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