/*
 * 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;
	}
}
