by 2, "very good" quality.
68 : */
69 : static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
70 : 16, 11, 10, 16, 24, 40, 51, 61,
71 : 12, 12, 14, 19, 26, 58, 60, 55,
72 : 14, 13, 16, 24, 40, 57, 69, 56,
73 : 14, 17, 22, 29, 51, 87, 80, 62,
74 : 18, 22, 37, 56, 68, 109, 103, 77,
75 : 24, 35, 55, 64, 81, 104, 113, 92,
76 : 49, 64, 78, 87, 103, 121, 120, 101,
77 : 72, 92, 95, 98, 112, 100, 103, 99
78 : };
79 : static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
80 : 17, 18, 24, 47, 99, 99, 99, 99,
81 : 18, 21, 26, 66, 99, 99, 99, 99,
82 : 24, 26, 56, 99, 99, 99, 99, 99,
83 : 47, 66, 99, 99, 99, 99, 99, 99,
84 : 99, 99, 99, 99, 99, 99, 99, 99,
85 : 99, 99, 99, 99, 99, 99, 99, 99,
86 : 99, 99, 99, 99, 99, 99, 99, 99,
87 : 99, 99, 99, 99, 99, 99, 99, 99
88 : };
89 :
90 :
91 : #if JPEG_LIB_VERSION >= 70
92 : GLOBAL(void)
93 : jpeg_default_qtables (j_compress_ptr cinfo, boolean force_baseline)
94 : /* Set or change the 'quality' (quantization) setting, using default tables
95 : * and straight percentage-scaling quality scales.
96 : * This entry point allows different scalings for luminance and chrominance.
97 : */
98 : {
99 : /* Set up two quantization tables using the specified scaling */
100 : jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
101 : cinfo->q_scale_factor[0], force_baseline);
102 : jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
103 : cinfo->q_scale_factor[1], force_baseline);
104 : }
105 : #endif
106 :
107 :
108 : GLOBAL(void)
109 6 : jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
110 : boolean force_baseline)
111 : /* Set or change the 'quality' (quantization) setting, using default tables
112 : * and a straight percentage-scaling quality scale. In most cases it's better
113 : * to use jpeg_set_quality (below); this entry point is provided for
114 : * applications that insist on a linear percentage scaling.
115 : */
116 : {
117 : /* Set up two quantization tables using the specified scaling */
118 6 : jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
119 : scale_factor, force_baseline);
120 6 : jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
121 : scale_factor, force_baseline);
122 6 : }
123 :
124 :
125 : GLOBAL(int)
126 6 : jpeg_quality_scaling (int quality)
127 : /* Convert a user-specified quality rating to a percentage scaling factor
128 : * for an underlying quantization table, using our recommended scaling curve.
129 : * The input 'quality' factor should be 0 (terrible) to 100 (very good).
130 : */
131 : {
132 : /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */
133 6 : if (quality <= 0) quality = 1;
134 6 : if (quality > 100) quality = 100;
135 :
136 : /* The basic table is used as-is (scaling 100) for a quality of 50.
137 : * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
138 : * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
139 : * to make all the table entries 1 (hence, minimum quantization loss).
140 : * Qualities 1..50 are converted to scaling percentage 5000/Q.
141 : */
142 6 : if (quality < 50)
143 0 : quality = 5000 / quality;
144 : else
145 6 : quality = 200 - quality*2;
146 :
147 6 : return quality;
148 : }
149 :
150 :
151 : GLOBAL(void)
152 6 : jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
153 : /* Set or change the 'quality' (quantization) setting, using default tables.
154 : * This is the standard quality-adjusting entry point for typical user
155 : * interfaces; only those who want detailed control over quantization tables
156 : * would use the preceding three routines directly.
157 : */
158 : {
159 : /* Convert user 0-100 rating to percentage scaling */
160 6 : quality = jpeg_quality_scaling(quality);
161 :
162 : /* Set up standard quality tables */
163 6 : jpeg_set_linear_quality(cinfo, quality, force_baseline);
164 6 : }
165 :
166 :
167 : /*
168 : * Huffman table setup routines
169 : */
170 :
171 : LOCAL(void)
172 12 : add_huff_table (j_compress_ptr cinfo,
173 : JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val)
174 : /* Define a Huffman table */
175 : {
176 : int nsymbols, len;
177 :
178 12 : if (*htblptr == NULL)
179 12 : *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
180 :
181 : /* Copy the number-of-symbols-of-each-code-length counts */
182 12 : MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
183 :
184 : /* Validate the counts. We do this here mainly so we can copy the right
185 : * number of symbols from the val[] array, without risking marching off
186 : * the end of memory. jchuff.c will do a more thorough test later.
187 : */
188 12 : nsymbols = 0;
189 204 : for (len = 1; len <= 16; len++)
190 192 : nsymbols += bits[len];
191 12 : if (nsymbols < 1 || nsymbols > 256)
192 0 : ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
193 :
194 12 : MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8));
195 :
196 : /* Initialize sent_table FALSE so table will be written to JPEG file. */
197 12 : (*htblptr)->sent_table = FALSE;
198 12 : }
199 :
200 :
201 : LOCAL(void)
202 3 : std_huff_tables (j_compress_ptr cinfo)
203 : /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
204 : /* IMPORTANT: these are only valid for 8-bit data precision! */
205 : {
206 : static const UINT8 bits_dc_luminance[17] =
207 : { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
208 : static const UINT8 val_dc_luminance[] =
209 : { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
210 :
211 : static const UINT8 bits_dc_chrominance[17] =
212 : { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
213 : static const UINT8 val_dc_chrominance[] =
214 : { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
215 :
216 : static const UINT8 bits_ac_luminance[17] =
217 : { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
218 : static const UINT8 val_ac_luminance[] =
219 : { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
220 : 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
221 : 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
222 : 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
223 : 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
224 : 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
225 : 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
226 : 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
227 : 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
228 : 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
229 : 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
230 : 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
231 : 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
232 : 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
233 : 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
234 : 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
235 : 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
236 : 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
237 : 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
238 : 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
239 : 0xf9, 0xfa };
240 :
241 : static const UINT8 bits_ac_chrominance[17] =
242 : { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
243 : static const UINT8 val_ac_chrominance[] =
244 : { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
245 : 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
246 : 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
247 : 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
248 : 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
249 : 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
250 : 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
251 : 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
252 : 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
253 : 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
254 : 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
255 : 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
256 : 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
257 : 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
258 : 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
259 : 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
260 : 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
261 : 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
262 : 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
263 : 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
264 : 0xf9, 0xfa };
265 :
266 3 : add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0],
267 : bits_dc_luminance, val_dc_luminance);
268 3 : add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0],
269 : bits_ac_luminance, val_ac_luminance);
270 3 : add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1],
271 : bits_dc_chrominance, val_dc_chrominance);
272 3 : add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1],
273 : bits_ac_chrominance, val_ac_chrominance);
274 3 : }
275 :
276 :
277 : /*
278 : * Default parameter setup for compression.
279 : *
280 : * Applications that don't choose to use this routine must do their
281 : * own setup of all these parameters. Alternately, you can call this
282 : * to establish defaults and then alter parameters selectively. This
283 : * is the recommended approach since, if we add any new parameters,
284 : * your code will still work (they'll be set to reasonable defaults).
285 : */
286 :
287 : GLOBAL(void)
288 3 : jpeg_set_defaults (j_compress_ptr cinfo)
289 : {
290 : int i;
291 :
292 : /* Safety check to ensure start_compress not called yet. */
293 3 : if (cinfo->global_state != CSTATE_START)
294 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
295 :
296 : /* Allocate comp_info array large enough for maximum component count.
297 : * Array is made permanent in case application wants to compress
298 : * multiple images at same param settings.
299 : */
300 3 : if (cinfo->comp_info == NULL)
301 3 : cinfo->comp_info = (jpeg_component_info *)
302 3 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
303 : MAX_COMPONENTS * SIZEOF(jpeg_component_info));
304 :
305 : /* Initialize everything not dependent on the color space */
306 :
307 : #if JPEG_LIB_VERSION >= 70
308 : cinfo->scale_num = 1; /* 1:1 scaling */
309 : cinfo->scale_denom = 1;
310 : #endif
311 3 : cinfo->data_precision = BITS_IN_JSAMPLE;
312 : /* Set up two quantization tables using default quality of 75 */
313 3 : jpeg_set_quality(cinfo, 75, TRUE);
314 : /* Set up two Huffman tables */
315 3 : std_huff_tables(cinfo);
316 :
317 : /* Initialize default arithmetic coding conditioning */
318 51 : for (i = 0; i < NUM_ARITH_TBLS; i++) {
319 48 : cinfo->arith_dc_L[i] = 0;
320 48 : cinfo->arith_dc_U[i] = 1;
321 48 : cinfo->arith_ac_K[i] = 5;
322 : }
323 :
324 : /* Default is no multiple-scan output */
325 3 : cinfo->scan_info = NULL;
326 3 : cinfo->num_scans = 0;
327 :
328 : /* Expect normal source image, not raw downsampled data */
329 3 : cinfo->raw_data_in = FALSE;
330 :
331 : /* Use Huffman coding, not arithmetic coding, by default */
332 3 : cinfo->arith_code = FALSE;
333 :
334 : /* By default, don't do extra passes to optimize entropy coding */
335 3 : cinfo->optimize_coding = FALSE;
336 : /* The standard Huffman tables are only valid for 8-bit data precision.
337 : * If the precision is higher, force optimization on so that usable
338 : * tables will be computed. This test can be removed if default tables
339 : * are supplied that are valid for the desired precision.
340 : */
341 3 : if (cinfo->data_precision > 8)
342 0 : cinfo->optimize_coding = TRUE;
343 :
344 : /* By default, use the simpler non-cosited sampling alignment */
345 3 : cinfo->CCIR601_sampling = FALSE;
346 :
347 : #if JPEG_LIB_VERSION >= 70
348 : /* By default, apply fancy downsampling */
349 : cinfo->do_fancy_downsampling = TRUE;
350 : #endif
351 :
352 : /* No input smoothing */
353 3 : cinfo->smoothing_factor = 0;
354 :
355 : /* DCT algorithm preference */
356 3 : cinfo->dct_method = JDCT_DEFAULT;
357 :
358 : /* No restart markers */
359 3 : cinfo->restart_interval = 0;
360 3 : cinfo->restart_in_rows = 0;
361 :
362 : /* Fill in default JFIF marker parameters. Note that whether the marker
363 : * will actually be written is determined by jpeg_set_colorspace.
364 : *
365 : * By default, the library emits JFIF version code 1.01.
366 : * An application that wants to emit JFIF 1.02 extension markers should set
367 : * JFIF_minor_version to 2. We could probably get away with just defaulting
368 : * to 1.02, but there may still be some decoders in use that will complain
369 : * about that; saying 1.01 should minimize compatibility problems.
370 : */
371 3 : cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
372 3 : cinfo->JFIF_minor_version = 1;
373 3 : cinfo->density_unit = 0; /* Pixel size is unknown by default */
374 3 : cinfo->X_density = 1; /* Pixel aspect ratio is square by default */
375 3 : cinfo->Y_density = 1;
376 :
377 : /* Choose JPEG colorspace based on input space, set defaults accordingly */
378 :
379 3 : jpeg_default_colorspace(cinfo);
380 3 : }
381 :
382 :
383 : /*
384 : * Select an appropriate JPEG colorspace for in_color_space.
385 : */
386 :
387 : GLOBAL(void)
388 3 : jpeg_default_colorspace (j_compress_ptr cinfo)
389 : {
390 3 : switch (cinfo->in_color_space) {
391 : case JCS_GRAYSCALE:
392 0 : jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
393 0 : break;
394 : case JCS_RGB:
395 : case JCS_EXT_RGB:
396 : case JCS_EXT_RGBX:
397 : case JCS_EXT_BGR:
398 : case JCS_EXT_BGRX:
399 : case JCS_EXT_XBGR:
400 : case JCS_EXT_XRGB:
401 : case JCS_EXT_RGBA:
402 : case JCS_EXT_BGRA:
403 : case JCS_EXT_ABGR:
404 : case JCS_EXT_ARGB:
405 3 : jpeg_set_colorspace(cinfo, JCS_YCbCr);
406 3 : break;
407 : case JCS_YCbCr:
408 0 : jpeg_set_colorspace(cinfo, JCS_YCbCr);
409 0 : break;
410 : case JCS_CMYK:
411 0 : jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
412 0 : break;
413 : case JCS_YCCK:
414 0 : jpeg_set_colorspace(cinfo, JCS_YCCK);
415 0 : break;
416 : case JCS_UNKNOWN:
417 0 : jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
418 0 : break;
419 : default:
420 0 : ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
421 : }
422 3 : }
423 :
424 :
425 : /*
426 : * Set the JPEG colorspace, and choose colorspace-dependent default values.
427 : */
428 :
429 : GLOBAL(void)
430 3 : jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
431 : {
432 : jpeg_component_info * compptr;
433 : int ci;
434 :
435 : #define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \
436 : (compptr = &cinfo->comp_info[index], \
437 : compptr->component_id = (id), \
438 : compptr->h_samp_factor = (hsamp), \
439 : compptr->v_samp_factor = (vsamp), \
440 : compptr->quant_tbl_no = (quant), \
441 : compptr->dc_tbl_no = (dctbl), \
442 : compptr->ac_tbl_no = (actbl) )
443 :
444 : /* Safety check to ensure start_compress not called yet. */
445 3 : if (cinfo->global_state != CSTATE_START)
446 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
447 :
448 : /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
449 : * tables 1 for chrominance components.
450 : */
451 :
452 3 : cinfo->jpeg_color_space = colorspace;
453 :
454 3 : cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
455 3 : cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */
456 :
457 3 : switch (colorspace) {
458 : case JCS_GRAYSCALE:
459 0 : cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
460 0 : cinfo->num_components = 1;
461 : /* JFIF specifies component ID 1 */
462 0 : SET_COMP(0, 1, 1,1, 0, 0,0);
463 0 : break;
464 : case JCS_RGB:
465 0 : cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
466 0 : cinfo->num_components = 3;
467 0 : SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0);
468 0 : SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
469 0 : SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0);
470 0 : break;
471 : case JCS_YCbCr:
472 3 : cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
473 3 : cinfo->num_components = 3;
474 : /* JFIF specifies component IDs 1,2,3 */
475 : /* We default to 2x2 subsamples of chrominance */
476 3 : SET_COMP(0, 1, 2,2, 0, 0,0);
477 3 : SET_COMP(1, 2, 1,1, 1, 1,1);
478 3 : SET_COMP(2, 3, 1,1, 1, 1,1);
479 3 : break;
480 : case JCS_CMYK:
481 0 : cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
482 0 : cinfo->num_components = 4;
483 0 : SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
484 0 : SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
485 0 : SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
486 0 : SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
487 0 : break;
488 : case JCS_YCCK:
489 0 : cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
490 0 : cinfo->num_components = 4;
491 0 : SET_COMP(0, 1, 2,2, 0, 0,0);
492 0 : SET_COMP(1, 2, 1,1, 1, 1,1);
493 0 : SET_COMP(2, 3, 1,1, 1, 1,1);
494 0 : SET_COMP(3, 4, 2,2, 0, 0,0);
495 0 : break;
496 : case JCS_UNKNOWN:
497 0 : cinfo->num_components = cinfo->input_components;
498 0 : if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
499 0 : ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
500 : MAX_COMPONENTS);
501 0 : for (ci = 0; ci < cinfo->num_components; ci++) {
502 0 : SET_COMP(ci, ci, 1,1, 0, 0,0);
503 : }
504 0 : break;
505 : default:
506 0 : ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
507 : }
508 3 : }
509 :
510 :
511 : #ifdef C_PROGRESSIVE_SUPPORTED
512 :
513 : LOCAL(jpeg_scan_info *)
514 0 : fill_a_scan (jpeg_scan_info * scanptr, int ci,
515 : int Ss, int Se, int Ah, int Al)
516 : /* Support routine: generate one scan for specified component */
517 : {
518 0 : scanptr->comps_in_scan = 1;
519 0 : scanptr->component_index[0] = ci;
520 0 : scanptr->Ss = Ss;
521 0 : scanptr->Se = Se;
522 0 : scanptr->Ah = Ah;
523 0 : scanptr->Al = Al;
524 0 : scanptr++;
525 0 : return scanptr;
526 : }
527 :
528 : LOCAL(jpeg_scan_info *)
529 0 : fill_scans (jpeg_scan_info * scanptr, int ncomps,
530 : int Ss, int Se, int Ah, int Al)
531 : /* Support routine: generate one scan for each component */
532 : {
533 : int ci;
534 :
535 0 : for (ci = 0; ci < ncomps; ci++) {
536 0 : scanptr->comps_in_scan = 1;
537 0 : scanptr->component_index[0] = ci;
538 0 : scanptr->Ss = Ss;
539 0 : scanptr->Se = Se;
540 0 : scanptr->Ah = Ah;
541 0 : scanptr->Al = Al;
542 0 : scanptr++;
543 : }
544 0 : return scanptr;
545 : }
546 :
547 : LOCAL(jpeg_scan_info *)
548 0 : fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al)
549 : /* Support routine: generate interleaved DC scan if possible, else N scans */
550 : {
551 : int ci;
552 :
553 0 : if (ncomps <= MAX_COMPS_IN_SCAN) {
554 : /* Single interleaved DC scan */
555 0 : scanptr->comps_in_scan = ncomps;
556 0 : for (ci = 0; ci < ncomps; ci++)
557 0 : scanptr->component_index[ci] = ci;
558 0 : scanptr->Ss = scanptr->Se = 0;
559 0 : scanptr->Ah = Ah;
560 0 : scanptr->Al = Al;
561 0 : scanptr++;
562 : } else {
563 : /* Noninterleaved DC scan for each component */
564 0 : scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al);
565 : }
566 0 : return scanptr;
567 : }
568 :
569 :
570 : /*
571 : * Create a recommended progressive-JPEG script.
572 : * cinfo->num_components and cinfo->jpeg_color_space must be correct.
573 : */
574 :
575 : GLOBAL(void)
576 0 : jpeg_simple_progression (j_compress_ptr cinfo)
577 : {
578 0 : int ncomps = cinfo->num_components;
579 : int nscans;
580 : jpeg_scan_info * scanptr;
581 :
582 : /* Safety check to ensure start_compress not called yet. */
583 0 : if (cinfo->global_state != CSTATE_START)
584 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
585 :
586 : /* Figure space needed for script. Calculation must match code below! */
587 0 : if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
588 : /* Custom script for YCbCr color images. */
589 0 : nscans = 10;
590 : } else {
591 : /* All-purpose script for other color spaces. */
592 0 : if (ncomps > MAX_COMPS_IN_SCAN)
593 0 : nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */
594 : else
595 0 : nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */
596 : }
597 :
598 : /* Allocate space for script.
599 : * We need to put it in the permanent pool in case the application performs
600 : * multiple compressions without changing the settings. To avoid a memory
601 : * leak if jpeg_simple_progression is called repeatedly for the same JPEG
602 : * object, we try to re-use previously allocated space, and we allocate
603 : * enough space to handle YCbCr even if initially asked for grayscale.
604 : */
605 0 : if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
606 0 : cinfo->script_space_size = MAX(nscans, 10);
607 0 : cinfo->script_space = (jpeg_scan_info *)
608 0 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
609 0 : cinfo->script_space_size * SIZEOF(jpeg_scan_info));
610 : }
611 0 : scanptr = cinfo->script_space;
612 0 : cinfo->scan_info = scanptr;
613 0 : cinfo->num_scans = nscans;
614 :
615 0 : if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
616 : /* Custom script for YCbCr color images. */
617 : /* Initial DC scan */
618 0 : scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
619 : /* Initial AC scan: get some luma data out in a hurry */
620 0 : scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
621 : /* Chroma data is too small to be worth expending many scans on */
622 0 : scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
623 0 : scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
624 : /* Complete spectral selection for luma AC */
625 0 : scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
626 : /* Refine next bit of luma AC */
627 0 : scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
628 : /* Finish DC successive approximation */
629 0 : scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
630 : /* Finish AC successive approximation */
631 0 : scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
632 0 : scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
633 : /* Luma bottom bit comes last since it's usually largest scan */
634 0 : scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
635 : } else {
636 : /* All-purpose script for other color spaces. */
637 : /* Successive approximation first pass */
638 0 : scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
639 0 : scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
640 0 : scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
641 : /* Successive approximation second pass */
642 0 : scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
643 : /* Successive approximation final pass */
644 0 : scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
645 0 : scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
646 : }
647 0 : }
648 :
649 : #endif /* C_PROGRESSIVE_SUPPORTED */
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