4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 1997-2020 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.
9 * This file provides common declarations for the various JPEG modules.
10 * These declarations are considered internal to the JPEG library; most
11 * applications using the library shouldn't need to include this file.
15 /* Declarations for both compression & decompression */
17 typedef enum { /* Operating modes for buffer controllers */
18 JBUF_PASS_THRU
, /* Plain stripwise operation */
19 /* Remaining modes require a full-image buffer to have been created */
20 JBUF_SAVE_SOURCE
, /* Run source subobject only, save output */
21 JBUF_CRANK_DEST
, /* Run dest subobject only, using saved data */
22 JBUF_SAVE_AND_PASS
/* Run both subobjects, save output */
25 /* Values of global_state field (jdapi.c has some dependencies on ordering!) */
26 #define CSTATE_START 100 /* after create_compress */
27 #define CSTATE_SCANNING 101 /* start_compress done, write_scanlines OK */
28 #define CSTATE_RAW_OK 102 /* start_compress done, write_raw_data OK */
29 #define CSTATE_WRCOEFS 103 /* jpeg_write_coefficients done */
30 #define DSTATE_START 200 /* after create_decompress */
31 #define DSTATE_INHEADER 201 /* reading header markers, no SOS yet */
32 #define DSTATE_READY 202 /* found SOS, ready for start_decompress */
33 #define DSTATE_PRELOAD 203 /* reading multiscan file in start_decompress*/
34 #define DSTATE_PRESCAN 204 /* performing dummy pass for 2-pass quant */
35 #define DSTATE_SCANNING 205 /* start_decompress done, read_scanlines OK */
36 #define DSTATE_RAW_OK 206 /* start_decompress done, read_raw_data OK */
37 #define DSTATE_BUFIMAGE 207 /* expecting jpeg_start_output */
38 #define DSTATE_BUFPOST 208 /* looking for SOS/EOI in jpeg_finish_output */
39 #define DSTATE_RDCOEFS 209 /* reading file in jpeg_read_coefficients */
40 #define DSTATE_STOPPING 210 /* looking for EOI in jpeg_finish_decompress */
43 /* Declarations for compression modules */
45 /* Master control module */
46 struct jpeg_comp_master
{
47 JMETHOD(void, prepare_for_pass
, (j_compress_ptr cinfo
));
48 JMETHOD(void, pass_startup
, (j_compress_ptr cinfo
));
49 JMETHOD(void, finish_pass
, (j_compress_ptr cinfo
));
51 /* State variables made visible to other modules */
52 boolean call_pass_startup
; /* True if pass_startup must be called */
53 boolean is_last_pass
; /* True during last pass */
56 /* Main buffer control (downsampled-data buffer) */
57 struct jpeg_c_main_controller
{
58 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
, J_BUF_MODE pass_mode
));
59 JMETHOD(void, process_data
, (j_compress_ptr cinfo
,
60 JSAMPARRAY input_buf
, JDIMENSION
*in_row_ctr
,
61 JDIMENSION in_rows_avail
));
64 /* Compression preprocessing (downsampling input buffer control) */
65 struct jpeg_c_prep_controller
{
66 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
, J_BUF_MODE pass_mode
));
67 JMETHOD(void, pre_process_data
, (j_compress_ptr cinfo
,
69 JDIMENSION
*in_row_ctr
,
70 JDIMENSION in_rows_avail
,
71 JSAMPIMAGE output_buf
,
72 JDIMENSION
*out_row_group_ctr
,
73 JDIMENSION out_row_groups_avail
));
76 /* Coefficient buffer control */
77 struct jpeg_c_coef_controller
{
78 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
, J_BUF_MODE pass_mode
));
79 JMETHOD(boolean
, compress_data
, (j_compress_ptr cinfo
,
80 JSAMPIMAGE input_buf
));
83 /* Colorspace conversion */
84 struct jpeg_color_converter
{
85 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
));
86 JMETHOD(void, color_convert
, (j_compress_ptr cinfo
,
87 JSAMPARRAY input_buf
, JSAMPIMAGE output_buf
,
88 JDIMENSION output_row
, int num_rows
));
92 struct jpeg_downsampler
{
93 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
));
94 JMETHOD(void, downsample
, (j_compress_ptr cinfo
,
95 JSAMPIMAGE input_buf
, JDIMENSION in_row_index
,
96 JSAMPIMAGE output_buf
,
97 JDIMENSION out_row_group_index
));
99 boolean need_context_rows
; /* TRUE if need rows above & below */
102 /* Forward DCT (also controls coefficient quantization) */
103 typedef JMETHOD(void, forward_DCT_ptr
,
104 (j_compress_ptr cinfo
, jpeg_component_info
* compptr
,
105 JSAMPARRAY sample_data
, JBLOCKROW coef_blocks
,
106 JDIMENSION start_col
, JDIMENSION num_blocks
));
108 struct jpeg_forward_dct
{
109 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
));
110 /* It is useful to allow each component to have a separate FDCT method. */
111 forward_DCT_ptr forward_DCT
[MAX_COMPONENTS
];
114 /* Entropy encoding */
115 struct jpeg_entropy_encoder
{
116 JMETHOD(void, start_pass
, (j_compress_ptr cinfo
, boolean gather_statistics
));
117 JMETHOD(boolean
, encode_mcu
, (j_compress_ptr cinfo
, JBLOCKARRAY MCU_data
));
118 JMETHOD(void, finish_pass
, (j_compress_ptr cinfo
));
122 struct jpeg_marker_writer
{
123 JMETHOD(void, write_file_header
, (j_compress_ptr cinfo
));
124 JMETHOD(void, write_frame_header
, (j_compress_ptr cinfo
));
125 JMETHOD(void, write_scan_header
, (j_compress_ptr cinfo
));
126 JMETHOD(void, write_file_trailer
, (j_compress_ptr cinfo
));
127 JMETHOD(void, write_tables_only
, (j_compress_ptr cinfo
));
128 /* These routines are exported to allow insertion of extra markers */
129 /* Probably only COM and APPn markers should be written this way */
130 JMETHOD(void, write_marker_header
, (j_compress_ptr cinfo
, int marker
,
131 unsigned int datalen
));
132 JMETHOD(void, write_marker_byte
, (j_compress_ptr cinfo
, int val
));
136 /* Declarations for decompression modules */
138 /* Master control module */
139 struct jpeg_decomp_master
{
140 JMETHOD(void, prepare_for_output_pass
, (j_decompress_ptr cinfo
));
141 JMETHOD(void, finish_output_pass
, (j_decompress_ptr cinfo
));
143 /* State variables made visible to other modules */
144 boolean is_dummy_pass
; /* True during 1st pass for 2-pass quant */
147 /* Input control module */
148 struct jpeg_input_controller
{
149 JMETHOD(int, consume_input
, (j_decompress_ptr cinfo
));
150 JMETHOD(void, reset_input_controller
, (j_decompress_ptr cinfo
));
151 JMETHOD(void, start_input_pass
, (j_decompress_ptr cinfo
));
152 JMETHOD(void, finish_input_pass
, (j_decompress_ptr cinfo
));
154 /* State variables made visible to other modules */
155 boolean has_multiple_scans
; /* True if file has multiple scans */
156 boolean eoi_reached
; /* True when EOI has been consumed */
159 /* Main buffer control (downsampled-data buffer) */
160 struct jpeg_d_main_controller
{
161 JMETHOD(void, start_pass
, (j_decompress_ptr cinfo
, J_BUF_MODE pass_mode
));
162 JMETHOD(void, process_data
, (j_decompress_ptr cinfo
,
163 JSAMPARRAY output_buf
, JDIMENSION
*out_row_ctr
,
164 JDIMENSION out_rows_avail
));
167 /* Coefficient buffer control */
168 struct jpeg_d_coef_controller
{
169 JMETHOD(void, start_input_pass
, (j_decompress_ptr cinfo
));
170 JMETHOD(int, consume_data
, (j_decompress_ptr cinfo
));
171 JMETHOD(void, start_output_pass
, (j_decompress_ptr cinfo
));
172 JMETHOD(int, decompress_data
, (j_decompress_ptr cinfo
,
173 JSAMPIMAGE output_buf
));
174 /* Pointer to array of coefficient virtual arrays, or NULL if none */
175 jvirt_barray_ptr
*coef_arrays
;
178 /* Decompression postprocessing (color quantization buffer control) */
179 struct jpeg_d_post_controller
{
180 JMETHOD(void, start_pass
, (j_decompress_ptr cinfo
, J_BUF_MODE pass_mode
));
181 JMETHOD(void, post_process_data
, (j_decompress_ptr cinfo
,
182 JSAMPIMAGE input_buf
,
183 JDIMENSION
*in_row_group_ctr
,
184 JDIMENSION in_row_groups_avail
,
185 JSAMPARRAY output_buf
,
186 JDIMENSION
*out_row_ctr
,
187 JDIMENSION out_rows_avail
));
190 /* Marker reading & parsing */
191 struct jpeg_marker_reader
{
192 JMETHOD(void, reset_marker_reader
, (j_decompress_ptr cinfo
));
193 /* Read markers until SOS or EOI.
194 * Returns same codes as are defined for jpeg_consume_input:
195 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
197 JMETHOD(int, read_markers
, (j_decompress_ptr cinfo
));
198 /* Read a restart marker --- exported for use by entropy decoder only */
199 jpeg_marker_parser_method read_restart_marker
;
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
, JBLOCKARRAY MCU_data
));
214 JMETHOD(void, finish_pass
, (j_decompress_ptr cinfo
));
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 /* Definition of range extension bits for decompression processes.
263 * See the comments with prepare_range_limit_table (in jdmaster.c)
265 * The recommended default value for normal applications is 2.
266 * Applications with special requirements may use a different value.
267 * For example, Ghostscript wants to use 3 for proper handling of
268 * wacky images with oversize coefficient values.
272 #define RANGE_CENTER (CENTERJSAMPLE << RANGE_BITS)
275 /* Miscellaneous useful macros */
278 #define MAX(a,b) ((a) > (b) ? (a) : (b))
280 #define MIN(a,b) ((a) < (b) ? (a) : (b))
283 /* We assume that right shift corresponds to signed division by 2 with
284 * rounding towards minus infinity. This is correct for typical "arithmetic
285 * shift" instructions that shift in copies of the sign bit. But some
286 * C compilers implement >> with an unsigned shift. For these machines you
287 * must define RIGHT_SHIFT_IS_UNSIGNED.
288 * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
289 * It is only applied with constant shift counts. SHIFT_TEMPS must be
290 * included in the variables of any routine using RIGHT_SHIFT.
293 #ifdef RIGHT_SHIFT_IS_UNSIGNED
294 #define SHIFT_TEMPS INT32 shift_temp;
295 #define RIGHT_SHIFT(x,shft) \
296 ((shift_temp = (x)) < 0 ? \
297 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
298 (shift_temp >> (shft)))
301 #define RIGHT_SHIFT(x,shft) ((x) >> (shft))
304 /* Descale and correctly round an INT32 value that's scaled by N bits.
305 * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
306 * the fudge factor is correct for either sign of X.
309 #define DESCALE(x,n) RIGHT_SHIFT((x) + ((INT32) 1 << ((n)-1)), n)
312 /* Short forms of external names for systems with brain-damaged linkers. */
314 #ifdef NEED_SHORT_EXTERNAL_NAMES
315 #define jinit_compress_master jICompress
316 #define jinit_c_master_control jICMaster
317 #define jinit_c_main_controller jICMainC
318 #define jinit_c_prep_controller jICPrepC
319 #define jinit_c_coef_controller jICCoefC
320 #define jinit_color_converter jICColor
321 #define jinit_downsampler jIDownsampler
322 #define jinit_forward_dct jIFDCT
323 #define jinit_huff_encoder jIHEncoder
324 #define jinit_arith_encoder jIAEncoder
325 #define jinit_marker_writer jIMWriter
326 #define jinit_master_decompress jIDMaster
327 #define jinit_d_main_controller jIDMainC
328 #define jinit_d_coef_controller jIDCoefC
329 #define jinit_d_post_controller jIDPostC
330 #define jinit_input_controller jIInCtlr
331 #define jinit_marker_reader jIMReader
332 #define jinit_huff_decoder jIHDecoder
333 #define jinit_arith_decoder jIADecoder
334 #define jinit_inverse_dct jIIDCT
335 #define jinit_upsampler jIUpsampler
336 #define jinit_color_deconverter jIDColor
337 #define jinit_1pass_quantizer jI1Quant
338 #define jinit_2pass_quantizer jI2Quant
339 #define jinit_merged_upsampler jIMUpsampler
340 #define jinit_memory_mgr jIMemMgr
341 #define jdiv_round_up jDivRound
342 #define jround_up jRound
343 #define jzero_far jZeroFar
344 #define jcopy_sample_rows jCopySamples
345 #define jcopy_block_row jCopyBlocks
346 #define jpeg_zigzag_order jZIGTable
347 #define jpeg_natural_order jZAGTable
348 #define jpeg_natural_order7 jZAG7Table
349 #define jpeg_natural_order6 jZAG6Table
350 #define jpeg_natural_order5 jZAG5Table
351 #define jpeg_natural_order4 jZAG4Table
352 #define jpeg_natural_order3 jZAG3Table
353 #define jpeg_natural_order2 jZAG2Table
354 #define jpeg_aritab jAriTab
355 #endif /* NEED_SHORT_EXTERNAL_NAMES */
358 /* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
359 * and coefficient-block arrays. This won't work on 80x86 because the arrays
360 * are FAR and we're assuming a small-pointer memory model. However, some
361 * DOS compilers provide far-pointer versions of memcpy() and memset() even
362 * in the small-model libraries. These will be used if USE_FMEM is defined.
363 * Otherwise, the routines in jutils.c do it the hard way.
366 #ifndef NEED_FAR_POINTERS /* normal case, same as regular macro */
367 #define FMEMZERO(target,size) MEMZERO(target,size)
368 #else /* 80x86 case */
370 #define FMEMZERO(target,size) _fmemset((void FAR *)(target), 0, (size_t)(size))
372 EXTERN(void) jzero_far
JPP((void FAR
* target
, size_t bytestozero
));
373 #define FMEMZERO(target,size) jzero_far(target, size)
378 /* Compression module initialization routines */
379 EXTERN(void) jinit_compress_master
JPP((j_compress_ptr cinfo
));
380 EXTERN(void) jinit_c_master_control
JPP((j_compress_ptr cinfo
,
381 boolean transcode_only
));
382 EXTERN(void) jinit_c_main_controller
JPP((j_compress_ptr cinfo
,
383 boolean need_full_buffer
));
384 EXTERN(void) jinit_c_prep_controller
JPP((j_compress_ptr cinfo
,
385 boolean need_full_buffer
));
386 EXTERN(void) jinit_c_coef_controller
JPP((j_compress_ptr cinfo
,
387 boolean need_full_buffer
));
388 EXTERN(void) jinit_color_converter
JPP((j_compress_ptr cinfo
));
389 EXTERN(void) jinit_downsampler
JPP((j_compress_ptr cinfo
));
390 EXTERN(void) jinit_forward_dct
JPP((j_compress_ptr cinfo
));
391 EXTERN(void) jinit_huff_encoder
JPP((j_compress_ptr cinfo
));
392 EXTERN(void) jinit_arith_encoder
JPP((j_compress_ptr cinfo
));
393 EXTERN(void) jinit_marker_writer
JPP((j_compress_ptr cinfo
));
394 /* Decompression module initialization routines */
395 EXTERN(void) jinit_master_decompress
JPP((j_decompress_ptr cinfo
));
396 EXTERN(void) jinit_d_main_controller
JPP((j_decompress_ptr cinfo
,
397 boolean need_full_buffer
));
398 EXTERN(void) jinit_d_coef_controller
JPP((j_decompress_ptr cinfo
,
399 boolean need_full_buffer
));
400 EXTERN(void) jinit_d_post_controller
JPP((j_decompress_ptr cinfo
,
401 boolean need_full_buffer
));
402 EXTERN(void) jinit_input_controller
JPP((j_decompress_ptr cinfo
));
403 EXTERN(void) jinit_marker_reader
JPP((j_decompress_ptr cinfo
));
404 EXTERN(void) jinit_huff_decoder
JPP((j_decompress_ptr cinfo
));
405 EXTERN(void) jinit_arith_decoder
JPP((j_decompress_ptr cinfo
));
406 EXTERN(void) jinit_inverse_dct
JPP((j_decompress_ptr cinfo
));
407 EXTERN(void) jinit_upsampler
JPP((j_decompress_ptr cinfo
));
408 EXTERN(void) jinit_color_deconverter
JPP((j_decompress_ptr cinfo
));
409 EXTERN(void) jinit_1pass_quantizer
JPP((j_decompress_ptr cinfo
));
410 EXTERN(void) jinit_2pass_quantizer
JPP((j_decompress_ptr cinfo
));
411 EXTERN(void) jinit_merged_upsampler
JPP((j_decompress_ptr cinfo
));
412 /* Memory manager initialization */
413 EXTERN(void) jinit_memory_mgr
JPP((j_common_ptr cinfo
));
415 /* Utility routines in jutils.c */
416 EXTERN(long) jdiv_round_up
JPP((long a
, long b
));
417 EXTERN(long) jround_up
JPP((long a
, long b
));
418 EXTERN(void) jcopy_sample_rows
JPP((JSAMPARRAY input_array
,
419 JSAMPARRAY output_array
,
420 int num_rows
, JDIMENSION num_cols
));
421 EXTERN(void) jcopy_block_row
JPP((JBLOCKROW input_row
, JBLOCKROW output_row
,
422 JDIMENSION num_blocks
));
423 /* Constant tables in jutils.c */
424 #if 0 /* This table is not actually needed in v6a */
425 extern const int jpeg_zigzag_order
[]; /* natural coef order to zigzag order */
427 extern const int jpeg_natural_order
[]; /* zigzag coef order to natural order */
428 extern const int jpeg_natural_order7
[]; /* zz to natural order for 7x7 block */
429 extern const int jpeg_natural_order6
[]; /* zz to natural order for 6x6 block */
430 extern const int jpeg_natural_order5
[]; /* zz to natural order for 5x5 block */
431 extern const int jpeg_natural_order4
[]; /* zz to natural order for 4x4 block */
432 extern const int jpeg_natural_order3
[]; /* zz to natural order for 3x3 block */
433 extern const int jpeg_natural_order2
[]; /* zz to natural order for 2x2 block */
435 /* Arithmetic coding probability estimation tables in jaricom.c */
436 extern const INT32 jpeg_aritab
[];
438 /* Suppress undefined-structure complaints if necessary. */
440 #ifdef INCOMPLETE_TYPES_BROKEN
441 #ifndef AM_MEMORY_MANAGER /* only jmemmgr.c defines these */
442 struct jvirt_sarray_control
{ long dummy
; };
443 struct jvirt_barray_control
{ long dummy
; };
445 #endif /* INCOMPLETE_TYPES_BROKEN */