jpeglib.h 48 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. #include <stdio.h>
  16. /*
  17. * First we include the configuration files that record how this
  18. * installation of the JPEG library is set up. jconfig.h can be
  19. * generated automatically for many systems. jmorecfg.h contains
  20. * manual configuration options that most people need not worry about.
  21. */
  22. #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
  23. #include "jconfig.h" /* widely used configuration options */
  24. #endif
  25. #include "jmorecfg.h" /* seldom changed options */
  26. #ifdef __cplusplus
  27. #ifndef DONT_USE_EXTERN_C
  28. extern "C" {
  29. #endif
  30. #endif
  31. /* Version ID for the JPEG library.
  32. * Might be useful for tests like "#if JPEG_LIB_VERSION >= 70".
  33. */
  34. #define JPEG_LIB_VERSION 70 /* Version 7.0 */
  35. /* Various constants determining the sizes of things.
  36. * All of these are specified by the JPEG standard, so don't change them
  37. * if you want to be compatible.
  38. */
  39. #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
  40. #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
  41. #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
  42. #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
  43. #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
  44. #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
  45. #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
  46. /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
  47. * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
  48. * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
  49. * to handle it. We even let you do this from the jconfig.h file. However,
  50. * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
  51. * sometimes emits noncompliant files doesn't mean you should too.
  52. */
  53. #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
  54. #ifndef D_MAX_BLOCKS_IN_MCU
  55. #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
  56. #endif
  57. /* Data structures for images (arrays of samples and of DCT coefficients).
  58. * On 80x86 machines, the image arrays are too big for near pointers,
  59. * but the pointer arrays can fit in near memory.
  60. */
  61. typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */
  62. typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
  63. typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
  64. typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
  65. typedef JBLOCK FAR *JBLOCKROW; /* pointer to one row of coefficient blocks */
  66. typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
  67. typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
  68. typedef JCOEF FAR *JCOEFPTR; /* useful in a couple of places */
  69. /* Types for JPEG compression parameters and working tables. */
  70. /* DCT coefficient quantization tables. */
  71. typedef struct {
  72. /* This array gives the coefficient quantizers in natural array order
  73. * (not the zigzag order in which they are stored in a JPEG DQT marker).
  74. * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
  75. */
  76. UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
  77. /* This field is used only during compression. It's initialized FALSE when
  78. * the table is created, and set TRUE when it's been output to the file.
  79. * You could suppress output of a table by setting this to TRUE.
  80. * (See jpeg_suppress_tables for an example.)
  81. */
  82. boolean sent_table; /* TRUE when table has been output */
  83. } JQUANT_TBL;
  84. /* Huffman coding tables. */
  85. typedef struct {
  86. /* These two fields directly represent the contents of a JPEG DHT marker */
  87. UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
  88. /* length k bits; bits[0] is unused */
  89. UINT8 huffval[256]; /* The symbols, in order of incr code length */
  90. /* This field is used only during compression. It's initialized FALSE when
  91. * the table is created, and set TRUE when it's been output to the file.
  92. * You could suppress output of a table by setting this to TRUE.
  93. * (See jpeg_suppress_tables for an example.)
  94. */
  95. boolean sent_table; /* TRUE when table has been output */
  96. } JHUFF_TBL;
  97. /* Basic info about one component (color channel). */
  98. typedef struct {
  99. /* These values are fixed over the whole image. */
  100. /* For compression, they must be supplied by parameter setup; */
  101. /* for decompression, they are read from the SOF marker. */
  102. int component_id; /* identifier for this component (0..255) */
  103. int component_index; /* its index in SOF or cinfo->comp_info[] */
  104. int h_samp_factor; /* horizontal sampling factor (1..4) */
  105. int v_samp_factor; /* vertical sampling factor (1..4) */
  106. int quant_tbl_no; /* quantization table selector (0..3) */
  107. /* These values may vary between scans. */
  108. /* For compression, they must be supplied by parameter setup; */
  109. /* for decompression, they are read from the SOS marker. */
  110. /* The decompressor output side may not use these variables. */
  111. int dc_tbl_no; /* DC entropy table selector (0..3) */
  112. int ac_tbl_no; /* AC entropy table selector (0..3) */
  113. /* Remaining fields should be treated as private by applications. */
  114. /* These values are computed during compression or decompression startup: */
  115. /* Component's size in DCT blocks.
  116. * Any dummy blocks added to complete an MCU are not counted; therefore
  117. * these values do not depend on whether a scan is interleaved or not.
  118. */
  119. JDIMENSION width_in_blocks;
  120. JDIMENSION height_in_blocks;
  121. /* Size of a DCT block in samples,
  122. * reflecting any scaling we choose to apply during the DCT step.
  123. * Values from 1 to 16 are supported.
  124. * Note that different components may receive different DCT scalings.
  125. */
  126. int DCT_h_scaled_size;
  127. int DCT_v_scaled_size;
  128. /* The downsampled dimensions are the component's actual, unpadded number
  129. * of samples at the main buffer (preprocessing/compression interface);
  130. * DCT scaling is included, so
  131. * downsampled_width = ceil(image_width * Hi/Hmax * DCT_h_scaled_size/DCTSIZE)
  132. * and similarly for height.
  133. */
  134. JDIMENSION downsampled_width; /* actual width in samples */
  135. JDIMENSION downsampled_height; /* actual height in samples */
  136. /* This flag is used only for decompression. In cases where some of the
  137. * components will be ignored (eg grayscale output from YCbCr image),
  138. * we can skip most computations for the unused components.
  139. */
  140. boolean component_needed; /* do we need the value of this component? */
  141. /* These values are computed before starting a scan of the component. */
  142. /* The decompressor output side may not use these variables. */
  143. int MCU_width; /* number of blocks per MCU, horizontally */
  144. int MCU_height; /* number of blocks per MCU, vertically */
  145. int MCU_blocks; /* MCU_width * MCU_height */
  146. int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_scaled_size */
  147. int last_col_width; /* # of non-dummy blocks across in last MCU */
  148. int last_row_height; /* # of non-dummy blocks down in last MCU */
  149. /* Saved quantization table for component; NULL if none yet saved.
  150. * See jdinput.c comments about the need for this information.
  151. * This field is currently used only for decompression.
  152. */
  153. JQUANT_TBL * quant_table;
  154. /* Private per-component storage for DCT or IDCT subsystem. */
  155. void * dct_table;
  156. } jpeg_component_info;
  157. /* The script for encoding a multiple-scan file is an array of these: */
  158. typedef struct {
  159. int comps_in_scan; /* number of components encoded in this scan */
  160. int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
  161. int Ss, Se; /* progressive JPEG spectral selection parms */
  162. int Ah, Al; /* progressive JPEG successive approx. parms */
  163. } jpeg_scan_info;
  164. /* The decompressor can save APPn and COM markers in a list of these: */
  165. typedef struct jpeg_marker_struct FAR * jpeg_saved_marker_ptr;
  166. struct jpeg_marker_struct {
  167. jpeg_saved_marker_ptr next; /* next in list, or NULL */
  168. UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
  169. unsigned int original_length; /* # bytes of data in the file */
  170. unsigned int data_length; /* # bytes of data saved at data[] */
  171. JOCTET FAR * data; /* the data contained in the marker */
  172. /* the marker length word is not counted in data_length or original_length */
  173. };
  174. /* Known color spaces. */
  175. typedef enum {
  176. JCS_UNKNOWN, /* error/unspecified */
  177. JCS_GRAYSCALE, /* monochrome */
  178. JCS_RGB, /* red/green/blue */
  179. JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
  180. JCS_CMYK, /* C/M/Y/K */
  181. JCS_YCCK /* Y/Cb/Cr/K */
  182. } J_COLOR_SPACE;
  183. /* DCT/IDCT algorithm options. */
  184. typedef enum {
  185. JDCT_ISLOW, /* slow but accurate integer algorithm */
  186. JDCT_IFAST, /* faster, less accurate integer method */
  187. JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
  188. } J_DCT_METHOD;
  189. #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
  190. #define JDCT_DEFAULT JDCT_ISLOW
  191. #endif
  192. #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
  193. #define JDCT_FASTEST JDCT_IFAST
  194. #endif
  195. /* Dithering options for decompression. */
  196. typedef enum {
  197. JDITHER_NONE, /* no dithering */
  198. JDITHER_ORDERED, /* simple ordered dither */
  199. JDITHER_FS /* Floyd-Steinberg error diffusion dither */
  200. } J_DITHER_MODE;
  201. /* Common fields between JPEG compression and decompression master structs. */
  202. #define jpeg_common_fields \
  203. struct jpeg_error_mgr * err; /* Error handler module */\
  204. struct jpeg_memory_mgr * mem; /* Memory manager module */\
  205. struct jpeg_progress_mgr * progress; /* Progress monitor, or NULL if none */\
  206. void * client_data; /* Available for use by application */\
  207. boolean is_decompressor; /* So common code can tell which is which */\
  208. int global_state /* For checking call sequence validity */
  209. /* Routines that are to be used by both halves of the library are declared
  210. * to receive a pointer to this structure. There are no actual instances of
  211. * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
  212. */
  213. struct jpeg_common_struct {
  214. jpeg_common_fields; /* Fields common to both master struct types */
  215. /* Additional fields follow in an actual jpeg_compress_struct or
  216. * jpeg_decompress_struct. All three structs must agree on these
  217. * initial fields! (This would be a lot cleaner in C++.)
  218. */
  219. };
  220. typedef struct jpeg_common_struct * j_common_ptr;
  221. typedef struct jpeg_compress_struct * j_compress_ptr;
  222. typedef struct jpeg_decompress_struct * j_decompress_ptr;
  223. /* Master record for a compression instance */
  224. struct jpeg_compress_struct {
  225. jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
  226. /* Destination for compressed data */
  227. struct jpeg_destination_mgr * dest;
  228. /* Description of source image --- these fields must be filled in by
  229. * outer application before starting compression. in_color_space must
  230. * be correct before you can even call jpeg_set_defaults().
  231. */
  232. JDIMENSION image_width; /* input image width */
  233. JDIMENSION image_height; /* input image height */
  234. int input_components; /* # of color components in input image */
  235. /* KEVINJ: HACK!!!!!!!!!!!!!!
  236. Seems that if RGB_PIXELSIZE is 4, then RGBA works. However, I don't want to change this via a define. I don't know what else doing that
  237. would break or no longer work. So I use this boolean to only use 4 for my specific application. */
  238. int hack_use_input_components_as_RGB_PIXELSIZE;
  239. J_COLOR_SPACE in_color_space; /* colorspace of input image */
  240. double input_gamma; /* image gamma of input image */
  241. /* Compression parameters --- these fields must be set before calling
  242. * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
  243. * initialize everything to reasonable defaults, then changing anything
  244. * the application specifically wants to change. That way you won't get
  245. * burnt when new parameters are added. Also note that there are several
  246. * helper routines to simplify changing parameters.
  247. */
  248. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  249. JDIMENSION jpeg_width; /* scaled JPEG image width */
  250. JDIMENSION jpeg_height; /* scaled JPEG image height */
  251. /* Dimensions of actual JPEG image that will be written to file,
  252. * derived from input dimensions by scaling factors above.
  253. * These fields are computed by jpeg_start_compress().
  254. * You can also use jpeg_calc_jpeg_dimensions() to determine these values
  255. * in advance of calling jpeg_start_compress().
  256. */
  257. int data_precision; /* bits of precision in image data */
  258. int num_components; /* # of color components in JPEG image */
  259. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  260. jpeg_component_info * comp_info;
  261. /* comp_info[i] describes component that appears i'th in SOF */
  262. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  263. int q_scale_factor[NUM_QUANT_TBLS];
  264. /* ptrs to coefficient quantization tables, or NULL if not defined,
  265. * and corresponding scale factors (percentage, initialized 100).
  266. */
  267. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  268. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  269. /* ptrs to Huffman coding tables, or NULL if not defined */
  270. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  271. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  272. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  273. int num_scans; /* # of entries in scan_info array */
  274. const jpeg_scan_info * scan_info; /* script for multi-scan file, or NULL */
  275. /* The default value of scan_info is NULL, which causes a single-scan
  276. * sequential JPEG file to be emitted. To create a multi-scan file,
  277. * set num_scans and scan_info to point to an array of scan definitions.
  278. */
  279. boolean raw_data_in; /* TRUE=caller supplies downsampled data */
  280. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  281. boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
  282. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  283. boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
  284. int smoothing_factor; /* 1..100, or 0 for no input smoothing */
  285. J_DCT_METHOD dct_method; /* DCT algorithm selector */
  286. /* The restart interval can be specified in absolute MCUs by setting
  287. * restart_interval, or in MCU rows by setting restart_in_rows
  288. * (in which case the correct restart_interval will be figured
  289. * for each scan).
  290. */
  291. unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
  292. int restart_in_rows; /* if > 0, MCU rows per restart interval */
  293. /* Parameters controlling emission of special markers. */
  294. boolean write_JFIF_header; /* should a JFIF marker be written? */
  295. UINT8 JFIF_major_version; /* What to write for the JFIF version number */
  296. UINT8 JFIF_minor_version;
  297. /* These three values are not used by the JPEG code, merely copied */
  298. /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
  299. /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
  300. /* ratio is defined by X_density/Y_density even when density_unit=0. */
  301. UINT8 density_unit; /* JFIF code for pixel size units */
  302. UINT16 X_density; /* Horizontal pixel density */
  303. UINT16 Y_density; /* Vertical pixel density */
  304. boolean write_Adobe_marker; /* should an Adobe marker be written? */
  305. /* State variable: index of next scanline to be written to
  306. * jpeg_write_scanlines(). Application may use this to control its
  307. * processing loop, e.g., "while (next_scanline < image_height)".
  308. */
  309. JDIMENSION next_scanline; /* 0 .. image_height-1 */
  310. /* Remaining fields are known throughout compressor, but generally
  311. * should not be touched by a surrounding application.
  312. */
  313. /*
  314. * These fields are computed during compression startup
  315. */
  316. boolean progressive_mode; /* TRUE if scan script uses progressive mode */
  317. int max_h_samp_factor; /* largest h_samp_factor */
  318. int max_v_samp_factor; /* largest v_samp_factor */
  319. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  320. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  321. JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
  322. /* The coefficient controller receives data in units of MCU rows as defined
  323. * for fully interleaved scans (whether the JPEG file is interleaved or not).
  324. * There are v_samp_factor * DCTSIZE sample rows of each component in an
  325. * "iMCU" (interleaved MCU) row.
  326. */
  327. /*
  328. * These fields are valid during any one scan.
  329. * They describe the components and MCUs actually appearing in the scan.
  330. */
  331. int comps_in_scan; /* # of JPEG components in this scan */
  332. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  333. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  334. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  335. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  336. int blocks_in_MCU; /* # of DCT blocks per MCU */
  337. int MCU_membership[C_MAX_BLOCKS_IN_MCU];
  338. /* MCU_membership[i] is index in cur_comp_info of component owning */
  339. /* i'th block in an MCU */
  340. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  341. /*
  342. * Links to compression subobjects (methods and private variables of modules)
  343. */
  344. struct jpeg_comp_master * master;
  345. struct jpeg_c_main_controller * main;
  346. struct jpeg_c_prep_controller * prep;
  347. struct jpeg_c_coef_controller * coef;
  348. struct jpeg_marker_writer * marker;
  349. struct jpeg_color_converter * cconvert;
  350. struct jpeg_downsampler * downsample;
  351. struct jpeg_forward_dct * fdct;
  352. struct jpeg_entropy_encoder * entropy;
  353. jpeg_scan_info * script_space; /* workspace for jpeg_simple_progression */
  354. int script_space_size;
  355. };
  356. /* Master record for a decompression instance */
  357. struct jpeg_decompress_struct {
  358. jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
  359. /* Source of compressed data */
  360. struct jpeg_source_mgr * src;
  361. /* Basic description of image --- filled in by jpeg_read_header(). */
  362. /* Application may inspect these values to decide how to process image. */
  363. JDIMENSION image_width; /* nominal image width (from SOF marker) */
  364. JDIMENSION image_height; /* nominal image height */
  365. int num_components; /* # of color components in JPEG image */
  366. J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
  367. /* Decompression processing parameters --- these fields must be set before
  368. * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
  369. * them to default values.
  370. */
  371. J_COLOR_SPACE out_color_space; /* colorspace for output */
  372. unsigned int scale_num, scale_denom; /* fraction by which to scale image */
  373. double output_gamma; /* image gamma wanted in output */
  374. boolean buffered_image; /* TRUE=multiple output passes */
  375. boolean raw_data_out; /* TRUE=downsampled data wanted */
  376. J_DCT_METHOD dct_method; /* IDCT algorithm selector */
  377. boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
  378. boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
  379. boolean quantize_colors; /* TRUE=colormapped output wanted */
  380. /* the following are ignored if not quantize_colors: */
  381. J_DITHER_MODE dither_mode; /* type of color dithering to use */
  382. boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
  383. int desired_number_of_colors; /* max # colors to use in created colormap */
  384. /* these are significant only in buffered-image mode: */
  385. boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
  386. boolean enable_external_quant;/* enable future use of external colormap */
  387. boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
  388. /* Description of actual output image that will be returned to application.
  389. * These fields are computed by jpeg_start_decompress().
  390. * You can also use jpeg_calc_output_dimensions() to determine these values
  391. * in advance of calling jpeg_start_decompress().
  392. */
  393. JDIMENSION output_width; /* scaled image width */
  394. JDIMENSION output_height; /* scaled image height */
  395. int out_color_components; /* # of color components in out_color_space */
  396. int output_components; /* # of color components returned */
  397. /* output_components is 1 (a colormap index) when quantizing colors;
  398. * otherwise it equals out_color_components.
  399. */
  400. int rec_outbuf_height; /* min recommended height of scanline buffer */
  401. /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
  402. * high, space and time will be wasted due to unnecessary data copying.
  403. * Usually rec_outbuf_height will be 1 or 2, at most 4.
  404. */
  405. /* When quantizing colors, the output colormap is described by these fields.
  406. * The application can supply a colormap by setting colormap non-NULL before
  407. * calling jpeg_start_decompress; otherwise a colormap is created during
  408. * jpeg_start_decompress or jpeg_start_output.
  409. * The map has out_color_components rows and actual_number_of_colors columns.
  410. */
  411. int actual_number_of_colors; /* number of entries in use */
  412. JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
  413. /* State variables: these variables indicate the progress of decompression.
  414. * The application may examine these but must not modify them.
  415. */
  416. /* Row index of next scanline to be read from jpeg_read_scanlines().
  417. * Application may use this to control its processing loop, e.g.,
  418. * "while (output_scanline < output_height)".
  419. */
  420. JDIMENSION output_scanline; /* 0 .. output_height-1 */
  421. /* Current input scan number and number of iMCU rows completed in scan.
  422. * These indicate the progress of the decompressor input side.
  423. */
  424. int input_scan_number; /* Number of SOS markers seen so far */
  425. JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
  426. /* The "output scan number" is the notional scan being displayed by the
  427. * output side. The decompressor will not allow output scan/row number
  428. * to get ahead of input scan/row, but it can fall arbitrarily far behind.
  429. */
  430. int output_scan_number; /* Nominal scan number being displayed */
  431. JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
  432. /* Current progression status. coef_bits[c][i] indicates the precision
  433. * with which component c's DCT coefficient i (in zigzag order) is known.
  434. * It is -1 when no data has yet been received, otherwise it is the point
  435. * transform (shift) value for the most recent scan of the coefficient
  436. * (thus, 0 at completion of the progression).
  437. * This pointer is NULL when reading a non-progressive file.
  438. */
  439. int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
  440. /* Internal JPEG parameters --- the application usually need not look at
  441. * these fields. Note that the decompressor output side may not use
  442. * any parameters that can change between scans.
  443. */
  444. /* Quantization and Huffman tables are carried forward across input
  445. * datastreams when processing abbreviated JPEG datastreams.
  446. */
  447. JQUANT_TBL * quant_tbl_ptrs[NUM_QUANT_TBLS];
  448. /* ptrs to coefficient quantization tables, or NULL if not defined */
  449. JHUFF_TBL * dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
  450. JHUFF_TBL * ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
  451. /* ptrs to Huffman coding tables, or NULL if not defined */
  452. /* These parameters are never carried across datastreams, since they
  453. * are given in SOF/SOS markers or defined to be reset by SOI.
  454. */
  455. int data_precision; /* bits of precision in image data */
  456. jpeg_component_info * comp_info;
  457. /* comp_info[i] describes component that appears i'th in SOF */
  458. boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
  459. boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
  460. UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
  461. UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
  462. UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
  463. unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
  464. /* These fields record data obtained from optional markers recognized by
  465. * the JPEG library.
  466. */
  467. boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
  468. /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
  469. UINT8 JFIF_major_version; /* JFIF version number */
  470. UINT8 JFIF_minor_version;
  471. UINT8 density_unit; /* JFIF code for pixel size units */
  472. UINT16 X_density; /* Horizontal pixel density */
  473. UINT16 Y_density; /* Vertical pixel density */
  474. boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
  475. UINT8 Adobe_transform; /* Color transform code from Adobe marker */
  476. boolean CCIR601_sampling; /* TRUE=first samples are cosited */
  477. /* Aside from the specific data retained from APPn markers known to the
  478. * library, the uninterpreted contents of any or all APPn and COM markers
  479. * can be saved in a list for examination by the application.
  480. */
  481. jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
  482. /* Remaining fields are known throughout decompressor, but generally
  483. * should not be touched by a surrounding application.
  484. */
  485. /*
  486. * These fields are computed during decompression startup
  487. */
  488. int max_h_samp_factor; /* largest h_samp_factor */
  489. int max_v_samp_factor; /* largest v_samp_factor */
  490. int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
  491. int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
  492. JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
  493. /* The coefficient controller's input and output progress is measured in
  494. * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
  495. * in fully interleaved JPEG scans, but are used whether the scan is
  496. * interleaved or not. We define an iMCU row as v_samp_factor DCT block
  497. * rows of each component. Therefore, the IDCT output contains
  498. * v_samp_factor*DCT_v_scaled_size sample rows of a component per iMCU row.
  499. */
  500. JSAMPLE * sample_range_limit; /* table for fast range-limiting */
  501. /*
  502. * These fields are valid during any one scan.
  503. * They describe the components and MCUs actually appearing in the scan.
  504. * Note that the decompressor output side must not use these fields.
  505. */
  506. int comps_in_scan; /* # of JPEG components in this scan */
  507. jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN];
  508. /* *cur_comp_info[i] describes component that appears i'th in SOS */
  509. JDIMENSION MCUs_per_row; /* # of MCUs across the image */
  510. JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
  511. int blocks_in_MCU; /* # of DCT blocks per MCU */
  512. int MCU_membership[D_MAX_BLOCKS_IN_MCU];
  513. /* MCU_membership[i] is index in cur_comp_info of component owning */
  514. /* i'th block in an MCU */
  515. int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
  516. /* This field is shared between entropy decoder and marker parser.
  517. * It is either zero or the code of a JPEG marker that has been
  518. * read from the data source, but has not yet been processed.
  519. */
  520. int unread_marker;
  521. /*
  522. * Links to decompression subobjects (methods, private variables of modules)
  523. */
  524. struct jpeg_decomp_master * master;
  525. struct jpeg_d_main_controller * main;
  526. struct jpeg_d_coef_controller * coef;
  527. struct jpeg_d_post_controller * post;
  528. struct jpeg_input_controller * inputctl;
  529. struct jpeg_marker_reader * marker;
  530. struct jpeg_entropy_decoder * entropy;
  531. struct jpeg_inverse_dct * idct;
  532. struct jpeg_upsampler * upsample;
  533. struct jpeg_color_deconverter * cconvert;
  534. struct jpeg_color_quantizer * cquantize;
  535. };
  536. /* "Object" declarations for JPEG modules that may be supplied or called
  537. * directly by the surrounding application.
  538. * As with all objects in the JPEG library, these structs only define the
  539. * publicly visible methods and state variables of a module. Additional
  540. * private fields may exist after the public ones.
  541. */
  542. /* Error handler object */
  543. struct jpeg_error_mgr {
  544. /* Error exit handler: does not return to caller */
  545. JMETHOD(void, error_exit, (j_common_ptr cinfo));
  546. /* Conditionally emit a trace or warning message */
  547. JMETHOD(void, emit_message, (j_common_ptr cinfo, int msg_level));
  548. /* Routine that actually outputs a trace or error message */
  549. JMETHOD(void, output_message, (j_common_ptr cinfo));
  550. /* Format a message string for the most recent JPEG error or message */
  551. JMETHOD(void, format_message, (j_common_ptr cinfo, char * buffer));
  552. #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
  553. /* Reset error state variables at start of a new image */
  554. JMETHOD(void, reset_error_mgr, (j_common_ptr cinfo));
  555. /* The message ID code and any parameters are saved here.
  556. * A message can have one string parameter or up to 8 int parameters.
  557. */
  558. int msg_code;
  559. #define JMSG_STR_PARM_MAX 80
  560. union {
  561. int i[8];
  562. char s[JMSG_STR_PARM_MAX];
  563. } msg_parm;
  564. /* Standard state variables for error facility */
  565. int trace_level; /* max msg_level that will be displayed */
  566. /* For recoverable corrupt-data errors, we emit a warning message,
  567. * but keep going unless emit_message chooses to abort. emit_message
  568. * should count warnings in num_warnings. The surrounding application
  569. * can check for bad data by seeing if num_warnings is nonzero at the
  570. * end of processing.
  571. */
  572. long num_warnings; /* number of corrupt-data warnings */
  573. /* These fields point to the table(s) of error message strings.
  574. * An application can change the table pointer to switch to a different
  575. * message list (typically, to change the language in which errors are
  576. * reported). Some applications may wish to add additional error codes
  577. * that will be handled by the JPEG library error mechanism; the second
  578. * table pointer is used for this purpose.
  579. *
  580. * First table includes all errors generated by JPEG library itself.
  581. * Error code 0 is reserved for a "no such error string" message.
  582. */
  583. const char * const * jpeg_message_table; /* Library errors */
  584. int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
  585. /* Second table can be added by application (see cjpeg/djpeg for example).
  586. * It contains strings numbered first_addon_message..last_addon_message.
  587. */
  588. const char * const * addon_message_table; /* Non-library errors */
  589. int first_addon_message; /* code for first string in addon table */
  590. int last_addon_message; /* code for last string in addon table */
  591. };
  592. /* Progress monitor object */
  593. struct jpeg_progress_mgr {
  594. JMETHOD(void, progress_monitor, (j_common_ptr cinfo));
  595. long pass_counter; /* work units completed in this pass */
  596. long pass_limit; /* total number of work units in this pass */
  597. int completed_passes; /* passes completed so far */
  598. int total_passes; /* total number of passes expected */
  599. };
  600. /* Data destination object for compression */
  601. struct jpeg_destination_mgr {
  602. JOCTET * next_output_byte; /* => next byte to write in buffer */
  603. size_t free_in_buffer; /* # of byte spaces remaining in buffer */
  604. JMETHOD(void, init_destination, (j_compress_ptr cinfo));
  605. JMETHOD(boolean, empty_output_buffer, (j_compress_ptr cinfo));
  606. JMETHOD(void, term_destination, (j_compress_ptr cinfo));
  607. };
  608. /* Data source object for decompression */
  609. struct jpeg_source_mgr {
  610. const JOCTET * next_input_byte; /* => next byte to read from buffer */
  611. size_t bytes_in_buffer; /* # of bytes remaining in buffer */
  612. JMETHOD(void, init_source, (j_decompress_ptr cinfo));
  613. JMETHOD(boolean, fill_input_buffer, (j_decompress_ptr cinfo));
  614. JMETHOD(void, skip_input_data, (j_decompress_ptr cinfo, long num_bytes));
  615. JMETHOD(boolean, resync_to_restart, (j_decompress_ptr cinfo, int desired));
  616. JMETHOD(void, term_source, (j_decompress_ptr cinfo));
  617. };
  618. /* Memory manager object.
  619. * Allocates "small" objects (a few K total), "large" objects (tens of K),
  620. * and "really big" objects (virtual arrays with backing store if needed).
  621. * The memory manager does not allow individual objects to be freed; rather,
  622. * each created object is assigned to a pool, and whole pools can be freed
  623. * at once. This is faster and more convenient than remembering exactly what
  624. * to free, especially where malloc()/free() are not too speedy.
  625. * NB: alloc routines never return NULL. They exit to error_exit if not
  626. * successful.
  627. */
  628. #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
  629. #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
  630. #define JPOOL_NUMPOOLS 2
  631. typedef struct jvirt_sarray_control * jvirt_sarray_ptr;
  632. typedef struct jvirt_barray_control * jvirt_barray_ptr;
  633. struct jpeg_memory_mgr {
  634. /* Method pointers */
  635. JMETHOD(void *, alloc_small, (j_common_ptr cinfo, int pool_id,
  636. size_t sizeofobject));
  637. JMETHOD(void FAR *, alloc_large, (j_common_ptr cinfo, int pool_id,
  638. size_t sizeofobject));
  639. JMETHOD(JSAMPARRAY, alloc_sarray, (j_common_ptr cinfo, int pool_id,
  640. JDIMENSION samplesperrow,
  641. JDIMENSION numrows));
  642. JMETHOD(JBLOCKARRAY, alloc_barray, (j_common_ptr cinfo, int pool_id,
  643. JDIMENSION blocksperrow,
  644. JDIMENSION numrows));
  645. JMETHOD(jvirt_sarray_ptr, request_virt_sarray, (j_common_ptr cinfo,
  646. int pool_id,
  647. boolean pre_zero,
  648. JDIMENSION samplesperrow,
  649. JDIMENSION numrows,
  650. JDIMENSION maxaccess));
  651. JMETHOD(jvirt_barray_ptr, request_virt_barray, (j_common_ptr cinfo,
  652. int pool_id,
  653. boolean pre_zero,
  654. JDIMENSION blocksperrow,
  655. JDIMENSION numrows,
  656. JDIMENSION maxaccess));
  657. JMETHOD(void, realize_virt_arrays, (j_common_ptr cinfo));
  658. JMETHOD(JSAMPARRAY, access_virt_sarray, (j_common_ptr cinfo,
  659. jvirt_sarray_ptr ptr,
  660. JDIMENSION start_row,
  661. JDIMENSION num_rows,
  662. boolean writable));
  663. JMETHOD(JBLOCKARRAY, access_virt_barray, (j_common_ptr cinfo,
  664. jvirt_barray_ptr ptr,
  665. JDIMENSION start_row,
  666. JDIMENSION num_rows,
  667. boolean writable));
  668. JMETHOD(void, free_pool, (j_common_ptr cinfo, int pool_id));
  669. JMETHOD(void, self_destruct, (j_common_ptr cinfo));
  670. /* Limit on memory allocation for this JPEG object. (Note that this is
  671. * merely advisory, not a guaranteed maximum; it only affects the space
  672. * used for virtual-array buffers.) May be changed by outer application
  673. * after creating the JPEG object.
  674. */
  675. long max_memory_to_use;
  676. /* Maximum allocation request accepted by alloc_large. */
  677. long max_alloc_chunk;
  678. };
  679. /* Routine signature for application-supplied marker processing methods.
  680. * Need not pass marker code since it is stored in cinfo->unread_marker.
  681. */
  682. typedef JMETHOD(boolean, jpeg_marker_parser_method, (j_decompress_ptr cinfo));
  683. /* Declarations for routines called by application.
  684. * The JPP macro hides prototype parameters from compilers that can't cope.
  685. * Note JPP requires double parentheses.
  686. */
  687. #ifdef HAVE_PROTOTYPES
  688. #define JPP(arglist) arglist
  689. #else
  690. #define JPP(arglist) ()
  691. #endif
  692. /* Short forms of external names for systems with brain-damaged linkers.
  693. * We shorten external names to be unique in the first six letters, which
  694. * is good enough for all known systems.
  695. * (If your compiler itself needs names to be unique in less than 15
  696. * characters, you are out of luck. Get a better compiler.)
  697. */
  698. #ifdef NEED_SHORT_EXTERNAL_NAMES
  699. #define jpeg_std_error jStdError
  700. #define jpeg_CreateCompress jCreaCompress
  701. #define jpeg_CreateDecompress jCreaDecompress
  702. #define jpeg_destroy_compress jDestCompress
  703. #define jpeg_destroy_decompress jDestDecompress
  704. #define jpeg_stdio_dest jStdDest
  705. #define jpeg_stdio_src jStdSrc
  706. #define jpeg_memory_src jMemSrc
  707. #define jpeg_set_defaults jSetDefaults
  708. #define jpeg_set_colorspace jSetColorspace
  709. #define jpeg_default_colorspace jDefColorspace
  710. #define jpeg_set_quality jSetQuality
  711. #define jpeg_set_linear_quality jSetLQuality
  712. #define jpeg_default_qtables jDefQTables
  713. #define jpeg_add_quant_table jAddQuantTable
  714. #define jpeg_quality_scaling jQualityScaling
  715. #define jpeg_simple_progression jSimProgress
  716. #define jpeg_suppress_tables jSuppressTables
  717. #define jpeg_alloc_quant_table jAlcQTable
  718. #define jpeg_alloc_huff_table jAlcHTable
  719. #define jpeg_start_compress jStrtCompress
  720. #define jpeg_write_scanlines jWrtScanlines
  721. #define jpeg_finish_compress jFinCompress
  722. #define jpeg_calc_jpeg_dimensions jCjpegDimensions
  723. #define jpeg_write_raw_data jWrtRawData
  724. #define jpeg_write_marker jWrtMarker
  725. #define jpeg_write_m_header jWrtMHeader
  726. #define jpeg_write_m_byte jWrtMByte
  727. #define jpeg_write_tables jWrtTables
  728. #define jpeg_read_header jReadHeader
  729. #define jpeg_start_decompress jStrtDecompress
  730. #define jpeg_read_scanlines jReadScanlines
  731. #define jpeg_finish_decompress jFinDecompress
  732. #define jpeg_read_raw_data jReadRawData
  733. #define jpeg_has_multiple_scans jHasMultScn
  734. #define jpeg_start_output jStrtOutput
  735. #define jpeg_finish_output jFinOutput
  736. #define jpeg_input_complete jInComplete
  737. #define jpeg_new_colormap jNewCMap
  738. #define jpeg_consume_input jConsumeInput
  739. #define jpeg_calc_output_dimensions jCalcDimensions
  740. #define jpeg_save_markers jSaveMarkers
  741. #define jpeg_set_marker_processor jSetMarker
  742. #define jpeg_read_coefficients jReadCoefs
  743. #define jpeg_write_coefficients jWrtCoefs
  744. #define jpeg_copy_critical_parameters jCopyCrit
  745. #define jpeg_abort_compress jAbrtCompress
  746. #define jpeg_abort_decompress jAbrtDecompress
  747. #define jpeg_abort jAbort
  748. #define jpeg_destroy jDestroy
  749. #define jpeg_resync_to_restart jResyncRestart
  750. #endif /* NEED_SHORT_EXTERNAL_NAMES */
  751. /* Default error-management setup */
  752. EXTERN(struct jpeg_error_mgr *) jpeg_std_error
  753. JPP((struct jpeg_error_mgr * err));
  754. /* Initialization of JPEG compression objects.
  755. * jpeg_create_compress() and jpeg_create_decompress() are the exported
  756. * names that applications should call. These expand to calls on
  757. * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
  758. * passed for version mismatch checking.
  759. * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
  760. */
  761. #define jpeg_create_compress(cinfo) \
  762. jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
  763. (size_t) sizeof(struct jpeg_compress_struct))
  764. #define jpeg_create_decompress(cinfo) \
  765. jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
  766. (size_t) sizeof(struct jpeg_decompress_struct))
  767. EXTERN(void) jpeg_CreateCompress JPP((j_compress_ptr cinfo,
  768. int version, size_t structsize));
  769. EXTERN(void) jpeg_CreateDecompress JPP((j_decompress_ptr cinfo,
  770. int version, size_t structsize));
  771. /* Destruction of JPEG compression objects */
  772. EXTERN(void) jpeg_destroy_compress JPP((j_compress_ptr cinfo));
  773. EXTERN(void) jpeg_destroy_decompress JPP((j_decompress_ptr cinfo));
  774. /* Standard data source and destination managers: stdio streams. */
  775. /* Caller is responsible for opening the file before and closing after. */
  776. EXTERN(void) jpeg_stdio_dest JPP((j_compress_ptr cinfo, FILE * outfile));
  777. EXTERN(void) jpeg_stdio_src JPP((j_decompress_ptr cinfo, FILE * infile));
  778. EXTERN(void) jpeg_memory_src (j_decompress_ptr cinfo, const JOCTET * buffer, size_t bufsize);
  779. /* Default parameter setup for compression */
  780. EXTERN(void) jpeg_set_defaults JPP((j_compress_ptr cinfo));
  781. /* Compression parameter setup aids */
  782. EXTERN(void) jpeg_set_colorspace JPP((j_compress_ptr cinfo,
  783. J_COLOR_SPACE colorspace));
  784. EXTERN(void) jpeg_default_colorspace JPP((j_compress_ptr cinfo));
  785. EXTERN(void) jpeg_set_quality JPP((j_compress_ptr cinfo, int quality,
  786. boolean force_baseline));
  787. EXTERN(void) jpeg_set_linear_quality JPP((j_compress_ptr cinfo,
  788. int scale_factor,
  789. boolean force_baseline));
  790. EXTERN(void) jpeg_default_qtables JPP((j_compress_ptr cinfo,
  791. boolean force_baseline));
  792. EXTERN(void) jpeg_add_quant_table JPP((j_compress_ptr cinfo, int which_tbl,
  793. const unsigned int *basic_table,
  794. int scale_factor,
  795. boolean force_baseline));
  796. EXTERN(int) jpeg_quality_scaling JPP((int quality));
  797. EXTERN(void) jpeg_simple_progression JPP((j_compress_ptr cinfo));
  798. EXTERN(void) jpeg_suppress_tables JPP((j_compress_ptr cinfo,
  799. boolean suppress));
  800. EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table JPP((j_common_ptr cinfo));
  801. EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table JPP((j_common_ptr cinfo));
  802. /* Main entry points for compression */
  803. EXTERN(void) jpeg_start_compress JPP((j_compress_ptr cinfo,
  804. boolean write_all_tables));
  805. EXTERN(JDIMENSION) jpeg_write_scanlines JPP((j_compress_ptr cinfo,
  806. JSAMPARRAY scanlines,
  807. JDIMENSION num_lines));
  808. EXTERN(void) jpeg_finish_compress JPP((j_compress_ptr cinfo));
  809. /* Precalculate JPEG dimensions for current compression parameters. */
  810. EXTERN(void) jpeg_calc_jpeg_dimensions JPP((j_compress_ptr cinfo));
  811. /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
  812. EXTERN(JDIMENSION) jpeg_write_raw_data JPP((j_compress_ptr cinfo,
  813. JSAMPIMAGE data,
  814. JDIMENSION num_lines));
  815. /* Write a special marker. See libjpeg.txt concerning safe usage. */
  816. EXTERN(void) jpeg_write_marker
  817. JPP((j_compress_ptr cinfo, int marker,
  818. const JOCTET * dataptr, unsigned int datalen));
  819. /* Same, but piecemeal. */
  820. EXTERN(void) jpeg_write_m_header
  821. JPP((j_compress_ptr cinfo, int marker, unsigned int datalen));
  822. EXTERN(void) jpeg_write_m_byte
  823. JPP((j_compress_ptr cinfo, int val));
  824. /* Alternate compression function: just write an abbreviated table file */
  825. EXTERN(void) jpeg_write_tables JPP((j_compress_ptr cinfo));
  826. /* Decompression startup: read start of JPEG datastream to see what's there */
  827. EXTERN(int) jpeg_read_header JPP((j_decompress_ptr cinfo,
  828. boolean require_image));
  829. /* Return value is one of: */
  830. #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
  831. #define JPEG_HEADER_OK 1 /* Found valid image datastream */
  832. #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
  833. /* If you pass require_image = TRUE (normal case), you need not check for
  834. * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  835. * JPEG_SUSPENDED is only possible if you use a data source module that can
  836. * give a suspension return (the stdio source module doesn't).
  837. */
  838. /* Main entry points for decompression */
  839. EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
  840. EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
  841. JSAMPARRAY scanlines,
  842. JDIMENSION max_lines));
  843. EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
  844. /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
  845. EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
  846. JSAMPIMAGE data,
  847. JDIMENSION max_lines));
  848. /* Additional entry points for buffered-image mode. */
  849. EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
  850. EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
  851. int scan_number));
  852. EXTERN(boolean) jpeg_finish_output JPP((j_decompress_ptr cinfo));
  853. EXTERN(boolean) jpeg_input_complete JPP((j_decompress_ptr cinfo));
  854. EXTERN(void) jpeg_new_colormap JPP((j_decompress_ptr cinfo));
  855. EXTERN(int) jpeg_consume_input JPP((j_decompress_ptr cinfo));
  856. /* Return value is one of: */
  857. /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
  858. #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
  859. #define JPEG_REACHED_EOI 2 /* Reached end of image */
  860. #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
  861. #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
  862. /* Precalculate output dimensions for current decompression parameters. */
  863. EXTERN(void) jpeg_calc_output_dimensions JPP((j_decompress_ptr cinfo));
  864. /* Control saving of COM and APPn markers into marker_list. */
  865. EXTERN(void) jpeg_save_markers
  866. JPP((j_decompress_ptr cinfo, int marker_code,
  867. unsigned int length_limit));
  868. /* Install a special processing method for COM or APPn markers. */
  869. EXTERN(void) jpeg_set_marker_processor
  870. JPP((j_decompress_ptr cinfo, int marker_code,
  871. jpeg_marker_parser_method routine));
  872. /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
  873. EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients JPP((j_decompress_ptr cinfo));
  874. EXTERN(void) jpeg_write_coefficients JPP((j_compress_ptr cinfo,
  875. jvirt_barray_ptr * coef_arrays));
  876. EXTERN(void) jpeg_copy_critical_parameters JPP((j_decompress_ptr srcinfo,
  877. j_compress_ptr dstinfo));
  878. /* If you choose to abort compression or decompression before completing
  879. * jpeg_finish_(de)compress, then you need to clean up to release memory,
  880. * temporary files, etc. You can just call jpeg_destroy_(de)compress
  881. * if you're done with the JPEG object, but if you want to clean it up and
  882. * reuse it, call this:
  883. */
  884. EXTERN(void) jpeg_abort_compress JPP((j_compress_ptr cinfo));
  885. EXTERN(void) jpeg_abort_decompress JPP((j_decompress_ptr cinfo));
  886. /* Generic versions of jpeg_abort and jpeg_destroy that work on either
  887. * flavor of JPEG object. These may be more convenient in some places.
  888. */
  889. EXTERN(void) jpeg_abort JPP((j_common_ptr cinfo));
  890. EXTERN(void) jpeg_destroy JPP((j_common_ptr cinfo));
  891. /* Default restart-marker-resync procedure for use by data source modules */
  892. EXTERN(boolean) jpeg_resync_to_restart JPP((j_decompress_ptr cinfo,
  893. int desired));
  894. /* These marker codes are exported since applications and data source modules
  895. * are likely to want to use them.
  896. */
  897. #define JPEG_RST0 0xD0 /* RST0 marker code */
  898. #define JPEG_EOI 0xD9 /* EOI marker code */
  899. #define JPEG_APP0 0xE0 /* APP0 marker code */
  900. #define JPEG_COM 0xFE /* COM marker code */
  901. /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
  902. * for structure definitions that are never filled in, keep it quiet by
  903. * supplying dummy definitions for the various substructures.
  904. */
  905. #ifdef INCOMPLETE_TYPES_BROKEN
  906. #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
  907. struct jvirt_sarray_control { long dummy; };
  908. struct jvirt_barray_control { long dummy; };
  909. struct jpeg_comp_master { long dummy; };
  910. struct jpeg_c_main_controller { long dummy; };
  911. struct jpeg_c_prep_controller { long dummy; };
  912. struct jpeg_c_coef_controller { long dummy; };
  913. struct jpeg_marker_writer { long dummy; };
  914. struct jpeg_color_converter { long dummy; };
  915. struct jpeg_downsampler { long dummy; };
  916. struct jpeg_forward_dct { long dummy; };
  917. struct jpeg_entropy_encoder { long dummy; };
  918. struct jpeg_decomp_master { long dummy; };
  919. struct jpeg_d_main_controller { long dummy; };
  920. struct jpeg_d_coef_controller { long dummy; };
  921. struct jpeg_d_post_controller { long dummy; };
  922. struct jpeg_input_controller { long dummy; };
  923. struct jpeg_marker_reader { long dummy; };
  924. struct jpeg_entropy_decoder { long dummy; };
  925. struct jpeg_inverse_dct { long dummy; };
  926. struct jpeg_upsampler { long dummy; };
  927. struct jpeg_color_deconverter { long dummy; };
  928. struct jpeg_color_quantizer { long dummy; };
  929. #endif /* JPEG_INTERNALS */
  930. #endif /* INCOMPLETE_TYPES_BROKEN */
  931. /*
  932. * The JPEG library modules define JPEG_INTERNALS before including this file.
  933. * The internal structure declarations are read only when that is true.
  934. * Applications using the library should not include jpegint.h, but may wish
  935. * to include jerror.h.
  936. */
  937. #ifdef JPEG_INTERNALS
  938. #include "jpegint.h" /* fetch private declarations */
  939. #include "jerror.h" /* fetch error codes too */
  940. #endif
  941. #ifdef __cplusplus
  942. #ifndef DONT_USE_EXTERN_C
  943. }
  944. #endif
  945. #endif
  946. #endif /* JPEGLIB_H */
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