7 * Copyright (C) 1991-1995, Thomas G. Lane.
9 * This file is part of the Independent JPEG Group's software.
11 * For conditions of distribution and use, see the accompanying README file.
15 * This file provides common declarations for the various JPEG modules.
17 * These declarations are considered internal to the JPEG library; most
19 * applications using the library shouldn't need to include this file.
27 /* Declarations for both compression & decompression */
31 typedef enum { /* Operating modes for buffer controllers */
33 JBUF_PASS_THRU, /* Plain stripwise operation */
35 /* Remaining modes require a full-image buffer to have been created */
37 JBUF_SAVE_SOURCE, /* Run source subobject only, save output */
39 JBUF_CRANK_DEST, /* Run dest subobject only, using saved data */
41 JBUF_SAVE_AND_PASS /* Run both subobjects, save output */
47 /* Values of global_state field (jdapi.c has some dependencies on ordering!) */
49 #define CSTATE_START 100 /* after create_compress */
51 #define CSTATE_SCANNING 101 /* start_compress done, write_scanlines OK */
53 #define CSTATE_RAW_OK 102 /* start_compress done, write_raw_data OK */
55 #define CSTATE_WRCOEFS 103 /* jpeg_write_coefficients done */
57 #define DSTATE_START 200 /* after create_decompress */
59 #define DSTATE_INHEADER 201 /* reading header markers, no SOS yet */
61 #define DSTATE_READY 202 /* found SOS, ready for start_decompress */
63 #define DSTATE_PRELOAD 203 /* reading multiscan file in start_decompress*/
65 #define DSTATE_PRESCAN 204 /* performing dummy pass for 2-pass quant */
67 #define DSTATE_SCANNING 205 /* start_decompress done, read_scanlines OK */
69 #define DSTATE_RAW_OK 206 /* start_decompress done, read_raw_data OK */
71 #define DSTATE_BUFIMAGE 207 /* expecting jpeg_start_output */
73 #define DSTATE_BUFPOST 208 /* looking for SOS/EOI in jpeg_finish_output */
75 #define DSTATE_RDCOEFS 209 /* reading file in jpeg_read_coefficients */
77 #define DSTATE_STOPPING 210 /* looking for EOI in jpeg_finish_decompress */
83 /* Declarations for compression modules */
87 /* Master control module */
89 struct jpeg_comp_master {
91 JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
93 JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
95 JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
99 /* State variables made visible to other modules */
101 boolean call_pass_startup; /* True if pass_startup must be called */
103 boolean is_last_pass; /* True during last pass */
109 /* Main buffer control (downsampled-data buffer) */
111 struct jpeg_c_main_controller {
113 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
115 JMETHOD(void, process_data, (j_compress_ptr cinfo,
117 JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
119 JDIMENSION in_rows_avail));
125 /* Compression preprocessing (downsampling input buffer control) */
127 struct jpeg_c_prep_controller {
129 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
131 JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
133 JSAMPARRAY input_buf,
135 JDIMENSION *in_row_ctr,
137 JDIMENSION in_rows_avail,
139 JSAMPIMAGE output_buf,
141 JDIMENSION *out_row_group_ctr,
143 JDIMENSION out_row_groups_avail));
149 /* Coefficient buffer control */
151 struct jpeg_c_coef_controller {
153 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
155 JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
157 JSAMPIMAGE input_buf));
163 /* Colorspace conversion */
165 struct jpeg_color_converter {
167 JMETHOD(void, start_pass, (j_compress_ptr cinfo));
169 JMETHOD(void, color_convert, (j_compress_ptr cinfo,
171 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
173 JDIMENSION output_row, int num_rows));
181 struct jpeg_downsampler {
183 JMETHOD(void, start_pass, (j_compress_ptr cinfo));
185 JMETHOD(void, downsample, (j_compress_ptr cinfo,
187 JSAMPIMAGE input_buf, JDIMENSION in_row_index,
189 JSAMPIMAGE output_buf,
191 JDIMENSION out_row_group_index));
195 boolean need_context_rows; /* TRUE if need rows above & below */
201 /* Forward DCT (also controls coefficient quantization) */
203 struct jpeg_forward_dct {
205 JMETHOD(void, start_pass, (j_compress_ptr cinfo));
207 /* perhaps this should be an array??? */
209 JMETHOD(void, forward_DCT, (j_compress_ptr cinfo,
211 jpeg_component_info * compptr,
213 JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
215 JDIMENSION start_row, JDIMENSION start_col,
217 JDIMENSION num_blocks));
223 /* Entropy encoding */
225 struct jpeg_entropy_encoder {
227 JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
229 JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
231 JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
239 struct jpeg_marker_writer {
241 /* write_any_marker is exported for use by applications */
243 /* Probably only COM and APPn markers should be written */
245 JMETHOD(void, write_any_marker, (j_compress_ptr cinfo, int marker,
247 const JOCTET *dataptr, unsigned int datalen));
249 JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
251 JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
253 JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
255 JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
257 JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
265 /* Declarations for decompression modules */
269 /* Master control module */
271 struct jpeg_decomp_master {
273 JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
275 JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
279 /* State variables made visible to other modules */
281 boolean is_dummy_pass; /* True during 1st pass for 2-pass quant */
287 /* Input control module */
289 struct jpeg_input_controller {
291 JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
293 JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
295 JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
297 JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
301 /* State variables made visible to other modules */
303 boolean has_multiple_scans; /* True if file has multiple scans */
305 boolean eoi_reached; /* True when EOI has been consumed */
311 /* Main buffer control (downsampled-data buffer) */
313 struct jpeg_d_main_controller {
315 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
317 JMETHOD(void, process_data, (j_decompress_ptr cinfo,
319 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
321 JDIMENSION out_rows_avail));
327 /* Coefficient buffer control */
329 struct jpeg_d_coef_controller {
331 JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
333 JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
335 JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
337 JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
339 JSAMPIMAGE output_buf));
341 /* Pointer to array of coefficient virtual arrays, or NULL if none */
343 jvirt_barray_ptr *coef_arrays;
349 /* Decompression postprocessing (color quantization buffer control) */
351 struct jpeg_d_post_controller {
353 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
355 JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
357 JSAMPIMAGE input_buf,
359 JDIMENSION *in_row_group_ctr,
361 JDIMENSION in_row_groups_avail,
363 JSAMPARRAY output_buf,
365 JDIMENSION *out_row_ctr,
367 JDIMENSION out_rows_avail));
373 /* Marker reading & parsing */
375 struct jpeg_marker_reader {
377 JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
379 /* Read markers until SOS or EOI.
381 * Returns same codes as are defined for jpeg_consume_input:
383 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
387 JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
389 /* Read a restart marker --- exported for use by entropy decoder only */
391 jpeg_marker_parser_method read_restart_marker;
393 /* Application-overridable marker processing methods */
395 jpeg_marker_parser_method process_COM;
397 jpeg_marker_parser_method process_APPn[16];
401 /* State of marker reader --- nominally internal, but applications
403 * supplying COM or APPn handlers might like to know the state.
407 boolean saw_SOI; /* found SOI? */
409 boolean saw_SOF; /* found SOF? */
411 int next_restart_num; /* next restart number expected (0-7) */
413 unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
419 /* Entropy decoding */
421 struct jpeg_entropy_decoder {
423 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
425 JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
427 JBLOCKROW *MCU_data));
433 /* Inverse DCT (also performs dequantization) */
435 typedef JMETHOD(void, inverse_DCT_method_ptr,
437 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
441 JSAMPARRAY output_buf, JDIMENSION output_col));
445 struct jpeg_inverse_dct {
447 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
449 /* It is useful to allow each component to have a separate IDCT method. */
451 inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
457 /* Upsampling (note that upsampler must also call color converter) */
459 struct jpeg_upsampler {
461 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
463 JMETHOD(void, upsample, (j_decompress_ptr cinfo,
465 JSAMPIMAGE input_buf,
467 JDIMENSION *in_row_group_ctr,
469 JDIMENSION in_row_groups_avail,
471 JSAMPARRAY output_buf,
473 JDIMENSION *out_row_ctr,
475 JDIMENSION out_rows_avail));
479 boolean need_context_rows; /* TRUE if need rows above & below */
485 /* Colorspace conversion */
487 struct jpeg_color_deconverter {
489 JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
491 JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
493 JSAMPIMAGE input_buf, JDIMENSION input_row,
495 JSAMPARRAY output_buf, int num_rows));
501 /* Color quantization or color precision reduction */
503 struct jpeg_color_quantizer {
505 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
507 JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
509 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
513 JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
515 JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
523 /* Miscellaneous useful macros */
529 #define MAX(a,b) ((a) > (b) ? (a) : (b))
533 #define MIN(a,b) ((a) < (b) ? (a) : (b))
539 /* We assume that right shift corresponds to signed division by 2 with
541 * rounding towards minus infinity. This is correct for typical "arithmetic
543 * shift" instructions that shift in copies of the sign bit. But some
545 * C compilers implement >> with an unsigned shift. For these machines you
547 * must define RIGHT_SHIFT_IS_UNSIGNED.
549 * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
551 * It is only applied with constant shift counts. SHIFT_TEMPS must be
553 * included in the variables of any routine using RIGHT_SHIFT.
559 #ifdef RIGHT_SHIFT_IS_UNSIGNED
561 #define SHIFT_TEMPS INT32 shift_temp;
563 #define RIGHT_SHIFT(x,shft) \
565 ((shift_temp = (x)) < 0 ? \
567 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
569 (shift_temp >> (shft)))
575 #define RIGHT_SHIFT(x,shft) ((x) >> (shft))
583 /* Short forms of external names for systems with brain-damaged linkers. */
587 #ifdef NEED_SHORT_EXTERNAL_NAMES
589 #define jinit_compress_master jICompress
591 #define jinit_c_master_control jICMaster
593 #define jinit_c_main_controller jICMainC
595 #define jinit_c_prep_controller jICPrepC
597 #define jinit_c_coef_controller jICCoefC
599 #define jinit_color_converter jICColor
601 #define jinit_downsampler jIDownsampler
603 #define jinit_forward_dct jIFDCT
605 #define jinit_huff_encoder jIHEncoder
607 #define jinit_phuff_encoder jIPHEncoder
609 #define jinit_marker_writer jIMWriter
611 #define jinit_master_decompress jIDMaster
613 #define jinit_d_main_controller jIDMainC
615 #define jinit_d_coef_controller jIDCoefC
617 #define jinit_d_post_controller jIDPostC
619 #define jinit_input_controller jIInCtlr
621 #define jinit_marker_reader jIMReader
623 #define jinit_huff_decoder jIHDecoder
625 #define jinit_phuff_decoder jIPHDecoder
627 #define jinit_inverse_dct jIIDCT
629 #define jinit_upsampler jIUpsampler
631 #define jinit_color_deconverter jIDColor
633 #define jinit_1pass_quantizer jI1Quant
635 #define jinit_2pass_quantizer jI2Quant
637 #define jinit_merged_upsampler jIMUpsampler
639 #define jinit_memory_mgr jIMemMgr
641 #define jdiv_round_up jDivRound
643 #define jround_up jRound
645 #define jcopy_sample_rows jCopySamples
647 #define jcopy_block_row jCopyBlocks
649 #define jzero_far jZeroFar
651 #define jpeg_zigzag_order jZIGTable
653 #define jpeg_natural_order jZAGTable
655 #endif /* NEED_SHORT_EXTERNAL_NAMES */
661 /* Compression module initialization routines */
663 EXTERN void jinit_compress_master JPP((j_compress_ptr cinfo));
665 EXTERN void jinit_c_master_control JPP((j_compress_ptr cinfo,
667 boolean transcode_only));
669 EXTERN void jinit_c_main_controller JPP((j_compress_ptr cinfo,
671 boolean need_full_buffer));
673 EXTERN void jinit_c_prep_controller JPP((j_compress_ptr cinfo,
675 boolean need_full_buffer));
677 EXTERN void jinit_c_coef_controller JPP((j_compress_ptr cinfo,
679 boolean need_full_buffer));
681 EXTERN void jinit_color_converter JPP((j_compress_ptr cinfo));
683 EXTERN void jinit_downsampler JPP((j_compress_ptr cinfo));
685 EXTERN void jinit_forward_dct JPP((j_compress_ptr cinfo));
687 EXTERN void jinit_huff_encoder JPP((j_compress_ptr cinfo));
689 EXTERN void jinit_phuff_encoder JPP((j_compress_ptr cinfo));
691 EXTERN void jinit_marker_writer JPP((j_compress_ptr cinfo));
693 /* Decompression module initialization routines */
695 EXTERN void jinit_master_decompress JPP((j_decompress_ptr cinfo));
697 EXTERN void jinit_d_main_controller JPP((j_decompress_ptr cinfo,
699 boolean need_full_buffer));
701 EXTERN void jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
703 boolean need_full_buffer));
705 EXTERN void jinit_d_post_controller JPP((j_decompress_ptr cinfo,
707 boolean need_full_buffer));
709 EXTERN void jinit_input_controller JPP((j_decompress_ptr cinfo));
711 EXTERN void jinit_marker_reader JPP((j_decompress_ptr cinfo));
713 EXTERN void jinit_huff_decoder JPP((j_decompress_ptr cinfo));
715 EXTERN void jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
717 EXTERN void jinit_inverse_dct JPP((j_decompress_ptr cinfo));
719 EXTERN void jinit_upsampler JPP((j_decompress_ptr cinfo));
721 EXTERN void jinit_color_deconverter JPP((j_decompress_ptr cinfo));
723 EXTERN void jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
725 EXTERN void jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
727 EXTERN void jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
729 /* Memory manager initialization */
731 EXTERN void jinit_memory_mgr JPP((j_common_ptr cinfo));
735 /* Utility routines in jutils.c */
737 EXTERN long jdiv_round_up JPP((long a, long b));
739 EXTERN long jround_up JPP((long a, long b));
741 EXTERN void jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
743 JSAMPARRAY output_array, int dest_row,
745 int num_rows, JDIMENSION num_cols));
747 EXTERN void jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
749 JDIMENSION num_blocks));
751 EXTERN void jzero_far JPP((void FAR * target, size_t bytestozero));
753 /* Constant tables in jutils.c */
755 extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
757 extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
761 /* Suppress undefined-structure complaints if necessary. */
765 #ifdef INCOMPLETE_TYPES_BROKEN
767 #ifndef AM_MEMORY_MANAGER /* only jmemmgr.c defines these */
769 struct jvirt_sarray_control { long dummy; };
771 struct jvirt_barray_control { long dummy; };
775 #endif /* INCOMPLETE_TYPES_BROKEN */