ref: 182dda4dd9335704b78347f74c37f7343c4c65cd
dir: /DoConfig/fltk/jpeg/jcmaster.c/
/* * jcmaster.c * * Copyright (C) 1991-1997, Thomas G. Lane. * Modified 2003-2013 by Guido Vollbeding. * 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. */ /* * Compute JPEG image dimensions and related values. * NOTE: this is exported for possible use by application. * Hence it mustn't do anything that can't be done twice. */ GLOBAL(void) jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo) /* Do computations that are needed before master selection phase */ { #ifdef DCT_SCALING_SUPPORTED /* Sanity check on input image dimensions to prevent overflow in * following calculation. * We do check jpeg_width and jpeg_height in initial_setup below, * but image_width and image_height can come from arbitrary data, * and we need some space for multiplication by block_size. */ if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24)) ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); /* Compute actual JPEG image dimensions and DCT scaling choices. */ if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/1 scaling */ cinfo->jpeg_width = cinfo->image_width * cinfo->block_size; cinfo->jpeg_height = cinfo->image_height * cinfo->block_size; cinfo->min_DCT_h_scaled_size = 1; cinfo->min_DCT_v_scaled_size = 1; } else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/2 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L); cinfo->min_DCT_h_scaled_size = 2; cinfo->min_DCT_v_scaled_size = 2; } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/3 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L); cinfo->min_DCT_h_scaled_size = 3; cinfo->min_DCT_v_scaled_size = 3; } else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/4 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L); cinfo->min_DCT_h_scaled_size = 4; cinfo->min_DCT_v_scaled_size = 4; } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/5 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L); cinfo->min_DCT_h_scaled_size = 5; cinfo->min_DCT_v_scaled_size = 5; } else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/6 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L); cinfo->min_DCT_h_scaled_size = 6; cinfo->min_DCT_v_scaled_size = 6; } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/7 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L); cinfo->min_DCT_h_scaled_size = 7; cinfo->min_DCT_v_scaled_size = 7; } else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/8 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L); cinfo->min_DCT_h_scaled_size = 8; cinfo->min_DCT_v_scaled_size = 8; } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/9 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L); cinfo->min_DCT_h_scaled_size = 9; cinfo->min_DCT_v_scaled_size = 9; } else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/10 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L); cinfo->min_DCT_h_scaled_size = 10; cinfo->min_DCT_v_scaled_size = 10; } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/11 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L); cinfo->min_DCT_h_scaled_size = 11; cinfo->min_DCT_v_scaled_size = 11; } else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/12 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L); cinfo->min_DCT_h_scaled_size = 12; cinfo->min_DCT_v_scaled_size = 12; } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/13 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L); cinfo->min_DCT_h_scaled_size = 13; cinfo->min_DCT_v_scaled_size = 13; } else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/14 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L); cinfo->min_DCT_h_scaled_size = 14; cinfo->min_DCT_v_scaled_size = 14; } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) { /* Provide block_size/15 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L); cinfo->min_DCT_h_scaled_size = 15; cinfo->min_DCT_v_scaled_size = 15; } else { /* Provide block_size/16 scaling */ cinfo->jpeg_width = (JDIMENSION) jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L); cinfo->jpeg_height = (JDIMENSION) jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L); cinfo->min_DCT_h_scaled_size = 16; cinfo->min_DCT_v_scaled_size = 16; } #else /* !DCT_SCALING_SUPPORTED */ /* Hardwire it to "no scaling" */ cinfo->jpeg_width = cinfo->image_width; cinfo->jpeg_height = cinfo->image_height; cinfo->min_DCT_h_scaled_size = DCTSIZE; cinfo->min_DCT_v_scaled_size = DCTSIZE; #endif /* DCT_SCALING_SUPPORTED */ } LOCAL(void) jpeg_calc_trans_dimensions (j_compress_ptr cinfo) { if (cinfo->min_DCT_h_scaled_size != cinfo->min_DCT_v_scaled_size) ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->min_DCT_h_scaled_size, cinfo->min_DCT_v_scaled_size); cinfo->block_size = cinfo->min_DCT_h_scaled_size; } LOCAL(void) initial_setup (j_compress_ptr cinfo, boolean transcode_only) /* Do computations that are needed before master selection phase */ { int ci, ssize; jpeg_component_info *compptr; if (transcode_only) jpeg_calc_trans_dimensions(cinfo); else jpeg_calc_jpeg_dimensions(cinfo); /* Sanity check on block_size */ if (cinfo->block_size < 1 || cinfo->block_size > 16) ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->block_size, cinfo->block_size); /* Derive natural_order from block_size */ switch (cinfo->block_size) { case 2: cinfo->natural_order = jpeg_natural_order2; break; case 3: cinfo->natural_order = jpeg_natural_order3; break; case 4: cinfo->natural_order = jpeg_natural_order4; break; case 5: cinfo->natural_order = jpeg_natural_order5; break; case 6: cinfo->natural_order = jpeg_natural_order6; break; case 7: cinfo->natural_order = jpeg_natural_order7; break; default: cinfo->natural_order = jpeg_natural_order; break; } /* Derive lim_Se from block_size */ cinfo->lim_Se = cinfo->block_size < DCTSIZE ? cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1; /* Sanity check on image dimensions */ if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 || cinfo->num_components <= 0) ERREXIT(cinfo, JERR_EMPTY_IMAGE); /* Make sure image isn't bigger than I can handle */ if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION || (long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION) ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); /* Only 8 to 12 bits data precision are supported for DCT based JPEG */ if (cinfo->data_precision < 8 || cinfo->data_precision > 12) 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 = MAX(cinfo->max_h_samp_factor, compptr->h_samp_factor); cinfo->max_v_samp_factor = 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; /* In selecting the actual DCT scaling for each component, we try to * scale down the chroma components via DCT scaling rather than downsampling. * This saves time if the downsampler gets to use 1:1 scaling. * Note this code adapts subsampling ratios which are powers of 2. */ ssize = 1; #ifdef DCT_SCALING_SUPPORTED while (cinfo->min_DCT_h_scaled_size * ssize <= (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) && (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) { ssize = ssize * 2; } #endif compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize; ssize = 1; #ifdef DCT_SCALING_SUPPORTED while (cinfo->min_DCT_v_scaled_size * ssize <= (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) && (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) { ssize = ssize * 2; } #endif compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize; /* We don't support DCT ratios larger than 2. */ if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2) compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2; else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2) compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2; /* Size in DCT blocks */ compptr->width_in_blocks = (JDIMENSION) jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor, (long) (cinfo->max_h_samp_factor * cinfo->block_size)); compptr->height_in_blocks = (JDIMENSION) jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor, (long) (cinfo->max_v_samp_factor * cinfo->block_size)); /* Size in samples */ compptr->downsampled_width = (JDIMENSION) jdiv_round_up((long) cinfo->jpeg_width * (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size), (long) (cinfo->max_h_samp_factor * cinfo->block_size)); compptr->downsampled_height = (JDIMENSION) jdiv_round_up((long) cinfo->jpeg_height * (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size), (long) (cinfo->max_v_samp_factor * cinfo->block_size)); /* Don't need quantization scale after DCT, * until color conversion says otherwise. */ compptr->component_needed = FALSE; } /* 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->jpeg_height, (long) (cinfo->max_v_samp_factor * cinfo->block_size)); } #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 /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that * seems wrong: the upper bound ought to depend on data precision. * Perhaps they really meant 0..N+1 for N-bit precision. * Here we allow 0..10 for 8-bit data; Al larger than 10 results in * out-of-range reconstructed DC values during the first DC scan, * which might cause problems for some decoders. */ #if BITS_IN_JSAMPLE == 8 #define MAX_AH_AL 10 #else #define MAX_AH_AL 13 #endif if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 || Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL) 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); } } } LOCAL(void) reduce_script (j_compress_ptr cinfo) /* Adapt scan script for use with reduced block size; * assume that script has been validated before. */ { jpeg_scan_info * scanptr; int idxout, idxin; /* Circumvent const declaration for this function */ scanptr = (jpeg_scan_info *) cinfo->scan_info; idxout = 0; for (idxin = 0; idxin < cinfo->num_scans; idxin++) { /* After skipping, idxout becomes smaller than idxin */ if (idxin != idxout) /* Copy rest of data; * note we stay in given chunk of allocated memory. */ scanptr[idxout] = scanptr[idxin]; if (scanptr[idxout].Ss > cinfo->lim_Se) /* Entire scan out of range - skip this entry */ continue; if (scanptr[idxout].Se > cinfo->lim_Se) /* Limit scan to end of block */ scanptr[idxout].Se = cinfo->lim_Se; idxout++; } cinfo->num_scans = idxout; } #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]]; } if (cinfo->progressive_mode) { cinfo->Ss = scanptr->Ss; cinfo->Se = scanptr->Se; cinfo->Ah = scanptr->Ah; cinfo->Al = scanptr->Al; return; } } 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 = cinfo->block_size * cinfo->block_size - 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 = compptr->DCT_h_scaled_size; 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->jpeg_width, (long) (cinfo->max_h_samp_factor * cinfo->block_size)); cinfo->MCU_rows_in_scan = (JDIMENSION) jdiv_round_up((long) cinfo->jpeg_height, (long) (cinfo->max_v_samp_factor * cinfo->block_size)); 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 * compptr->DCT_h_scaled_size; /* 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) 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->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 = &master->pub; 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, transcode_only); if (cinfo->scan_info != NULL) { #ifdef C_MULTISCAN_FILES_SUPPORTED validate_script(cinfo); if (cinfo->block_size < DCTSIZE) reduce_script(cinfo); #else ERREXIT(cinfo, JERR_NOT_COMPILED); #endif } else { cinfo->progressive_mode = FALSE; cinfo->num_scans = 1; } if (cinfo->optimize_coding) cinfo->arith_code = FALSE; /* disable arithmetic coding */ else if (! cinfo->arith_code && (cinfo->progressive_mode || (cinfo->block_size > 1 && cinfo->block_size < DCTSIZE))) /* TEMPORARY HACK ??? */ /* assume default tables no good for progressive or reduced AC mode */ cinfo->optimize_coding = TRUE; /* force Huffman optimization */ /* 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; }