1 /* 2 * jpegint.h 3 * 4 * Copyright (C) 1991-1994, 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 JBUF_CRANK_SOURCE, /* Run source subobject, no output expected */ 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 */ 23 } J_BUF_MODE; 24 25 /* Values of global_state field */ 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 DSTATE_START 200 /* after create_decompress */ 30 #define DSTATE_INHEADER 201 /* read_header initialized but not done */ 31 #define DSTATE_READY 202 /* read_header done, found image */ 32 #define DSTATE_SCANNING 203 /* start_decompress done, read_scanlines OK */ 33 #define DSTATE_RAW_OK 204 /* start_decompress done, read_raw_data OK */ 34 #define DSTATE_STOPPING 205 /* done reading data, looking for EOI */ 35 36 37 /* Declarations for compression modules */ 38 39 /* Master control module */ 40 struct jpeg_comp_master { 41 JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo)); 42 JMETHOD(void, pass_startup, (j_compress_ptr cinfo)); 43 JMETHOD(void, finish_pass, (j_compress_ptr cinfo)); 44 45 /* State variables made visible to other modules */ 46 boolean call_pass_startup; /* True if pass_startup must be called */ 47 boolean is_last_pass; /* True during last pass */ 48 }; 49 50 /* Main buffer control (downsampled-data buffer) */ 51 struct jpeg_c_main_controller { 52 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode)); 53 JMETHOD(void, process_data, (j_compress_ptr cinfo, 54 JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, 55 JDIMENSION in_rows_avail)); 56 }; 57 58 /* Compression preprocessing (downsampling input buffer control) */ 59 struct jpeg_c_prep_controller { 60 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode)); 61 JMETHOD(void, pre_process_data, (j_compress_ptr cinfo, 62 JSAMPARRAY input_buf, 63 JDIMENSION *in_row_ctr, 64 JDIMENSION in_rows_avail, 65 JSAMPIMAGE output_buf, 66 JDIMENSION *out_row_group_ctr, 67 JDIMENSION out_row_groups_avail)); 68 }; 69 70 /* Coefficient buffer control */ 71 struct jpeg_c_coef_controller { 72 JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode)); 73 JMETHOD(void, compress_data, (j_compress_ptr cinfo, 74 JSAMPIMAGE input_buf, 75 JDIMENSION *in_mcu_ctr)); 76 }; 77 78 /* Colorspace conversion */ 79 struct jpeg_color_converter { 80 JMETHOD(void, start_pass, (j_compress_ptr cinfo)); 81 JMETHOD(void, color_convert, (j_compress_ptr cinfo, 82 JSAMPARRAY input_buf, JSAMPIMAGE output_buf, 83 JDIMENSION output_row, int num_rows)); 84 }; 85 86 /* Downsampling */ 87 struct jpeg_downsampler { 88 JMETHOD(void, start_pass, (j_compress_ptr cinfo)); 89 JMETHOD(void, downsample, (j_compress_ptr cinfo, 90 JSAMPIMAGE input_buf, JDIMENSION in_row_index, 91 JSAMPIMAGE output_buf, 92 JDIMENSION out_row_group_index)); 93 94 boolean need_context_rows; /* TRUE if need rows above & below */ 95 }; 96 97 /* Forward DCT (also controls coefficient quantization) */ 98 struct jpeg_forward_dct { 99 JMETHOD(void, start_pass, (j_compress_ptr cinfo)); 100 /* perhaps this should be an array??? */ 101 JMETHOD(void, forward_DCT, (j_compress_ptr cinfo, 102 jpeg_component_info * compptr, 103 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, 104 JDIMENSION start_row, JDIMENSION start_col, 105 JDIMENSION num_blocks)); 106 }; 107 108 /* Entropy encoding */ 109 struct jpeg_entropy_encoder { 110 JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics)); 111 JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data)); 112 JMETHOD(void, finish_pass, (j_compress_ptr cinfo)); 113 }; 114 115 /* Marker writing */ 116 struct jpeg_marker_writer { 117 /* write_any_marker is exported for use by applications */ 118 /* Probably only COM and APPn markers should be written */ 119 JMETHOD(void, write_any_marker, (j_compress_ptr cinfo, int marker, 120 const JOCTET *dataptr, unsigned int datalen)); 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 }; 127 128 129 /* Declarations for decompression modules */ 130 131 /* Master control module */ 132 struct jpeg_decomp_master { 133 JMETHOD(void, prepare_for_pass, (j_decompress_ptr cinfo)); 134 JMETHOD(void, finish_pass, (j_decompress_ptr cinfo)); 135 136 /* State variables made visible to other modules */ 137 boolean is_last_pass; /* True during last pass */ 138 boolean eoi_processed; /* True if EOI marker already read */ 139 }; 140 141 /* Main buffer control (downsampled-data buffer) */ 142 struct jpeg_d_main_controller { 143 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)); 144 JMETHOD(void, process_data, (j_decompress_ptr cinfo, 145 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, 146 JDIMENSION out_rows_avail)); 147 /* During input-only passes, output_buf and out_rows_avail are ignored. 148 * out_row_ctr is incremented towards the limit num_chunks. 149 */ 150 JDIMENSION num_chunks; /* number of chunks to be processed in pass */ 151 }; 152 153 /* Coefficient buffer control */ 154 struct jpeg_d_coef_controller { 155 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)); 156 JMETHOD(boolean, decompress_data, (j_decompress_ptr cinfo, 157 JSAMPIMAGE output_buf)); 158 }; 159 160 /* Decompression postprocessing (color quantization buffer control) */ 161 struct jpeg_d_post_controller { 162 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)); 163 JMETHOD(void, post_process_data, (j_decompress_ptr cinfo, 164 JSAMPIMAGE input_buf, 165 JDIMENSION *in_row_group_ctr, 166 JDIMENSION in_row_groups_avail, 167 JSAMPARRAY output_buf, 168 JDIMENSION *out_row_ctr, 169 JDIMENSION out_rows_avail)); 170 }; 171 172 /* Marker reading & parsing */ 173 struct jpeg_marker_reader { 174 JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo)); 175 /* Read markers until SOS or EOI. 176 * Returns same codes as are defined for jpeg_read_header, 177 * but HEADER_OK and HEADER_TABLES_ONLY merely indicate which marker type 178 * stopped the scan --- further validation is needed to declare file OK. 179 */ 180 JMETHOD(int, read_markers, (j_decompress_ptr cinfo)); 181 /* Read a restart marker --- exported for use by entropy decoder only */ 182 jpeg_marker_parser_method read_restart_marker; 183 /* Application-overridable marker processing methods */ 184 jpeg_marker_parser_method process_COM; 185 jpeg_marker_parser_method process_APPn[16]; 186 187 /* State of marker reader --- nominally internal, but applications 188 * supplying COM or APPn handlers might like to know the state. 189 */ 190 boolean saw_SOI; /* found SOI? */ 191 boolean saw_SOF; /* found SOF? */ 192 int next_restart_num; /* next restart number expected (0-7) */ 193 unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */ 194 }; 195 196 /* Entropy decoding */ 197 struct jpeg_entropy_decoder { 198 JMETHOD(void, start_pass, (j_decompress_ptr cinfo)); 199 JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo, 200 JBLOCKROW *MCU_data)); 201 }; 202 203 /* Inverse DCT (also performs dequantization) */ 204 typedef JMETHOD(void, inverse_DCT_method_ptr, 205 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 206 JCOEFPTR coef_block, 207 JSAMPARRAY output_buf, JDIMENSION output_col)); 208 209 struct jpeg_inverse_dct { 210 JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo)); 211 JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo)); 212 /* It is useful to allow each component to have a separate IDCT method. */ 213 inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS]; 214 }; 215 216 /* Upsampling (note that upsampler must also call color converter) */ 217 struct jpeg_upsampler { 218 JMETHOD(void, start_pass, (j_decompress_ptr cinfo)); 219 JMETHOD(void, upsample, (j_decompress_ptr cinfo, 220 JSAMPIMAGE input_buf, 221 JDIMENSION *in_row_group_ctr, 222 JDIMENSION in_row_groups_avail, 223 JSAMPARRAY output_buf, 224 JDIMENSION *out_row_ctr, 225 JDIMENSION out_rows_avail)); 226 227 boolean need_context_rows; /* TRUE if need rows above & below */ 228 }; 229 230 /* Colorspace conversion */ 231 struct jpeg_color_deconverter { 232 JMETHOD(void, start_pass, (j_decompress_ptr cinfo)); 233 JMETHOD(void, color_convert, (j_decompress_ptr cinfo, 234 JSAMPIMAGE input_buf, JDIMENSION input_row, 235 JSAMPARRAY output_buf, int num_rows)); 236 }; 237 238 /* Color quantization or color precision reduction */ 239 struct jpeg_color_quantizer { 240 JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan)); 241 JMETHOD(void, color_quantize, (j_decompress_ptr cinfo, 242 JSAMPARRAY input_buf, JSAMPARRAY output_buf, 243 int num_rows)); 244 JMETHOD(void, finish_pass, (j_decompress_ptr cinfo)); 245 }; 246 247 248 /* Miscellaneous useful macros */ 249 250 #undef MAX 251 #define MAX(a,b) ((a) > (b) ? (a) : (b)) 252 #undef MIN 253 #define MIN(a,b) ((a) < (b) ? (a) : (b)) 254 255 256 /* We assume that right shift corresponds to signed division by 2 with 257 * rounding towards minus infinity. This is correct for typical "arithmetic 258 * shift" instructions that shift in copies of the sign bit. But some 259 * C compilers implement >> with an unsigned shift. For these machines you 260 * must define RIGHT_SHIFT_IS_UNSIGNED. 261 * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity. 262 * It is only applied with constant shift counts. SHIFT_TEMPS must be 263 * included in the variables of any routine using RIGHT_SHIFT. 264 */ 265 266 #ifdef RIGHT_SHIFT_IS_UNSIGNED 267 #define SHIFT_TEMPS INT32 shift_temp; 268 #define RIGHT_SHIFT(x,shft) \ 269 ((shift_temp = (x)) < 0 ? \ 270 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \ 271 (shift_temp >> (shft))) 272 #else 273 #define SHIFT_TEMPS 274 #define RIGHT_SHIFT(x,shft) ((x) >> (shft)) 275 #endif 276 277 278 /* Short forms of external names for systems with brain-damaged linkers. */ 279 280 #ifdef NEED_SHORT_EXTERNAL_NAMES 281 #define jinit_master_compress jICMaster 282 #define jinit_c_main_controller jICMainC 283 #define jinit_c_prep_controller jICPrepC 284 #define jinit_c_coef_controller jICCoefC 285 #define jinit_color_converter jICColor 286 #define jinit_downsampler jIDownsampler 287 #define jinit_forward_dct jIFDCT 288 #define jinit_huff_encoder jIHEncoder 289 #define jinit_marker_writer jIMWriter 290 #define jinit_master_decompress jIDMaster 291 #define jinit_d_main_controller jIDMainC 292 #define jinit_d_coef_controller jIDCoefC 293 #define jinit_d_post_controller jIDPostC 294 #define jinit_marker_reader jIMReader 295 #define jinit_huff_decoder jIHDecoder 296 #define jinit_inverse_dct jIIDCT 297 #define jinit_upsampler jIUpsampler 298 #define jinit_color_deconverter jIDColor 299 #define jinit_1pass_quantizer jI1Quant 300 #define jinit_2pass_quantizer jI2Quant 301 #define jinit_merged_upsampler jIMUpsampler 302 #define jinit_memory_mgr jIMemMgr 303 #define jdiv_round_up jDivRound 304 #define jround_up jRound 305 #define jcopy_sample_rows jCopySamples 306 #define jcopy_block_row jCopyBlocks 307 #define jzero_far jZeroFar 308 #endif /* NEED_SHORT_EXTERNAL_NAMES */ 309 310 311 /* Compression module initialization routines */ 312 EXTERN void jinit_master_compress JPP((j_compress_ptr cinfo)); 313 EXTERN void jinit_c_main_controller JPP((j_compress_ptr cinfo, 314 boolean need_full_buffer)); 315 EXTERN void jinit_c_prep_controller JPP((j_compress_ptr cinfo, 316 boolean need_full_buffer)); 317 EXTERN void jinit_c_coef_controller JPP((j_compress_ptr cinfo, 318 boolean need_full_buffer)); 319 EXTERN void jinit_color_converter JPP((j_compress_ptr cinfo)); 320 EXTERN void jinit_downsampler JPP((j_compress_ptr cinfo)); 321 EXTERN void jinit_forward_dct JPP((j_compress_ptr cinfo)); 322 EXTERN void jinit_huff_encoder JPP((j_compress_ptr cinfo)); 323 EXTERN void jinit_marker_writer JPP((j_compress_ptr cinfo)); 324 /* Decompression module initialization routines */ 325 EXTERN void jinit_master_decompress JPP((j_decompress_ptr cinfo)); 326 EXTERN void jinit_d_main_controller JPP((j_decompress_ptr cinfo, 327 boolean need_full_buffer)); 328 EXTERN void jinit_d_coef_controller JPP((j_decompress_ptr cinfo, 329 boolean need_full_buffer)); 330 EXTERN void jinit_d_post_controller JPP((j_decompress_ptr cinfo, 331 boolean need_full_buffer)); 332 EXTERN void jinit_marker_reader JPP((j_decompress_ptr cinfo)); 333 EXTERN void jinit_huff_decoder JPP((j_decompress_ptr cinfo)); 334 EXTERN void jinit_inverse_dct JPP((j_decompress_ptr cinfo)); 335 EXTERN void jinit_upsampler JPP((j_decompress_ptr cinfo)); 336 EXTERN void jinit_color_deconverter JPP((j_decompress_ptr cinfo)); 337 EXTERN void jinit_1pass_quantizer JPP((j_decompress_ptr cinfo)); 338 EXTERN void jinit_2pass_quantizer JPP((j_decompress_ptr cinfo)); 339 EXTERN void jinit_merged_upsampler JPP((j_decompress_ptr cinfo)); 340 /* Memory manager initialization */ 341 EXTERN void jinit_memory_mgr JPP((j_common_ptr cinfo)); 342 343 /* Utility routines in jutils.c */ 344 EXTERN long jdiv_round_up JPP((long a, long b)); 345 EXTERN long jround_up JPP((long a, long b)); 346 EXTERN void jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row, 347 JSAMPARRAY output_array, int dest_row, 348 int num_rows, JDIMENSION num_cols)); 349 EXTERN void jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row, 350 JDIMENSION num_blocks)); 351 EXTERN void jzero_far JPP((void FAR * target, size_t bytestozero)); 352 353 354 /* Suppress undefined-structure complaints if necessary. */ 355 356 #ifdef INCOMPLETE_TYPES_BROKEN 357 #ifndef AM_MEMORY_MANAGER /* only jmemmgr.c defines these */ 358 struct jvirt_sarray_control { long dummy; }; 359 struct jvirt_barray_control { long dummy; }; 360 #endif 361 #endif /* INCOMPLETE_TYPES_BROKEN */ 362