// * jcmaster.c // * // * Copyright (C) 1991-1995, Thomas G. Lane. // * This file is part of the Independent JPEG Group's software. // * For conditions of distribution and use, see the accompanying README file. // * // * This file contains master control logic for the JPEG compressor. // * These routines are concerned with parameter validation, initial setup, // * and inter-pass control (determining the number of passes and the work // * to be done in each pass). #define JPEG_INTERNALS #include "JINCLUDE.h" #include "JPEGLIB.h" // Private state typedef enum { main_pass, // input data, also do first output step huff_opt_pass, // Huffman code optimization pass output_pass // data output pass } c_pass_type; typedef struct { struct jpeg_comp_master pub; // public fields c_pass_type pass_type; // the type of the current pass int pass_number; // # of passes completed int total_passes; // total # of passes needed int scan_number; // current index in scan_info[] } my_comp_master; typedef my_comp_master * my_master_ptr; // * Support routines that do various essential calculations. LOCAL void initial_setup (j_compress_ptr cinfo) // Do computations that are needed before master selection phase { int ci; jpeg_component_info *compptr; LONG samplesperrow; JDIMENSION jd_samplesperrow; // Sanity check on image dimensions if (cinfo->image_height <= 0 || cinfo->image_width <= 0 || cinfo->num_components <= 0 || cinfo->input_components <= 0) ERREXIT(cinfo, JERR_EMPTY_IMAGE); // Make sure image isn't bigger than I can handle if ((LONG) cinfo->image_height > (LONG) JPEG_MAX_DIMENSION || (LONG) cinfo->image_width > (LONG) JPEG_MAX_DIMENSION) ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); // Width of an input scanline must be representable as JDIMENSION. samplesperrow = (LONG) cinfo->image_width * (LONG) cinfo->input_components; jd_samplesperrow = (JDIMENSION) samplesperrow; if ((LONG) jd_samplesperrow != samplesperrow) ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); // For now, precision must match compiled-in value... if (cinfo->data_precision != BITS_IN_JSAMPLE) ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); // Check that number of components won't exceed internal array sizes if (cinfo->num_components > MAX_COMPONENTS) ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, MAX_COMPONENTS); // Compute maximum sampling factors; check factor validity cinfo->max_h_samp_factor = 1; cinfo->max_v_samp_factor = 1; for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) ERREXIT(cinfo, JERR_BAD_SAMPLING); cinfo->max_h_samp_factor = BAS_Max(cinfo->max_h_samp_factor, compptr->h_samp_factor); cinfo->max_v_samp_factor = BAS_Max(cinfo->max_v_samp_factor, compptr->v_samp_factor); } // Compute dimensions of components for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { // Fill in the correct component_index value; don't rely on application compptr->component_index = ci; // For compression, we never do DCT scaling. compptr->DCT_scaled_size = DCTSIZE; // Size in DCT blocks compptr->width_in_blocks = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_width * (LONG) compptr->h_samp_factor, (LONG) (cinfo->max_h_samp_factor * DCTSIZE)); compptr->height_in_blocks = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_height * (LONG) compptr->v_samp_factor, (LONG) (cinfo->max_v_samp_factor * DCTSIZE)); // Size in samples compptr->downsampled_width = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_width * (LONG) compptr->h_samp_factor, (LONG) cinfo->max_h_samp_factor); compptr->downsampled_height = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_height * (LONG) compptr->v_samp_factor, (LONG) cinfo->max_v_samp_factor); // Mark component needed (this flag isn't actually used for compression) compptr->component_needed = TRUE; } // Compute number of fully interleaved MCU rows (number of times that // * main controller will call coefficient controller). cinfo->total_iMCU_rows = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_height, (LONG) (cinfo->max_v_samp_factor*DCTSIZE)); } #ifdef C_MULTISCAN_FILES_SUPPORTED LOCAL void validate_script (j_compress_ptr cinfo) // Verify that the scan script in cinfo->scan_info[] is valid; also // * determine whether it uses progressive JPEG, and set cinfo->progressive_mode. { const jpeg_scan_info * scanptr; int scanno, ncomps, ci, coefi, thisi; int Ss, Se, Ah, Al; boolean component_sent[MAX_COMPONENTS]; #ifdef C_PROGRESSIVE_SUPPORTED int * last_bitpos_ptr; int last_bitpos[MAX_COMPONENTS][DCTSIZE2]; // -1 until that coefficient has been seen; then last Al for it #endif if (cinfo->num_scans <= 0) ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0); // For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1; // * for progressive JPEG, no scan can have this. scanptr = cinfo->scan_info; if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) { #ifdef C_PROGRESSIVE_SUPPORTED cinfo->progressive_mode = TRUE; last_bitpos_ptr = & last_bitpos[0][0]; for (ci = 0; ci < cinfo->num_components; ci++) for (coefi = 0; coefi < DCTSIZE2; coefi++) *last_bitpos_ptr++ = -1; #else ERREXIT(cinfo, JERR_NOT_COMPILED); #endif } else { cinfo->progressive_mode = FALSE; for (ci = 0; ci < cinfo->num_components; ci++) component_sent[ci] = FALSE; } for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) { // Validate component indexes ncomps = scanptr->comps_in_scan; if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN) ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN); for (ci = 0; ci < ncomps; ci++) { thisi = scanptr->component_index[ci]; if (thisi < 0 || thisi >= cinfo->num_components) ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); // Components must appear in SOF order within each scan if (ci > 0 && thisi <= scanptr->component_index[ci-1]) ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); } // Validate progression parameters Ss = scanptr->Ss; Se = scanptr->Se; Ah = scanptr->Ah; Al = scanptr->Al; if (cinfo->progressive_mode) { #ifdef C_PROGRESSIVE_SUPPORTED if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 || Ah < 0 || Ah > 13 || Al < 0 || Al > 13) ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); if (Ss == 0) { if (Se != 0) // DC and AC together not OK ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); } else { if (ncomps != 1) // AC scans must be for only one component ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); } for (ci = 0; ci < ncomps; ci++) { last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0]; if (Ss != 0 && last_bitpos_ptr[0] < 0) // AC without prior DC scan ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); for (coefi = Ss; coefi <= Se; coefi++) { if (last_bitpos_ptr[coefi] < 0) { // first scan of this coefficient if (Ah != 0) ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); } else { // not first scan if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1) ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); } last_bitpos_ptr[coefi] = Al; } } #endif } else { // For sequential JPEG, all progression parameters must be these: if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0) ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno); // Make sure components are not sent twice for (ci = 0; ci < ncomps; ci++) { thisi = scanptr->component_index[ci]; if (component_sent[thisi]) ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno); component_sent[thisi] = TRUE; } } } // Now verify that everything got sent. if (cinfo->progressive_mode) { #ifdef C_PROGRESSIVE_SUPPORTED // For progressive mode, we only check that at least some DC data // * got sent for each component; the spec does not require that all bits // * of all coefficients be transmitted. Would it be wiser to enforce // * transmission of all coefficient bits?? for (ci = 0; ci < cinfo->num_components; ci++) { if (last_bitpos[ci][0] < 0) ERREXIT(cinfo, JERR_MISSING_DATA); } #endif } else { for (ci = 0; ci < cinfo->num_components; ci++) { if (! component_sent[ci]) ERREXIT(cinfo, JERR_MISSING_DATA); } } } #endif // C_MULTISCAN_FILES_SUPPORTED LOCAL void select_scan_parameters (j_compress_ptr cinfo) // Set up the scan parameters for the current scan { int ci; #ifdef C_MULTISCAN_FILES_SUPPORTED if (cinfo->scan_info != NULL) { // Prepare for current scan --- the script is already validated my_master_ptr master = (my_master_ptr) cinfo->master; const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number; cinfo->comps_in_scan = scanptr->comps_in_scan; for (ci = 0; ci < scanptr->comps_in_scan; ci++) { cinfo->cur_comp_info[ci] = &cinfo->comp_info[scanptr->component_index[ci]]; } cinfo->Ss = scanptr->Ss; cinfo->Se = scanptr->Se; cinfo->Ah = scanptr->Ah; cinfo->Al = scanptr->Al; } else #endif { // Prepare for single sequential-JPEG scan containing all components if (cinfo->num_components > MAX_COMPS_IN_SCAN) ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, MAX_COMPS_IN_SCAN); cinfo->comps_in_scan = cinfo->num_components; for (ci = 0; ci < cinfo->num_components; ci++) { cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci]; } cinfo->Ss = 0; cinfo->Se = DCTSIZE2-1; cinfo->Ah = 0; cinfo->Al = 0; } } LOCAL void per_scan_setup (j_compress_ptr cinfo) // Do computations that are needed before processing a JPEG scan // cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set { int ci, mcublks, tmp; jpeg_component_info *compptr; if (cinfo->comps_in_scan == 1) { // Noninterleaved (single-component) scan compptr = cinfo->cur_comp_info[0]; // Overall image size in MCUs cinfo->MCUs_per_row = compptr->width_in_blocks; cinfo->MCU_rows_in_scan = compptr->height_in_blocks; // For noninterleaved scan, always one block per MCU compptr->MCU_width = 1; compptr->MCU_height = 1; compptr->MCU_blocks = 1; compptr->MCU_sample_width = DCTSIZE; compptr->last_col_width = 1; // For noninterleaved scans, it is convenient to define last_row_height // * as the number of block rows present in the last iMCU row. tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); if (tmp == 0) tmp = compptr->v_samp_factor; compptr->last_row_height = tmp; // Prepare array describing MCU composition cinfo->blocks_in_MCU = 1; cinfo->MCU_membership[0] = 0; } else { // Interleaved (multi-component) scan if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, MAX_COMPS_IN_SCAN); // Overall image size in MCUs cinfo->MCUs_per_row = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_width, (LONG) (cinfo->max_h_samp_factor*DCTSIZE)); cinfo->MCU_rows_in_scan = (JDIMENSION) jdiv_round_up((LONG) cinfo->image_height, (LONG) (cinfo->max_v_samp_factor*DCTSIZE)); cinfo->blocks_in_MCU = 0; for (ci = 0; ci < cinfo->comps_in_scan; ci++) { compptr = cinfo->cur_comp_info[ci]; // Sampling factors give # of blocks of component in each MCU compptr->MCU_width = compptr->h_samp_factor; compptr->MCU_height = compptr->v_samp_factor; compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE; // Figure number of non-dummy blocks in last MCU column & row tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); if (tmp == 0) tmp = compptr->MCU_width; compptr->last_col_width = tmp; tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); if (tmp == 0) tmp = compptr->MCU_height; compptr->last_row_height = tmp; // Prepare array describing MCU composition mcublks = compptr->MCU_blocks; if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU) ERREXIT(cinfo, JERR_BAD_MCU_SIZE); while (mcublks-- > 0) { cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; } } } // Convert restart specified in rows to actual MCU count. // Note that count must fit in 16 bits, so we provide limiting. if (cinfo->restart_in_rows > 0) { LONG nominal = (LONG) cinfo->restart_in_rows * (LONG) cinfo->MCUs_per_row; cinfo->restart_interval = (unsigned int) BAS_Min(nominal, 65535L); } } // * Per-pass setup. // * This is called at the beginning of each pass. We determine which modules // * will be active during this pass and give them appropriate start_pass calls. // * We also set is_last_pass to indicate whether any more passes will be // * required. METHODDEF void prepare_for_pass (j_compress_ptr cinfo) { my_master_ptr master = (my_master_ptr) cinfo->master; switch (master->pass_type) { case main_pass: // Initial pass: will collect input data, and do either Huffman // * optimization or data output for the first scan. select_scan_parameters(cinfo); per_scan_setup(cinfo); if (! cinfo->raw_data_in) { (*cinfo->cconvert->start_pass) (cinfo); (*cinfo->downsample->start_pass) (cinfo); (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU); } (*cinfo->fdct->start_pass) (cinfo); (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding); (*cinfo->coef->start_pass) (cinfo, (master->total_passes > 1 ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); if (cinfo->optimize_coding) { // No immediate data output; postpone writing frame/scan headers master->pub.call_pass_startup = FALSE; } else { // Will write frame/scan headers at first jpeg_write_scanlines call master->pub.call_pass_startup = TRUE; } break; #ifdef ENTROPY_OPT_SUPPORTED case huff_opt_pass: // Do Huffman optimization for a scan after the first one. select_scan_parameters(cinfo); per_scan_setup(cinfo); if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) { (*cinfo->entropy->start_pass) (cinfo, TRUE); (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); master->pub.call_pass_startup = FALSE; break; } // Special case: Huffman DC refinement scans need no Huffman table // * and therefore we can skip the optimization pass for them. master->pass_type = output_pass; master->pass_number++; //FALLTHROUGH #endif case output_pass: // Do a data-output pass. // We need not repeat per-scan setup if prior optimization pass did it. if (! cinfo->optimize_coding) { select_scan_parameters(cinfo); per_scan_setup(cinfo); } (*cinfo->entropy->start_pass) (cinfo, FALSE); (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); // We emit frame/scan headers now if (master->scan_number == 0) (*cinfo->marker->write_frame_header) (cinfo); (*cinfo->marker->write_scan_header) (cinfo); master->pub.call_pass_startup = FALSE; break; default: ERREXIT(cinfo, JERR_NOT_COMPILED); } master->pub.is_last_pass = (master->pass_number == master->total_passes-1); // Set up progress monitor's pass info if present if (cinfo->progress != NULL) { cinfo->progress->completed_passes = master->pass_number; cinfo->progress->total_passes = master->total_passes; } } // * Special start-of-pass hook. // * This is called by jpeg_write_scanlines if call_pass_startup is TRUE. // * In single-pass processing, we need this hook because we don't want to // * write frame/scan headers during jpeg_start_compress; we want to let the // * application write COM markers etc. between jpeg_start_compress and the // * jpeg_write_scanlines loop. // * In multi-pass processing, this routine is not used. METHODDEF void pass_startup (j_compress_ptr cinfo) { cinfo->master->call_pass_startup = FALSE; // reset flag so call only once (*cinfo->marker->write_frame_header) (cinfo); (*cinfo->marker->write_scan_header) (cinfo); } // * Finish up at end of pass. METHODDEF void finish_pass_master (j_compress_ptr cinfo) { my_master_ptr master = (my_master_ptr) cinfo->master; // The entropy coder always needs an end-of-pass call, // * either to analyze statistics or to flush its output buffer. (*cinfo->entropy->finish_pass) (cinfo); // Update state for next pass switch (master->pass_type) { case main_pass: // next pass is either output of scan 0 (after optimization) // * or output of scan 1 (if no optimization). master->pass_type = output_pass; if (! cinfo->optimize_coding) master->scan_number++; break; case huff_opt_pass: // next pass is always output of current scan master->pass_type = output_pass; break; case output_pass: // next pass is either optimization or output of next scan if (cinfo->optimize_coding) master->pass_type = huff_opt_pass; master->scan_number++; break; } master->pass_number++; } // * Initialize master compression control. GLOBAL void jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only) { my_master_ptr master; master = (my_master_ptr) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(my_comp_master)); cinfo->master = (struct jpeg_comp_master *) master; master->pub.prepare_for_pass = prepare_for_pass; master->pub.pass_startup = pass_startup; master->pub.finish_pass = finish_pass_master; master->pub.is_last_pass = FALSE; // Validate parameters, determine derived values initial_setup(cinfo); if (cinfo->scan_info != NULL) { #ifdef C_MULTISCAN_FILES_SUPPORTED validate_script(cinfo); #else ERREXIT(cinfo, JERR_NOT_COMPILED); #endif } else { cinfo->progressive_mode = FALSE; cinfo->num_scans = 1; } if (cinfo->progressive_mode) // TEMPORARY HACK ??? cinfo->optimize_coding = TRUE; // assume default tables no good for progressive mode // Initialize my private state if (transcode_only) { // no main pass in transcoding if (cinfo->optimize_coding) master->pass_type = huff_opt_pass; else master->pass_type = output_pass; } else { // for normal compression, first pass is always this type: master->pass_type = main_pass; } master->scan_number = 0; master->pass_number = 0; if (cinfo->optimize_coding) master->total_passes = cinfo->num_scans * 2; else master->total_passes = cinfo->num_scans; }