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.
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.
14 /* Declarations for both compression & decompression */
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 */
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 */
42 /* Declarations for compression modules */
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));
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 */
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));
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,
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));
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));
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));
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));
98 boolean need_context_rows; /* TRUE if need rows above & below */
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));
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));
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));
134 /* Declarations for decompression modules */
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));
141 /* State variables made visible to other modules */
142 boolean is_dummy_pass; /* True during 1st pass for 2-pass quant */
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));
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 */
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));
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;
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));
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.
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;
199 /* State of marker reader --- nominally internal, but applications
200 * supplying COM or APPn handlers might like to know the state.
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 */
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));
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 */
219 /* Inverse DCT (also performs dequantization) */
220 typedef JMETHOD(void, inverse_DCT_method_ptr,
221 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
223 JSAMPARRAY output_buf, JDIMENSION output_col));
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];
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));
242 boolean need_context_rows; /* TRUE if need rows above & below */
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));
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,
259 JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
260 JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
264 /* Miscellaneous useful macros */
267 #define MAX(a,b) ((a) > (b) ? (a) : (b))
269 #define MIN(a,b) ((a) < (b) ? (a) : (b))
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.
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)))
290 #define RIGHT_SHIFT(x,shft) ((x) >> (shft))
294 /* Short forms of external names for systems with brain-damaged linkers. */
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 */
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));
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 */
383 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
385 /* Suppress undefined-structure complaints if necessary. */
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; };
392 #endif /* INCOMPLETE_TYPES_BROKEN */