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 /*

  * 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.

  * libjpeg-turbo Modifications:

  * Copyright (C) 2010, D. R. Commander.

  * 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"

 #include "jpegcomp.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.

  */

 #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 */

 {

   /* 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

 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;

 #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);

   /* 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. */

 #if JPEG_LIB_VERSION >= 70

     compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = DCTSIZE;

 #else

     compptr->DCT_scaled_size = DCTSIZE;

 #endif

     /* 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 * DCTSIZE));

     compptr->height_in_blocks = (JDIMENSION)

       jdiv_round_up((long) cinfo->_jpeg_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->_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 controller).

    */

   cinfo->total_iMCU_rows = (JDIMENSION)

     jdiv_round_up((long) cinfo->_jpeg_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->_jpeg_width,

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

     cinfo->MCU_rows_in_scan = (JDIMENSION)

       jdiv_round_up((long) cinfo->_jpeg_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, transcode_only);

   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 && !cinfo->arith_code)	/*  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;

 }