| Index: third_party/libjpeg_turbo/jdphuff.c
 | 
| ===================================================================
 | 
| --- third_party/libjpeg_turbo/jdphuff.c	(revision 0)
 | 
| +++ third_party/libjpeg_turbo/jdphuff.c	(revision 0)
 | 
| @@ -0,0 +1,668 @@
 | 
| +/*
 | 
| + * 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.
 | 
| + */
 | 
| +
 | 
| +#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 */
 | 
| 
 |