jpeglib.h 48 KB

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  1. /*
  2. * jpeglib.h
  3. *
  4. * Copyright (C) 1991-1998, Thomas G. Lane.
  5. * Modified 2002-2012 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 IDs for the JPEG library.
  31. * Might be useful for tests like "#if JPEG_LIB_VERSION >= 90".
  32. */
  33. #define JPEG_LIB_VERSION 90 /* Compatibility version 9.0 */
  34. #define JPEG_LIB_VERSION_MAJOR 9
  35. #define JPEG_LIB_VERSION_MINOR 0
  36. /* Various constants determining the sizes of things.
  37. * All of these are specified by the JPEG standard, so don't change them
  38. * if you want to be compatible.
  39. */
  40. #define DCTSIZE 8 /* The basic DCT block is 8x8 coefficients */
  41. #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
  42. #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
  43. #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
  44. #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
  45. #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
  46. #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
  47. /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
  48. * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
  49. * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
  50. * to handle it. We even let you do this from the jconfig.h file. However,
  51. * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
  52. * sometimes emits noncompliant files doesn't mean you should too.
  53. */
  54. #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
  55. #ifndef D_MAX_BLOCKS_IN_MCU
  56. #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
  57. #endif
  58. /* Data structures for images (arrays of samples and of DCT coefficients).
  59. * On 80x86 machines, the image arrays are too big for near pointers,
  60. * but the pointer arrays can fit in near memory.
  61. */
  62. typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
  63. typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
  64. typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
  65. typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
  66. typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
  67. typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
  68. typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
  69. typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
  70. /* Types for JPEG compression parameters and working tables. */
  71. /* DCT coefficient quantization tables. */
  72. typedef struct {
  73. /* This array gives the coefficient quantizers in natural array order
  74. * (not the zigzag order in which they are stored in a JPEG DQT marker).
  75. * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
  76. */
  77. UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
  78. /* This field is used only during compression. It's initialized FALSE when
  79. * the table is created, and set TRUE when it's been output to the file.
  80. * You could suppress output of a table by setting this to TRUE.
  81. * (See jpeg_suppress_tables for an example.)
  82. */
  83. boolean sent_table; /* TRUE when table has been output */
  84. } JQUANT_TBL;
  85. /* Huffman coding tables. */
  86. typedef struct {
  87. /* These two fields directly represent the contents of a JPEG DHT marker */
  88. UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
  89. /* length k bits; bits[0] is unused */
  90. UINT8 huffval[256]; /* The symbols, in order of incr code length */
  91. /* This field is used only during compression. It's initialized FALSE when
  92. * the table is created, and set TRUE when it's been output to the file.
  93. * You could suppress output of a table by setting this to TRUE.
  94. * (See jpeg_suppress_tables for an example.)
  95. */
  96. boolean sent_table; /* TRUE when table has been output */
  97. } JHUFF_TBL;
  98. /* Basic info about one component (color channel). */
  99. typedef struct {
  100. /* These values are fixed over the whole image. */
  101. /* For compression, they must be supplied by parameter setup; */
  102. /* for decompression, they are read from the SOF marker. */
  103. int component_id; /* identifier for this component (0..255) */
  104. int component_index; /* its index in SOF or cinfo->comp_info[] */
  105. int h_samp_factor; /* horizontal sampling factor (1..4) */
  106. int v_samp_factor; /* vertical sampling factor (1..4) */
  107. int quant_tbl_no; /* quantization table selector (0..3) */
  108. /* These values may vary between scans. */
  109. /* For compression, they must be supplied by parameter setup; */
  110. /* for decompression, they are read from the SOS marker. */
  111. /* The decompressor output side may not use these variables. */
  112. int dc_tbl_no; /* DC entropy table selector (0..3) */
  113. int ac_tbl_no; /* AC entropy table selector (0..3) */
  114. /* Remaining fields should be treated as private by applications. */
  115. /* These values are computed during compression or decompression startup: */
  116. /* Component's size in DCT blocks.
  117. * Any dummy blocks added to complete an MCU are not counted; therefore
  118. * these values do not depend on whether a scan is interleaved or not.
  119. */
  120. JDIMENSION width_in_blocks;
  121. JDIMENSION height_in_blocks;
  122. /* Size of a DCT block in samples,
  123. * reflecting any scaling we choose to apply during the DCT step.
  124. * Values from 1 to 16 are supported.
  125. * Note that different components may receive different DCT scalings.
  126. */
  127. int DCT_h_scaled_size;
  128. int DCT_v_scaled_size;
  129. /* The downsampled dimensions are the component's actual, unpadded number
  130. * of samples at the main buffer (preprocessing/compression interface);
  131. * DCT scaling is included, so
  132. * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
  133. * and similarly for height.
  134. */
  135. JDIMENSION downsampled_width; /* actual width in samples */
  136. JDIMENSION downsampled_height; /* actual height in samples */
  137. /* This flag is used only for decompression. In cases where some of the
  138. * components will be ignored (eg grayscale output from YCbCr image),
  139. * we can skip most computations for the unused components.
  140. */
  141. boolean component_needed; /* do we need the value of this component? */
  142. /* These values are computed before starting a scan of the component. */
  143. /* The decompressor output side may not use these variables. */
  144. int MCU_width; /* number of blocks per MCU, horizontally */
  145. int MCU_height; /* number of blocks per MCU, vertically */
  146. int MCU_blocks; /* MCU_width * MCU_height */
  147. int MCU_sample_width; /* MCU width in samples: MCU_width * DCT_h_scaled_size */
  148. int last_col_width; /* # of non-dummy blocks across in last MCU */
  149. int last_row_height; /* # of non-dummy blocks down in last MCU */
  150. /* Saved quantization table for component; NULL if none yet saved.
  151. * See jdinput.c comments about the need for this information.
  152. * This field is currently used only for decompression.
  153. */
  154. JQUANT_TBL * quant_table;
  155. /* Private per-component storage for DCT or IDCT subsystem. */
  156. void * dct_table;
  157. } jpeg_component_info;
  158. /* The script for encoding a multiple-scan file is an array of these: */
  159. typedef struct {
  160. int comps_in_scan; /* number of components encoded in this scan */
  161. int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
  162. int Ss, Se; /* progressive JPEG spectral selection parms */
  163. int Ah, Al; /* progressive JPEG successive approx. parms */
  164. } jpeg_scan_info;
  165. /* The decompressor can save APPn and COM markers in a list of these: */
  166. typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
  167. struct jpeg_marker_struct {
  168. jpeg_saved_marker_ptr next; /* next in list, or NULL */
  169. UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
  170. unsigned int original_length; /* # bytes of data in the file */
  171. unsigned int data_length; /* # bytes of data saved at data[] */
  172. JOCTET FAR * data; /* the data contained in the marker */
  173. /* the marker length word is not counted in data_length or original_length */
  174. };
  175. /* Known color spaces. */
  176. typedef enum {
  177. JCS_UNKNOWN, /* error/unspecified */
  178. JCS_GRAYSCALE, /* monochrome */
  179. JCS_RGB, /* red/green/blue */
  180. JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
  181. JCS_CMYK, /* C/M/Y/K */
  182. JCS_YCCK /* Y/Cb/Cr/K */
  183. } J_COLOR_SPACE;
  184. /* Supported color transforms. */
  185. typedef enum {
  186. JCT_NONE = 0,
  187. JCT_SUBTRACT_GREEN = 1
  188. } J_COLOR_TRANSFORM;
  189. /* DCT/IDCT algorithm options. */
  190. typedef enum {
  191. JDCT_ISLOW, /* slow but accurate integer algorithm */
  192. JDCT_IFAST, /* faster, less accurate integer method */
  193. JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
  194. } J_DCT_METHOD;
  195. #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
  196. #define JDCT_DEFAULT JDCT_ISLOW
  197. #endif
  198. #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
  199. #define JDCT_FASTEST JDCT_IFAST
  200. #endif
  201. /* Dithering options for decompression. */
  202. typedef enum {
  203. JDITHER_NONE, /* no dithering */
  204. JDITHER_ORDERED, /* simple ordered dither */
  205. JDITHER_FS /* Floyd-Steinberg error diffusion dither */
  206. } J_DITHER_MODE;
  207. /* Common fields between JPEG compression and decompression master structs. */
  208. #define jpeg_common_fields \
  209. struct jpeg_error_mgr * err; /* Error handler module */\
  210. struct jpeg_memory_mgr * mem; /* Memory manager module */\
  211. struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
  212. void * client_data; /* Available for use by application */\
  213. boolean is_decompressor; /* So common code can tell which is which */\
  214. int global_state /* For checking call sequence validity */
  215. /* Routines that are to be used by both halves of the library are declared
  216. * to receive a pointer to this structure. There are no actual instances of
  217. * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
  218. */
  219. struct jpeg_common_struct {
  220. jpeg_common_fields; /* Fields common to both master struct types */
  221. /* Additional fields follow in an actual jpeg_compress_struct or
  222. * jpeg_decompress_struct. All three structs must agree on these
  223. * initial fields! (This would be a lot cleaner in C++.)
  224. */
  225. };
  226. typedef struct jpeg_common_struct * j_common_ptr;
  227. typedef struct jpeg_compress_struct * j_compress_ptr;
  228. typedef struct jpeg_decompress_struct * j_decompress_ptr;
  229. /* Master record for a compression instance */
  230. struct jpeg_compress_struct {
  231. jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
  232. /* Destination for compressed data */
  233. struct jpeg_destination_mgr * dest;
  234. /* Description of source image --- these fields must be filled in by
  235. * outer application before starting compression. in_color_space must
  236. * be correct before you can even call jpeg_set_defaults().
  237. */
  238. JDIMENSION image_width; /* input image width */
  239. JDIMENSION image_height; /* input image height */
  240. int input_components; /* # of color components in input image */
  241. J_COLOR_SPACE in_color_space; /* colorspace of input image */
  242. double input_gamma; /* image gamma of input image */
  243. /* Compression parameters --- these fields must be set before calling
  244. * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
  245. * initialize everything to reasonable defaults, then changing anything
  246. * the application specifically wants to change. That way you won't get
  247. * burnt when new parameters are added. Also note that there are several
  248. * helper routines to simplify changing parameters.
  249. */
  250. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  251. JDIMENSION jpeg_width; /* scaled JPEG image width */
  252. JDIMENSION jpeg_height; /* scaled JPEG image height */
  253. /* Dimensions of actual JPEG image that will be written to file,
  254. * derived from input dimensions by scaling factors above.
  255. * These fields are computed by jpeg_start_compress().
  256. * You can also use jpeg_calc_jpeg_dimensions() to determine these values
  257. * in advance of calling jpeg_start_compress().
  258. */
  259. int data_precision; /* bits of precision in image data */
  260. int num_components; /* # of color components in JPEG image */
  261. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  262. jpeg_component_info * comp_info;
  263. /* comp_info[i] describes component that appears i'th in SOF */
  264. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  265. int q_scale_factor[NUM_QUANT_TBLS];
  266. /* ptrs to coefficient quantization tables, or NULL if not defined,
  267. * and corresponding scale factors (percentage, initialized 100).
  268. */
  269. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  270. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  271. /* ptrs to Huffman coding tables, or NULL if not defined */
  272. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  273. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  274. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  275. int num_scans; /* # of entries in scan_info array */
  276. const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
  277. /* The default value of scan_info is NULL, which causes a single-scan
  278. * sequential JPEG file to be emitted. To create a multi-scan file,
  279. * set num_scans and scan_info to point to an array of scan definitions.
  280. */
  281. boolean raw_data_in; /* TRUE=caller supplies downsampled data */
  282. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  283. boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
  284. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  285. boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
  286. int smoothing_factor; /* 1..100, or 0 for no input smoothing */
  287. J_DCT_METHOD dct_method; /* DCT algorithm selector */
  288. /* The restart interval can be specified in absolute MCUs by setting
  289. * restart_interval, or in MCU rows by setting restart_in_rows
  290. * (in which case the correct restart_interval will be figured
  291. * for each scan).
  292. */
  293. unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
  294. int restart_in_rows; /* if > 0, MCU rows per restart interval */
  295. /* Parameters controlling emission of special markers. */
  296. boolean write_JFIF_header; /* should a JFIF marker be written? */
  297. UINT8 JFIF_major_version; /* What to write for the JFIF version number */
  298. UINT8 JFIF_minor_version;
  299. /* These three values are not used by the JPEG code, merely copied */
  300. /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
  301. /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
  302. /* ratio is defined by X_density/Y_density even when density_unit=0. */
  303. UINT8 density_unit; /* JFIF code for pixel size units */
  304. UINT16 X_density; /* Horizontal pixel density */
  305. UINT16 Y_density; /* Vertical pixel density */
  306. boolean write_Adobe_marker; /* should an Adobe marker be written? */
  307. J_COLOR_TRANSFORM color_transform;
  308. /* Color transform identifier, writes LSE marker if nonzero */
  309. /* State variable: index of next scanline to be written to
  310. * jpeg_write_scanlines(). Application may use this to control its
  311. * processing loop, e.g., "while (next_scanline < image_height)".
  312. */
  313. JDIMENSION next_scanline; /* 0 .. image_height-1 */
  314. /* Remaining fields are known throughout compressor, but generally
  315. * should not be touched by a surrounding application.
  316. */
  317. /*
  318. * These fields are computed during compression startup
  319. */
  320. boolean progressive_mode; /* TRUE if scan script uses progressive mode */
  321. int max_h_samp_factor; /* largest h_samp_factor */
  322. int max_v_samp_factor; /* largest v_samp_factor */
  323. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  324. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  325. JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
  326. /* The coefficient controller receives data in units of MCU rows as defined
  327. * for fully interleaved scans (whether the JPEG file is interleaved or not).
  328. * There are v_samp_factor * DCTSIZE sample rows of each component in an
  329. * "iMCU" (interleaved MCU) row.
  330. */
  331. /*
  332. * These fields are valid during any one scan.
  333. * They describe the components and MCUs actually appearing in the scan.
  334. */
  335. int comps_in_scan; /* # of JPEG components in this scan */
  336. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  337. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  338. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  339. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  340. int blocks_in_MCU; /* # of DCT blocks per MCU */
  341. int MCU_membership[C_MAX_BLOCKS_IN_MCU];
  342. /* MCU_membership[i] is index in cur_comp_info of component owning */
  343. /* i'th block in an MCU */
  344. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  345. int block_size; /* the basic DCT block size: 1..16 */
  346. const int * natural_order; /* natural-order position array */
  347. int lim_Se; /* min( Se, DCTSIZE2-1 ) */
  348. /*
  349. * Links to compression subobjects (methods and private variables of modules)
  350. */
  351. struct jpeg_comp_master * master;
  352. struct jpeg_c_main_controller * main;
  353. struct jpeg_c_prep_controller * prep;
  354. struct jpeg_c_coef_controller * coef;
  355. struct jpeg_marker_writer * marker;
  356. struct jpeg_color_converter * cconvert;
  357. struct jpeg_downsampler * downsample;
  358. struct jpeg_forward_dct * fdct;
  359. struct jpeg_entropy_encoder * entropy;
  360. jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
  361. int script_space_size;
  362. };
  363. /* Master record for a decompression instance */
  364. struct jpeg_decompress_struct {
  365. jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
  366. /* Source of compressed data */
  367. struct jpeg_source_mgr * src;
  368. /* Basic description of image --- filled in by jpeg_read_header(). */
  369. /* Application may inspect these values to decide how to process image. */
  370. JDIMENSION image_width; /* nominal image width (from SOF marker) */
  371. JDIMENSION image_height; /* nominal image height */
  372. int num_components; /* # of color components in JPEG image */
  373. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  374. /* Decompression processing parameters --- these fields must be set before
  375. * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
  376. * them to default values.
  377. */
  378. J_COLOR_SPACE out_color_space; /* colorspace for output */
  379. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  380. double output_gamma; /* image gamma wanted in output */
  381. boolean buffered_image; /* TRUE=multiple output passes */
  382. boolean raw_data_out; /* TRUE=downsampled data wanted */
  383. J_DCT_METHOD dct_method; /* IDCT algorithm selector */
  384. boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
  385. boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
  386. boolean quantize_colors; /* TRUE=colormapped output wanted */
  387. /* the following are ignored if not quantize_colors: */
  388. J_DITHER_MODE dither_mode; /* type of color dithering to use */
  389. boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
  390. int desired_number_of_colors; /* max # colors to use in created colormap */
  391. /* these are significant only in buffered-image mode: */
  392. boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
  393. boolean enable_external_quant;/* enable future use of external colormap */
  394. boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
  395. /* Description of actual output image that will be returned to application.
  396. * These fields are computed by jpeg_start_decompress().
  397. * You can also use jpeg_calc_output_dimensions() to determine these values
  398. * in advance of calling jpeg_start_decompress().
  399. */
  400. JDIMENSION output_width; /* scaled image width */
  401. JDIMENSION output_height; /* scaled image height */
  402. int out_color_components; /* # of color components in out_color_space */
  403. int output_components; /* # of color components returned */
  404. /* output_components is 1 (a colormap index) when quantizing colors;
  405. * otherwise it equals out_color_components.
  406. */
  407. int rec_outbuf_height; /* min recommended height of scanline buffer */
  408. /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
  409. * high, space and time will be wasted due to unnecessary data copying.
  410. * Usually rec_outbuf_height will be 1 or 2, at most 4.
  411. */
  412. /* When quantizing colors, the output colormap is described by these fields.
  413. * The application can supply a colormap by setting colormap non-NULL before
  414. * calling jpeg_start_decompress; otherwise a colormap is created during
  415. * jpeg_start_decompress or jpeg_start_output.
  416. * The map has out_color_components rows and actual_number_of_colors columns.
  417. */
  418. int actual_number_of_colors; /* number of entries in use */
  419. JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
  420. /* State variables: these variables indicate the progress of decompression.
  421. * The application may examine these but must not modify them.
  422. */
  423. /* Row index of next scanline to be read from jpeg_read_scanlines().
  424. * Application may use this to control its processing loop, e.g.,
  425. * "while (output_scanline < output_height)".
  426. */
  427. JDIMENSION output_scanline; /* 0 .. output_height-1 */
  428. /* Current input scan number and number of iMCU rows completed in scan.
  429. * These indicate the progress of the decompressor input side.
  430. */
  431. int input_scan_number; /* Number of SOS markers seen so far */
  432. JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
  433. /* The "output scan number" is the notional scan being displayed by the
  434. * output side. The decompressor will not allow output scan/row number
  435. * to get ahead of input scan/row, but it can fall arbitrarily far behind.
  436. */
  437. int output_scan_number; /* Nominal scan number being displayed */
  438. JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
  439. /* Current progression status. coef_bits[c][i] indicates the precision
  440. * with which component c's DCT coefficient i (in zigzag order) is known.
  441. * It is -1 when no data has yet been received, otherwise it is the point
  442. * transform (shift) value for the most recent scan of the coefficient
  443. * (thus, 0 at completion of the progression).
  444. * This pointer is NULL when reading a non-progressive file.
  445. */
  446. int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
  447. /* Internal JPEG parameters --- the application usually need not look at
  448. * these fields. Note that the decompressor output side may not use
  449. * any parameters that can change between scans.
  450. */
  451. /* Quantization and Huffman tables are carried forward across input
  452. * datastreams when processing abbreviated JPEG datastreams.
  453. */
  454. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  455. /* ptrs to coefficient quantization tables, or NULL if not defined */
  456. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  457. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  458. /* ptrs to Huffman coding tables, or NULL if not defined */
  459. /* These parameters are never carried across datastreams, since they
  460. * are given in SOF/SOS markers or defined to be reset by SOI.
  461. */
  462. int data_precision; /* bits of precision in image data */
  463. jpeg_component_info * comp_info;
  464. /* comp_info[i] describes component that appears i'th in SOF */
  465. boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
  466. boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
  467. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  468. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  469. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  470. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  471. unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
  472. /* These fields record data obtained from optional markers recognized by
  473. * the JPEG library.
  474. */
  475. boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
  476. /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
  477. UINT8 JFIF_major_version; /* JFIF version number */
  478. UINT8 JFIF_minor_version;
  479. UINT8 density_unit; /* JFIF code for pixel size units */
  480. UINT16 X_density; /* Horizontal pixel density */
  481. UINT16 Y_density; /* Vertical pixel density */
  482. boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
  483. UINT8 Adobe_transform; /* Color transform code from Adobe marker */
  484. J_COLOR_TRANSFORM color_transform;
  485. /* Color transform identifier derived from LSE marker, otherwise zero */
  486. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  487. /* Aside from the specific data retained from APPn markers known to the
  488. * library, the uninterpreted contents of any or all APPn and COM markers
  489. * can be saved in a list for examination by the application.
  490. */
  491. jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
  492. /* Remaining fields are known throughout decompressor, but generally
  493. * should not be touched by a surrounding application.
  494. */
  495. /*
  496. * These fields are computed during decompression startup
  497. */
  498. int max_h_samp_factor; /* largest h_samp_factor */
  499. int max_v_samp_factor; /* largest v_samp_factor */
  500. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  501. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  502. JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
  503. /* The coefficient controller's input and output progress is measured in
  504. * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
  505. * in fully interleaved JPEG scans, but are used whether the scan is
  506. * interleaved or not. We define an iMCU row as v_samp_factor DCT block
  507. * rows of each component. Therefore, the IDCT output contains
  508. * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
  509. */
  510. JSAMPLE * sample_range_limit; /* table for fast range-limiting */
  511. /*
  512. * These fields are valid during any one scan.
  513. * They describe the components and MCUs actually appearing in the scan.
  514. * Note that the decompressor output side must not use these fields.
  515. */
  516. int comps_in_scan; /* # of JPEG components in this scan */
  517. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  518. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  519. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  520. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  521. int blocks_in_MCU; /* # of DCT blocks per MCU */
  522. int MCU_membership[D_MAX_BLOCKS_IN_MCU];
  523. /* MCU_membership[i] is index in cur_comp_info of component owning */
  524. /* i'th block in an MCU */
  525. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  526. /* These fields are derived from Se of first SOS marker.
  527. */
  528. int block_size; /* the basic DCT block size: 1..16 */
  529. const int * natural_order; /* natural-order position array for entropy decode */
  530. int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
  531. /* This field is shared between entropy decoder and marker parser.
  532. * It is either zero or the code of a JPEG marker that has been
  533. * read from the data source, but has not yet been processed.
  534. */
  535. int unread_marker;
  536. /*
  537. * Links to decompression subobjects (methods, private variables of modules)
  538. */
  539. struct jpeg_decomp_master * master;
  540. struct jpeg_d_main_controller * main;
  541. struct jpeg_d_coef_controller * coef;
  542. struct jpeg_d_post_controller * post;
  543. struct jpeg_input_controller * inputctl;
  544. struct jpeg_marker_reader * marker;
  545. struct jpeg_entropy_decoder * entropy;
  546. struct jpeg_inverse_dct * idct;
  547. struct jpeg_upsampler * upsample;
  548. struct jpeg_color_deconverter * cconvert;
  549. struct jpeg_color_quantizer * cquantize;
  550. };
  551. /* "Object" declarations for JPEG modules that may be supplied or called
  552. * directly by the surrounding application.
  553. * As with all objects in the JPEG library, these structs only define the
  554. * publicly visible methods and state variables of a module. Additional
  555. * private fields may exist after the public ones.
  556. */
  557. /* Error handler object */
  558. struct jpeg_error_mgr {
  559. /* Error exit handler: does not return to caller */
  560. JMETHOD(noreturn_t, error_exit, (j_common_ptr cinfo));
  561. /* Conditionally emit a trace or warning message */
  562. JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
  563. /* Routine that actually outputs a trace or error message */
  564. JMETHOD(void, output_message, (j_common_ptr cinfo));
  565. /* Format a message string for the most recent JPEG error or message */
  566. JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
  567. #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
  568. /* Reset error state variables at start of a new image */
  569. JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
  570. /* The message ID code and any parameters are saved here.
  571. * A message can have one string parameter or up to 8 int parameters.
  572. */
  573. int msg_code;
  574. #define JMSG_STR_PARM_MAX 80
  575. union {
  576. int i[8];
  577. char s[JMSG_STR_PARM_MAX];
  578. } msg_parm;
  579. /* Standard state variables for error facility */
  580. int trace_level; /* max msg_level that will be displayed */
  581. /* For recoverable corrupt-data errors, we emit a warning message,
  582. * but keep going unless emit_message chooses to abort. emit_message
  583. * should count warnings in num_warnings. The surrounding application
  584. * can check for bad data by seeing if num_warnings is nonzero at the
  585. * end of processing.
  586. */
  587. long num_warnings; /* number of corrupt-data warnings */
  588. /* These fields point to the table(s) of error message strings.
  589. * An application can change the table pointer to switch to a different
  590. * message list (typically, to change the language in which errors are
  591. * reported). Some applications may wish to add additional error codes
  592. * that will be handled by the JPEG library error mechanism; the second
  593. * table pointer is used for this purpose.
  594. *
  595. * First table includes all errors generated by JPEG library itself.
  596. * Error code 0 is reserved for a "no such error string" message.
  597. */
  598. const char * const * jpeg_message_table; /* Library errors */
  599. int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
  600. /* Second table can be added by application (see cjpeg/djpeg for example).
  601. * It contains strings numbered first_addon_message..last_addon_message.
  602. */
  603. const char * const * addon_message_table; /* Non-library errors */
  604. int first_addon_message; /* code for first string in addon table */
  605. int last_addon_message; /* code for last string in addon table */
  606. };
  607. /* Progress monitor object */
  608. struct jpeg_progress_mgr {
  609. JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
  610. long pass_counter; /* work units completed in this pass */
  611. long pass_limit; /* total number of work units in this pass */
  612. int completed_passes; /* passes completed so far */
  613. int total_passes; /* total number of passes expected */
  614. };
  615. /* Data destination object for compression */
  616. struct jpeg_destination_mgr {
  617. JOCTET * next_output_byte; /* => next byte to write in buffer */
  618. size_t free_in_buffer; /* # of byte spaces remaining in buffer */
  619. JMETHOD(void, init_destination, (j_compress_ptr cinfo));
  620. JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
  621. JMETHOD(void, term_destination, (j_compress_ptr cinfo));
  622. };
  623. /* Data source object for decompression */
  624. struct jpeg_source_mgr {
  625. const JOCTET * next_input_byte; /* => next byte to read from buffer */
  626. size_t bytes_in_buffer; /* # of bytes remaining in buffer */
  627. JMETHOD(void, init_source, (j_decompress_ptr cinfo));
  628. JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
  629. JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
  630. JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
  631. JMETHOD(void, term_source, (j_decompress_ptr cinfo));
  632. };
  633. /* Memory manager object.
  634. * Allocates "small" objects (a few K total), "large" objects (tens of K),
  635. * and "really big" objects (virtual arrays with backing store if needed).
  636. * The memory manager does not allow individual objects to be freed; rather,
  637. * each created object is assigned to a pool, and whole pools can be freed
  638. * at once. This is faster and more convenient than remembering exactly what
  639. * to free, especially where malloc()/free() are not too speedy.
  640. * NB: alloc routines never return NULL. They exit to error_exit if not
  641. * successful.
  642. */
  643. #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
  644. #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
  645. #define JPOOL_NUMPOOLS 2
  646. typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
  647. typedef struct jvirt_barray_control * jvirt_barray_ptr;
  648. struct jpeg_memory_mgr {
  649. /* Method pointers */
  650. JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
  651. size_t sizeofobject));
  652. JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
  653. size_t sizeofobject));
  654. JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
  655. JDIMENSION samplesperrow,
  656. JDIMENSION numrows));
  657. JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
  658. JDIMENSION blocksperrow,
  659. JDIMENSION numrows));
  660. JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
  661. int pool_id,
  662. boolean pre_zero,
  663. JDIMENSION samplesperrow,
  664. JDIMENSION numrows,
  665. JDIMENSION maxaccess));
  666. JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
  667. int pool_id,
  668. boolean pre_zero,
  669. JDIMENSION blocksperrow,
  670. JDIMENSION numrows,
  671. JDIMENSION maxaccess));
  672. JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
  673. JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
  674. jvirt_sarray_ptr ptr,
  675. JDIMENSION start_row,
  676. JDIMENSION num_rows,
  677. boolean writable));
  678. JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
  679. jvirt_barray_ptr ptr,
  680. JDIMENSION start_row,
  681. JDIMENSION num_rows,
  682. boolean writable));
  683. JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
  684. JMETHOD(void, self_destruct, (j_common_ptr cinfo));
  685. /* Limit on memory allocation for this JPEG object. (Note that this is
  686. * merely advisory, not a guaranteed maximum; it only affects the space
  687. * used for virtual-array buffers.) May be changed by outer application
  688. * after creating the JPEG object.
  689. */
  690. long max_memory_to_use;
  691. /* Maximum allocation request accepted by alloc_large. */
  692. long max_alloc_chunk;
  693. };
  694. /* Routine signature for application-supplied marker processing methods.
  695. * Need not pass marker code since it is stored in cinfo->unread_marker.
  696. */
  697. typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
  698. /* Declarations for routines called by application.
  699. * The JPP macro hides prototype parameters from compilers that can't cope.
  700. * Note JPP requires double parentheses.
  701. */
  702. #ifdef HAVE_PROTOTYPES
  703. #define JPP(arglist) arglist
  704. #else
  705. #define JPP(arglist) ()
  706. #endif
  707. /* Short forms of external names for systems with brain-damaged linkers.
  708. * We shorten external names to be unique in the first six letters, which
  709. * is good enough for all known systems.
  710. * (If your compiler itself needs names to be unique in less than 15
  711. * characters, you are out of luck. Get a better compiler.)
  712. */
  713. #ifdef NEED_SHORT_EXTERNAL_NAMES
  714. #define jpeg_std_error jStdError
  715. #define jpeg_CreateCompress jCreaCompress
  716. #define jpeg_CreateDecompress jCreaDecompress
  717. #define jpeg_destroy_compress jDestCompress
  718. #define jpeg_destroy_decompress jDestDecompress
  719. #define jpeg_stdio_dest jStdDest
  720. #define jpeg_stdio_src jStdSrc
  721. #define jpeg_mem_dest jMemDest
  722. #define jpeg_mem_src jMemSrc
  723. #define jpeg_set_defaults jSetDefaults
  724. #define jpeg_set_colorspace jSetColorspace
  725. #define jpeg_default_colorspace jDefColorspace
  726. #define jpeg_set_quality jSetQuality
  727. #define jpeg_set_linear_quality jSetLQuality
  728. #define jpeg_default_qtables jDefQTables
  729. #define jpeg_add_quant_table jAddQuantTable
  730. #define jpeg_quality_scaling jQualityScaling
  731. #define jpeg_simple_progression jSimProgress
  732. #define jpeg_suppress_tables jSuppressTables
  733. #define jpeg_alloc_quant_table jAlcQTable
  734. #define jpeg_alloc_huff_table jAlcHTable
  735. #define jpeg_start_compress jStrtCompress
  736. #define jpeg_write_scanlines jWrtScanlines
  737. #define jpeg_finish_compress jFinCompress
  738. #define jpeg_calc_jpeg_dimensions jCjpegDimensions
  739. #define jpeg_write_raw_data jWrtRawData
  740. #define jpeg_write_marker jWrtMarker
  741. #define jpeg_write_m_header jWrtMHeader
  742. #define jpeg_write_m_byte jWrtMByte
  743. #define jpeg_write_tables jWrtTables
  744. #define jpeg_read_header jReadHeader
  745. #define jpeg_start_decompress jStrtDecompress
  746. #define jpeg_read_scanlines jReadScanlines
  747. #define jpeg_finish_decompress jFinDecompress
  748. #define jpeg_read_raw_data jReadRawData
  749. #define jpeg_has_multiple_scans jHasMultScn
  750. #define jpeg_start_output jStrtOutput
  751. #define jpeg_finish_output jFinOutput
  752. #define jpeg_input_complete jInComplete
  753. #define jpeg_new_colormap jNewCMap
  754. #define jpeg_consume_input jConsumeInput
  755. #define jpeg_core_output_dimensions jCoreDimensions
  756. #define jpeg_calc_output_dimensions jCalcDimensions
  757. #define jpeg_save_markers jSaveMarkers
  758. #define jpeg_set_marker_processor jSetMarker
  759. #define jpeg_read_coefficients jReadCoefs
  760. #define jpeg_write_coefficients jWrtCoefs
  761. #define jpeg_copy_critical_parameters jCopyCrit
  762. #define jpeg_abort_compress jAbrtCompress
  763. #define jpeg_abort_decompress jAbrtDecompress
  764. #define jpeg_abort jAbort
  765. #define jpeg_destroy jDestroy
  766. #define jpeg_resync_to_restart jResyncRestart
  767. #endif /* NEED_SHORT_EXTERNAL_NAMES */
  768. /* Default error-management setup */
  769. EXTERN(struct jpeg_error_mgr *) jpeg_std_error
  770. JPP((struct jpeg_error_mgr * err));
  771. /* Initialization of JPEG compression objects.
  772. * jpeg_create_compress() and jpeg_create_decompress() are the exported
  773. * names that applications should call. These expand to calls on
  774. * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
  775. * passed for version mismatch checking.
  776. * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
  777. */
  778. #define jpeg_create_compress(cinfo) \
  779. jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
  780. (size_t) sizeof(struct jpeg_compress_struct))
  781. #define jpeg_create_decompress(cinfo) \
  782. jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
  783. (size_t) sizeof(struct jpeg_decompress_struct))
  784. EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
  785. int version, size_t structsize));
  786. EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
  787. int version, size_t structsize));
  788. /* Destruction of JPEG compression objects */
  789. EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
  790. EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
  791. /* Standard data source and destination managers: stdio streams. */
  792. /* Caller is responsible for opening the file before and closing after. */
  793. EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
  794. EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
  795. /* Data source and destination managers: memory buffers. */
  796. EXTERN(void) jpeg_mem_dest JPP((j_compress_ptr cinfo,
  797. unsigned char ** outbuffer,
  798. unsigned long * outsize));
  799. EXTERN(void) jpeg_mem_src JPP((j_decompress_ptr cinfo,
  800. unsigned char * inbuffer,
  801. unsigned long insize));
  802. /* Default parameter setup for compression */
  803. EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
  804. /* Compression parameter setup aids */
  805. EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
  806. J_COLOR_SPACE colorspace));
  807. EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
  808. EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
  809. boolean force_baseline));
  810. EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
  811. int scale_factor,
  812. boolean force_baseline));
  813. EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
  814. boolean force_baseline));
  815. EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
  816. const unsigned int *basic_table,
  817. int scale_factor,
  818. boolean force_baseline));
  819. EXTERN(int) jpeg_quality_scaling JPP((int quality));
  820. EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
  821. EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
  822. boolean suppress));
  823. EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
  824. EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
  825. /* Main entry points for compression */
  826. EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
  827. boolean write_all_tables));
  828. EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
  829. JSAMPARRAY scanlines,
  830. JDIMENSION num_lines));
  831. EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
  832. /* Precalculate JPEG dimensions for current compression parameters. */
  833. EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
  834. /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
  835. EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
  836. JSAMPIMAGE data,
  837. JDIMENSION num_lines));
  838. /* Write a special marker. See libjpeg.txt concerning safe usage. */
  839. EXTERN(void) jpeg_write_marker
  840. JPP((j_compress_ptr cinfo, int marker,
  841. const JOCTET * dataptr, unsigned int datalen));
  842. /* Same, but piecemeal. */
  843. EXTERN(void) jpeg_write_m_header
  844. JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
  845. EXTERN(void) jpeg_write_m_byte
  846. JPP((j_compress_ptr cinfo, int val));
  847. /* Alternate compression function: just write an abbreviated table file */
  848. EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
  849. /* Decompression startup: read start of JPEG datastream to see what's there */
  850. EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
  851. boolean require_image));
  852. /* Return value is one of: */
  853. #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
  854. #define JPEG_HEADER_OK 1 /* Found valid image datastream */
  855. #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
  856. /* If you pass require_image = TRUE (normal case), you need not check for
  857. * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  858. * JPEG_SUSPENDED is only possible if you use a data source module that can
  859. * give a suspension return (the stdio source module doesn't).
  860. */
  861. /* Main entry points for decompression */
  862. EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
  863. EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
  864. JSAMPARRAY scanlines,
  865. JDIMENSION max_lines));
  866. EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
  867. /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
  868. EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
  869. JSAMPIMAGE data,
  870. JDIMENSION max_lines));
  871. /* Additional entry points for buffered-image mode. */
  872. EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
  873. EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
  874. int scan_number));
  875. EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
  876. EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
  877. EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
  878. EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
  879. /* Return value is one of: */
  880. /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
  881. #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
  882. #define JPEG_REACHED_EOI 2 /* Reached end of image */
  883. #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
  884. #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
  885. /* Precalculate output dimensions for current decompression parameters. */
  886. EXTERN(void) jpeg_core_output_dimensions JPP((j_decompress_ptr cinfo));
  887. EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
  888. /* Control saving of COM and APPn markers into marker_list. */
  889. EXTERN(void) jpeg_save_markers
  890. JPP((j_decompress_ptr cinfo, int marker_code,
  891. unsigned int length_limit));
  892. /* Install a special processing method for COM or APPn markers. */
  893. EXTERN(void) jpeg_set_marker_processor
  894. JPP((j_decompress_ptr cinfo, int marker_code,
  895. jpeg_marker_parser_method routine));
  896. /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
  897. EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
  898. EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
  899. jvirt_barray_ptr * coef_arrays));
  900. EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
  901. j_compress_ptr dstinfo));
  902. /* If you choose to abort compression or decompression before completing
  903. * jpeg_finish_(de)compress, then you need to clean up to release memory,
  904. * temporary files, etc. You can just call jpeg_destroy_(de)compress
  905. * if you're done with the JPEG object, but if you want to clean it up and
  906. * reuse it, call this:
  907. */
  908. EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
  909. EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
  910. /* Generic versions of jpeg_abort and jpeg_destroy that work on either
  911. * flavor of JPEG object. These may be more convenient in some places.
  912. */
  913. EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
  914. EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
  915. /* Default restart-marker-resync procedure for use by data source modules */
  916. EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
  917. int desired));
  918. /* These marker codes are exported since applications and data source modules
  919. * are likely to want to use them.
  920. */
  921. #define JPEG_RST0 0xD0 /* RST0 marker code */
  922. #define JPEG_EOI 0xD9 /* EOI marker code */
  923. #define JPEG_APP0 0xE0 /* APP0 marker code */
  924. #define JPEG_COM 0xFE /* COM marker code */
  925. /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
  926. * for structure definitions that are never filled in, keep it quiet by
  927. * supplying dummy definitions for the various substructures.
  928. */
  929. #ifdef INCOMPLETE_TYPES_BROKEN
  930. #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
  931. struct jvirt_sarray_control { long dummy; };
  932. struct jvirt_barray_control { long dummy; };
  933. struct jpeg_comp_master { long dummy; };
  934. struct jpeg_c_main_controller { long dummy; };
  935. struct jpeg_c_prep_controller { long dummy; };
  936. struct jpeg_c_coef_controller { long dummy; };
  937. struct jpeg_marker_writer { long dummy; };
  938. struct jpeg_color_converter { long dummy; };
  939. struct jpeg_downsampler { long dummy; };
  940. struct jpeg_forward_dct { long dummy; };
  941. struct jpeg_entropy_encoder { long dummy; };
  942. struct jpeg_decomp_master { long dummy; };
  943. struct jpeg_d_main_controller { long dummy; };
  944. struct jpeg_d_coef_controller { long dummy; };
  945. struct jpeg_d_post_controller { long dummy; };
  946. struct jpeg_input_controller { long dummy; };
  947. struct jpeg_marker_reader { long dummy; };
  948. struct jpeg_entropy_decoder { long dummy; };
  949. struct jpeg_inverse_dct { long dummy; };
  950. struct jpeg_upsampler { long dummy; };
  951. struct jpeg_color_deconverter { long dummy; };
  952. struct jpeg_color_quantizer { long dummy; };
  953. #endif /* JPEG_INTERNALS */
  954. #endif /* INCOMPLETE_TYPES_BROKEN */
  955. /*
  956. * The JPEG library modules define JPEG_INTERNALS before including this file.
  957. * The internal structure declarations are read only when that is true.
  958. * Applications using the library should not include jpegint.h, but may wish
  959. * to include jerror.h.
  960. */
  961. #ifdef JPEG_INTERNALS
  962. #include "jpegint.h" /* fetch private declarations */
  963. #include "jerror.h" /* fetch error codes too */
  964. #endif
  965. #ifdef __cplusplus
  966. #ifndef DONT_USE_EXTERN_C
  967. }
  968. #endif
  969. #endif
  970. #endif /* JPEGLIB_H */