jpeglib.h 49 KB

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  1. /*
  2. * jpeglib.h
  3. *
  4. * This file was part of the Independent JPEG Group's software:
  5. * Copyright (C) 1991-1998, Thomas G. Lane.
  6. * Modified 2002-2009 by Guido Vollbeding.
  7. * libjpeg-turbo Modifications:
  8. * Copyright (C) 2009-2011, 2013-2014, 2016-2017, D. R. Commander.
  9. * Copyright (C) 2015, Google, Inc.
  10. * For conditions of distribution and use, see the accompanying README.ijg
  11. * file.
  12. *
  13. * This file defines the application interface for the JPEG library.
  14. * Most applications using the library need only include this file,
  15. * and perhaps jerror.h if they want to know the exact error codes.
  16. */
  17. #ifndef JPEGLIB_H
  18. #define JPEGLIB_H
  19. /* Begin chromium edits */
  20. #include "jpeglibmangler.h"
  21. /* End chromium edits */
  22. /*
  23. * First we include the configuration files that record how this
  24. * installation of the JPEG library is set up. jconfig.h can be
  25. * generated automatically for many systems. jmorecfg.h contains
  26. * manual configuration options that most people need not worry about.
  27. */
  28. #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
  29. #include "jconfig.h" /* widely used configuration options */
  30. #endif
  31. #include "jmorecfg.h" /* seldom changed options */
  32. #ifdef __cplusplus
  33. #ifndef DONT_USE_EXTERN_C
  34. extern "C" {
  35. #endif
  36. #endif
  37. /* Various constants determining the sizes of things.
  38. * All of these are specified by the JPEG standard, so don't change them
  39. * if you want to be compatible.
  40. */
  41. #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
  42. #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
  43. #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
  44. #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
  45. #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
  46. #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
  47. #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
  48. /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
  49. * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
  50. * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
  51. * to handle it. We even let you do this from the jconfig.h file. However,
  52. * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
  53. * sometimes emits noncompliant files doesn't mean you should too.
  54. */
  55. #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
  56. #ifndef D_MAX_BLOCKS_IN_MCU
  57. #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
  58. #endif
  59. /* Data structures for images (arrays of samples and of DCT coefficients).
  60. */
  61. typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */
  62. typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
  63. typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
  64. typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
  65. typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */
  66. typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
  67. typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
  68. typedef JCOEF *JCOEFPTR; /* useful in a couple of places */
  69. /* Types for JPEG compression parameters and working tables. */
  70. /* DCT coefficient quantization tables. */
  71. typedef struct {
  72. /* This array gives the coefficient quantizers in natural array order
  73. * (not the zigzag order in which they are stored in a JPEG DQT marker).
  74. * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
  75. */
  76. UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
  77. /* This field is used only during compression. It's initialized FALSE when
  78. * the table is created, and set TRUE when it's been output to the file.
  79. * You could suppress output of a table by setting this to TRUE.
  80. * (See jpeg_suppress_tables for an example.)
  81. */
  82. boolean sent_table; /* TRUE when table has been output */
  83. } JQUANT_TBL;
  84. /* Huffman coding tables. */
  85. typedef struct {
  86. /* These two fields directly represent the contents of a JPEG DHT marker */
  87. UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
  88. /* length k bits; bits[0] is unused */
  89. UINT8 huffval[256]; /* The symbols, in order of incr code length */
  90. /* This field is used only during compression. It's initialized FALSE when
  91. * the table is created, and set TRUE when it's been output to the file.
  92. * You could suppress output of a table by setting this to TRUE.
  93. * (See jpeg_suppress_tables for an example.)
  94. */
  95. boolean sent_table; /* TRUE when table has been output */
  96. } JHUFF_TBL;
  97. /* Basic info about one component (color channel). */
  98. typedef struct {
  99. /* These values are fixed over the whole image. */
  100. /* For compression, they must be supplied by parameter setup; */
  101. /* for decompression, they are read from the SOF marker. */
  102. int component_id; /* identifier for this component (0..255) */
  103. int component_index; /* its index in SOF or cinfo->comp_info[] */
  104. int h_samp_factor; /* horizontal sampling factor (1..4) */
  105. int v_samp_factor; /* vertical sampling factor (1..4) */
  106. int quant_tbl_no; /* quantization table selector (0..3) */
  107. /* These values may vary between scans. */
  108. /* For compression, they must be supplied by parameter setup; */
  109. /* for decompression, they are read from the SOS marker. */
  110. /* The decompressor output side may not use these variables. */
  111. int dc_tbl_no; /* DC entropy table selector (0..3) */
  112. int ac_tbl_no; /* AC entropy table selector (0..3) */
  113. /* Remaining fields should be treated as private by applications. */
  114. /* These values are computed during compression or decompression startup: */
  115. /* Component's size in DCT blocks.
  116. * Any dummy blocks added to complete an MCU are not counted; therefore
  117. * these values do not depend on whether a scan is interleaved or not.
  118. */
  119. JDIMENSION width_in_blocks;
  120. JDIMENSION height_in_blocks;
  121. /* Size of a DCT block in samples. Always DCTSIZE for compression.
  122. * For decompression this is the size of the output from one DCT block,
  123. * reflecting any scaling we choose to apply during the IDCT step.
  124. * Values from 1 to 16 are supported.
  125. * Note that different components may receive different IDCT scalings.
  126. */
  127. #if JPEG_LIB_VERSION >= 70
  128. int DCT_h_scaled_size;
  129. int DCT_v_scaled_size;
  130. #else
  131. int DCT_scaled_size;
  132. #endif
  133. /* The downsampled dimensions are the component's actual, unpadded number
  134. * of samples at the main buffer (preprocessing/compression interface), thus
  135. * downsampled_width = ceil(image_width * Hi/Hmax)
  136. * and similarly for height. For decompression, IDCT scaling is included, so
  137. * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
  138. */
  139. JDIMENSION downsampled_width; /* actual width in samples */
  140. JDIMENSION downsampled_height; /* actual height in samples */
  141. /* This flag is used only for decompression. In cases where some of the
  142. * components will be ignored (eg grayscale output from YCbCr image),
  143. * we can skip most computations for the unused components.
  144. */
  145. boolean component_needed; /* do we need the value of this component? */
  146. /* These values are computed before starting a scan of the component. */
  147. /* The decompressor output side may not use these variables. */
  148. int MCU_width; /* number of blocks per MCU, horizontally */
  149. int MCU_height; /* number of blocks per MCU, vertically */
  150. int MCU_blocks; /* MCU_width * MCU_height */
  151. int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
  152. int last_col_width; /* # of non-dummy blocks across in last MCU */
  153. int last_row_height; /* # of non-dummy blocks down in last MCU */
  154. /* Saved quantization table for component; NULL if none yet saved.
  155. * See jdinput.c comments about the need for this information.
  156. * This field is currently used only for decompression.
  157. */
  158. JQUANT_TBL *quant_table;
  159. /* Private per-component storage for DCT or IDCT subsystem. */
  160. void *dct_table;
  161. } jpeg_component_info;
  162. /* The script for encoding a multiple-scan file is an array of these: */
  163. typedef struct {
  164. int comps_in_scan; /* number of components encoded in this scan */
  165. int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
  166. int Ss, Se; /* progressive JPEG spectral selection parms */
  167. int Ah, Al; /* progressive JPEG successive approx. parms */
  168. } jpeg_scan_info;
  169. /* The decompressor can save APPn and COM markers in a list of these: */
  170. typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
  171. struct jpeg_marker_struct {
  172. jpeg_saved_marker_ptr next; /* next in list, or NULL */
  173. UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
  174. unsigned int original_length; /* # bytes of data in the file */
  175. unsigned int data_length; /* # bytes of data saved at data[] */
  176. JOCTET *data; /* the data contained in the marker */
  177. /* the marker length word is not counted in data_length or original_length */
  178. };
  179. /* Known color spaces. */
  180. #define JCS_EXTENSIONS 1
  181. #define JCS_ALPHA_EXTENSIONS 1
  182. typedef enum {
  183. JCS_UNKNOWN, /* error/unspecified */
  184. JCS_GRAYSCALE, /* monochrome */
  185. JCS_RGB, /* red/green/blue as specified by the RGB_RED,
  186. RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
  187. JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
  188. JCS_CMYK, /* C/M/Y/K */
  189. JCS_YCCK, /* Y/Cb/Cr/K */
  190. JCS_EXT_RGB, /* red/green/blue */
  191. JCS_EXT_RGBX, /* red/green/blue/x */
  192. JCS_EXT_BGR, /* blue/green/red */
  193. JCS_EXT_BGRX, /* blue/green/red/x */
  194. JCS_EXT_XBGR, /* x/blue/green/red */
  195. JCS_EXT_XRGB, /* x/red/green/blue */
  196. /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
  197. or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
  198. order to ensure the best performance, libjpeg-turbo can set that byte to
  199. whatever value it wishes. Use the following colorspace constants to
  200. ensure that the X byte is set to 0xFF, so that it can be interpreted as an
  201. opaque alpha channel. */
  202. JCS_EXT_RGBA, /* red/green/blue/alpha */
  203. JCS_EXT_BGRA, /* blue/green/red/alpha */
  204. JCS_EXT_ABGR, /* alpha/blue/green/red */
  205. JCS_EXT_ARGB, /* alpha/red/green/blue */
  206. JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue */
  207. } J_COLOR_SPACE;
  208. /* DCT/IDCT algorithm options. */
  209. typedef enum {
  210. JDCT_ISLOW, /* slow but accurate integer algorithm */
  211. JDCT_IFAST, /* faster, less accurate integer method */
  212. JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
  213. } J_DCT_METHOD;
  214. #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
  215. #define JDCT_DEFAULT JDCT_ISLOW
  216. #endif
  217. #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
  218. #define JDCT_FASTEST JDCT_IFAST
  219. #endif
  220. /* Dithering options for decompression. */
  221. typedef enum {
  222. JDITHER_NONE, /* no dithering */
  223. JDITHER_ORDERED, /* simple ordered dither */
  224. JDITHER_FS /* Floyd-Steinberg error diffusion dither */
  225. } J_DITHER_MODE;
  226. /* Common fields between JPEG compression and decompression master structs. */
  227. #define jpeg_common_fields \
  228. struct jpeg_error_mgr *err; /* Error handler module */ \
  229. struct jpeg_memory_mgr *mem; /* Memory manager module */ \
  230. struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */ \
  231. void *client_data; /* Available for use by application */ \
  232. boolean is_decompressor; /* So common code can tell which is which */ \
  233. int global_state /* For checking call sequence validity */
  234. /* Routines that are to be used by both halves of the library are declared
  235. * to receive a pointer to this structure. There are no actual instances of
  236. * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
  237. */
  238. struct jpeg_common_struct {
  239. jpeg_common_fields; /* Fields common to both master struct types */
  240. /* Additional fields follow in an actual jpeg_compress_struct or
  241. * jpeg_decompress_struct. All three structs must agree on these
  242. * initial fields! (This would be a lot cleaner in C++.)
  243. */
  244. };
  245. typedef struct jpeg_common_struct *j_common_ptr;
  246. typedef struct jpeg_compress_struct *j_compress_ptr;
  247. typedef struct jpeg_decompress_struct *j_decompress_ptr;
  248. /* Master record for a compression instance */
  249. struct jpeg_compress_struct {
  250. jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
  251. /* Destination for compressed data */
  252. struct jpeg_destination_mgr *dest;
  253. /* Description of source image --- these fields must be filled in by
  254. * outer application before starting compression. in_color_space must
  255. * be correct before you can even call jpeg_set_defaults().
  256. */
  257. JDIMENSION image_width; /* input image width */
  258. JDIMENSION image_height; /* input image height */
  259. int input_components; /* # of color components in input image */
  260. J_COLOR_SPACE in_color_space; /* colorspace of input image */
  261. double input_gamma; /* image gamma of input image */
  262. /* Compression parameters --- these fields must be set before calling
  263. * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
  264. * initialize everything to reasonable defaults, then changing anything
  265. * the application specifically wants to change. That way you won't get
  266. * burnt when new parameters are added. Also note that there are several
  267. * helper routines to simplify changing parameters.
  268. */
  269. #if JPEG_LIB_VERSION >= 70
  270. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  271. JDIMENSION jpeg_width; /* scaled JPEG image width */
  272. JDIMENSION jpeg_height; /* scaled JPEG image height */
  273. /* Dimensions of actual JPEG image that will be written to file,
  274. * derived from input dimensions by scaling factors above.
  275. * These fields are computed by jpeg_start_compress().
  276. * You can also use jpeg_calc_jpeg_dimensions() to determine these values
  277. * in advance of calling jpeg_start_compress().
  278. */
  279. #endif
  280. int data_precision; /* bits of precision in image data */
  281. int num_components; /* # of color components in JPEG image */
  282. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  283. jpeg_component_info *comp_info;
  284. /* comp_info[i] describes component that appears i'th in SOF */
  285. JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
  286. #if JPEG_LIB_VERSION >= 70
  287. int q_scale_factor[NUM_QUANT_TBLS];
  288. #endif
  289. /* ptrs to coefficient quantization tables, or NULL if not defined,
  290. * and corresponding scale factors (percentage, initialized 100).
  291. */
  292. JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  293. JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  294. /* ptrs to Huffman coding tables, or NULL if not defined */
  295. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  296. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  297. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  298. int num_scans; /* # of entries in scan_info array */
  299. const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
  300. /* The default value of scan_info is NULL, which causes a single-scan
  301. * sequential JPEG file to be emitted. To create a multi-scan file,
  302. * set num_scans and scan_info to point to an array of scan definitions.
  303. */
  304. boolean raw_data_in; /* TRUE=caller supplies downsampled data */
  305. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  306. boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
  307. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  308. #if JPEG_LIB_VERSION >= 70
  309. boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
  310. #endif
  311. int smoothing_factor; /* 1..100, or 0 for no input smoothing */
  312. J_DCT_METHOD dct_method; /* DCT algorithm selector */
  313. /* The restart interval can be specified in absolute MCUs by setting
  314. * restart_interval, or in MCU rows by setting restart_in_rows
  315. * (in which case the correct restart_interval will be figured
  316. * for each scan).
  317. */
  318. unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
  319. int restart_in_rows; /* if > 0, MCU rows per restart interval */
  320. /* Parameters controlling emission of special markers. */
  321. boolean write_JFIF_header; /* should a JFIF marker be written? */
  322. UINT8 JFIF_major_version; /* What to write for the JFIF version number */
  323. UINT8 JFIF_minor_version;
  324. /* These three values are not used by the JPEG code, merely copied */
  325. /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
  326. /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
  327. /* ratio is defined by X_density/Y_density even when density_unit=0. */
  328. UINT8 density_unit; /* JFIF code for pixel size units */
  329. UINT16 X_density; /* Horizontal pixel density */
  330. UINT16 Y_density; /* Vertical pixel density */
  331. boolean write_Adobe_marker; /* should an Adobe marker be written? */
  332. /* State variable: index of next scanline to be written to
  333. * jpeg_write_scanlines(). Application may use this to control its
  334. * processing loop, e.g., "while (next_scanline < image_height)".
  335. */
  336. JDIMENSION next_scanline; /* 0 .. image_height-1 */
  337. /* Remaining fields are known throughout compressor, but generally
  338. * should not be touched by a surrounding application.
  339. */
  340. /*
  341. * These fields are computed during compression startup
  342. */
  343. boolean progressive_mode; /* TRUE if scan script uses progressive mode */
  344. int max_h_samp_factor; /* largest h_samp_factor */
  345. int max_v_samp_factor; /* largest v_samp_factor */
  346. #if JPEG_LIB_VERSION >= 70
  347. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  348. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  349. #endif
  350. JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
  351. /* The coefficient controller receives data in units of MCU rows as defined
  352. * for fully interleaved scans (whether the JPEG file is interleaved or not).
  353. * There are v_samp_factor * DCTSIZE sample rows of each component in an
  354. * "iMCU" (interleaved MCU) row.
  355. */
  356. /*
  357. * These fields are valid during any one scan.
  358. * They describe the components and MCUs actually appearing in the scan.
  359. */
  360. int comps_in_scan; /* # of JPEG components in this scan */
  361. jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
  362. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  363. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  364. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  365. int blocks_in_MCU; /* # of DCT blocks per MCU */
  366. int MCU_membership[C_MAX_BLOCKS_IN_MCU];
  367. /* MCU_membership[i] is index in cur_comp_info of component owning */
  368. /* i'th block in an MCU */
  369. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  370. #if JPEG_LIB_VERSION >= 80
  371. int block_size; /* the basic DCT block size: 1..16 */
  372. const int *natural_order; /* natural-order position array */
  373. int lim_Se; /* min( Se, DCTSIZE2-1 ) */
  374. #endif
  375. /*
  376. * Links to compression subobjects (methods and private variables of modules)
  377. */
  378. struct jpeg_comp_master *master;
  379. struct jpeg_c_main_controller *main;
  380. struct jpeg_c_prep_controller *prep;
  381. struct jpeg_c_coef_controller *coef;
  382. struct jpeg_marker_writer *marker;
  383. struct jpeg_color_converter *cconvert;
  384. struct jpeg_downsampler *downsample;
  385. struct jpeg_forward_dct *fdct;
  386. struct jpeg_entropy_encoder *entropy;
  387. jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
  388. int script_space_size;
  389. };
  390. /* Master record for a decompression instance */
  391. struct jpeg_decompress_struct {
  392. jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
  393. /* Source of compressed data */
  394. struct jpeg_source_mgr *src;
  395. /* Basic description of image --- filled in by jpeg_read_header(). */
  396. /* Application may inspect these values to decide how to process image. */
  397. JDIMENSION image_width; /* nominal image width (from SOF marker) */
  398. JDIMENSION image_height; /* nominal image height */
  399. int num_components; /* # of color components in JPEG image */
  400. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  401. /* Decompression processing parameters --- these fields must be set before
  402. * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
  403. * them to default values.
  404. */
  405. J_COLOR_SPACE out_color_space; /* colorspace for output */
  406. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  407. double output_gamma; /* image gamma wanted in output */
  408. boolean buffered_image; /* TRUE=multiple output passes */
  409. boolean raw_data_out; /* TRUE=downsampled data wanted */
  410. J_DCT_METHOD dct_method; /* IDCT algorithm selector */
  411. boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
  412. boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
  413. boolean quantize_colors; /* TRUE=colormapped output wanted */
  414. /* the following are ignored if not quantize_colors: */
  415. J_DITHER_MODE dither_mode; /* type of color dithering to use */
  416. boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
  417. int desired_number_of_colors; /* max # colors to use in created colormap */
  418. /* these are significant only in buffered-image mode: */
  419. boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
  420. boolean enable_external_quant;/* enable future use of external colormap */
  421. boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
  422. /* Description of actual output image that will be returned to application.
  423. * These fields are computed by jpeg_start_decompress().
  424. * You can also use jpeg_calc_output_dimensions() to determine these values
  425. * in advance of calling jpeg_start_decompress().
  426. */
  427. JDIMENSION output_width; /* scaled image width */
  428. JDIMENSION output_height; /* scaled image height */
  429. int out_color_components; /* # of color components in out_color_space */
  430. int output_components; /* # of color components returned */
  431. /* output_components is 1 (a colormap index) when quantizing colors;
  432. * otherwise it equals out_color_components.
  433. */
  434. int rec_outbuf_height; /* min recommended height of scanline buffer */
  435. /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
  436. * high, space and time will be wasted due to unnecessary data copying.
  437. * Usually rec_outbuf_height will be 1 or 2, at most 4.
  438. */
  439. /* When quantizing colors, the output colormap is described by these fields.
  440. * The application can supply a colormap by setting colormap non-NULL before
  441. * calling jpeg_start_decompress; otherwise a colormap is created during
  442. * jpeg_start_decompress or jpeg_start_output.
  443. * The map has out_color_components rows and actual_number_of_colors columns.
  444. */
  445. int actual_number_of_colors; /* number of entries in use */
  446. JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
  447. /* State variables: these variables indicate the progress of decompression.
  448. * The application may examine these but must not modify them.
  449. */
  450. /* Row index of next scanline to be read from jpeg_read_scanlines().
  451. * Application may use this to control its processing loop, e.g.,
  452. * "while (output_scanline < output_height)".
  453. */
  454. JDIMENSION output_scanline; /* 0 .. output_height-1 */
  455. /* Current input scan number and number of iMCU rows completed in scan.
  456. * These indicate the progress of the decompressor input side.
  457. */
  458. int input_scan_number; /* Number of SOS markers seen so far */
  459. JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
  460. /* The "output scan number" is the notional scan being displayed by the
  461. * output side. The decompressor will not allow output scan/row number
  462. * to get ahead of input scan/row, but it can fall arbitrarily far behind.
  463. */
  464. int output_scan_number; /* Nominal scan number being displayed */
  465. JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
  466. /* Current progression status. coef_bits[c][i] indicates the precision
  467. * with which component c's DCT coefficient i (in zigzag order) is known.
  468. * It is -1 when no data has yet been received, otherwise it is the point
  469. * transform (shift) value for the most recent scan of the coefficient
  470. * (thus, 0 at completion of the progression).
  471. * This pointer is NULL when reading a non-progressive file.
  472. */
  473. int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
  474. /* Internal JPEG parameters --- the application usually need not look at
  475. * these fields. Note that the decompressor output side may not use
  476. * any parameters that can change between scans.
  477. */
  478. /* Quantization and Huffman tables are carried forward across input
  479. * datastreams when processing abbreviated JPEG datastreams.
  480. */
  481. JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
  482. /* ptrs to coefficient quantization tables, or NULL if not defined */
  483. JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  484. JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  485. /* ptrs to Huffman coding tables, or NULL if not defined */
  486. /* These parameters are never carried across datastreams, since they
  487. * are given in SOF/SOS markers or defined to be reset by SOI.
  488. */
  489. int data_precision; /* bits of precision in image data */
  490. jpeg_component_info *comp_info;
  491. /* comp_info[i] describes component that appears i'th in SOF */
  492. #if JPEG_LIB_VERSION >= 80
  493. boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
  494. #endif
  495. boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
  496. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  497. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  498. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  499. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  500. unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
  501. /* These fields record data obtained from optional markers recognized by
  502. * the JPEG library.
  503. */
  504. boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
  505. /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
  506. UINT8 JFIF_major_version; /* JFIF version number */
  507. UINT8 JFIF_minor_version;
  508. UINT8 density_unit; /* JFIF code for pixel size units */
  509. UINT16 X_density; /* Horizontal pixel density */
  510. UINT16 Y_density; /* Vertical pixel density */
  511. boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
  512. UINT8 Adobe_transform; /* Color transform code from Adobe marker */
  513. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  514. /* Aside from the specific data retained from APPn markers known to the
  515. * library, the uninterpreted contents of any or all APPn and COM markers
  516. * can be saved in a list for examination by the application.
  517. */
  518. jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
  519. /* Remaining fields are known throughout decompressor, but generally
  520. * should not be touched by a surrounding application.
  521. */
  522. /*
  523. * These fields are computed during decompression startup
  524. */
  525. int max_h_samp_factor; /* largest h_samp_factor */
  526. int max_v_samp_factor; /* largest v_samp_factor */
  527. #if JPEG_LIB_VERSION >= 70
  528. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  529. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  530. #else
  531. int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */
  532. #endif
  533. JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
  534. /* The coefficient controller's input and output progress is measured in
  535. * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
  536. * in fully interleaved JPEG scans, but are used whether the scan is
  537. * interleaved or not. We define an iMCU row as v_samp_factor DCT block
  538. * rows of each component. Therefore, the IDCT output contains
  539. * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
  540. */
  541. JSAMPLE *sample_range_limit; /* table for fast range-limiting */
  542. /*
  543. * These fields are valid during any one scan.
  544. * They describe the components and MCUs actually appearing in the scan.
  545. * Note that the decompressor output side must not use these fields.
  546. */
  547. int comps_in_scan; /* # of JPEG components in this scan */
  548. jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
  549. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  550. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  551. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  552. int blocks_in_MCU; /* # of DCT blocks per MCU */
  553. int MCU_membership[D_MAX_BLOCKS_IN_MCU];
  554. /* MCU_membership[i] is index in cur_comp_info of component owning */
  555. /* i'th block in an MCU */
  556. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  557. #if JPEG_LIB_VERSION >= 80
  558. /* These fields are derived from Se of first SOS marker.
  559. */
  560. int block_size; /* the basic DCT block size: 1..16 */
  561. const int *natural_order; /* natural-order position array for entropy decode */
  562. int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
  563. #endif
  564. /* This field is shared between entropy decoder and marker parser.
  565. * It is either zero or the code of a JPEG marker that has been
  566. * read from the data source, but has not yet been processed.
  567. */
  568. int unread_marker;
  569. /*
  570. * Links to decompression subobjects (methods, private variables of modules)
  571. */
  572. struct jpeg_decomp_master *master;
  573. struct jpeg_d_main_controller *main;
  574. struct jpeg_d_coef_controller *coef;
  575. struct jpeg_d_post_controller *post;
  576. struct jpeg_input_controller *inputctl;
  577. struct jpeg_marker_reader *marker;
  578. struct jpeg_entropy_decoder *entropy;
  579. struct jpeg_inverse_dct *idct;
  580. struct jpeg_upsampler *upsample;
  581. struct jpeg_color_deconverter *cconvert;
  582. struct jpeg_color_quantizer *cquantize;
  583. };
  584. /* "Object" declarations for JPEG modules that may be supplied or called
  585. * directly by the surrounding application.
  586. * As with all objects in the JPEG library, these structs only define the
  587. * publicly visible methods and state variables of a module. Additional
  588. * private fields may exist after the public ones.
  589. */
  590. /* Error handler object */
  591. struct jpeg_error_mgr {
  592. /* Error exit handler: does not return to caller */
  593. void (*error_exit) (j_common_ptr cinfo);
  594. /* Conditionally emit a trace or warning message */
  595. void (*emit_message) (j_common_ptr cinfo, int msg_level);
  596. /* Routine that actually outputs a trace or error message */
  597. void (*output_message) (j_common_ptr cinfo);
  598. /* Format a message string for the most recent JPEG error or message */
  599. void (*format_message) (j_common_ptr cinfo, char *buffer);
  600. #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
  601. /* Reset error state variables at start of a new image */
  602. void (*reset_error_mgr) (j_common_ptr cinfo);
  603. /* The message ID code and any parameters are saved here.
  604. * A message can have one string parameter or up to 8 int parameters.
  605. */
  606. int msg_code;
  607. #define JMSG_STR_PARM_MAX 80
  608. union {
  609. int i[8];
  610. char s[JMSG_STR_PARM_MAX];
  611. } msg_parm;
  612. /* Standard state variables for error facility */
  613. int trace_level; /* max msg_level that will be displayed */
  614. /* For recoverable corrupt-data errors, we emit a warning message,
  615. * but keep going unless emit_message chooses to abort. emit_message
  616. * should count warnings in num_warnings. The surrounding application
  617. * can check for bad data by seeing if num_warnings is nonzero at the
  618. * end of processing.
  619. */
  620. long num_warnings; /* number of corrupt-data warnings */
  621. /* These fields point to the table(s) of error message strings.
  622. * An application can change the table pointer to switch to a different
  623. * message list (typically, to change the language in which errors are
  624. * reported). Some applications may wish to add additional error codes
  625. * that will be handled by the JPEG library error mechanism; the second
  626. * table pointer is used for this purpose.
  627. *
  628. * First table includes all errors generated by JPEG library itself.
  629. * Error code 0 is reserved for a "no such error string" message.
  630. */
  631. const char * const *jpeg_message_table; /* Library errors */
  632. int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
  633. /* Second table can be added by application (see cjpeg/djpeg for example).
  634. * It contains strings numbered first_addon_message..last_addon_message.
  635. */
  636. const char * const *addon_message_table; /* Non-library errors */
  637. int first_addon_message; /* code for first string in addon table */
  638. int last_addon_message; /* code for last string in addon table */
  639. };
  640. /* Progress monitor object */
  641. struct jpeg_progress_mgr {
  642. void (*progress_monitor) (j_common_ptr cinfo);
  643. long pass_counter; /* work units completed in this pass */
  644. long pass_limit; /* total number of work units in this pass */
  645. int completed_passes; /* passes completed so far */
  646. int total_passes; /* total number of passes expected */
  647. };
  648. /* Data destination object for compression */
  649. struct jpeg_destination_mgr {
  650. JOCTET *next_output_byte; /* => next byte to write in buffer */
  651. size_t free_in_buffer; /* # of byte spaces remaining in buffer */
  652. void (*init_destination) (j_compress_ptr cinfo);
  653. boolean (*empty_output_buffer) (j_compress_ptr cinfo);
  654. void (*term_destination) (j_compress_ptr cinfo);
  655. };
  656. /* Data source object for decompression */
  657. struct jpeg_source_mgr {
  658. const JOCTET *next_input_byte; /* => next byte to read from buffer */
  659. size_t bytes_in_buffer; /* # of bytes remaining in buffer */
  660. void (*init_source) (j_decompress_ptr cinfo);
  661. boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
  662. void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
  663. boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
  664. void (*term_source) (j_decompress_ptr cinfo);
  665. };
  666. /* Memory manager object.
  667. * Allocates "small" objects (a few K total), "large" objects (tens of K),
  668. * and "really big" objects (virtual arrays with backing store if needed).
  669. * The memory manager does not allow individual objects to be freed; rather,
  670. * each created object is assigned to a pool, and whole pools can be freed
  671. * at once. This is faster and more convenient than remembering exactly what
  672. * to free, especially where malloc()/free() are not too speedy.
  673. * NB: alloc routines never return NULL. They exit to error_exit if not
  674. * successful.
  675. */
  676. #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
  677. #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
  678. #define JPOOL_NUMPOOLS 2
  679. typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
  680. typedef struct jvirt_barray_control *jvirt_barray_ptr;
  681. struct jpeg_memory_mgr {
  682. /* Method pointers */
  683. void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
  684. void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
  685. size_t sizeofobject);
  686. JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
  687. JDIMENSION samplesperrow, JDIMENSION numrows);
  688. JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
  689. JDIMENSION blocksperrow, JDIMENSION numrows);
  690. jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
  691. boolean pre_zero,
  692. JDIMENSION samplesperrow,
  693. JDIMENSION numrows,
  694. JDIMENSION maxaccess);
  695. jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
  696. boolean pre_zero,
  697. JDIMENSION blocksperrow,
  698. JDIMENSION numrows,
  699. JDIMENSION maxaccess);
  700. void (*realize_virt_arrays) (j_common_ptr cinfo);
  701. JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
  702. JDIMENSION start_row, JDIMENSION num_rows,
  703. boolean writable);
  704. JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
  705. JDIMENSION start_row, JDIMENSION num_rows,
  706. boolean writable);
  707. void (*free_pool) (j_common_ptr cinfo, int pool_id);
  708. void (*self_destruct) (j_common_ptr cinfo);
  709. /* Limit on memory allocation for this JPEG object. (Note that this is
  710. * merely advisory, not a guaranteed maximum; it only affects the space
  711. * used for virtual-array buffers.) May be changed by outer application
  712. * after creating the JPEG object.
  713. */
  714. long max_memory_to_use;
  715. /* Maximum allocation request accepted by alloc_large. */
  716. long max_alloc_chunk;
  717. };
  718. /* Routine signature for application-supplied marker processing methods.
  719. * Need not pass marker code since it is stored in cinfo->unread_marker.
  720. */
  721. typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
  722. /* Originally, this macro was used as a way of defining function prototypes
  723. * for both modern compilers as well as older compilers that did not support
  724. * prototype parameters. libjpeg-turbo has never supported these older,
  725. * non-ANSI compilers, but the macro is still included because there is some
  726. * software out there that uses it.
  727. */
  728. #define JPP(arglist) arglist
  729. /* Default error-management setup */
  730. EXTERN(struct jpeg_error_mgr *) jpeg_std_error(struct jpeg_error_mgr *err);
  731. /* Initialization of JPEG compression objects.
  732. * jpeg_create_compress() and jpeg_create_decompress() are the exported
  733. * names that applications should call. These expand to calls on
  734. * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
  735. * passed for version mismatch checking.
  736. * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
  737. */
  738. #define jpeg_create_compress(cinfo) \
  739. jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
  740. (size_t)sizeof(struct jpeg_compress_struct))
  741. #define jpeg_create_decompress(cinfo) \
  742. jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
  743. (size_t)sizeof(struct jpeg_decompress_struct))
  744. EXTERN(void) jpeg_CreateCompress(j_compress_ptr cinfo, int version,
  745. size_t structsize);
  746. EXTERN(void) jpeg_CreateDecompress(j_decompress_ptr cinfo, int version,
  747. size_t structsize);
  748. /* Destruction of JPEG compression objects */
  749. EXTERN(void) jpeg_destroy_compress(j_compress_ptr cinfo);
  750. EXTERN(void) jpeg_destroy_decompress(j_decompress_ptr cinfo);
  751. /* Standard data source and destination managers: stdio streams. */
  752. /* Caller is responsible for opening the file before and closing after. */
  753. EXTERN(void) jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile);
  754. EXTERN(void) jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile);
  755. #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
  756. /* Data source and destination managers: memory buffers. */
  757. EXTERN(void) jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer,
  758. unsigned long *outsize);
  759. EXTERN(void) jpeg_mem_src(j_decompress_ptr cinfo,
  760. const unsigned char *inbuffer, unsigned long insize);
  761. #endif
  762. /* Default parameter setup for compression */
  763. EXTERN(void) jpeg_set_defaults(j_compress_ptr cinfo);
  764. /* Compression parameter setup aids */
  765. EXTERN(void) jpeg_set_colorspace(j_compress_ptr cinfo,
  766. J_COLOR_SPACE colorspace);
  767. EXTERN(void) jpeg_default_colorspace(j_compress_ptr cinfo);
  768. EXTERN(void) jpeg_set_quality(j_compress_ptr cinfo, int quality,
  769. boolean force_baseline);
  770. EXTERN(void) jpeg_set_linear_quality(j_compress_ptr cinfo, int scale_factor,
  771. boolean force_baseline);
  772. #if JPEG_LIB_VERSION >= 70
  773. EXTERN(void) jpeg_default_qtables(j_compress_ptr cinfo,
  774. boolean force_baseline);
  775. #endif
  776. EXTERN(void) jpeg_add_quant_table(j_compress_ptr cinfo, int which_tbl,
  777. const unsigned int *basic_table,
  778. int scale_factor, boolean force_baseline);
  779. EXTERN(int) jpeg_quality_scaling(int quality);
  780. EXTERN(void) jpeg_simple_progression(j_compress_ptr cinfo);
  781. EXTERN(void) jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress);
  782. EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table(j_common_ptr cinfo);
  783. EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table(j_common_ptr cinfo);
  784. /* Main entry points for compression */
  785. EXTERN(void) jpeg_start_compress(j_compress_ptr cinfo,
  786. boolean write_all_tables);
  787. EXTERN(JDIMENSION) jpeg_write_scanlines(j_compress_ptr cinfo,
  788. JSAMPARRAY scanlines,
  789. JDIMENSION num_lines);
  790. EXTERN(void) jpeg_finish_compress(j_compress_ptr cinfo);
  791. #if JPEG_LIB_VERSION >= 70
  792. /* Precalculate JPEG dimensions for current compression parameters. */
  793. EXTERN(void) jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo);
  794. #endif
  795. /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
  796. EXTERN(JDIMENSION) jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data,
  797. JDIMENSION num_lines);
  798. /* Write a special marker. See libjpeg.txt concerning safe usage. */
  799. EXTERN(void) jpeg_write_marker(j_compress_ptr cinfo, int marker,
  800. const JOCTET *dataptr, unsigned int datalen);
  801. /* Same, but piecemeal. */
  802. EXTERN(void) jpeg_write_m_header(j_compress_ptr cinfo, int marker,
  803. unsigned int datalen);
  804. EXTERN(void) jpeg_write_m_byte(j_compress_ptr cinfo, int val);
  805. /* Alternate compression function: just write an abbreviated table file */
  806. EXTERN(void) jpeg_write_tables(j_compress_ptr cinfo);
  807. /* Write ICC profile. See libjpeg.txt for usage information. */
  808. EXTERN(void) jpeg_write_icc_profile(j_compress_ptr cinfo,
  809. const JOCTET *icc_data_ptr,
  810. unsigned int icc_data_len);
  811. /* Decompression startup: read start of JPEG datastream to see what's there */
  812. EXTERN(int) jpeg_read_header(j_decompress_ptr cinfo, boolean require_image);
  813. /* Return value is one of: */
  814. #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
  815. #define JPEG_HEADER_OK 1 /* Found valid image datastream */
  816. #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
  817. /* If you pass require_image = TRUE (normal case), you need not check for
  818. * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  819. * JPEG_SUSPENDED is only possible if you use a data source module that can
  820. * give a suspension return (the stdio source module doesn't).
  821. */
  822. /* Main entry points for decompression */
  823. EXTERN(boolean) jpeg_start_decompress(j_decompress_ptr cinfo);
  824. EXTERN(JDIMENSION) jpeg_read_scanlines(j_decompress_ptr cinfo,
  825. JSAMPARRAY scanlines,
  826. JDIMENSION max_lines);
  827. EXTERN(JDIMENSION) jpeg_skip_scanlines(j_decompress_ptr cinfo,
  828. JDIMENSION num_lines);
  829. EXTERN(void) jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
  830. JDIMENSION *width);
  831. EXTERN(boolean) jpeg_finish_decompress(j_decompress_ptr cinfo);
  832. /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
  833. EXTERN(JDIMENSION) jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data,
  834. JDIMENSION max_lines);
  835. /* Additional entry points for buffered-image mode. */
  836. EXTERN(boolean) jpeg_has_multiple_scans(j_decompress_ptr cinfo);
  837. EXTERN(boolean) jpeg_start_output(j_decompress_ptr cinfo, int scan_number);
  838. EXTERN(boolean) jpeg_finish_output(j_decompress_ptr cinfo);
  839. EXTERN(boolean) jpeg_input_complete(j_decompress_ptr cinfo);
  840. EXTERN(void) jpeg_new_colormap(j_decompress_ptr cinfo);
  841. EXTERN(int) jpeg_consume_input(j_decompress_ptr cinfo);
  842. /* Return value is one of: */
  843. /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
  844. #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
  845. #define JPEG_REACHED_EOI 2 /* Reached end of image */
  846. #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
  847. #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
  848. /* Precalculate output dimensions for current decompression parameters. */
  849. #if JPEG_LIB_VERSION >= 80
  850. EXTERN(void) jpeg_core_output_dimensions(j_decompress_ptr cinfo);
  851. #endif
  852. EXTERN(void) jpeg_calc_output_dimensions(j_decompress_ptr cinfo);
  853. /* Control saving of COM and APPn markers into marker_list. */
  854. EXTERN(void) jpeg_save_markers(j_decompress_ptr cinfo, int marker_code,
  855. unsigned int length_limit);
  856. /* Install a special processing method for COM or APPn markers. */
  857. EXTERN(void) jpeg_set_marker_processor(j_decompress_ptr cinfo,
  858. int marker_code,
  859. jpeg_marker_parser_method routine);
  860. /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
  861. EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients(j_decompress_ptr cinfo);
  862. EXTERN(void) jpeg_write_coefficients(j_compress_ptr cinfo,
  863. jvirt_barray_ptr *coef_arrays);
  864. EXTERN(void) jpeg_copy_critical_parameters(j_decompress_ptr srcinfo,
  865. j_compress_ptr dstinfo);
  866. /* If you choose to abort compression or decompression before completing
  867. * jpeg_finish_(de)compress, then you need to clean up to release memory,
  868. * temporary files, etc. You can just call jpeg_destroy_(de)compress
  869. * if you're done with the JPEG object, but if you want to clean it up and
  870. * reuse it, call this:
  871. */
  872. EXTERN(void) jpeg_abort_compress(j_compress_ptr cinfo);
  873. EXTERN(void) jpeg_abort_decompress(j_decompress_ptr cinfo);
  874. /* Generic versions of jpeg_abort and jpeg_destroy that work on either
  875. * flavor of JPEG object. These may be more convenient in some places.
  876. */
  877. EXTERN(void) jpeg_abort(j_common_ptr cinfo);
  878. EXTERN(void) jpeg_destroy(j_common_ptr cinfo);
  879. /* Default restart-marker-resync procedure for use by data source modules */
  880. EXTERN(boolean) jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired);
  881. /* Read ICC profile. See libjpeg.txt for usage information. */
  882. EXTERN(boolean) jpeg_read_icc_profile(j_decompress_ptr cinfo,
  883. JOCTET **icc_data_ptr,
  884. unsigned int *icc_data_len);
  885. /* These marker codes are exported since applications and data source modules
  886. * are likely to want to use them.
  887. */
  888. #define JPEG_RST0 0xD0 /* RST0 marker code */
  889. #define JPEG_EOI 0xD9 /* EOI marker code */
  890. #define JPEG_APP0 0xE0 /* APP0 marker code */
  891. #define JPEG_COM 0xFE /* COM marker code */
  892. /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
  893. * for structure definitions that are never filled in, keep it quiet by
  894. * supplying dummy definitions for the various substructures.
  895. */
  896. #ifdef INCOMPLETE_TYPES_BROKEN
  897. #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
  898. struct jvirt_sarray_control { long dummy; };
  899. struct jvirt_barray_control { long dummy; };
  900. struct jpeg_comp_master { long dummy; };
  901. struct jpeg_c_main_controller { long dummy; };
  902. struct jpeg_c_prep_controller { long dummy; };
  903. struct jpeg_c_coef_controller { long dummy; };
  904. struct jpeg_marker_writer { long dummy; };
  905. struct jpeg_color_converter { long dummy; };
  906. struct jpeg_downsampler { long dummy; };
  907. struct jpeg_forward_dct { long dummy; };
  908. struct jpeg_entropy_encoder { long dummy; };
  909. struct jpeg_decomp_master { long dummy; };
  910. struct jpeg_d_main_controller { long dummy; };
  911. struct jpeg_d_coef_controller { long dummy; };
  912. struct jpeg_d_post_controller { long dummy; };
  913. struct jpeg_input_controller { long dummy; };
  914. struct jpeg_marker_reader { long dummy; };
  915. struct jpeg_entropy_decoder { long dummy; };
  916. struct jpeg_inverse_dct { long dummy; };
  917. struct jpeg_upsampler { long dummy; };
  918. struct jpeg_color_deconverter { long dummy; };
  919. struct jpeg_color_quantizer { long dummy; };
  920. #endif /* JPEG_INTERNALS */
  921. #endif /* INCOMPLETE_TYPES_BROKEN */
  922. /*
  923. * The JPEG library modules define JPEG_INTERNALS before including this file.
  924. * The internal structure declarations are read only when that is true.
  925. * Applications using the library should not include jpegint.h, but may wish
  926. * to include jerror.h.
  927. */
  928. #ifdef JPEG_INTERNALS
  929. #include "jpegint.h" /* fetch private declarations */
  930. #include "jerror.h" /* fetch error codes too */
  931. #endif
  932. #ifdef __cplusplus
  933. #ifndef DONT_USE_EXTERN_C
  934. }
  935. #endif
  936. #endif
  937. #endif /* JPEGLIB_H */