/media/libjpeg/jcparam.c

http://github.com/zpao/v8monkey · C · 645 lines · 404 code · 84 blank · 157 comment · 52 complexity · 6fe68fee8d9ffbadda4ea4c59e220797 MD5 · raw file

  1. /*
  2. * jcparam.c
  3. *
  4. * Copyright (C) 1991-1998, Thomas G. Lane.
  5. * Modified 2003-2008 by Guido Vollbeding.
  6. * Copyright (C) 2009-2010, 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. #define JPEG_INTERNALS
  15. #include "jinclude.h"
  16. #include "jpeglib.h"
  17. /*
  18. * Quantization table setup routines
  19. */
  20. GLOBAL(void)
  21. jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
  22. const unsigned int *basic_table,
  23. int scale_factor, boolean force_baseline)
  24. /* Define a quantization table equal to the basic_table times
  25. * a scale factor (given as a percentage).
  26. * If force_baseline is TRUE, the computed quantization table entries
  27. * are limited to 1..255 for JPEG baseline compatibility.
  28. */
  29. {
  30. JQUANT_TBL ** qtblptr;
  31. int i;
  32. long temp;
  33. /* Safety check to ensure start_compress not called yet. */
  34. if (cinfo->global_state != CSTATE_START)
  35. ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  36. if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
  37. ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);
  38. qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];
  39. if (*qtblptr == NULL)
  40. *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);
  41. for (i = 0; i < DCTSIZE2; i++) {
  42. temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
  43. /* limit the values to the valid range */
  44. if (temp <= 0L) temp = 1L;
  45. if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
  46. if (force_baseline && temp > 255L)
  47. temp = 255L; /* limit to baseline range if requested */
  48. (*qtblptr)->quantval[i] = (UINT16) temp;
  49. }
  50. /* Initialize sent_table FALSE so table will be written to JPEG file. */
  51. (*qtblptr)->sent_table = FALSE;
  52. }
  53. /* These are the sample quantization tables given in JPEG spec section K.1.
  54. * The spec says that the values given produce "good" quality, and
  55. * when divided by 2, "very good" quality.
  56. */
  57. static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
  58. 16, 11, 10, 16, 24, 40, 51, 61,
  59. 12, 12, 14, 19, 26, 58, 60, 55,
  60. 14, 13, 16, 24, 40, 57, 69, 56,
  61. 14, 17, 22, 29, 51, 87, 80, 62,
  62. 18, 22, 37, 56, 68, 109, 103, 77,
  63. 24, 35, 55, 64, 81, 104, 113, 92,
  64. 49, 64, 78, 87, 103, 121, 120, 101,
  65. 72, 92, 95, 98, 112, 100, 103, 99
  66. };
  67. static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
  68. 17, 18, 24, 47, 99, 99, 99, 99,
  69. 18, 21, 26, 66, 99, 99, 99, 99,
  70. 24, 26, 56, 99, 99, 99, 99, 99,
  71. 47, 66, 99, 99, 99, 99, 99, 99,
  72. 99, 99, 99, 99, 99, 99, 99, 99,
  73. 99, 99, 99, 99, 99, 99, 99, 99,
  74. 99, 99, 99, 99, 99, 99, 99, 99,
  75. 99, 99, 99, 99, 99, 99, 99, 99
  76. };
  77. #if JPEG_LIB_VERSION >= 70
  78. GLOBAL(void)
  79. jpeg_default_qtables (j_compress_ptr cinfo, boolean force_baseline)
  80. /* Set or change the 'quality' (quantization) setting, using default tables
  81. * and straight percentage-scaling quality scales.
  82. * This entry point allows different scalings for luminance and chrominance.
  83. */
  84. {
  85. /* Set up two quantization tables using the specified scaling */
  86. jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
  87. cinfo->q_scale_factor[0], force_baseline);
  88. jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
  89. cinfo->q_scale_factor[1], force_baseline);
  90. }
  91. #endif
  92. GLOBAL(void)
  93. jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
  94. boolean force_baseline)
  95. /* Set or change the 'quality' (quantization) setting, using default tables
  96. * and a straight percentage-scaling quality scale. In most cases it's better
  97. * to use jpeg_set_quality (below); this entry point is provided for
  98. * applications that insist on a linear percentage scaling.
  99. */
  100. {
  101. /* Set up two quantization tables using the specified scaling */
  102. jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
  103. scale_factor, force_baseline);
  104. jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
  105. scale_factor, force_baseline);
  106. }
  107. GLOBAL(int)
  108. jpeg_quality_scaling (int quality)
  109. /* Convert a user-specified quality rating to a percentage scaling factor
  110. * for an underlying quantization table, using our recommended scaling curve.
  111. * The input 'quality' factor should be 0 (terrible) to 100 (very good).
  112. */
  113. {
  114. /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */
  115. if (quality <= 0) quality = 1;
  116. if (quality > 100) quality = 100;
  117. /* The basic table is used as-is (scaling 100) for a quality of 50.
  118. * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
  119. * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
  120. * to make all the table entries 1 (hence, minimum quantization loss).
  121. * Qualities 1..50 are converted to scaling percentage 5000/Q.
  122. */
  123. if (quality < 50)
  124. quality = 5000 / quality;
  125. else
  126. quality = 200 - quality*2;
  127. return quality;
  128. }
  129. GLOBAL(void)
  130. jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
  131. /* Set or change the 'quality' (quantization) setting, using default tables.
  132. * This is the standard quality-adjusting entry point for typical user
  133. * interfaces; only those who want detailed control over quantization tables
  134. * would use the preceding three routines directly.
  135. */
  136. {
  137. /* Convert user 0-100 rating to percentage scaling */
  138. quality = jpeg_quality_scaling(quality);
  139. /* Set up standard quality tables */
  140. jpeg_set_linear_quality(cinfo, quality, force_baseline);
  141. }
  142. /*
  143. * Huffman table setup routines
  144. */
  145. LOCAL(void)
  146. add_huff_table (j_compress_ptr cinfo,
  147. JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val)
  148. /* Define a Huffman table */
  149. {
  150. int nsymbols, len;
  151. if (*htblptr == NULL)
  152. *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
  153. /* Copy the number-of-symbols-of-each-code-length counts */
  154. MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
  155. /* Validate the counts. We do this here mainly so we can copy the right
  156. * number of symbols from the val[] array, without risking marching off
  157. * the end of memory. jchuff.c will do a more thorough test later.
  158. */
  159. nsymbols = 0;
  160. for (len = 1; len <= 16; len++)
  161. nsymbols += bits[len];
  162. if (nsymbols < 1 || nsymbols > 256)
  163. ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
  164. MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8));
  165. /* Initialize sent_table FALSE so table will be written to JPEG file. */
  166. (*htblptr)->sent_table = FALSE;
  167. }
  168. LOCAL(void)
  169. std_huff_tables (j_compress_ptr cinfo)
  170. /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
  171. /* IMPORTANT: these are only valid for 8-bit data precision! */
  172. {
  173. static const UINT8 bits_dc_luminance[17] =
  174. { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
  175. static const UINT8 val_dc_luminance[] =
  176. { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
  177. static const UINT8 bits_dc_chrominance[17] =
  178. { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
  179. static const UINT8 val_dc_chrominance[] =
  180. { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
  181. static const UINT8 bits_ac_luminance[17] =
  182. { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
  183. static const UINT8 val_ac_luminance[] =
  184. { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
  185. 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
  186. 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
  187. 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
  188. 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
  189. 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
  190. 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
  191. 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
  192. 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
  193. 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
  194. 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
  195. 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  196. 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
  197. 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
  198. 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
  199. 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
  200. 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
  201. 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
  202. 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
  203. 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  204. 0xf9, 0xfa };
  205. static const UINT8 bits_ac_chrominance[17] =
  206. { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
  207. static const UINT8 val_ac_chrominance[] =
  208. { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
  209. 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
  210. 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
  211. 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
  212. 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
  213. 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
  214. 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
  215. 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
  216. 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
  217. 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
  218. 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
  219. 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  220. 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
  221. 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
  222. 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
  223. 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
  224. 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
  225. 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
  226. 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
  227. 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  228. 0xf9, 0xfa };
  229. add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0],
  230. bits_dc_luminance, val_dc_luminance);
  231. add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0],
  232. bits_ac_luminance, val_ac_luminance);
  233. add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1],
  234. bits_dc_chrominance, val_dc_chrominance);
  235. add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1],
  236. bits_ac_chrominance, val_ac_chrominance);
  237. }
  238. /*
  239. * Default parameter setup for compression.
  240. *
  241. * Applications that don't choose to use this routine must do their
  242. * own setup of all these parameters. Alternately, you can call this
  243. * to establish defaults and then alter parameters selectively. This
  244. * is the recommended approach since, if we add any new parameters,
  245. * your code will still work (they'll be set to reasonable defaults).
  246. */
  247. GLOBAL(void)
  248. jpeg_set_defaults (j_compress_ptr cinfo)
  249. {
  250. int i;
  251. /* Safety check to ensure start_compress not called yet. */
  252. if (cinfo->global_state != CSTATE_START)
  253. ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  254. /* Allocate comp_info array large enough for maximum component count.
  255. * Array is made permanent in case application wants to compress
  256. * multiple images at same param settings.
  257. */
  258. if (cinfo->comp_info == NULL)
  259. cinfo->comp_info = (jpeg_component_info *)
  260. (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
  261. MAX_COMPONENTS * SIZEOF(jpeg_component_info));
  262. /* Initialize everything not dependent on the color space */
  263. #if JPEG_LIB_VERSION >= 70
  264. cinfo->scale_num = 1; /* 1:1 scaling */
  265. cinfo->scale_denom = 1;
  266. #endif
  267. cinfo->data_precision = BITS_IN_JSAMPLE;
  268. /* Set up two quantization tables using default quality of 75 */
  269. jpeg_set_quality(cinfo, 75, TRUE);
  270. /* Set up two Huffman tables */
  271. std_huff_tables(cinfo);
  272. /* Initialize default arithmetic coding conditioning */
  273. for (i = 0; i < NUM_ARITH_TBLS; i++) {
  274. cinfo->arith_dc_L[i] = 0;
  275. cinfo->arith_dc_U[i] = 1;
  276. cinfo->arith_ac_K[i] = 5;
  277. }
  278. /* Default is no multiple-scan output */
  279. cinfo->scan_info = NULL;
  280. cinfo->num_scans = 0;
  281. /* Expect normal source image, not raw downsampled data */
  282. cinfo->raw_data_in = FALSE;
  283. /* Use Huffman coding, not arithmetic coding, by default */
  284. cinfo->arith_code = FALSE;
  285. /* By default, don't do extra passes to optimize entropy coding */
  286. cinfo->optimize_coding = FALSE;
  287. /* The standard Huffman tables are only valid for 8-bit data precision.
  288. * If the precision is higher, force optimization on so that usable
  289. * tables will be computed. This test can be removed if default tables
  290. * are supplied that are valid for the desired precision.
  291. */
  292. if (cinfo->data_precision > 8)
  293. cinfo->optimize_coding = TRUE;
  294. /* By default, use the simpler non-cosited sampling alignment */
  295. cinfo->CCIR601_sampling = FALSE;
  296. #if JPEG_LIB_VERSION >= 70
  297. /* By default, apply fancy downsampling */
  298. cinfo->do_fancy_downsampling = TRUE;
  299. #endif
  300. /* No input smoothing */
  301. cinfo->smoothing_factor = 0;
  302. /* DCT algorithm preference */
  303. cinfo->dct_method = JDCT_DEFAULT;
  304. /* No restart markers */
  305. cinfo->restart_interval = 0;
  306. cinfo->restart_in_rows = 0;
  307. /* Fill in default JFIF marker parameters. Note that whether the marker
  308. * will actually be written is determined by jpeg_set_colorspace.
  309. *
  310. * By default, the library emits JFIF version code 1.01.
  311. * An application that wants to emit JFIF 1.02 extension markers should set
  312. * JFIF_minor_version to 2. We could probably get away with just defaulting
  313. * to 1.02, but there may still be some decoders in use that will complain
  314. * about that; saying 1.01 should minimize compatibility problems.
  315. */
  316. cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
  317. cinfo->JFIF_minor_version = 1;
  318. cinfo->density_unit = 0; /* Pixel size is unknown by default */
  319. cinfo->X_density = 1; /* Pixel aspect ratio is square by default */
  320. cinfo->Y_density = 1;
  321. /* Choose JPEG colorspace based on input space, set defaults accordingly */
  322. jpeg_default_colorspace(cinfo);
  323. }
  324. /*
  325. * Select an appropriate JPEG colorspace for in_color_space.
  326. */
  327. GLOBAL(void)
  328. jpeg_default_colorspace (j_compress_ptr cinfo)
  329. {
  330. switch (cinfo->in_color_space) {
  331. case JCS_GRAYSCALE:
  332. jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
  333. break;
  334. case JCS_RGB:
  335. case JCS_EXT_RGB:
  336. case JCS_EXT_RGBX:
  337. case JCS_EXT_BGR:
  338. case JCS_EXT_BGRX:
  339. case JCS_EXT_XBGR:
  340. case JCS_EXT_XRGB:
  341. jpeg_set_colorspace(cinfo, JCS_YCbCr);
  342. break;
  343. case JCS_YCbCr:
  344. jpeg_set_colorspace(cinfo, JCS_YCbCr);
  345. break;
  346. case JCS_CMYK:
  347. jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
  348. break;
  349. case JCS_YCCK:
  350. jpeg_set_colorspace(cinfo, JCS_YCCK);
  351. break;
  352. case JCS_UNKNOWN:
  353. jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
  354. break;
  355. default:
  356. ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
  357. }
  358. }
  359. /*
  360. * Set the JPEG colorspace, and choose colorspace-dependent default values.
  361. */
  362. GLOBAL(void)
  363. jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
  364. {
  365. jpeg_component_info * compptr;
  366. int ci;
  367. #define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \
  368. (compptr = &cinfo->comp_info[index], \
  369. compptr->component_id = (id), \
  370. compptr->h_samp_factor = (hsamp), \
  371. compptr->v_samp_factor = (vsamp), \
  372. compptr->quant_tbl_no = (quant), \
  373. compptr->dc_tbl_no = (dctbl), \
  374. compptr->ac_tbl_no = (actbl) )
  375. /* Safety check to ensure start_compress not called yet. */
  376. if (cinfo->global_state != CSTATE_START)
  377. ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  378. /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
  379. * tables 1 for chrominance components.
  380. */
  381. cinfo->jpeg_color_space = colorspace;
  382. cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
  383. cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */
  384. switch (colorspace) {
  385. case JCS_GRAYSCALE:
  386. cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
  387. cinfo->num_components = 1;
  388. /* JFIF specifies component ID 1 */
  389. SET_COMP(0, 1, 1,1, 0, 0,0);
  390. break;
  391. case JCS_RGB:
  392. cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
  393. cinfo->num_components = 3;
  394. SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0);
  395. SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
  396. SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0);
  397. break;
  398. case JCS_YCbCr:
  399. cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
  400. cinfo->num_components = 3;
  401. /* JFIF specifies component IDs 1,2,3 */
  402. /* We default to 2x2 subsamples of chrominance */
  403. SET_COMP(0, 1, 2,2, 0, 0,0);
  404. SET_COMP(1, 2, 1,1, 1, 1,1);
  405. SET_COMP(2, 3, 1,1, 1, 1,1);
  406. break;
  407. case JCS_CMYK:
  408. cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
  409. cinfo->num_components = 4;
  410. SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
  411. SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
  412. SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
  413. SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
  414. break;
  415. case JCS_YCCK:
  416. cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
  417. cinfo->num_components = 4;
  418. SET_COMP(0, 1, 2,2, 0, 0,0);
  419. SET_COMP(1, 2, 1,1, 1, 1,1);
  420. SET_COMP(2, 3, 1,1, 1, 1,1);
  421. SET_COMP(3, 4, 2,2, 0, 0,0);
  422. break;
  423. case JCS_UNKNOWN:
  424. cinfo->num_components = cinfo->input_components;
  425. if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
  426. ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
  427. MAX_COMPONENTS);
  428. for (ci = 0; ci < cinfo->num_components; ci++) {
  429. SET_COMP(ci, ci, 1,1, 0, 0,0);
  430. }
  431. break;
  432. default:
  433. ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
  434. }
  435. }
  436. #ifdef C_PROGRESSIVE_SUPPORTED
  437. LOCAL(jpeg_scan_info *)
  438. fill_a_scan (jpeg_scan_info * scanptr, int ci,
  439. int Ss, int Se, int Ah, int Al)
  440. /* Support routine: generate one scan for specified component */
  441. {
  442. scanptr->comps_in_scan = 1;
  443. scanptr->component_index[0] = ci;
  444. scanptr->Ss = Ss;
  445. scanptr->Se = Se;
  446. scanptr->Ah = Ah;
  447. scanptr->Al = Al;
  448. scanptr++;
  449. return scanptr;
  450. }
  451. LOCAL(jpeg_scan_info *)
  452. fill_scans (jpeg_scan_info * scanptr, int ncomps,
  453. int Ss, int Se, int Ah, int Al)
  454. /* Support routine: generate one scan for each component */
  455. {
  456. int ci;
  457. for (ci = 0; ci < ncomps; ci++) {
  458. scanptr->comps_in_scan = 1;
  459. scanptr->component_index[0] = ci;
  460. scanptr->Ss = Ss;
  461. scanptr->Se = Se;
  462. scanptr->Ah = Ah;
  463. scanptr->Al = Al;
  464. scanptr++;
  465. }
  466. return scanptr;
  467. }
  468. LOCAL(jpeg_scan_info *)
  469. fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al)
  470. /* Support routine: generate interleaved DC scan if possible, else N scans */
  471. {
  472. int ci;
  473. if (ncomps <= MAX_COMPS_IN_SCAN) {
  474. /* Single interleaved DC scan */
  475. scanptr->comps_in_scan = ncomps;
  476. for (ci = 0; ci < ncomps; ci++)
  477. scanptr->component_index[ci] = ci;
  478. scanptr->Ss = scanptr->Se = 0;
  479. scanptr->Ah = Ah;
  480. scanptr->Al = Al;
  481. scanptr++;
  482. } else {
  483. /* Noninterleaved DC scan for each component */
  484. scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al);
  485. }
  486. return scanptr;
  487. }
  488. /*
  489. * Create a recommended progressive-JPEG script.
  490. * cinfo->num_components and cinfo->jpeg_color_space must be correct.
  491. */
  492. GLOBAL(void)
  493. jpeg_simple_progression (j_compress_ptr cinfo)
  494. {
  495. int ncomps = cinfo->num_components;
  496. int nscans;
  497. jpeg_scan_info * scanptr;
  498. /* Safety check to ensure start_compress not called yet. */
  499. if (cinfo->global_state != CSTATE_START)
  500. ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  501. /* Figure space needed for script. Calculation must match code below! */
  502. if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
  503. /* Custom script for YCbCr color images. */
  504. nscans = 10;
  505. } else {
  506. /* All-purpose script for other color spaces. */
  507. if (ncomps > MAX_COMPS_IN_SCAN)
  508. nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */
  509. else
  510. nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */
  511. }
  512. /* Allocate space for script.
  513. * We need to put it in the permanent pool in case the application performs
  514. * multiple compressions without changing the settings. To avoid a memory
  515. * leak if jpeg_simple_progression is called repeatedly for the same JPEG
  516. * object, we try to re-use previously allocated space, and we allocate
  517. * enough space to handle YCbCr even if initially asked for grayscale.
  518. */
  519. if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
  520. cinfo->script_space_size = MAX(nscans, 10);
  521. cinfo->script_space = (jpeg_scan_info *)
  522. (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
  523. cinfo->script_space_size * SIZEOF(jpeg_scan_info));
  524. }
  525. scanptr = cinfo->script_space;
  526. cinfo->scan_info = scanptr;
  527. cinfo->num_scans = nscans;
  528. if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
  529. /* Custom script for YCbCr color images. */
  530. /* Initial DC scan */
  531. scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
  532. /* Initial AC scan: get some luma data out in a hurry */
  533. scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
  534. /* Chroma data is too small to be worth expending many scans on */
  535. scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
  536. scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
  537. /* Complete spectral selection for luma AC */
  538. scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
  539. /* Refine next bit of luma AC */
  540. scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
  541. /* Finish DC successive approximation */
  542. scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
  543. /* Finish AC successive approximation */
  544. scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
  545. scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
  546. /* Luma bottom bit comes last since it's usually largest scan */
  547. scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
  548. } else {
  549. /* All-purpose script for other color spaces. */
  550. /* Successive approximation first pass */
  551. scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
  552. scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
  553. scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
  554. /* Successive approximation second pass */
  555. scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
  556. /* Successive approximation final pass */
  557. scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
  558. scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
  559. }
  560. }
  561. #endif /* C_PROGRESSIVE_SUPPORTED */