kc3-lang/libjpeg-turbo/src/jcmaster.c

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• Hash : 9758c8a7
  Author :
  Date : 2024-11-18T13:40:08
  

  Exclude more code if !(C|D)_LOSSLESS_SUPPORTED
  

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• src/jcmaster.c

• /*
   * 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);
  
    /* Lossy JPEG images must have 8 or 12 bits per sample.  Lossless JPEG images
     * can have 2 to 16 bits per sample.
     */
  #ifdef C_LOSSLESS_SUPPORTED
    if (cinfo->master->lossless) {
      if (cinfo->data_precision < 2 || cinfo->data_precision > 16)
        ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
    } else
  #endif
    {
      if (cinfo->data_precision != 8 && cinfo->data_precision != 12)
        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;
    }
  
  #ifdef C_LOSSLESS_SUPPORTED
    /* 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;
    }
  #endif
  
    /* 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 ")";
  }
  

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