/*

 * jcmaster.c

 *

 * This file was part of the Independent JPEG Group's software:

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

 * Modified 2003-2010 by Guido Vollbeding.

 * Lossless JPEG Modifications:

 * Copyright (C) 1999, Ken Murchison.

 * libjpeg-turbo Modifications:

 * Copyright (C) 2010, 2016, 2018, 2022-2024, D. R. Commander.

 * For conditions of distribution and use, see the accompanying README.ijg

 * 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"

#include "jpegapicomp.h"

#include "jcmaster.h"

/*

 * Support routines that do various essential calculations.

 */

#if JPEG_LIB_VERSION >= 70

/*

 * 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 */

{

  int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;

  /* Hardwire it to "no scaling" */

  cinfo->jpeg_width = cinfo->image_width;

  cinfo->jpeg_height = cinfo->image_height;

  cinfo->min_DCT_h_scaled_size = data_unit;

  cinfo->min_DCT_v_scaled_size = data_unit;

}

#endif

LOCAL(boolean)

using_std_huff_tables(j_compress_ptr cinfo)

{

  int i;

  static const UINT8 bits_dc_luminance[17] = {

    /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0

  };

  static const UINT8 val_dc_luminance[] = {

    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

  };

  static const UINT8 bits_dc_chrominance[17] = {

    /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0

  };

  static const UINT8 val_dc_chrominance[] = {

    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

  };

  static const UINT8 bits_ac_luminance[17] = {

    /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d

  };

  static const UINT8 val_ac_luminance[] = {

    0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,

    0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,

    0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,

    0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,

    0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,

    0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,

    0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,

    0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,

    0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,

    0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,

    0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,

    0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,

    0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,

    0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,

    0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,

    0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,

    0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,

    0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,

    0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,

    0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,

    0xf9, 0xfa

  };

  static const UINT8 bits_ac_chrominance[17] = {

    /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77

  };

  static const UINT8 val_ac_chrominance[] = {

    0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,

    0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,

    0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,

    0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,

    0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,

    0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,

    0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,

    0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,

    0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,

    0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,

    0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,

    0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,

    0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,

    0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,

    0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,

    0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,

    0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,

    0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,

    0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,

    0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,

    0xf9, 0xfa

  };

  if (cinfo->dc_huff_tbl_ptrs[0] == NULL ||

      cinfo->ac_huff_tbl_ptrs[0] == NULL ||

      cinfo->dc_huff_tbl_ptrs[1] == NULL ||

      cinfo->ac_huff_tbl_ptrs[1] == NULL)

    return FALSE;

  for (i = 2; i < NUM_HUFF_TBLS; i++) {

    if (cinfo->dc_huff_tbl_ptrs[i] != NULL ||

        cinfo->ac_huff_tbl_ptrs[i] != NULL)

      return FALSE;

  }

  if (memcmp(cinfo->dc_huff_tbl_ptrs[0]->bits, bits_dc_luminance,

             sizeof(bits_dc_luminance)) ||

      memcmp(cinfo->dc_huff_tbl_ptrs[0]->huffval, val_dc_luminance,

             sizeof(val_dc_luminance)) ||

      memcmp(cinfo->ac_huff_tbl_ptrs[0]->bits, bits_ac_luminance,

             sizeof(bits_ac_luminance)) ||

      memcmp(cinfo->ac_huff_tbl_ptrs[0]->huffval, val_ac_luminance,

             sizeof(val_ac_luminance)) ||

      memcmp(cinfo->dc_huff_tbl_ptrs[1]->bits, bits_dc_chrominance,

             sizeof(bits_dc_chrominance)) ||

      memcmp(cinfo->dc_huff_tbl_ptrs[1]->huffval, val_dc_chrominance,

             sizeof(val_dc_chrominance)) ||

      memcmp(cinfo->ac_huff_tbl_ptrs[1]->bits, bits_ac_chrominance,

             sizeof(bits_ac_chrominance)) ||

      memcmp(cinfo->ac_huff_tbl_ptrs[1]->huffval, val_ac_chrominance,

             sizeof(val_ac_chrominance)))

    return FALSE;

  return TRUE;

}

LOCAL(void)

initial_setup(j_compress_ptr cinfo, boolean transcode_only)

/* Do computations that are needed before master selection phase */

{

  int ci;

  jpeg_component_info *compptr;

  long samplesperrow;

  JDIMENSION jd_samplesperrow;

  int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;

#if JPEG_LIB_VERSION >= 70

#if JPEG_LIB_VERSION >= 80

  if (!transcode_only)

#endif

    jpeg_calc_jpeg_dimensions(cinfo);

#endif

  /* 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);

#ifdef C_LOSSLESS_SUPPORTED

  if (cinfo->data_precision != 8 && cinfo->data_precision != 12 &&

      cinfo->data_precision != 16)

#else

  if (cinfo->data_precision != 8 && cinfo->data_precision != 12)

#endif

    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. */

#if JPEG_LIB_VERSION >= 70

    compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = data_unit;

#else

    compptr->DCT_scaled_size = data_unit;

#endif

    /* Size in data units */

    compptr->width_in_blocks = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,

                    (long)(cinfo->max_h_samp_factor * data_unit));

    compptr->height_in_blocks = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_height * (long)compptr->v_samp_factor,

                    (long)(cinfo->max_v_samp_factor * data_unit));

    /* Size in samples */

    compptr->downsampled_width = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,

                    (long)cinfo->max_h_samp_factor);

    compptr->downsampled_height = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_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 or difference controller).

   */

  cinfo->total_iMCU_rows = (JDIMENSION)

    jdiv_round_up((long)cinfo->_jpeg_height,

                  (long)(cinfo->max_v_samp_factor * data_unit));

}

#if defined(C_MULTISCAN_FILES_SUPPORTED) || defined(C_LOSSLESS_SUPPORTED)

#define NEED_SCAN_SCRIPT

#endif

#ifdef NEED_SCAN_SCRIPT

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);

#ifndef C_MULTISCAN_FILES_SUPPORTED

  if (cinfo->num_scans > 1)

    ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

  scanptr = cinfo->scan_info;

  if (scanptr->Ss != 0 && scanptr->Se == 0) {

#ifdef C_LOSSLESS_SUPPORTED

    cinfo->master->lossless = TRUE;

    cinfo->progressive_mode = FALSE;

    for (ci = 0; ci < cinfo->num_components; ci++)

      component_sent[ci] = FALSE;

#else

    ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

  }

  /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;

   * for progressive JPEG, no scan can have this.

   */

  else if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2 - 1) {

#ifdef C_PROGRESSIVE_SUPPORTED

    cinfo->progressive_mode = TRUE;

    cinfo->master->lossless = FALSE;

    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 = cinfo->master->lossless = 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

      /* Rec. ITU-T T.81 | ISO/IEC 10918-1 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.

       */

      int max_Ah_Al = cinfo->data_precision == 12 ? 13 : 10;

      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 {

#ifdef C_LOSSLESS_SUPPORTED

      if (cinfo->master->lossless) {

        /* The JPEG spec simply gives the range 0..15 for Al (Pt), but that

         * seems wrong: the upper bound ought to depend on data precision.

         * Perhaps they really meant 0..N-1 for N-bit precision, which is what

         * we allow here.  Values greater than or equal to the data precision

         * will result in a blank image.

         */

        if (Ss < 1 || Ss > 7 ||         /* predictor selection value */

            Se != 0 || Ah != 0 ||

            Al < 0 || Al >= cinfo->data_precision) /* point transform */

          ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

      } else

#endif

      {

        /* 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 /* NEED_SCAN_SCRIPT */

LOCAL(void)

select_scan_parameters(j_compress_ptr cinfo)

/* Set up the scan parameters for the current scan */

{

  int ci;

#ifdef NEED_SCAN_SCRIPT

  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];

    }

    if (!cinfo->master->lossless) {

      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;

  int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;

  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 = data_unit;

    compptr->last_col_width = 1;

    /* For noninterleaved scans, it is convenient to define last_row_height

     * as the number of block rows present in the last iMCU row.

     */

    tmp = (int)(compptr->height_in_blocks % compptr->v_samp_factor);

    if (tmp == 0) tmp = compptr->v_samp_factor;

    compptr->last_row_height = tmp;

    /* Prepare array describing MCU composition */

    cinfo->blocks_in_MCU = 1;

    cinfo->MCU_membership[0] = 0;

  } else {

    /* Interleaved (multi-component) scan */

    if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)

      ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,

               MAX_COMPS_IN_SCAN);

    /* Overall image size in MCUs */

    cinfo->MCUs_per_row = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_width,

                    (long)(cinfo->max_h_samp_factor * data_unit));

    cinfo->MCU_rows_in_scan = (JDIMENSION)

      jdiv_round_up((long)cinfo->_jpeg_height,

                    (long)(cinfo->max_v_samp_factor * data_unit));

    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 * data_unit;

      /* 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->master->lossless) {

      (*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++;

#endif

    FALLTHROUGH                 /*FALLTHROUGH*/

  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 = (my_master_ptr)cinfo->master;

  boolean empty_huff_tables = TRUE;

  int i;

  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;

  if (cinfo->scan_info != NULL) {

#ifdef NEED_SCAN_SCRIPT

    validate_script(cinfo);

#else

    ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

  } else {

    cinfo->progressive_mode = FALSE;

    cinfo->num_scans = 1;

  }

  /* Disable smoothing and subsampling in lossless mode, since those are lossy

   * algorithms.  Set the JPEG colorspace to the input colorspace.  Disable raw

   * (downsampled) data input, because it isn't particularly useful without

   * subsampling and has not been tested in lossless mode.

   */

  if (cinfo->master->lossless) {

    int ci;

    jpeg_component_info *compptr;

    cinfo->raw_data_in = FALSE;

    cinfo->smoothing_factor = 0;

    jpeg_default_colorspace(cinfo);

    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;

         ci++, compptr++)

      compptr->h_samp_factor = compptr->v_samp_factor = 1;

  }

  /* Validate parameters, determine derived values */

  initial_setup(cinfo, transcode_only);

  if (cinfo->arith_code)

    cinfo->optimize_coding = FALSE;

  else {

    if (cinfo->master->lossless ||      /*  TEMPORARY HACK ??? */

        cinfo->progressive_mode)

      cinfo->optimize_coding = TRUE; /* assume default tables no good for

                                        progressive mode or lossless mode */

    for (i = 0; i < NUM_HUFF_TBLS; i++) {

      if (cinfo->dc_huff_tbl_ptrs[i] != NULL ||

          cinfo->ac_huff_tbl_ptrs[i] != NULL) {

        empty_huff_tables = FALSE;

        break;

      }

    }

    if (cinfo->data_precision == 12 && !cinfo->optimize_coding &&

        (empty_huff_tables || using_std_huff_tables(cinfo)))

      cinfo->optimize_coding = TRUE; /* assume default tables no good for

                                        12-bit data precision */

  }

  /* 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;

  master->jpeg_version = PACKAGE_NAME " version " VERSION " (build " BUILD ")";

}