/* * 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 = 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; /* 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) 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; } }