jpeglib.h 46 KB

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  1. /*
  2. * jpeglib.h
  3. *
  4. * Copyright (C) 1991-1998, Thomas G. Lane.
  5. * Modified 2002-2009 by Guido Vollbeding.
  6. * This file is part of the Independent JPEG Group's software.
  7. * For conditions of distribution and use, see the accompanying README file.
  8. *
  9. * This file defines the application interface for the JPEG library.
  10. * Most applications using the library need only include this file,
  11. * and perhaps jerror.h if they want to know the exact error codes.
  12. */
  13. #ifndef JPEGLIB_H
  14. #define JPEGLIB_H
  15. /*
  16. * First we include the configuration files that record how this
  17. * installation of the JPEG library is set up. jconfig.h can be
  18. * generated automatically for many systems. jmorecfg.h contains
  19. * manual configuration options that most people need not worry about.
  20. */
  21. #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
  22. #include "jconfig.h" /* widely used configuration options */
  23. #endif
  24. #include "jmorecfg.h" /* seldom changed options */
  25. #ifdef __cplusplus
  26. #ifndef DONT_USE_EXTERN_C
  27. extern "C" {
  28. #endif
  29. #endif
  30. /* Version ID for the JPEG library.
  31. * Might be useful for tests like "#if JPEG_LIB_VERSION >= 70".
  32. */
  33. #define JPEG_LIB_VERSION 70 /* Version 7.0 */
  34. /* Various constants determining the sizes of things.
  35. * All of these are specified by the JPEG standard, so don't change them
  36. * if you want to be compatible.
  37. */
  38. #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
  39. #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
  40. #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
  41. #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
  42. #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
  43. #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
  44. #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
  45. /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
  46. * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
  47. * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
  48. * to handle it. We even let you do this from the jconfig.h file. However,
  49. * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
  50. * sometimes emits noncompliant files doesn't mean you should too.
  51. */
  52. #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
  53. #ifndef D_MAX_BLOCKS_IN_MCU
  54. #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
  55. #endif
  56. /* Data structures for images (arrays of samples and of DCT coefficients).
  57. * On 80x86 machines, the image arrays are too big for near pointers,
  58. * but the pointer arrays can fit in near memory.
  59. */
  60. typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
  61. typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
  62. typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
  63. typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
  64. typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
  65. typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
  66. typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
  67. typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
  68. /* Types for JPEG compression parameters and working tables. */
  69. /* DCT coefficient quantization tables. */
  70. typedef struct {
  71. /* This array gives the coefficient quantizers in natural array order
  72. * (not the zigzag order in which they are stored in a JPEG DQT marker).
  73. * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
  74. */
  75. UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
  76. /* This field is used only during compression. It's initialized FALSE when
  77. * the table is created, and set TRUE when it's been output to the file.
  78. * You could suppress output of a table by setting this to TRUE.
  79. * (See jpeg_suppress_tables for an example.)
  80. */
  81. boolean sent_table; /* TRUE when table has been output */
  82. } JQUANT_TBL;
  83. /* Huffman coding tables. */
  84. typedef struct {
  85. /* These two fields directly represent the contents of a JPEG DHT marker */
  86. UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
  87. /* length k bits; bits[0] is unused */
  88. UINT8 huffval[256]; /* The symbols, in order of incr code length */
  89. /* This field is used only during compression. It's initialized FALSE when
  90. * the table is created, and set TRUE when it's been output to the file.
  91. * You could suppress output of a table by setting this to TRUE.
  92. * (See jpeg_suppress_tables for an example.)
  93. */
  94. boolean sent_table; /* TRUE when table has been output */
  95. } JHUFF_TBL;
  96. /* Basic info about one component (color channel). */
  97. typedef struct {
  98. /* These values are fixed over the whole image. */
  99. /* For compression, they must be supplied by parameter setup; */
  100. /* for decompression, they are read from the SOF marker. */
  101. int component_id; /* identifier for this component (0..255) */
  102. int component_index; /* its index in SOF or cinfo->comp_info[] */
  103. int h_samp_factor; /* horizontal sampling factor (1..4) */
  104. int v_samp_factor; /* vertical sampling factor (1..4) */
  105. int quant_tbl_no; /* quantization table selector (0..3) */
  106. /* These values may vary between scans. */
  107. /* For compression, they must be supplied by parameter setup; */
  108. /* for decompression, they are read from the SOS marker. */
  109. /* The decompressor output side may not use these variables. */
  110. int dc_tbl_no; /* DC entropy table selector (0..3) */
  111. int ac_tbl_no; /* AC entropy table selector (0..3) */
  112. /* Remaining fields should be treated as private by applications. */
  113. /* These values are computed during compression or decompression startup: */
  114. /* Component's size in DCT blocks.
  115. * Any dummy blocks added to complete an MCU are not counted; therefore
  116. * these values do not depend on whether a scan is interleaved or not.
  117. */
  118. JDIMENSION width_in_blocks;
  119. JDIMENSION height_in_blocks;
  120. /* Size of a DCT block in samples,
  121. * reflecting any scaling we choose to apply during the DCT step.
  122. * Values from 1 to 16 are supported.
  123. * Note that different components may receive different DCT scalings.
  124. */
  125. int DCT_h_scaled_size;
  126. int DCT_v_scaled_size;
  127. /* The downsampled dimensions are the component's actual, unpadded number
  128. * of samples at the main buffer (preprocessing/compression interface);
  129. * DCT scaling is included, so
  130. * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
  131. * and similarly for height.
  132. */
  133. JDIMENSION downsampled_width; /* actual width in samples */
  134. JDIMENSION downsampled_height; /* actual height in samples */
  135. /* This flag is used only for decompression. In cases where some of the
  136. * components will be ignored (eg grayscale output from YCbCr image),
  137. * we can skip most computations for the unused components.
  138. */
  139. boolean component_needed; /* do we need the value of this component? */
  140. /* These values are computed before starting a scan of the component. */
  141. /* The decompressor output side may not use these variables. */
  142. int MCU_width; /* number of blocks per MCU, horizontally */
  143. int MCU_height; /* number of blocks per MCU, vertically */
  144. int MCU_blocks; /* MCU_width * MCU_height */
  145. int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */
  146. int last_col_width; /* # of non-dummy blocks across in last MCU */
  147. int last_row_height; /* # of non-dummy blocks down in last MCU */
  148. /* Saved quantization table for component; NULL if none yet saved.
  149. * See jdinput.c comments about the need for this information.
  150. * This field is currently used only for decompression.
  151. */
  152. JQUANT_TBL * quant_table;
  153. /* Private per-component storage for DCT or IDCT subsystem. */
  154. void * dct_table;
  155. } jpeg_component_info;
  156. /* The script for encoding a multiple-scan file is an array of these: */
  157. typedef struct {
  158. int comps_in_scan; /* number of components encoded in this scan */
  159. int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
  160. int Ss, Se; /* progressive JPEG spectral selection parms */
  161. int Ah, Al; /* progressive JPEG successive approx. parms */
  162. } jpeg_scan_info;
  163. /* The decompressor can save APPn and COM markers in a list of these: */
  164. typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
  165. struct jpeg_marker_struct {
  166. jpeg_saved_marker_ptr next; /* next in list, or NULL */
  167. UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
  168. unsigned int original_length; /* # bytes of data in the file */
  169. unsigned int data_length; /* # bytes of data saved at data[] */
  170. JOCTET FAR * data; /* the data contained in the marker */
  171. /* the marker length word is not counted in data_length or original_length */
  172. };
  173. /* Known color spaces. */
  174. typedef enum {
  175. JCS_UNKNOWN, /* error/unspecified */
  176. JCS_GRAYSCALE, /* monochrome */
  177. JCS_RGB, /* red/green/blue */
  178. JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
  179. JCS_CMYK, /* C/M/Y/K */
  180. JCS_YCCK /* Y/Cb/Cr/K */
  181. } J_COLOR_SPACE;
  182. /* DCT/IDCT algorithm options. */
  183. typedef enum {
  184. JDCT_ISLOW, /* slow but accurate integer algorithm */
  185. JDCT_IFAST, /* faster, less accurate integer method */
  186. JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
  187. } J_DCT_METHOD;
  188. #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
  189. #define JDCT_DEFAULT JDCT_ISLOW
  190. #endif
  191. #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
  192. #define JDCT_FASTEST JDCT_IFAST
  193. #endif
  194. /* Dithering options for decompression. */
  195. typedef enum {
  196. JDITHER_NONE, /* no dithering */
  197. JDITHER_ORDERED, /* simple ordered dither */
  198. JDITHER_FS /* Floyd-Steinberg error diffusion dither */
  199. } J_DITHER_MODE;
  200. /* Common fields between JPEG compression and decompression master structs. */
  201. #define jpeg_common_fields \
  202. struct jpeg_error_mgr * err; /* Error handler module */\
  203. struct jpeg_memory_mgr * mem; /* Memory manager module */\
  204. struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
  205. void * client_data; /* Available for use by application */\
  206. boolean is_decompressor; /* So common code can tell which is which */\
  207. int global_state /* For checking call sequence validity */
  208. /* Routines that are to be used by both halves of the library are declared
  209. * to receive a pointer to this structure. There are no actual instances of
  210. * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
  211. */
  212. struct jpeg_common_struct {
  213. jpeg_common_fields; /* Fields common to both master struct types */
  214. /* Additional fields follow in an actual jpeg_compress_struct or
  215. * jpeg_decompress_struct. All three structs must agree on these
  216. * initial fields! (This would be a lot cleaner in C++.)
  217. */
  218. };
  219. typedef struct jpeg_common_struct * j_common_ptr;
  220. typedef struct jpeg_compress_struct * j_compress_ptr;
  221. typedef struct jpeg_decompress_struct * j_decompress_ptr;
  222. /* Master record for a compression instance */
  223. struct jpeg_compress_struct {
  224. jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
  225. /* Destination for compressed data */
  226. struct jpeg_destination_mgr * dest;
  227. /* Description of source image --- these fields must be filled in by
  228. * outer application before starting compression. in_color_space must
  229. * be correct before you can even call jpeg_set_defaults().
  230. */
  231. JDIMENSION image_width; /* input image width */
  232. JDIMENSION image_height; /* input image height */
  233. int input_components; /* # of color components in input image */
  234. J_COLOR_SPACE in_color_space; /* colorspace of input image */
  235. double input_gamma; /* image gamma of input image */
  236. /* Compression parameters --- these fields must be set before calling
  237. * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
  238. * initialize everything to reasonable defaults, then changing anything
  239. * the application specifically wants to change. That way you won't get
  240. * burnt when new parameters are added. Also note that there are several
  241. * helper routines to simplify changing parameters.
  242. */
  243. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  244. JDIMENSION jpeg_width; /* scaled JPEG image width */
  245. JDIMENSION jpeg_height; /* scaled JPEG image height */
  246. /* Dimensions of actual JPEG image that will be written to file,
  247. * derived from input dimensions by scaling factors above.
  248. * These fields are computed by jpeg_start_compress().
  249. * You can also use jpeg_calc_jpeg_dimensions() to determine these values
  250. * in advance of calling jpeg_start_compress().
  251. */
  252. int data_precision; /* bits of precision in image data */
  253. int num_components; /* # of color components in JPEG image */
  254. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  255. jpeg_component_info * comp_info;
  256. /* comp_info[i] describes component that appears i'th in SOF */
  257. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  258. int q_scale_factor[NUM_QUANT_TBLS];
  259. /* ptrs to coefficient quantization tables, or NULL if not defined,
  260. * and corresponding scale factors (percentage, initialized 100).
  261. */
  262. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  263. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  264. /* ptrs to Huffman coding tables, or NULL if not defined */
  265. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  266. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  267. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  268. int num_scans; /* # of entries in scan_info array */
  269. const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
  270. /* The default value of scan_info is NULL, which causes a single-scan
  271. * sequential JPEG file to be emitted. To create a multi-scan file,
  272. * set num_scans and scan_info to point to an array of scan definitions.
  273. */
  274. boolean raw_data_in; /* TRUE=caller supplies downsampled data */
  275. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  276. boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
  277. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  278. boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
  279. int smoothing_factor; /* 1..100, or 0 for no input smoothing */
  280. J_DCT_METHOD dct_method; /* DCT algorithm selector */
  281. /* The restart interval can be specified in absolute MCUs by setting
  282. * restart_interval, or in MCU rows by setting restart_in_rows
  283. * (in which case the correct restart_interval will be figured
  284. * for each scan).
  285. */
  286. unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
  287. int restart_in_rows; /* if > 0, MCU rows per restart interval */
  288. /* Parameters controlling emission of special markers. */
  289. boolean write_JFIF_header; /* should a JFIF marker be written? */
  290. UINT8 JFIF_major_version; /* What to write for the JFIF version number */
  291. UINT8 JFIF_minor_version;
  292. /* These three values are not used by the JPEG code, merely copied */
  293. /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
  294. /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
  295. /* ratio is defined by X_density/Y_density even when density_unit=0. */
  296. UINT8 density_unit; /* JFIF code for pixel size units */
  297. UINT16 X_density; /* Horizontal pixel density */
  298. UINT16 Y_density; /* Vertical pixel density */
  299. boolean write_Adobe_marker; /* should an Adobe marker be written? */
  300. /* State variable: index of next scanline to be written to
  301. * jpeg_write_scanlines(). Application may use this to control its
  302. * processing loop, e.g., "while (next_scanline < image_height)".
  303. */
  304. JDIMENSION next_scanline; /* 0 .. image_height-1 */
  305. /* Remaining fields are known throughout compressor, but generally
  306. * should not be touched by a surrounding application.
  307. */
  308. /*
  309. * These fields are computed during compression startup
  310. */
  311. boolean progressive_mode; /* TRUE if scan script uses progressive mode */
  312. int max_h_samp_factor; /* largest h_samp_factor */
  313. int max_v_samp_factor; /* largest v_samp_factor */
  314. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  315. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  316. JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
  317. /* The coefficient controller receives data in units of MCU rows as defined
  318. * for fully interleaved scans (whether the JPEG file is interleaved or not).
  319. * There are v_samp_factor * DCTSIZE sample rows of each component in an
  320. * "iMCU" (interleaved MCU) row.
  321. */
  322. /*
  323. * These fields are valid during any one scan.
  324. * They describe the components and MCUs actually appearing in the scan.
  325. */
  326. int comps_in_scan; /* # of JPEG components in this scan */
  327. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  328. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  329. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  330. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  331. int blocks_in_MCU; /* # of DCT blocks per MCU */
  332. int MCU_membership[C_MAX_BLOCKS_IN_MCU];
  333. /* MCU_membership[i] is index in cur_comp_info of component owning */
  334. /* i'th block in an MCU */
  335. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  336. /*
  337. * Links to compression subobjects (methods and private variables of modules)
  338. */
  339. struct jpeg_comp_master * master;
  340. struct jpeg_c_main_controller * main;
  341. struct jpeg_c_prep_controller * prep;
  342. struct jpeg_c_coef_controller * coef;
  343. struct jpeg_marker_writer * marker;
  344. struct jpeg_color_converter * cconvert;
  345. struct jpeg_downsampler * downsample;
  346. struct jpeg_forward_dct * fdct;
  347. struct jpeg_entropy_encoder * entropy;
  348. jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
  349. int script_space_size;
  350. };
  351. /* Master record for a decompression instance */
  352. struct jpeg_decompress_struct {
  353. jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
  354. /* Source of compressed data */
  355. struct jpeg_source_mgr * src;
  356. /* Basic description of image --- filled in by jpeg_read_header(). */
  357. /* Application may inspect these values to decide how to process image. */
  358. JDIMENSION image_width; /* nominal image width (from SOF marker) */
  359. JDIMENSION image_height; /* nominal image height */
  360. int num_components; /* # of color components in JPEG image */
  361. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  362. /* Decompression processing parameters --- these fields must be set before
  363. * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
  364. * them to default values.
  365. */
  366. J_COLOR_SPACE out_color_space; /* colorspace for output */
  367. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  368. double output_gamma; /* image gamma wanted in output */
  369. boolean buffered_image; /* TRUE=multiple output passes */
  370. boolean raw_data_out; /* TRUE=downsampled data wanted */
  371. J_DCT_METHOD dct_method; /* IDCT algorithm selector */
  372. boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
  373. boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
  374. boolean quantize_colors; /* TRUE=colormapped output wanted */
  375. /* the following are ignored if not quantize_colors: */
  376. J_DITHER_MODE dither_mode; /* type of color dithering to use */
  377. boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
  378. int desired_number_of_colors; /* max # colors to use in created colormap */
  379. /* these are significant only in buffered-image mode: */
  380. boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
  381. boolean enable_external_quant;/* enable future use of external colormap */
  382. boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
  383. /* Description of actual output image that will be returned to application.
  384. * These fields are computed by jpeg_start_decompress().
  385. * You can also use jpeg_calc_output_dimensions() to determine these values
  386. * in advance of calling jpeg_start_decompress().
  387. */
  388. JDIMENSION output_width; /* scaled image width */
  389. JDIMENSION output_height; /* scaled image height */
  390. int out_color_components; /* # of color components in out_color_space */
  391. int output_components; /* # of color components returned */
  392. /* output_components is 1 (a colormap index) when quantizing colors;
  393. * otherwise it equals out_color_components.
  394. */
  395. int rec_outbuf_height; /* min recommended height of scanline buffer */
  396. /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
  397. * high, space and time will be wasted due to unnecessary data copying.
  398. * Usually rec_outbuf_height will be 1 or 2, at most 4.
  399. */
  400. /* When quantizing colors, the output colormap is described by these fields.
  401. * The application can supply a colormap by setting colormap non-NULL before
  402. * calling jpeg_start_decompress; otherwise a colormap is created during
  403. * jpeg_start_decompress or jpeg_start_output.
  404. * The map has out_color_components rows and actual_number_of_colors columns.
  405. */
  406. int actual_number_of_colors; /* number of entries in use */
  407. JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
  408. /* State variables: these variables indicate the progress of decompression.
  409. * The application may examine these but must not modify them.
  410. */
  411. /* Row index of next scanline to be read from jpeg_read_scanlines().
  412. * Application may use this to control its processing loop, e.g.,
  413. * "while (output_scanline < output_height)".
  414. */
  415. JDIMENSION output_scanline; /* 0 .. output_height-1 */
  416. /* Current input scan number and number of iMCU rows completed in scan.
  417. * These indicate the progress of the decompressor input side.
  418. */
  419. int input_scan_number; /* Number of SOS markers seen so far */
  420. JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
  421. /* The "output scan number" is the notional scan being displayed by the
  422. * output side. The decompressor will not allow output scan/row number
  423. * to get ahead of input scan/row, but it can fall arbitrarily far behind.
  424. */
  425. int output_scan_number; /* Nominal scan number being displayed */
  426. JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
  427. /* Current progression status. coef_bits[c][i] indicates the precision
  428. * with which component c's DCT coefficient i (in zigzag order) is known.
  429. * It is -1 when no data has yet been received, otherwise it is the point
  430. * transform (shift) value for the most recent scan of the coefficient
  431. * (thus, 0 at completion of the progression).
  432. * This pointer is NULL when reading a non-progressive file.
  433. */
  434. int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
  435. /* Internal JPEG parameters --- the application usually need not look at
  436. * these fields. Note that the decompressor output side may not use
  437. * any parameters that can change between scans.
  438. */
  439. /* Quantization and Huffman tables are carried forward across input
  440. * datastreams when processing abbreviated JPEG datastreams.
  441. */
  442. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  443. /* ptrs to coefficient quantization tables, or NULL if not defined */
  444. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  445. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  446. /* ptrs to Huffman coding tables, or NULL if not defined */
  447. /* These parameters are never carried across datastreams, since they
  448. * are given in SOF/SOS markers or defined to be reset by SOI.
  449. */
  450. int data_precision; /* bits of precision in image data */
  451. jpeg_component_info * comp_info;
  452. /* comp_info[i] describes component that appears i'th in SOF */
  453. boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
  454. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  455. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  456. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  457. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  458. unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
  459. /* These fields record data obtained from optional markers recognized by
  460. * the JPEG library.
  461. */
  462. boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
  463. /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
  464. UINT8 JFIF_major_version; /* JFIF version number */
  465. UINT8 JFIF_minor_version;
  466. UINT8 density_unit; /* JFIF code for pixel size units */
  467. UINT16 X_density; /* Horizontal pixel density */
  468. UINT16 Y_density; /* Vertical pixel density */
  469. boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
  470. UINT8 Adobe_transform; /* Color transform code from Adobe marker */
  471. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  472. /* Aside from the specific data retained from APPn markers known to the
  473. * library, the uninterpreted contents of any or all APPn and COM markers
  474. * can be saved in a list for examination by the application.
  475. */
  476. jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
  477. /* Remaining fields are known throughout decompressor, but generally
  478. * should not be touched by a surrounding application.
  479. */
  480. /*
  481. * These fields are computed during decompression startup
  482. */
  483. int max_h_samp_factor; /* largest h_samp_factor */
  484. int max_v_samp_factor; /* largest v_samp_factor */
  485. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  486. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  487. JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
  488. /* The coefficient controller's input and output progress is measured in
  489. * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
  490. * in fully interleaved JPEG scans, but are used whether the scan is
  491. * interleaved or not. We define an iMCU row as v_samp_factor DCT block
  492. * rows of each component. Therefore, the IDCT output contains
  493. * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
  494. */
  495. JSAMPLE * sample_range_limit; /* table for fast range-limiting */
  496. /*
  497. * These fields are valid during any one scan.
  498. * They describe the components and MCUs actually appearing in the scan.
  499. * Note that the decompressor output side must not use these fields.
  500. */
  501. int comps_in_scan; /* # of JPEG components in this scan */
  502. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  503. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  504. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  505. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  506. int blocks_in_MCU; /* # of DCT blocks per MCU */
  507. int MCU_membership[D_MAX_BLOCKS_IN_MCU];
  508. /* MCU_membership[i] is index in cur_comp_info of component owning */
  509. /* i'th block in an MCU */
  510. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  511. /* This field is shared between entropy decoder and marker parser.
  512. * It is either zero or the code of a JPEG marker that has been
  513. * read from the data source, but has not yet been processed.
  514. */
  515. int unread_marker;
  516. /*
  517. * Links to decompression subobjects (methods, private variables of modules)
  518. */
  519. struct jpeg_decomp_master * master;
  520. struct jpeg_d_main_controller * main;
  521. struct jpeg_d_coef_controller * coef;
  522. struct jpeg_d_post_controller * post;
  523. struct jpeg_input_controller * inputctl;
  524. struct jpeg_marker_reader * marker;
  525. struct jpeg_entropy_decoder * entropy;
  526. struct jpeg_inverse_dct * idct;
  527. struct jpeg_upsampler * upsample;
  528. struct jpeg_color_deconverter * cconvert;
  529. struct jpeg_color_quantizer * cquantize;
  530. };
  531. /* "Object" declarations for JPEG modules that may be supplied or called
  532. * directly by the surrounding application.
  533. * As with all objects in the JPEG library, these structs only define the
  534. * publicly visible methods and state variables of a module. Additional
  535. * private fields may exist after the public ones.
  536. */
  537. /* Error handler object */
  538. struct jpeg_error_mgr {
  539. /* Error exit handler: does not return to caller */
  540. JMETHOD(void, error_exit, (j_common_ptr cinfo));
  541. /* Conditionally emit a trace or warning message */
  542. JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
  543. /* Routine that actually outputs a trace or error message */
  544. JMETHOD(void, output_message, (j_common_ptr cinfo));
  545. /* Format a message string for the most recent JPEG error or message */
  546. JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
  547. #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
  548. /* Reset error state variables at start of a new image */
  549. JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
  550. /* The message ID code and any parameters are saved here.
  551. * A message can have one string parameter or up to 8 int parameters.
  552. */
  553. int msg_code;
  554. #define JMSG_STR_PARM_MAX 80
  555. union {
  556. int i[8];
  557. char s[JMSG_STR_PARM_MAX];
  558. } msg_parm;
  559. /* Standard state variables for error facility */
  560. int trace_level; /* max msg_level that will be displayed */
  561. /* For recoverable corrupt-data errors, we emit a warning message,
  562. * but keep going unless emit_message chooses to abort. emit_message
  563. * should count warnings in num_warnings. The surrounding application
  564. * can check for bad data by seeing if num_warnings is nonzero at the
  565. * end of processing.
  566. */
  567. long num_warnings; /* number of corrupt-data warnings */
  568. /* These fields point to the table(s) of error message strings.
  569. * An application can change the table pointer to switch to a different
  570. * message list (typically, to change the language in which errors are
  571. * reported). Some applications may wish to add additional error codes
  572. * that will be handled by the JPEG library error mechanism; the second
  573. * table pointer is used for this purpose.
  574. *
  575. * First table includes all errors generated by JPEG library itself.
  576. * Error code 0 is reserved for a "no such error string" message.
  577. */
  578. const char * const * jpeg_message_table; /* Library errors */
  579. int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
  580. /* Second table can be added by application (see cjpeg/djpeg for example).
  581. * It contains strings numbered first_addon_message..last_addon_message.
  582. */
  583. const char * const * addon_message_table; /* Non-library errors */
  584. int first_addon_message; /* code for first string in addon table */
  585. int last_addon_message; /* code for last string in addon table */
  586. };
  587. /* Progress monitor object */
  588. struct jpeg_progress_mgr {
  589. JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
  590. long pass_counter; /* work units completed in this pass */
  591. long pass_limit; /* total number of work units in this pass */
  592. int completed_passes; /* passes completed so far */
  593. int total_passes; /* total number of passes expected */
  594. };
  595. /* Data destination object for compression */
  596. struct jpeg_destination_mgr {
  597. JOCTET * next_output_byte; /* => next byte to write in buffer */
  598. size_t free_in_buffer; /* # of byte spaces remaining in buffer */
  599. JMETHOD(void, init_destination, (j_compress_ptr cinfo));
  600. JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
  601. JMETHOD(void, term_destination, (j_compress_ptr cinfo));
  602. };
  603. /* Data source object for decompression */
  604. struct jpeg_source_mgr {
  605. const JOCTET * next_input_byte; /* => next byte to read from buffer */
  606. size_t bytes_in_buffer; /* # of bytes remaining in buffer */
  607. JMETHOD(void, init_source, (j_decompress_ptr cinfo));
  608. JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
  609. JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
  610. JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
  611. JMETHOD(void, term_source, (j_decompress_ptr cinfo));
  612. };
  613. /* Memory manager object.
  614. * Allocates "small" objects (a few K total), "large" objects (tens of K),
  615. * and "really big" objects (virtual arrays with backing store if needed).
  616. * The memory manager does not allow individual objects to be freed; rather,
  617. * each created object is assigned to a pool, and whole pools can be freed
  618. * at once. This is faster and more convenient than remembering exactly what
  619. * to free, especially where malloc()/free() are not too speedy.
  620. * NB: alloc routines never return NULL. They exit to error_exit if not
  621. * successful.
  622. */
  623. #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
  624. #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
  625. #define JPOOL_NUMPOOLS 2
  626. typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
  627. typedef struct jvirt_barray_control * jvirt_barray_ptr;
  628. struct jpeg_memory_mgr {
  629. /* Method pointers */
  630. JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
  631. size_t sizeofobject));
  632. JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
  633. size_t sizeofobject));
  634. JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
  635. JDIMENSION samplesperrow,
  636. JDIMENSION numrows));
  637. JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
  638. JDIMENSION blocksperrow,
  639. JDIMENSION numrows));
  640. JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
  641. int pool_id,
  642. boolean pre_zero,
  643. JDIMENSION samplesperrow,
  644. JDIMENSION numrows,
  645. JDIMENSION maxaccess));
  646. JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
  647. int pool_id,
  648. boolean pre_zero,
  649. JDIMENSION blocksperrow,
  650. JDIMENSION numrows,
  651. JDIMENSION maxaccess));
  652. JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
  653. JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
  654. jvirt_sarray_ptr ptr,
  655. JDIMENSION start_row,
  656. JDIMENSION num_rows,
  657. boolean writable));
  658. JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
  659. jvirt_barray_ptr ptr,
  660. JDIMENSION start_row,
  661. JDIMENSION num_rows,
  662. boolean writable));
  663. JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
  664. JMETHOD(void, self_destruct, (j_common_ptr cinfo));
  665. /* Limit on memory allocation for this JPEG object. (Note that this is
  666. * merely advisory, not a guaranteed maximum; it only affects the space
  667. * used for virtual-array buffers.) May be changed by outer application
  668. * after creating the JPEG object.
  669. */
  670. long max_memory_to_use;
  671. /* Maximum allocation request accepted by alloc_large. */
  672. long max_alloc_chunk;
  673. };
  674. /* Routine signature for application-supplied marker processing methods.
  675. * Need not pass marker code since it is stored in cinfo->unread_marker.
  676. */
  677. typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
  678. /* Declarations for routines called by application.
  679. * The JPP macro hides prototype parameters from compilers that can't cope.
  680. * Note JPP requires double parentheses.
  681. */
  682. #ifdef HAVE_PROTOTYPES
  683. #define JPP(arglist) arglist
  684. #else
  685. #define JPP(arglist) ()
  686. #endif
  687. /* Short forms of external names for systems with brain-damaged linkers.
  688. * We shorten external names to be unique in the first six letters, which
  689. * is good enough for all known systems.
  690. * (If your compiler itself needs names to be unique in less than 15
  691. * characters, you are out of luck. Get a better compiler.)
  692. */
  693. #ifdef NEED_SHORT_EXTERNAL_NAMES
  694. #define jpeg_std_error jStdError
  695. #define jpeg_CreateCompress jCreaCompress
  696. #define jpeg_CreateDecompress jCreaDecompress
  697. #define jpeg_destroy_compress jDestCompress
  698. #define jpeg_destroy_decompress jDestDecompress
  699. #define jpeg_stdio_dest jStdDest
  700. #define jpeg_stdio_src jStdSrc
  701. #define jpeg_set_defaults jSetDefaults
  702. #define jpeg_set_colorspace jSetColorspace
  703. #define jpeg_default_colorspace jDefColorspace
  704. #define jpeg_set_quality jSetQuality
  705. #define jpeg_set_linear_quality jSetLQuality
  706. #define jpeg_default_qtables jDefQTables
  707. #define jpeg_add_quant_table jAddQuantTable
  708. #define jpeg_quality_scaling jQualityScaling
  709. #define jpeg_simple_progression jSimProgress
  710. #define jpeg_suppress_tables jSuppressTables
  711. #define jpeg_alloc_quant_table jAlcQTable
  712. #define jpeg_alloc_huff_table jAlcHTable
  713. #define jpeg_start_compress jStrtCompress
  714. #define jpeg_write_scanlines jWrtScanlines
  715. #define jpeg_finish_compress jFinCompress
  716. #define jpeg_calc_jpeg_dimensions jCjpegDimensions
  717. #define jpeg_write_raw_data jWrtRawData
  718. #define jpeg_write_marker jWrtMarker
  719. #define jpeg_write_m_header jWrtMHeader
  720. #define jpeg_write_m_byte jWrtMByte
  721. #define jpeg_write_tables jWrtTables
  722. #define jpeg_read_header jReadHeader
  723. #define jpeg_start_decompress jStrtDecompress
  724. #define jpeg_read_scanlines jReadScanlines
  725. #define jpeg_finish_decompress jFinDecompress
  726. #define jpeg_read_raw_data jReadRawData
  727. #define jpeg_has_multiple_scans jHasMultScn
  728. #define jpeg_start_output jStrtOutput
  729. #define jpeg_finish_output jFinOutput
  730. #define jpeg_input_complete jInComplete
  731. #define jpeg_new_colormap jNewCMap
  732. #define jpeg_consume_input jConsumeInput
  733. #define jpeg_calc_output_dimensions jCalcDimensions
  734. #define jpeg_save_markers jSaveMarkers
  735. #define jpeg_set_marker_processor jSetMarker
  736. #define jpeg_read_coefficients jReadCoefs
  737. #define jpeg_write_coefficients jWrtCoefs
  738. #define jpeg_copy_critical_parameters jCopyCrit
  739. #define jpeg_abort_compress jAbrtCompress
  740. #define jpeg_abort_decompress jAbrtDecompress
  741. #define jpeg_abort jAbort
  742. #define jpeg_destroy jDestroy
  743. #define jpeg_resync_to_restart jResyncRestart
  744. #endif /* NEED_SHORT_EXTERNAL_NAMES */
  745. /* Default error-management setup */
  746. EXTERN(struct jpeg_error_mgr *) jpeg_std_error
  747. JPP((struct jpeg_error_mgr * err));
  748. /* Initialization of JPEG compression objects.
  749. * jpeg_create_compress() and jpeg_create_decompress() are the exported
  750. * names that applications should call. These expand to calls on
  751. * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
  752. * passed for version mismatch checking.
  753. * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
  754. */
  755. #define jpeg_create_compress(cinfo) \
  756. jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
  757. (size_t) sizeof(struct jpeg_compress_struct))
  758. #define jpeg_create_decompress(cinfo) \
  759. jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
  760. (size_t) sizeof(struct jpeg_decompress_struct))
  761. EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
  762. int version, size_t structsize));
  763. EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
  764. int version, size_t structsize));
  765. /* Destruction of JPEG compression objects */
  766. EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
  767. EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
  768. /* Standard data source and destination managers: stdio streams. */
  769. /* Caller is responsible for opening the file before and closing after. */
  770. // EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
  771. // EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
  772. /* Default parameter setup for compression */
  773. EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
  774. /* Compression parameter setup aids */
  775. EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
  776. J_COLOR_SPACE colorspace));
  777. EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
  778. EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
  779. boolean force_baseline));
  780. EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
  781. int scale_factor,
  782. boolean force_baseline));
  783. EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
  784. boolean force_baseline));
  785. EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
  786. const unsigned int *basic_table,
  787. int scale_factor,
  788. boolean force_baseline));
  789. EXTERN(int) jpeg_quality_scaling JPP((int quality));
  790. EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
  791. EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
  792. boolean suppress));
  793. EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
  794. EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
  795. /* Main entry points for compression */
  796. EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
  797. boolean write_all_tables));
  798. EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
  799. JSAMPARRAY scanlines,
  800. JDIMENSION num_lines));
  801. EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
  802. /* Precalculate JPEG dimensions for current compression parameters. */
  803. EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
  804. /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
  805. EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
  806. JSAMPIMAGE data,
  807. JDIMENSION num_lines));
  808. /* Write a special marker. See libjpeg.txt concerning safe usage. */
  809. EXTERN(void) jpeg_write_marker
  810. JPP((j_compress_ptr cinfo, int marker,
  811. const JOCTET * dataptr, unsigned int datalen));
  812. /* Same, but piecemeal. */
  813. EXTERN(void) jpeg_write_m_header
  814. JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
  815. EXTERN(void) jpeg_write_m_byte
  816. JPP((j_compress_ptr cinfo, int val));
  817. /* Alternate compression function: just write an abbreviated table file */
  818. EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
  819. /* Decompression startup: read start of JPEG datastream to see what's there */
  820. EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
  821. boolean require_image));
  822. /* Return value is one of: */
  823. #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
  824. #define JPEG_HEADER_OK 1 /* Found valid image datastream */
  825. #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
  826. /* If you pass require_image = TRUE (normal case), you need not check for
  827. * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  828. * JPEG_SUSPENDED is only possible if you use a data source module that can
  829. * give a suspension return (the stdio source module doesn't).
  830. */
  831. /* Main entry points for decompression */
  832. EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
  833. EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
  834. JSAMPARRAY scanlines,
  835. JDIMENSION max_lines));
  836. EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
  837. /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
  838. EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
  839. JSAMPIMAGE data,
  840. JDIMENSION max_lines));
  841. /* Additional entry points for buffered-image mode. */
  842. EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
  843. EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
  844. int scan_number));
  845. EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
  846. EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
  847. EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
  848. EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
  849. /* Return value is one of: */
  850. /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
  851. #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
  852. #define JPEG_REACHED_EOI 2 /* Reached end of image */
  853. #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
  854. #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
  855. /* Precalculate output dimensions for current decompression parameters. */
  856. EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
  857. /* Control saving of COM and APPn markers into marker_list. */
  858. EXTERN(void) jpeg_save_markers
  859. JPP((j_decompress_ptr cinfo, int marker_code,
  860. unsigned int length_limit));
  861. /* Install a special processing method for COM or APPn markers. */
  862. EXTERN(void) jpeg_set_marker_processor
  863. JPP((j_decompress_ptr cinfo, int marker_code,
  864. jpeg_marker_parser_method routine));
  865. /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
  866. EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
  867. EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
  868. jvirt_barray_ptr * coef_arrays));
  869. EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
  870. j_compress_ptr dstinfo));
  871. /* If you choose to abort compression or decompression before completing
  872. * jpeg_finish_(de)compress, then you need to clean up to release memory,
  873. * temporary files, etc. You can just call jpeg_destroy_(de)compress
  874. * if you're done with the JPEG object, but if you want to clean it up and
  875. * reuse it, call this:
  876. */
  877. EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
  878. EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
  879. /* Generic versions of jpeg_abort and jpeg_destroy that work on either
  880. * flavor of JPEG object. These may be more convenient in some places.
  881. */
  882. EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
  883. EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
  884. /* Default restart-marker-resync procedure for use by data source modules */
  885. EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
  886. int desired));
  887. /* These marker codes are exported since applications and data source modules
  888. * are likely to want to use them.
  889. */
  890. #define JPEG_RST0 0xD0 /* RST0 marker code */
  891. #define JPEG_EOI 0xD9 /* EOI marker code */
  892. #define JPEG_APP0 0xE0 /* APP0 marker code */
  893. #define JPEG_COM 0xFE /* COM marker code */
  894. /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
  895. * for structure definitions that are never filled in, keep it quiet by
  896. * supplying dummy definitions for the various substructures.
  897. */
  898. #ifdef INCOMPLETE_TYPES_BROKEN
  899. #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
  900. struct jvirt_sarray_control { long dummy; };
  901. struct jvirt_barray_control { long dummy; };
  902. struct jpeg_comp_master { long dummy; };
  903. struct jpeg_c_main_controller { long dummy; };
  904. struct jpeg_c_prep_controller { long dummy; };
  905. struct jpeg_c_coef_controller { long dummy; };
  906. struct jpeg_marker_writer { long dummy; };
  907. struct jpeg_color_converter { long dummy; };
  908. struct jpeg_downsampler { long dummy; };
  909. struct jpeg_forward_dct { long dummy; };
  910. struct jpeg_entropy_encoder { long dummy; };
  911. struct jpeg_decomp_master { long dummy; };
  912. struct jpeg_d_main_controller { long dummy; };
  913. struct jpeg_d_coef_controller { long dummy; };
  914. struct jpeg_d_post_controller { long dummy; };
  915. struct jpeg_input_controller { long dummy; };
  916. struct jpeg_marker_reader { long dummy; };
  917. struct jpeg_entropy_decoder { long dummy; };
  918. struct jpeg_inverse_dct { long dummy; };
  919. struct jpeg_upsampler { long dummy; };
  920. struct jpeg_color_deconverter { long dummy; };
  921. struct jpeg_color_quantizer { long dummy; };
  922. #endif /* JPEG_INTERNALS */
  923. #endif /* INCOMPLETE_TYPES_BROKEN */
  924. /*
  925. * The JPEG library modules define JPEG_INTERNALS before including this file.
  926. * The internal structure declarations are read only when that is true.
  927. * Applications using the library should not include jpegint.h, but may wish
  928. * to include jerror.h.
  929. */
  930. #ifdef JPEG_INTERNALS
  931. #include "jpegint.h" /* fetch private declarations */
  932. #include "jerror.h" /* fetch error codes too */
  933. #endif
  934. #ifdef __cplusplus
  935. #ifndef DONT_USE_EXTERN_C
  936. }
  937. #endif
  938. #endif
  939. #endif /* JPEGLIB_H */