[wxWidgets.git] / src / jpeg / jcmaster.c

/*
 * jcmaster.c
 *
 * Copyright (C) 1991-1997, 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
      /* 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);
    }
  }
}

#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;
}
Commit	Line	Data
e1929140 RR	1	/*
	2	* jcmaster.c
	3	*
	4	* Copyright (C) 1991-1997, Thomas G. Lane.
	5	* This file is part of the Independent JPEG Group's software.
	6	* For conditions of distribution and use, see the accompanying README file.
	7	*
	8	* This file contains master control logic for the JPEG compressor.
	9	* These routines are concerned with parameter validation, initial setup,
	10	* and inter-pass control (determining the number of passes and the work
	11	* to be done in each pass).
	12	*/
	13
	14	#define JPEG_INTERNALS
	15	#include "jinclude.h"
	16	#include "jpeglib.h"
	17
	18
	19	/* Private state */
	20
	21	typedef enum {
	22	main_pass, /* input data, also do first output step */
	23	huff_opt_pass, /* Huffman code optimization pass */
	24	output_pass /* data output pass */
	25	} c_pass_type;
	26
	27	typedef struct {
	28	struct jpeg_comp_master pub; /* public fields */
	29
	30	c_pass_type pass_type; /* the type of the current pass */
	31
	32	int pass_number; /* # of passes completed */
	33	int total_passes; /* total # of passes needed */
	34
	35	int scan_number; /* current index in scan_info[] */
	36	} my_comp_master;
	37
	38	typedef my_comp_master * my_master_ptr;
	39
	40
	41	/*
	42	* Support routines that do various essential calculations.
	43	*/
	44
	45	LOCAL(void)
	46	initial_setup (j_compress_ptr cinfo)
	47	/* Do computations that are needed before master selection phase */
	48	{
	49	int ci;
	50	jpeg_component_info *compptr;
	51	long samplesperrow;
	52	JDIMENSION jd_samplesperrow;
	53
	54	/* Sanity check on image dimensions */
	55	if (cinfo->image_height <= 0 \|\| cinfo->image_width <= 0
	56	\|\| cinfo->num_components <= 0 \|\| cinfo->input_components <= 0)
	57	ERREXIT(cinfo, JERR_EMPTY_IMAGE);
	58
	59	/* Make sure image isn't bigger than I can handle */
	60	if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION \|\|
	61	(long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
	62	ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
	63
	64	/* Width of an input scanline must be representable as JDIMENSION. */
65	samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
66	jd_samplesperrow = (JDIMENSION) samplesperrow;
67	if ((long) jd_samplesperrow != samplesperrow)
68	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
69
70	/* For now, precision must match compiled-in value... */
71	if (cinfo->data_precision != BITS_IN_JSAMPLE)
72	ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
73
74	/* Check that number of components won't exceed internal array sizes */
75	if (cinfo->num_components > MAX_COMPONENTS)
76	ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
77	MAX_COMPONENTS);
78
79	/* Compute maximum sampling factors; check factor validity */
80	cinfo->max_h_samp_factor = 1;
81	cinfo->max_v_samp_factor = 1;
82	for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
83	ci++, compptr++) {
84	if (compptr->h_samp_factor<=0 \|\| compptr->h_samp_factor>MAX_SAMP_FACTOR \|\|
85	compptr->v_samp_factor<=0 \|\| compptr->v_samp_factor>MAX_SAMP_FACTOR)
86	ERREXIT(cinfo, JERR_BAD_SAMPLING);
87	cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
88	compptr->h_samp_factor);
89	cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
90	compptr->v_samp_factor);
91	}
92
93	/* Compute dimensions of components */
94	for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
95	ci++, compptr++) {
96	/* Fill in the correct component_index value; don't rely on application */
97	compptr->component_index = ci;
98	/* For compression, we never do DCT scaling. */
99	compptr->DCT_scaled_size = DCTSIZE;
100	/* Size in DCT blocks */
101	compptr->width_in_blocks = (JDIMENSION)
102	jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
103	(long) (cinfo->max_h_samp_factor * DCTSIZE));
104	compptr->height_in_blocks = (JDIMENSION)
105	jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
106	(long) (cinfo->max_v_samp_factor * DCTSIZE));
107	/* Size in samples */
108	compptr->downsampled_width = (JDIMENSION)
109	jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
110	(long) cinfo->max_h_samp_factor);
111	compptr->downsampled_height = (JDIMENSION)
112	jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
113	(long) cinfo->max_v_samp_factor);
114	/* Mark component needed (this flag isn't actually used for compression) */
115	compptr->component_needed = TRUE;
116	}
117
118	/* Compute number of fully interleaved MCU rows (number of times that
119	* main controller will call coefficient controller).
120	*/
121	cinfo->total_iMCU_rows = (JDIMENSION)
122	jdiv_round_up((long) cinfo->image_height,
123	(long) (cinfo->max_v_samp_factor*DCTSIZE));
124	}
125
126
127	#ifdef C_MULTISCAN_FILES_SUPPORTED
128
129	LOCAL(void)
130	validate_script (j_compress_ptr cinfo)
131	/* Verify that the scan script in cinfo->scan_info[] is valid; also
132	* determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
133	*/
134	{
135	const jpeg_scan_info * scanptr;
136	int scanno, ncomps, ci, coefi, thisi;
137	int Ss, Se, Ah, Al;
138	boolean component_sent[MAX_COMPONENTS];
139	#ifdef C_PROGRESSIVE_SUPPORTED
140	int * last_bitpos_ptr;
141	int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
142	/* -1 until that coefficient has been seen; then last Al for it */
143	#endif
144
145	if (cinfo->num_scans <= 0)
146	ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
147
148	/* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
149	* for progressive JPEG, no scan can have this.
150	*/
151	scanptr = cinfo->scan_info;
152	if (scanptr->Ss != 0 \|\| scanptr->Se != DCTSIZE2-1) {
153	#ifdef C_PROGRESSIVE_SUPPORTED
154	cinfo->progressive_mode = TRUE;
155	last_bitpos_ptr = & last_bitpos[0][0];
156	for (ci = 0; ci < cinfo->num_components; ci++)
157	for (coefi = 0; coefi < DCTSIZE2; coefi++)
158	*last_bitpos_ptr++ = -1;
159	#else
160	ERREXIT(cinfo, JERR_NOT_COMPILED);
161	#endif
162	} else {
163	cinfo->progressive_mode = FALSE;
164	for (ci = 0; ci < cinfo->num_components; ci++)
165	component_sent[ci] = FALSE;
166	}
167
168	for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {
169	/* Validate component indexes */
170	ncomps = scanptr->comps_in_scan;
171	if (ncomps <= 0 \|\| ncomps > MAX_COMPS_IN_SCAN)
172	ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);
173	for (ci = 0; ci < ncomps; ci++) {
174	thisi = scanptr->component_index[ci];
175	if (thisi < 0 \|\| thisi >= cinfo->num_components)
176	ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
177	/* Components must appear in SOF order within each scan */
178	if (ci > 0 && thisi <= scanptr->component_index[ci-1])
179	ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
180	}
181	/* Validate progression parameters */
182	Ss = scanptr->Ss;
183	Se = scanptr->Se;
184	Ah = scanptr->Ah;
185	Al = scanptr->Al;
186	if (cinfo->progressive_mode) {
187	#ifdef C_PROGRESSIVE_SUPPORTED
188	/* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that
189	* seems wrong: the upper bound ought to depend on data precision.
190	* Perhaps they really meant 0..N+1 for N-bit precision.
191	* Here we allow 0..10 for 8-bit data; Al larger than 10 results in
192	* out-of-range reconstructed DC values during the first DC scan,
193	* which might cause problems for some decoders.
194	*/
195	#if BITS_IN_JSAMPLE == 8
196	#define MAX_AH_AL 10
197	#else
198	#define MAX_AH_AL 13
199	#endif
200	if (Ss < 0 \|\| Ss >= DCTSIZE2 \|\| Se < Ss \|\| Se >= DCTSIZE2 \|\|
201	Ah < 0 \|\| Ah > MAX_AH_AL \|\| Al < 0 \|\| Al > MAX_AH_AL)
202	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
203	if (Ss == 0) {
204	if (Se != 0) /* DC and AC together not OK */
205	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
206	} else {
207	if (ncomps != 1) /* AC scans must be for only one component */
208	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
209	}
210	for (ci = 0; ci < ncomps; ci++) {
211	last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0];
212	if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
213	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
214	for (coefi = Ss; coefi <= Se; coefi++) {
215	if (last_bitpos_ptr[coefi] < 0) {
216	/* first scan of this coefficient */
217	if (Ah != 0)
218	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
219	} else {
220	/* not first scan */
221	if (Ah != last_bitpos_ptr[coefi] \|\| Al != Ah-1)
222	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
223	}
224	last_bitpos_ptr[coefi] = Al;
225	}
226	}
227	#endif
228	} else {
229	/* For sequential JPEG, all progression parameters must be these: */
230	if (Ss != 0 \|\| Se != DCTSIZE2-1 \|\| Ah != 0 \|\| Al != 0)
231	ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
232	/* Make sure components are not sent twice */
233	for (ci = 0; ci < ncomps; ci++) {
234	thisi = scanptr->component_index[ci];
235	if (component_sent[thisi])
236	ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
237	component_sent[thisi] = TRUE;
238	}
239	}
240	}
241
242	/* Now verify that everything got sent. */
243	if (cinfo->progressive_mode) {
244	#ifdef C_PROGRESSIVE_SUPPORTED
245	/* For progressive mode, we only check that at least some DC data
246	* got sent for each component; the spec does not require that all bits
247	* of all coefficients be transmitted. Would it be wiser to enforce
248	* transmission of all coefficient bits??
249	*/
250	for (ci = 0; ci < cinfo->num_components; ci++) {
251	if (last_bitpos[ci][0] < 0)
252	ERREXIT(cinfo, JERR_MISSING_DATA);
253	}
254	#endif
255	} else {
256	for (ci = 0; ci < cinfo->num_components; ci++) {
257	if (! component_sent[ci])
258	ERREXIT(cinfo, JERR_MISSING_DATA);
259	}
260	}
261	}
262
263	#endif /* C_MULTISCAN_FILES_SUPPORTED */
264
265
266	LOCAL(void)
267	select_scan_parameters (j_compress_ptr cinfo)
268	/* Set up the scan parameters for the current scan */
269	{
270	int ci;
271
272	#ifdef C_MULTISCAN_FILES_SUPPORTED
273	if (cinfo->scan_info != NULL) {
274	/* Prepare for current scan --- the script is already validated */
275	my_master_ptr master = (my_master_ptr) cinfo->master;
276	const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;
277
278	cinfo->comps_in_scan = scanptr->comps_in_scan;
279	for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
280	cinfo->cur_comp_info[ci] =
281	&cinfo->comp_info[scanptr->component_index[ci]];
282	}
283	cinfo->Ss = scanptr->Ss;
284	cinfo->Se = scanptr->Se;
285	cinfo->Ah = scanptr->Ah;
286	cinfo->Al = scanptr->Al;
287	}
288	else
289	#endif
290	{
291	/* Prepare for single sequential-JPEG scan containing all components */
292	if (cinfo->num_components > MAX_COMPS_IN_SCAN)
293	ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
294	MAX_COMPS_IN_SCAN);
295	cinfo->comps_in_scan = cinfo->num_components;
296	for (ci = 0; ci < cinfo->num_components; ci++) {
297	cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
298	}
299	cinfo->Ss = 0;
300	cinfo->Se = DCTSIZE2-1;
301	cinfo->Ah = 0;
302	cinfo->Al = 0;
303	}
304	}
305
306
307	LOCAL(void)
308	per_scan_setup (j_compress_ptr cinfo)
309	/* Do computations that are needed before processing a JPEG scan */
310	/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
311	{
312	int ci, mcublks, tmp;
313	jpeg_component_info *compptr;
314
315	if (cinfo->comps_in_scan == 1) {
316
317	/* Noninterleaved (single-component) scan */
318	compptr = cinfo->cur_comp_info[0];
319
320	/* Overall image size in MCUs */
321	cinfo->MCUs_per_row = compptr->width_in_blocks;
322	cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
323
324	/* For noninterleaved scan, always one block per MCU */
325	compptr->MCU_width = 1;
326	compptr->MCU_height = 1;
327	compptr->MCU_blocks = 1;
328	compptr->MCU_sample_width = DCTSIZE;
329	compptr->last_col_width = 1;
330	/* For noninterleaved scans, it is convenient to define last_row_height
331	* as the number of block rows present in the last iMCU row.
332	*/
333	tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
334	if (tmp == 0) tmp = compptr->v_samp_factor;
335	compptr->last_row_height = tmp;
336
337	/* Prepare array describing MCU composition */
338	cinfo->blocks_in_MCU = 1;
339	cinfo->MCU_membership[0] = 0;
340
341	} else {
342
343	/* Interleaved (multi-component) scan */
344	if (cinfo->comps_in_scan <= 0 \|\| cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
345	ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
346	MAX_COMPS_IN_SCAN);
347
348	/* Overall image size in MCUs */
349	cinfo->MCUs_per_row = (JDIMENSION)
350	jdiv_round_up((long) cinfo->image_width,
351	(long) (cinfo->max_h_samp_factor*DCTSIZE));
352	cinfo->MCU_rows_in_scan = (JDIMENSION)
353	jdiv_round_up((long) cinfo->image_height,
354	(long) (cinfo->max_v_samp_factor*DCTSIZE));
355
356	cinfo->blocks_in_MCU = 0;
357
358	for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
359	compptr = cinfo->cur_comp_info[ci];
360	/* Sampling factors give # of blocks of component in each MCU */
361	compptr->MCU_width = compptr->h_samp_factor;
362	compptr->MCU_height = compptr->v_samp_factor;
363	compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
364	compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
365	/* Figure number of non-dummy blocks in last MCU column & row */
366	tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
367	if (tmp == 0) tmp = compptr->MCU_width;
368	compptr->last_col_width = tmp;
369	tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
370	if (tmp == 0) tmp = compptr->MCU_height;
371	compptr->last_row_height = tmp;
372	/* Prepare array describing MCU composition */
373	mcublks = compptr->MCU_blocks;
374	if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
375	ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
376	while (mcublks-- > 0) {
377	cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
378	}
379	}
380
381	}
382
383	/* Convert restart specified in rows to actual MCU count. */
384	/* Note that count must fit in 16 bits, so we provide limiting. */
385	if (cinfo->restart_in_rows > 0) {
386	long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
387	cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);
388	}
389	}
390
391
392	/*
393	* Per-pass setup.
394	* This is called at the beginning of each pass. We determine which modules
395	* will be active during this pass and give them appropriate start_pass calls.
396	* We also set is_last_pass to indicate whether any more passes will be
397	* required.
398	*/
399
400	METHODDEF(void)
401	prepare_for_pass (j_compress_ptr cinfo)
402	{
403	my_master_ptr master = (my_master_ptr) cinfo->master;
404
405	switch (master->pass_type) {
406	case main_pass:
407	/* Initial pass: will collect input data, and do either Huffman
408	* optimization or data output for the first scan.
409	*/
410	select_scan_parameters(cinfo);
411	per_scan_setup(cinfo);
412	if (! cinfo->raw_data_in) {
413	(*cinfo->cconvert->start_pass) (cinfo);
414	(*cinfo->downsample->start_pass) (cinfo);
415	(*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
416	}
417	(*cinfo->fdct->start_pass) (cinfo);
418	(*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
419	(*cinfo->coef->start_pass) (cinfo,
420	(master->total_passes > 1 ?
421	JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
422	(*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
423	if (cinfo->optimize_coding) {
424	/* No immediate data output; postpone writing frame/scan headers */
425	master->pub.call_pass_startup = FALSE;
426	} else {
427	/* Will write frame/scan headers at first jpeg_write_scanlines call */
428	master->pub.call_pass_startup = TRUE;
429	}
430	break;
431	#ifdef ENTROPY_OPT_SUPPORTED
432	case huff_opt_pass:
433	/* Do Huffman optimization for a scan after the first one. */
434	select_scan_parameters(cinfo);
435	per_scan_setup(cinfo);
436	if (cinfo->Ss != 0 \|\| cinfo->Ah == 0 \|\| cinfo->arith_code) {
437	(*cinfo->entropy->start_pass) (cinfo, TRUE);
438	(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
439	master->pub.call_pass_startup = FALSE;
440	break;
441	}
442	/* Special case: Huffman DC refinement scans need no Huffman table
443	* and therefore we can skip the optimization pass for them.
444	*/
445	master->pass_type = output_pass;
446	master->pass_number++;
447	/FALLTHROUGH/
448	#endif
449	case output_pass:
450	/* Do a data-output pass. */
451	/* We need not repeat per-scan setup if prior optimization pass did it. */
452	if (! cinfo->optimize_coding) {
453	select_scan_parameters(cinfo);
454	per_scan_setup(cinfo);
455	}
456	(*cinfo->entropy->start_pass) (cinfo, FALSE);
457	(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
458	/* We emit frame/scan headers now */
459	if (master->scan_number == 0)
460	(*cinfo->marker->write_frame_header) (cinfo);
461	(*cinfo->marker->write_scan_header) (cinfo);
462	master->pub.call_pass_startup = FALSE;
463	break;
464	default:
465	ERREXIT(cinfo, JERR_NOT_COMPILED);
466	}
467
468	master->pub.is_last_pass = (master->pass_number == master->total_passes-1);
469
470	/* Set up progress monitor's pass info if present */
471	if (cinfo->progress != NULL) {
472	cinfo->progress->completed_passes = master->pass_number;
473	cinfo->progress->total_passes = master->total_passes;
474	}
475	}
476
477
478	/*
479	* Special start-of-pass hook.
480	* This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
481	* In single-pass processing, we need this hook because we don't want to
482	* write frame/scan headers during jpeg_start_compress; we want to let the
483	* application write COM markers etc. between jpeg_start_compress and the
484	* jpeg_write_scanlines loop.
485	* In multi-pass processing, this routine is not used.
486	*/
487
488	METHODDEF(void)
489	pass_startup (j_compress_ptr cinfo)
490	{
491	cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
492
493	(*cinfo->marker->write_frame_header) (cinfo);
494	(*cinfo->marker->write_scan_header) (cinfo);
495	}
496
497
498	/*
499	* Finish up at end of pass.
500	*/
501
502	METHODDEF(void)
503	finish_pass_master (j_compress_ptr cinfo)
504	{
505	my_master_ptr master = (my_master_ptr) cinfo->master;
506
507	/* The entropy coder always needs an end-of-pass call,
508	* either to analyze statistics or to flush its output buffer.
509	*/
510	(*cinfo->entropy->finish_pass) (cinfo);
511
512	/* Update state for next pass */
513	switch (master->pass_type) {
514	case main_pass:
515	/* next pass is either output of scan 0 (after optimization)
516	* or output of scan 1 (if no optimization).
517	*/
518	master->pass_type = output_pass;
519	if (! cinfo->optimize_coding)
520	master->scan_number++;
521	break;
522	case huff_opt_pass:
523	/* next pass is always output of current scan */
524	master->pass_type = output_pass;
525	break;
526	case output_pass:
527	/* next pass is either optimization or output of next scan */
528	if (cinfo->optimize_coding)
529	master->pass_type = huff_opt_pass;
530	master->scan_number++;
531	break;
532	}
533
534	master->pass_number++;
535	}
536
537
538	/*
539	* Initialize master compression control.
540	*/
541
542	GLOBAL(void)
543	jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)
544	{
545	my_master_ptr master;
546
547	master = (my_master_ptr)
548	(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
549	SIZEOF(my_comp_master));
550	cinfo->master = (struct jpeg_comp_master *) master;
551	master->pub.prepare_for_pass = prepare_for_pass;
552	master->pub.pass_startup = pass_startup;
553	master->pub.finish_pass = finish_pass_master;
554	master->pub.is_last_pass = FALSE;
555
556	/* Validate parameters, determine derived values */
557	initial_setup(cinfo);
558
559	if (cinfo->scan_info != NULL) {
560	#ifdef C_MULTISCAN_FILES_SUPPORTED
561	validate_script(cinfo);
562	#else
563	ERREXIT(cinfo, JERR_NOT_COMPILED);
564	#endif
565	} else {
566	cinfo->progressive_mode = FALSE;
567	cinfo->num_scans = 1;
568	}
569
570	if (cinfo->progressive_mode) /* TEMPORARY HACK ??? */
571	cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
572
573	/* Initialize my private state */
574	if (transcode_only) {
575	/* no main pass in transcoding */
576	if (cinfo->optimize_coding)
577	master->pass_type = huff_opt_pass;
578	else
579	master->pass_type = output_pass;
580	} else {
581	/* for normal compression, first pass is always this type: */
582	master->pass_type = main_pass;
583	}
584	master->scan_number = 0;
585	master->pass_number = 0;
586	if (cinfo->optimize_coding)
587	master->total_passes = cinfo->num_scans * 2;
588	else
589	master->total_passes = cinfo->num_scans;
590	}