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 /*

  * jdphuff.c

  *

  * Copyright (C) 1995-1997, Thomas G. Lane.

  * This file is part of the Independent JPEG Group's software.

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

  *

  * This file contains Huffman entropy decoding routines for progressive JPEG.

  *

  * Much of the complexity here has to do with supporting input suspension.

  * If the data source module demands suspension, we want to be able to back

  * up to the start of the current MCU.  To do this, we copy state variables

  * into local working storage, and update them back to the permanent

  * storage only upon successful completion of an MCU.

  */

 #define JPEG_INTERNALS

 #include "jinclude.h"

 #include "jpeglib.h"

 #include "jdhuff.h"		/* Declarations shared with jdhuff.c */

 #ifdef D_PROGRESSIVE_SUPPORTED

 /*

  * Expanded entropy decoder object for progressive Huffman decoding.

  *

  * The savable_state subrecord contains fields that change within an MCU,

  * but must not be updated permanently until we complete the MCU.

  */

 typedef struct {

   unsigned int EOBRUN;			/* remaining EOBs in EOBRUN */

   int last_dc_val[MAX_COMPS_IN_SCAN];	/* last DC coef for each component */

 } savable_state;

 /* This macro is to work around compilers with missing or broken

  * structure assignment.  You'll need to fix this code if you have

  * such a compiler and you change MAX_COMPS_IN_SCAN.

  */

 #ifndef NO_STRUCT_ASSIGN

 #define ASSIGN_STATE(dest,src)  ((dest) = (src))

 #else

 #if MAX_COMPS_IN_SCAN == 4

 #define ASSIGN_STATE(dest,src)  \

 	((dest).EOBRUN = (src).EOBRUN, \

 	 (dest).last_dc_val[0] = (src).last_dc_val[0], \

 	 (dest).last_dc_val[1] = (src).last_dc_val[1], \

 	 (dest).last_dc_val[2] = (src).last_dc_val[2], \

 	 (dest).last_dc_val[3] = (src).last_dc_val[3])

 #endif

 #endif

 typedef struct {

   struct jpeg_entropy_decoder pub; /* public fields */

   /* These fields are loaded into local variables at start of each MCU.

    * In case of suspension, we exit WITHOUT updating them.

    */

   bitread_perm_state bitstate;	/* Bit buffer at start of MCU */

   savable_state saved;		/* Other state at start of MCU */

   /* These fields are NOT loaded into local working state. */

   unsigned int restarts_to_go;	/* MCUs left in this restart interval */

   /* Pointers to derived tables (these workspaces have image lifespan) */

   d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];

   d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */

 } phuff_entropy_decoder;

 typedef phuff_entropy_decoder * phuff_entropy_ptr;

 /* Forward declarations */

 METHODDEF(boolean) decode_mcu_DC_first JPP((j_decompress_ptr cinfo,

 					    JBLOCKROW *MCU_data));

 METHODDEF(boolean) decode_mcu_AC_first JPP((j_decompress_ptr cinfo,

 					    JBLOCKROW *MCU_data));

 METHODDEF(boolean) decode_mcu_DC_refine JPP((j_decompress_ptr cinfo,

 					     JBLOCKROW *MCU_data));

 METHODDEF(boolean) decode_mcu_AC_refine JPP((j_decompress_ptr cinfo,

 					     JBLOCKROW *MCU_data));

 /*

  * Initialize for a Huffman-compressed scan.

  */

 METHODDEF(void)

 start_pass_phuff_decoder (j_decompress_ptr cinfo)

 {

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   boolean is_DC_band, bad;

   int ci, coefi, tbl;

   int *coef_bit_ptr;

   jpeg_component_info * compptr;

   is_DC_band = (cinfo->Ss == 0);

   /* Validate scan parameters */

   bad = FALSE;

   if (is_DC_band) {

     if (cinfo->Se != 0)

       bad = TRUE;

   } else {

     /* need not check Ss/Se < 0 since they came from unsigned bytes */

     if (cinfo->Ss > cinfo->Se || cinfo->Se >= DCTSIZE2)

       bad = TRUE;

     /* AC scans may have only one component */

     if (cinfo->comps_in_scan != 1)

       bad = TRUE;

   }

   if (cinfo->Ah != 0) {

     /* Successive approximation refinement scan: must have Al = Ah-1. */

     if (cinfo->Al != cinfo->Ah-1)

       bad = TRUE;

   }

   if (cinfo->Al > 13)		/* need not check for < 0 */

     bad = TRUE;

   /* Arguably the maximum Al value should be less than 13 for 8-bit precision,

    * but the spec doesn't say so, and we try to be liberal about what we

    * accept.  Note: large Al values could result in out-of-range DC

    * coefficients during early scans, leading to bizarre displays due to

    * overflows in the IDCT math.  But we won't crash.

    */

   if (bad)

     ERREXIT4(cinfo, JERR_BAD_PROGRESSION,

 	     cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);

   /* Update progression status, and verify that scan order is legal.

    * Note that inter-scan inconsistencies are treated as warnings

    * not fatal errors ... not clear if this is right way to behave.

    */

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

     int cindex = cinfo->cur_comp_info[ci]->component_index;

     coef_bit_ptr = & cinfo->coef_bits[cindex][0];

     if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */

       WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);

     for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {

       int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];

       if (cinfo->Ah != expected)

 	WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);

       coef_bit_ptr[coefi] = cinfo->Al;

     }

   }

   /* Select MCU decoding routine */

   if (cinfo->Ah == 0) {

     if (is_DC_band)

       entropy->pub.decode_mcu = decode_mcu_DC_first;

     else

       entropy->pub.decode_mcu = decode_mcu_AC_first;

   } else {

     if (is_DC_band)

       entropy->pub.decode_mcu = decode_mcu_DC_refine;

     else

       entropy->pub.decode_mcu = decode_mcu_AC_refine;

   }

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

     compptr = cinfo->cur_comp_info[ci];

     /* Make sure requested tables are present, and compute derived tables.

      * We may build same derived table more than once, but it's not expensive.

      */

     if (is_DC_band) {

       if (cinfo->Ah == 0) {	/* DC refinement needs no table */

 	tbl = compptr->dc_tbl_no;

 	jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,

 				& entropy->derived_tbls[tbl]);

       }

     } else {

       tbl = compptr->ac_tbl_no;

       jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,

 			      & entropy->derived_tbls[tbl]);

       /* remember the single active table */

       entropy->ac_derived_tbl = entropy->derived_tbls[tbl];

     }

     /* Initialize DC predictions to 0 */

     entropy->saved.last_dc_val[ci] = 0;

   }

   /* Initialize bitread state variables */

   entropy->bitstate.bits_left = 0;

   entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */

   entropy->pub.insufficient_data = FALSE;

   /* Initialize private state variables */

   entropy->saved.EOBRUN = 0;

   /* Initialize restart counter */

   entropy->restarts_to_go = cinfo->restart_interval;

 }

 /*

  * Figure F.12: extend sign bit.

  * On some machines, a shift and add will be faster than a table lookup.

  */

 #define AVOID_TABLES

 #ifdef AVOID_TABLES

 #define HUFF_EXTEND(x,s)  ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))

 #else

 #define HUFF_EXTEND(x,s)  ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))

 static const int extend_test[16] =   /* entry n is 2**(n-1) */

   { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,

     0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };

 static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */

   { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,

     ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,

     ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,

     ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };

 #endif /* AVOID_TABLES */

 /*

  * Check for a restart marker & resynchronize decoder.

  * Returns FALSE if must suspend.

  */

 LOCAL(boolean)

 process_restart (j_decompress_ptr cinfo)

 {

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   int ci;

   /* Throw away any unused bits remaining in bit buffer; */

   /* include any full bytes in next_marker's count of discarded bytes */

   cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;

   entropy->bitstate.bits_left = 0;

   /* Advance past the RSTn marker */

   if (! (*cinfo->marker->read_restart_marker) (cinfo))

     return FALSE;

   /* Re-initialize DC predictions to 0 */

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

     entropy->saved.last_dc_val[ci] = 0;

   /* Re-init EOB run count, too */

   entropy->saved.EOBRUN = 0;

   /* Reset restart counter */

   entropy->restarts_to_go = cinfo->restart_interval;

   /* Reset out-of-data flag, unless read_restart_marker left us smack up

    * against a marker.  In that case we will end up treating the next data

    * segment as empty, and we can avoid producing bogus output pixels by

    * leaving the flag set.

    */

   if (cinfo->unread_marker == 0)

     entropy->pub.insufficient_data = FALSE;

   return TRUE;

 }

 /*

  * Huffman MCU decoding.

  * Each of these routines decodes and returns one MCU's worth of

  * Huffman-compressed coefficients. 

  * The coefficients are reordered from zigzag order into natural array order,

  * but are not dequantized.

  *

  * The i'th block of the MCU is stored into the block pointed to by

  * MCU_data[i].  WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.

  *

  * We return FALSE if data source requested suspension.  In that case no

  * changes have been made to permanent state.  (Exception: some output

  * coefficients may already have been assigned.  This is harmless for

  * spectral selection, since we'll just re-assign them on the next call.

  * Successive approximation AC refinement has to be more careful, however.)

  */

 /*

  * MCU decoding for DC initial scan (either spectral selection,

  * or first pass of successive approximation).

  */

 METHODDEF(boolean)

 decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)

 {   

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   int Al = cinfo->Al;

   register int s, r;

   int blkn, ci;

   JBLOCKROW block;

   BITREAD_STATE_VARS;

   savable_state state;

   d_derived_tbl * tbl;

   jpeg_component_info * compptr;

   /* Process restart marker if needed; may have to suspend */

   if (cinfo->restart_interval) {

     if (entropy->restarts_to_go == 0)

       if (! process_restart(cinfo))

 	return FALSE;

   }

   /* If we've run out of data, just leave the MCU set to zeroes.

    * This way, we return uniform gray for the remainder of the segment.

    */

   if (! entropy->pub.insufficient_data) {

     /* Load up working state */

     BITREAD_LOAD_STATE(cinfo,entropy->bitstate);

     ASSIGN_STATE(state, entropy->saved);

     /* Outer loop handles each block in the MCU */

     for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {

       block = MCU_data[blkn];

       ci = cinfo->MCU_membership[blkn];

       compptr = cinfo->cur_comp_info[ci];

       tbl = entropy->derived_tbls[compptr->dc_tbl_no];

       /* Decode a single block's worth of coefficients */

       /* Section F.2.2.1: decode the DC coefficient difference */

       HUFF_DECODE(s, br_state, tbl, return FALSE, label1);

       if (s) {

 	CHECK_BIT_BUFFER(br_state, s, return FALSE);

 	r = GET_BITS(s);

 	s = HUFF_EXTEND(r, s);

       }

       /* Convert DC difference to actual value, update last_dc_val */

       s += state.last_dc_val[ci];

       state.last_dc_val[ci] = s;

       /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */

       (*block)[0] = (JCOEF) (s << Al);

     }

     /* Completed MCU, so update state */

     BITREAD_SAVE_STATE(cinfo,entropy->bitstate);

     ASSIGN_STATE(entropy->saved, state);

   }

   /* Account for restart interval (no-op if not using restarts) */

   entropy->restarts_to_go--;

   return TRUE;

 }

 /*

  * MCU decoding for AC initial scan (either spectral selection,

  * or first pass of successive approximation).

  */

 METHODDEF(boolean)

 decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)

 {   

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   int Se = cinfo->Se;

   int Al = cinfo->Al;

   register int s, k, r;

   unsigned int EOBRUN;

   JBLOCKROW block;

   BITREAD_STATE_VARS;

   d_derived_tbl * tbl;

   /* Process restart marker if needed; may have to suspend */

   if (cinfo->restart_interval) {

     if (entropy->restarts_to_go == 0)

       if (! process_restart(cinfo))

 	return FALSE;

   }

   /* If we've run out of data, just leave the MCU set to zeroes.

    * This way, we return uniform gray for the remainder of the segment.

    */

   if (! entropy->pub.insufficient_data) {

     /* Load up working state.

      * We can avoid loading/saving bitread state if in an EOB run.

      */

     EOBRUN = entropy->saved.EOBRUN;	/* only part of saved state we need */

     /* There is always only one block per MCU */

     if (EOBRUN > 0)		/* if it's a band of zeroes... */

       EOBRUN--;			/* ...process it now (we do nothing) */

     else {

       BITREAD_LOAD_STATE(cinfo,entropy->bitstate);

       block = MCU_data[0];

       tbl = entropy->ac_derived_tbl;

       for (k = cinfo->Ss; k <= Se; k++) {

 	HUFF_DECODE(s, br_state, tbl, return FALSE, label2);

 	r = s >> 4;

 	s &= 15;

 	if (s) {

 	  k += r;

 	  CHECK_BIT_BUFFER(br_state, s, return FALSE);

 	  r = GET_BITS(s);

 	  s = HUFF_EXTEND(r, s);

 	  /* Scale and output coefficient in natural (dezigzagged) order */

 	  (*block)[jpeg_natural_order[k]] = (JCOEF) (s << Al);

 	} else {

 	  if (r == 15) {	/* ZRL */

 	    k += 15;		/* skip 15 zeroes in band */

 	  } else {		/* EOBr, run length is 2^r + appended bits */

 	    EOBRUN = 1 << r;

 	    if (r) {		/* EOBr, r > 0 */

 	      CHECK_BIT_BUFFER(br_state, r, return FALSE);

 	      r = GET_BITS(r);

 	      EOBRUN += r;

 	    }

 	    EOBRUN--;		/* this band is processed at this moment */

 	    break;		/* force end-of-band */

 	  }

 	}

       }

       BITREAD_SAVE_STATE(cinfo,entropy->bitstate);

     }

     /* Completed MCU, so update state */

     entropy->saved.EOBRUN = EOBRUN;	/* only part of saved state we need */

   }

   /* Account for restart interval (no-op if not using restarts) */

   entropy->restarts_to_go--;

   return TRUE;

 }

 /*

  * MCU decoding for DC successive approximation refinement scan.

  * Note: we assume such scans can be multi-component, although the spec

  * is not very clear on the point.

  */

 METHODDEF(boolean)

 decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)

 {   

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   int p1 = 1 << cinfo->Al;	/* 1 in the bit position being coded */

   int blkn;

   JBLOCKROW block;

   BITREAD_STATE_VARS;

   /* Process restart marker if needed; may have to suspend */

   if (cinfo->restart_interval) {

     if (entropy->restarts_to_go == 0)

       if (! process_restart(cinfo))

 	return FALSE;

   }

   /* Not worth the cycles to check insufficient_data here,

    * since we will not change the data anyway if we read zeroes.

    */

   /* Load up working state */

   BITREAD_LOAD_STATE(cinfo,entropy->bitstate);

   /* Outer loop handles each block in the MCU */

   for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {

     block = MCU_data[blkn];

     /* Encoded data is simply the next bit of the two's-complement DC value */

     CHECK_BIT_BUFFER(br_state, 1, return FALSE);

     if (GET_BITS(1))

       (*block)[0] |= p1;

     /* Note: since we use |=, repeating the assignment later is safe */

   }

   /* Completed MCU, so update state */

   BITREAD_SAVE_STATE(cinfo,entropy->bitstate);

   /* Account for restart interval (no-op if not using restarts) */

   entropy->restarts_to_go--;

   return TRUE;

 }

 /*

  * MCU decoding for AC successive approximation refinement scan.

  */

 METHODDEF(boolean)

 decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)

 {   

   phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;

   int Se = cinfo->Se;

   int p1 = 1 << cinfo->Al;	/* 1 in the bit position being coded */

   int m1 = (-1) << cinfo->Al;	/* -1 in the bit position being coded */

   register int s, k, r;

   unsigned int EOBRUN;

   JBLOCKROW block;

   JCOEFPTR thiscoef;

   BITREAD_STATE_VARS;

   d_derived_tbl * tbl;

   int num_newnz;

   int newnz_pos[DCTSIZE2];

   /* Process restart marker if needed; may have to suspend */

   if (cinfo->restart_interval) {

     if (entropy->restarts_to_go == 0)

       if (! process_restart(cinfo))

 	return FALSE;

   }

   /* If we've run out of data, don't modify the MCU.

    */

   if (! entropy->pub.insufficient_data) {

     /* Load up working state */

     BITREAD_LOAD_STATE(cinfo,entropy->bitstate);

     EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */

     /* There is always only one block per MCU */

     block = MCU_data[0];

     tbl = entropy->ac_derived_tbl;

     /* If we are forced to suspend, we must undo the assignments to any newly

      * nonzero coefficients in the block, because otherwise we'd get confused

      * next time about which coefficients were already nonzero.

      * But we need not undo addition of bits to already-nonzero coefficients;

      * instead, we can test the current bit to see if we already did it.

      */

     num_newnz = 0;

     /* initialize coefficient loop counter to start of band */

     k = cinfo->Ss;

     if (EOBRUN == 0) {

       for (; k <= Se; k++) {

 	HUFF_DECODE(s, br_state, tbl, goto undoit, label3);

 	r = s >> 4;

 	s &= 15;

 	if (s) {

 	  if (s != 1)		/* size of new coef should always be 1 */

 	    WARNMS(cinfo, JWRN_HUFF_BAD_CODE);

 	  CHECK_BIT_BUFFER(br_state, 1, goto undoit);

 	  if (GET_BITS(1))

 	    s = p1;		/* newly nonzero coef is positive */

 	  else

 	    s = m1;		/* newly nonzero coef is negative */

 	} else {

 	  if (r != 15) {

 	    EOBRUN = 1 << r;	/* EOBr, run length is 2^r + appended bits */

 	    if (r) {

 	      CHECK_BIT_BUFFER(br_state, r, goto undoit);

 	      r = GET_BITS(r);

 	      EOBRUN += r;

 	    }

 	    break;		/* rest of block is handled by EOB logic */

 	  }

 	  /* note s = 0 for processing ZRL */

 	}

 	/* Advance over already-nonzero coefs and r still-zero coefs,

 	 * appending correction bits to the nonzeroes.  A correction bit is 1

 	 * if the absolute value of the coefficient must be increased.

 	 */

 	do {

 	  thiscoef = *block + jpeg_natural_order[k];

 	  if (*thiscoef != 0) {

 	    CHECK_BIT_BUFFER(br_state, 1, goto undoit);

 	    if (GET_BITS(1)) {

 	      if ((*thiscoef & p1) == 0) { /* do nothing if already set it */

 		if (*thiscoef >= 0)

 		  *thiscoef += p1;

 		else

 		  *thiscoef += m1;

 	      }

 	    }

 	  } else {

 	    if (--r < 0)

 	      break;		/* reached target zero coefficient */

 	  }

 	  k++;

 	} while (k <= Se);

 	if (s) {

 	  int pos = jpeg_natural_order[k];

 	  /* Output newly nonzero coefficient */

 	  (*block)[pos] = (JCOEF) s;

 	  /* Remember its position in case we have to suspend */

 	  newnz_pos[num_newnz++] = pos;

 	}

       }

     }

     if (EOBRUN > 0) {

       /* Scan any remaining coefficient positions after the end-of-band

        * (the last newly nonzero coefficient, if any).  Append a correction

        * bit to each already-nonzero coefficient.  A correction bit is 1

        * if the absolute value of the coefficient must be increased.

        */

       for (; k <= Se; k++) {

 	thiscoef = *block + jpeg_natural_order[k];

 	if (*thiscoef != 0) {

 	  CHECK_BIT_BUFFER(br_state, 1, goto undoit);

 	  if (GET_BITS(1)) {

 	    if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */

 	      if (*thiscoef >= 0)

 		*thiscoef += p1;

 	      else

 		*thiscoef += m1;

 	    }

 	  }

 	}

       }

       /* Count one block completed in EOB run */

       EOBRUN--;

     }

     /* Completed MCU, so update state */

     BITREAD_SAVE_STATE(cinfo,entropy->bitstate);

     entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */

   }

   /* Account for restart interval (no-op if not using restarts) */

   entropy->restarts_to_go--;

   return TRUE;

 undoit:

   /* Re-zero any output coefficients that we made newly nonzero */

   while (num_newnz > 0)

     (*block)[newnz_pos[--num_newnz]] = 0;

   return FALSE;

 }

 /*

  * Module initialization routine for progressive Huffman entropy decoding.

  */

 GLOBAL(void)

 jinit_phuff_decoder (j_decompress_ptr cinfo)

 {

   phuff_entropy_ptr entropy;

   int *coef_bit_ptr;

   int ci, i;

   entropy = (phuff_entropy_ptr)

     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

 				SIZEOF(phuff_entropy_decoder));

   cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;

   entropy->pub.start_pass = start_pass_phuff_decoder;

   /* Mark derived tables unallocated */

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

     entropy->derived_tbls[i] = NULL;

   }

   /* Create progression status table */

   cinfo->coef_bits = (int (*)[DCTSIZE2])

     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

 				cinfo->num_components*DCTSIZE2*SIZEOF(int));

   coef_bit_ptr = & cinfo->coef_bits[0][0];

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

     for (i = 0; i < DCTSIZE2; i++)

       *coef_bit_ptr++ = -1;

 }

 #endif /* D_PROGRESSIVE_SUPPORTED */