• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * jpegint.h
3  *
4  * Copyright (C) 1991-1997, Thomas G. Lane.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This file provides common declarations for the various JPEG modules.
9  * These declarations are considered internal to the JPEG library; most
10  * applications using the library shouldn't need to include this file.
11  */
12 
13 
14 /* Declarations for both compression & decompression */
15 
16 typedef enum {			/* Operating modes for buffer controllers */
17 	JBUF_PASS_THRU,		/* Plain stripwise operation */
18 	/* Remaining modes require a full-image buffer to have been created */
19 	JBUF_SAVE_SOURCE,	/* Run source subobject only, save output */
20 	JBUF_CRANK_DEST,	/* Run dest subobject only, using saved data */
21 	JBUF_SAVE_AND_PASS	/* Run both subobjects, save output */
22 } J_BUF_MODE;
23 
24 /* Values of global_state field (jdapi.c has some dependencies on ordering!) */
25 #define CSTATE_START	100	/* after create_compress */
26 #define CSTATE_SCANNING	101	/* start_compress done, write_scanlines OK */
27 #define CSTATE_RAW_OK	102	/* start_compress done, write_raw_data OK */
28 #define CSTATE_WRCOEFS	103	/* jpeg_write_coefficients done */
29 #define DSTATE_START	200	/* after create_decompress */
30 #define DSTATE_INHEADER	201	/* reading header markers, no SOS yet */
31 #define DSTATE_READY	202	/* found SOS, ready for start_decompress */
32 #define DSTATE_PRELOAD	203	/* reading multiscan file in start_decompress*/
33 #define DSTATE_PRESCAN	204	/* performing dummy pass for 2-pass quant */
34 #define DSTATE_SCANNING	205	/* start_decompress done, read_scanlines OK */
35 #define DSTATE_RAW_OK	206	/* start_decompress done, read_raw_data OK */
36 #define DSTATE_BUFIMAGE	207	/* expecting jpeg_start_output */
37 #define DSTATE_BUFPOST	208	/* looking for SOS/EOI in jpeg_finish_output */
38 #define DSTATE_RDCOEFS	209	/* reading file in jpeg_read_coefficients */
39 #define DSTATE_STOPPING	210	/* looking for EOI in jpeg_finish_decompress */
40 
41 
42 /* Declarations for compression modules */
43 
44 /* Master control module */
45 struct jpeg_comp_master {
46   JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
47   JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
48   JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
49 
50   /* State variables made visible to other modules */
51   boolean call_pass_startup;	/* True if pass_startup must be called */
52   boolean is_last_pass;		/* True during last pass */
53 };
54 
55 /* Main buffer control (downsampled-data buffer) */
56 struct jpeg_c_main_controller {
57   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
58   JMETHOD(void, process_data, (j_compress_ptr cinfo,
59 			       JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
60 			       JDIMENSION in_rows_avail));
61 };
62 
63 /* Compression preprocessing (downsampling input buffer control) */
64 struct jpeg_c_prep_controller {
65   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
66   JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
67 				   JSAMPARRAY input_buf,
68 				   JDIMENSION *in_row_ctr,
69 				   JDIMENSION in_rows_avail,
70 				   JSAMPIMAGE output_buf,
71 				   JDIMENSION *out_row_group_ctr,
72 				   JDIMENSION out_row_groups_avail));
73 };
74 
75 /* Coefficient buffer control */
76 struct jpeg_c_coef_controller {
77   JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
78   JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
79 				   JSAMPIMAGE input_buf));
80 };
81 
82 /* Colorspace conversion */
83 struct jpeg_color_converter {
84   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
85   JMETHOD(void, color_convert, (j_compress_ptr cinfo,
86 				JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
87 				JDIMENSION output_row, int num_rows));
88 };
89 
90 /* Downsampling */
91 struct jpeg_downsampler {
92   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
93   JMETHOD(void, downsample, (j_compress_ptr cinfo,
94 			     JSAMPIMAGE input_buf, JDIMENSION in_row_index,
95 			     JSAMPIMAGE output_buf,
96 			     JDIMENSION out_row_group_index));
97 
98   boolean need_context_rows;	/* TRUE if need rows above & below */
99 };
100 
101 /* Forward DCT (also controls coefficient quantization) */
102 struct jpeg_forward_dct {
103   JMETHOD(void, start_pass, (j_compress_ptr cinfo));
104   /* perhaps this should be an array??? */
105   JMETHOD(void, forward_DCT, (j_compress_ptr cinfo,
106 			      jpeg_component_info * compptr,
107 			      JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
108 			      JDIMENSION start_row, JDIMENSION start_col,
109 			      JDIMENSION num_blocks));
110 };
111 
112 /* Entropy encoding */
113 struct jpeg_entropy_encoder {
114   JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
115   JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
116   JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
117 };
118 
119 /* Marker writing */
120 struct jpeg_marker_writer {
121   JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
122   JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
123   JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
124   JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
125   JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
126   /* These routines are exported to allow insertion of extra markers */
127   /* Probably only COM and APPn markers should be written this way */
128   JMETHOD(void, write_marker_header, (j_compress_ptr cinfo, int marker,
129 				      unsigned int datalen));
130   JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
131 };
132 
133 
134 /* Declarations for decompression modules */
135 
136 /* Master control module */
137 struct jpeg_decomp_master {
138   JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
139   JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
140 
141   /* State variables made visible to other modules */
142   boolean is_dummy_pass;	/* True during 1st pass for 2-pass quant */
143 };
144 
145 /* Input control module */
146 struct jpeg_input_controller {
147   JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
148   JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
149   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
150   JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
151 
152   /* State variables made visible to other modules */
153   boolean has_multiple_scans;	/* True if file has multiple scans */
154   boolean eoi_reached;		/* True when EOI has been consumed */
155 };
156 
157 /* Main buffer control (downsampled-data buffer) */
158 struct jpeg_d_main_controller {
159   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
160   JMETHOD(void, process_data, (j_decompress_ptr cinfo,
161 			       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
162 			       JDIMENSION out_rows_avail));
163 };
164 
165 /* Coefficient buffer control */
166 struct jpeg_d_coef_controller {
167   JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
168   JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
169   JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
170   JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
171 				 JSAMPIMAGE output_buf));
172   /* Pointer to array of coefficient virtual arrays, or NULL if none */
173   jvirt_barray_ptr *coef_arrays;
174 };
175 
176 /* Decompression postprocessing (color quantization buffer control) */
177 struct jpeg_d_post_controller {
178   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
179   JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
180 				    JSAMPIMAGE input_buf,
181 				    JDIMENSION *in_row_group_ctr,
182 				    JDIMENSION in_row_groups_avail,
183 				    JSAMPARRAY output_buf,
184 				    JDIMENSION *out_row_ctr,
185 				    JDIMENSION out_rows_avail));
186 };
187 
188 /* Marker reading & parsing */
189 struct jpeg_marker_reader {
190   JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
191   /* Read markers until SOS or EOI.
192    * Returns same codes as are defined for jpeg_consume_input:
193    * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
194    */
195   JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
196   /* Read a restart marker --- exported for use by entropy decoder only */
197   jpeg_marker_parser_method read_restart_marker;
198 
199   /* State of marker reader --- nominally internal, but applications
200    * supplying COM or APPn handlers might like to know the state.
201    */
202   boolean saw_SOI;		/* found SOI? */
203   boolean saw_SOF;		/* found SOF? */
204   int next_restart_num;		/* next restart number expected (0-7) */
205   unsigned int discarded_bytes;	/* # of bytes skipped looking for a marker */
206 };
207 
208 /* Entropy decoding */
209 struct jpeg_entropy_decoder {
210   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
211   JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
212 				JBLOCKROW *MCU_data));
213 
214   /* This is here to share code between baseline and progressive decoders; */
215   /* other modules probably should not use it */
216   boolean insufficient_data;	/* set TRUE after emitting warning */
217 };
218 
219 /* Inverse DCT (also performs dequantization) */
220 typedef JMETHOD(void, inverse_DCT_method_ptr,
221 		(j_decompress_ptr cinfo, jpeg_component_info * compptr,
222 		 JCOEFPTR coef_block,
223 		 JSAMPARRAY output_buf, JDIMENSION output_col));
224 
225 struct jpeg_inverse_dct {
226   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
227   /* It is useful to allow each component to have a separate IDCT method. */
228   inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
229 };
230 
231 /* Upsampling (note that upsampler must also call color converter) */
232 struct jpeg_upsampler {
233   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
234   JMETHOD(void, upsample, (j_decompress_ptr cinfo,
235 			   JSAMPIMAGE input_buf,
236 			   JDIMENSION *in_row_group_ctr,
237 			   JDIMENSION in_row_groups_avail,
238 			   JSAMPARRAY output_buf,
239 			   JDIMENSION *out_row_ctr,
240 			   JDIMENSION out_rows_avail));
241 
242   boolean need_context_rows;	/* TRUE if need rows above & below */
243 };
244 
245 /* Colorspace conversion */
246 struct jpeg_color_deconverter {
247   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
248   JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
249 				JSAMPIMAGE input_buf, JDIMENSION input_row,
250 				JSAMPARRAY output_buf, int num_rows));
251 };
252 
253 /* Color quantization or color precision reduction */
254 struct jpeg_color_quantizer {
255   JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
256   JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
257 				 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
258 				 int num_rows));
259   JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
260   JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
261 };
262 
263 
264 /* Miscellaneous useful macros */
265 
266 #undef MAX
267 #define MAX(a,b)	((a) > (b) ? (a) : (b))
268 #undef MIN
269 #define MIN(a,b)	((a) < (b) ? (a) : (b))
270 
271 
272 /* We assume that right shift corresponds to signed division by 2 with
273  * rounding towards minus infinity.  This is correct for typical "arithmetic
274  * shift" instructions that shift in copies of the sign bit.  But some
275  * C compilers implement >> with an unsigned shift.  For these machines you
276  * must define RIGHT_SHIFT_IS_UNSIGNED.
277  * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
278  * It is only applied with constant shift counts.  SHIFT_TEMPS must be
279  * included in the variables of any routine using RIGHT_SHIFT.
280  */
281 
282 #ifdef RIGHT_SHIFT_IS_UNSIGNED
283 #define SHIFT_TEMPS	INT32 shift_temp;
284 #define RIGHT_SHIFT(x,shft)  \
285 	((shift_temp = (x)) < 0 ? \
286 	 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
287 	 (shift_temp >> (shft)))
288 #else
289 #define SHIFT_TEMPS
290 #define RIGHT_SHIFT(x,shft)	((x) >> (shft))
291 #endif
292 
293 
294 /* Short forms of external names for systems with brain-damaged linkers. */
295 
296 #ifdef NEED_SHORT_EXTERNAL_NAMES
297 #define jinit_compress_master	jICompress
298 #define jinit_c_master_control	jICMaster
299 #define jinit_c_main_controller	jICMainC
300 #define jinit_c_prep_controller	jICPrepC
301 #define jinit_c_coef_controller	jICCoefC
302 #define jinit_color_converter	jICColor
303 #define jinit_downsampler	jIDownsampler
304 #define jinit_forward_dct	jIFDCT
305 #define jinit_huff_encoder	jIHEncoder
306 #define jinit_phuff_encoder	jIPHEncoder
307 #define jinit_marker_writer	jIMWriter
308 #define jinit_master_decompress	jIDMaster
309 #define jinit_d_main_controller	jIDMainC
310 #define jinit_d_coef_controller	jIDCoefC
311 #define jinit_d_post_controller	jIDPostC
312 #define jinit_input_controller	jIInCtlr
313 #define jinit_marker_reader	jIMReader
314 #define jinit_huff_decoder	jIHDecoder
315 #define jinit_phuff_decoder	jIPHDecoder
316 #define jinit_inverse_dct	jIIDCT
317 #define jinit_upsampler		jIUpsampler
318 #define jinit_color_deconverter	jIDColor
319 #define jinit_1pass_quantizer	jI1Quant
320 #define jinit_2pass_quantizer	jI2Quant
321 #define jinit_merged_upsampler	jIMUpsampler
322 #define jinit_memory_mgr	jIMemMgr
323 #define jdiv_round_up		jDivRound
324 #define jround_up		jRound
325 #define jcopy_sample_rows	jCopySamples
326 #define jcopy_block_row		jCopyBlocks
327 #define jzero_far		jZeroFar
328 #define jpeg_zigzag_order	jZIGTable
329 #define jpeg_natural_order	jZAGTable
330 #endif /* NEED_SHORT_EXTERNAL_NAMES */
331 
332 
333 /* Compression module initialization routines */
334 EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
335 EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
336 					 boolean transcode_only));
337 EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
338 					  boolean need_full_buffer));
339 EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
340 					  boolean need_full_buffer));
341 EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
342 					  boolean need_full_buffer));
343 EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
344 EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
345 EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
346 EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
347 EXTERN(void) jinit_phuff_encoder JPP((j_compress_ptr cinfo));
348 EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
349 /* Decompression module initialization routines */
350 EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
351 EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
352 					  boolean need_full_buffer));
353 EXTERN(void) jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
354 					  boolean need_full_buffer));
355 EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
356 					  boolean need_full_buffer));
357 EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
358 EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
359 EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
360 EXTERN(void) jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
361 EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
362 EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
363 EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
364 EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
365 EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
366 EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
367 /* Memory manager initialization */
368 EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));
369 
370 /* Utility routines in jutils.c */
371 EXTERN(long) jdiv_round_up JPP((long a, long b));
372 EXTERN(long) jround_up JPP((long a, long b));
373 EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
374 				    JSAMPARRAY output_array, int dest_row,
375 				    int num_rows, JDIMENSION num_cols));
376 EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
377 				  JDIMENSION num_blocks));
378 EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
379 /* Constant tables in jutils.c */
380 #if 0				/* This table is not actually needed in v6a */
381 extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
382 #endif
383 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
384 
385 /* Suppress undefined-structure complaints if necessary. */
386 
387 #ifdef INCOMPLETE_TYPES_BROKEN
388 #ifndef AM_MEMORY_MANAGER	/* only jmemmgr.c defines these */
389 struct jvirt_sarray_control { long dummy; };
390 struct jvirt_barray_control { long dummy; };
391 #endif
392 #endif /* INCOMPLETE_TYPES_BROKEN */
393