4 * Copyright (C) 1991-1995, 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 /* write_any_marker is exported for use by applications */
122 /* Probably only COM and APPn markers should be written */
123 JMETHOD(void, write_any_marker, (j_compress_ptr cinfo, int marker,
124 const JOCTET *dataptr, unsigned int datalen));
125 JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
126 JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
127 JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
128 JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
129 JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
133 /* Declarations for decompression modules */
135 /* Master control module */
136 struct jpeg_decomp_master {
137 JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
138 JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
140 /* State variables made visible to other modules */
141 boolean is_dummy_pass; /* True during 1st pass for 2-pass quant */
144 /* Input control module */
145 struct jpeg_input_controller {
146 JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
147 JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
148 JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
149 JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
151 /* State variables made visible to other modules */
152 boolean has_multiple_scans; /* True if file has multiple scans */
153 boolean eoi_reached; /* True when EOI has been consumed */
156 /* Main buffer control (downsampled-data buffer) */
157 struct jpeg_d_main_controller {
158 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
159 JMETHOD(void, process_data, (j_decompress_ptr cinfo,
160 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
161 JDIMENSION out_rows_avail));
164 /* Coefficient buffer control */
165 struct jpeg_d_coef_controller {
166 JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
167 JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
168 JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
169 JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
170 JSAMPIMAGE output_buf));
171 /* Pointer to array of coefficient virtual arrays, or NULL if none */
172 jvirt_barray_ptr *coef_arrays;
175 /* Decompression postprocessing (color quantization buffer control) */
176 struct jpeg_d_post_controller {
177 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
178 JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
179 JSAMPIMAGE input_buf,
180 JDIMENSION *in_row_group_ctr,
181 JDIMENSION in_row_groups_avail,
182 JSAMPARRAY output_buf,
183 JDIMENSION *out_row_ctr,
184 JDIMENSION out_rows_avail));
187 /* Marker reading & parsing */
188 struct jpeg_marker_reader {
189 JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
190 /* Read markers until SOS or EOI.
191 * Returns same codes as are defined for jpeg_consume_input:
192 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
194 JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
195 /* Read a restart marker --- exported for use by entropy decoder only */
196 jpeg_marker_parser_method read_restart_marker;
197 /* Application-overridable marker processing methods */
198 jpeg_marker_parser_method process_COM;
199 jpeg_marker_parser_method process_APPn[16];
201 /* State of marker reader --- nominally internal, but applications
202 * supplying COM or APPn handlers might like to know the state.
204 boolean saw_SOI; /* found SOI? */
205 boolean saw_SOF; /* found SOF? */
206 int next_restart_num; /* next restart number expected (0-7) */
207 unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
210 /* Entropy decoding */
211 struct jpeg_entropy_decoder {
212 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
213 JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
214 JBLOCKROW *MCU_data));
217 /* Inverse DCT (also performs dequantization) */
218 typedef JMETHOD(void, inverse_DCT_method_ptr,
219 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
221 JSAMPARRAY output_buf, JDIMENSION output_col));
223 struct jpeg_inverse_dct {
224 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
225 /* It is useful to allow each component to have a separate IDCT method. */
226 inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
229 /* Upsampling (note that upsampler must also call color converter) */
230 struct jpeg_upsampler {
231 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
232 JMETHOD(void, upsample, (j_decompress_ptr cinfo,
233 JSAMPIMAGE input_buf,
234 JDIMENSION *in_row_group_ctr,
235 JDIMENSION in_row_groups_avail,
236 JSAMPARRAY output_buf,
237 JDIMENSION *out_row_ctr,
238 JDIMENSION out_rows_avail));
240 boolean need_context_rows; /* TRUE if need rows above & below */
243 /* Colorspace conversion */
244 struct jpeg_color_deconverter {
245 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
246 JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
247 JSAMPIMAGE input_buf, JDIMENSION input_row,
248 JSAMPARRAY output_buf, int num_rows));
251 /* Color quantization or color precision reduction */
252 struct jpeg_color_quantizer {
253 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
254 JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
255 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
257 JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
258 JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
262 /* Miscellaneous useful macros */
265 #define MAX(a,b) ((a) > (b) ? (a) : (b))
267 #define MIN(a,b) ((a) < (b) ? (a) : (b))
270 /* We assume that right shift corresponds to signed division by 2 with
271 * rounding towards minus infinity. This is correct for typical "arithmetic
272 * shift" instructions that shift in copies of the sign bit. But some
273 * C compilers implement >> with an unsigned shift. For these machines you
274 * must define RIGHT_SHIFT_IS_UNSIGNED.
275 * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
276 * It is only applied with constant shift counts. SHIFT_TEMPS must be
277 * included in the variables of any routine using RIGHT_SHIFT.
280 #ifdef RIGHT_SHIFT_IS_UNSIGNED
281 #define SHIFT_TEMPS INT32 shift_temp;
282 #define RIGHT_SHIFT(x,shft) \
283 ((shift_temp = (x)) < 0 ? \
284 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
285 (shift_temp >> (shft)))
288 #define RIGHT_SHIFT(x,shft) ((x) >> (shft))
292 /* Short forms of external names for systems with brain-damaged linkers. */
294 #ifdef NEED_SHORT_EXTERNAL_NAMES
295 #define jinit_compress_master jICompress
296 #define jinit_c_master_control jICMaster
297 #define jinit_c_main_controller jICMainC
298 #define jinit_c_prep_controller jICPrepC
299 #define jinit_c_coef_controller jICCoefC
300 #define jinit_color_converter jICColor
301 #define jinit_downsampler jIDownsampler
302 #define jinit_forward_dct jIFDCT
303 #define jinit_huff_encoder jIHEncoder
304 #define jinit_phuff_encoder jIPHEncoder
305 #define jinit_marker_writer jIMWriter
306 #define jinit_master_decompress jIDMaster
307 #define jinit_d_main_controller jIDMainC
308 #define jinit_d_coef_controller jIDCoefC
309 #define jinit_d_post_controller jIDPostC
310 #define jinit_input_controller jIInCtlr
311 #define jinit_marker_reader jIMReader
312 #define jinit_huff_decoder jIHDecoder
313 #define jinit_phuff_decoder jIPHDecoder
314 #define jinit_inverse_dct jIIDCT
315 #define jinit_upsampler jIUpsampler
316 #define jinit_color_deconverter jIDColor
317 #define jinit_1pass_quantizer jI1Quant
318 #define jinit_2pass_quantizer jI2Quant
319 #define jinit_merged_upsampler jIMUpsampler
320 #define jinit_memory_mgr jIMemMgr
321 #define jdiv_round_up jDivRound
322 #define jround_up jRound
323 #define jcopy_sample_rows jCopySamples
324 #define jcopy_block_row jCopyBlocks
325 #define jzero_far jZeroFar
326 #define jpeg_zigzag_order jZIGTable
327 #define jpeg_natural_order jZAGTable
328 #endif /* NEED_SHORT_EXTERNAL_NAMES */
331 /* Compression module initialization routines */
332 EXTERN void jinit_compress_master JPP((j_compress_ptr cinfo));
333 EXTERN void jinit_c_master_control JPP((j_compress_ptr cinfo,
334 boolean transcode_only));
335 EXTERN void jinit_c_main_controller JPP((j_compress_ptr cinfo,
336 boolean need_full_buffer));
337 EXTERN void jinit_c_prep_controller JPP((j_compress_ptr cinfo,
338 boolean need_full_buffer));
339 EXTERN void jinit_c_coef_controller JPP((j_compress_ptr cinfo,
340 boolean need_full_buffer));
341 EXTERN void jinit_color_converter JPP((j_compress_ptr cinfo));
342 EXTERN void jinit_downsampler JPP((j_compress_ptr cinfo));
343 EXTERN void jinit_forward_dct JPP((j_compress_ptr cinfo));
344 EXTERN void jinit_huff_encoder JPP((j_compress_ptr cinfo));
345 EXTERN void jinit_phuff_encoder JPP((j_compress_ptr cinfo));
346 EXTERN void jinit_marker_writer JPP((j_compress_ptr cinfo));
347 /* Decompression module initialization routines */
348 EXTERN void jinit_master_decompress JPP((j_decompress_ptr cinfo));
349 EXTERN void jinit_d_main_controller JPP((j_decompress_ptr cinfo,
350 boolean need_full_buffer));
351 EXTERN void jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
352 boolean need_full_buffer));
353 EXTERN void jinit_d_post_controller JPP((j_decompress_ptr cinfo,
354 boolean need_full_buffer));
355 EXTERN void jinit_input_controller JPP((j_decompress_ptr cinfo));
356 EXTERN void jinit_marker_reader JPP((j_decompress_ptr cinfo));
357 EXTERN void jinit_huff_decoder JPP((j_decompress_ptr cinfo));
358 EXTERN void jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
359 EXTERN void jinit_inverse_dct JPP((j_decompress_ptr cinfo));
360 EXTERN void jinit_upsampler JPP((j_decompress_ptr cinfo));
361 EXTERN void jinit_color_deconverter JPP((j_decompress_ptr cinfo));
362 EXTERN void jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
363 EXTERN void jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
364 EXTERN void jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
365 /* Memory manager initialization */
366 EXTERN void jinit_memory_mgr JPP((j_common_ptr cinfo));
368 /* Utility routines in jutils.c */
369 EXTERN long jdiv_round_up JPP((long a, long b));
370 EXTERN long jround_up JPP((long a, long b));
371 EXTERN void jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
372 JSAMPARRAY output_array, int dest_row,
373 int num_rows, JDIMENSION num_cols));
374 EXTERN void jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
375 JDIMENSION num_blocks));
376 EXTERN void jzero_far JPP((void FAR * target, size_t bytestozero));
377 /* Constant tables in jutils.c */
378 extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
379 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
381 /* Suppress undefined-structure complaints if necessary. */
383 #ifdef INCOMPLETE_TYPES_BROKEN
384 #ifndef AM_MEMORY_MANAGER /* only jmemmgr.c defines these */
385 struct jvirt_sarray_control { long dummy; };
386 struct jvirt_barray_control { long dummy; };
388 #endif /* INCOMPLETE_TYPES_BROKEN */