/*

 * jcmaster.c

 *

 * Copyright (C) 1991-1997, Thomas G. Lane.

 * Modified 2003-2010 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

  /* Compute actual JPEG image dimensions and DCT scaling choices. */

  if (cinfo->scale_num >= cinfo->scale_denom * 8) {

    /* Provide 8/1 scaling */

    cinfo->jpeg_width = cinfo->image_width << 3;

    cinfo->jpeg_height = cinfo->image_height << 3;

    cinfo->min_DCT_h_scaled_size = 1;

    cinfo->min_DCT_v_scaled_size = 1;

  } else if (cinfo->scale_num >= cinfo->scale_denom * 4) {

    /* Provide 4/1 scaling */

    cinfo->jpeg_width = cinfo->image_width << 2;

    cinfo->jpeg_height = cinfo->image_height << 2;

    cinfo->min_DCT_h_scaled_size = 2;

    cinfo->min_DCT_v_scaled_size = 2;

  } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 8) {

    /* Provide 8/3 scaling */

    cinfo->jpeg_width = (cinfo->image_width << 1) + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 2, 3L);

    cinfo->jpeg_height = (cinfo->image_height << 1) + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 2, 3L);

    cinfo->min_DCT_h_scaled_size = 3;

    cinfo->min_DCT_v_scaled_size = 3;

  } else if (cinfo->scale_num >= cinfo->scale_denom * 2) {

    /* Provide 2/1 scaling */

    cinfo->jpeg_width = cinfo->image_width << 1;

    cinfo->jpeg_height = cinfo->image_height << 1;

    cinfo->min_DCT_h_scaled_size = 4;

    cinfo->min_DCT_v_scaled_size = 4;

  } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * 8) {

    /* Provide 8/5 scaling */

    cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 3, 5L);

    cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 3, 5L);

    cinfo->min_DCT_h_scaled_size = 5;

    cinfo->min_DCT_v_scaled_size = 5;

  } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 4) {

    /* Provide 4/3 scaling */

    cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width, 3L);

    cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height, 3L);

    cinfo->min_DCT_h_scaled_size = 6;

    cinfo->min_DCT_v_scaled_size = 6;

  } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * 8) {

    /* Provide 8/7 scaling */

    cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width, 7L);

    cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height, 7L);

    cinfo->min_DCT_h_scaled_size = 7;

    cinfo->min_DCT_v_scaled_size = 7;

  } else if (cinfo->scale_num >= cinfo->scale_denom) {

    /* Provide 1/1 scaling */

    cinfo->jpeg_width = cinfo->image_width;

    cinfo->jpeg_height = cinfo->image_height;

    cinfo->min_DCT_h_scaled_size = 8;

    cinfo->min_DCT_v_scaled_size = 8;

  } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * 8) {

    /* Provide 8/9 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 8, 9L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 8, 9L);

    cinfo->min_DCT_h_scaled_size = 9;

    cinfo->min_DCT_v_scaled_size = 9;

  } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * 4) {

    /* Provide 4/5 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 4, 5L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 4, 5L);

    cinfo->min_DCT_h_scaled_size = 10;

    cinfo->min_DCT_v_scaled_size = 10;

  } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * 8) {

    /* Provide 8/11 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 8, 11L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 8, 11L);

    cinfo->min_DCT_h_scaled_size = 11;

    cinfo->min_DCT_v_scaled_size = 11;

  } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 2) {

    /* Provide 2/3 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 2, 3L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 2, 3L);

    cinfo->min_DCT_h_scaled_size = 12;

    cinfo->min_DCT_v_scaled_size = 12;

  } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * 8) {

    /* Provide 8/13 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 8, 13L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 8, 13L);

    cinfo->min_DCT_h_scaled_size = 13;

    cinfo->min_DCT_v_scaled_size = 13;

  } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * 4) {

    /* Provide 4/7 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 4, 7L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 4, 7L);

    cinfo->min_DCT_h_scaled_size = 14;

    cinfo->min_DCT_v_scaled_size = 14;

  } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * 8) {

    /* Provide 8/15 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width * 8, 15L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height * 8, 15L);

    cinfo->min_DCT_h_scaled_size = 15;

    cinfo->min_DCT_v_scaled_size = 15;

  } else {

    /* Provide 1/2 scaling */

    cinfo->jpeg_width = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_width, 2L);

    cinfo->jpeg_height = (JDIMENSION)

      jdiv_round_up((long) cinfo->image_height, 2L);

    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 */

  cinfo->block_size = DCTSIZE;

  cinfo->natural_order = jpeg_natural_order;

  cinfo->lim_Se = DCTSIZE2-1;

}

LOCAL(void)

jpeg_calc_trans_dimensions (j_compress_ptr cinfo)

{

  if (cinfo->min_DCT_h_scaled_size < 1 || cinfo->min_DCT_h_scaled_size > 16

      || 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;

  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;

  }

  cinfo->lim_Se = cinfo->block_size < DCTSIZE ?

    cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;

}

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;

  long samplesperrow;

  JDIMENSION jd_samplesperrow;

  if (transcode_only)

    jpeg_calc_trans_dimensions(cinfo);

  else

    jpeg_calc_jpeg_dimensions(cinfo);

  /* Sanity check on image dimensions */

  if (cinfo->jpeg_height <= 0 || cinfo->jpeg_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->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);

  /* 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;

    /* 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));

    /* 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->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 */