FCL/sf/mw/qt: comparison src/3rdparty/libjpeg/jchuff.c

equal deleted inserted replaced

-:b72c6db6890b
+:5dc02b23752f
 /*
 * jchuff.c
 *
 * Copyright (C) 1991-1997, Thomas G. Lane.
+* Modified 2006-2009 by Guido Vollbeding.
 * 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 encoding routines.
+* Both sequential and progressive modes are supported in this single module.
 *
 * Much of the complexity here has to do with supporting output suspension.
 * If the data destination 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 JPEG objects only upon successful completion of an MCU.
+*
+* We do not support output suspension for the progressive JPEG mode, since
+* the library currently does not allow multiple-scan files to be written
+* with output suspension.
 */
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
-#include "jchuff.h"		/* Declarations shared with jcphuff.c */
+/* The legal range of a DCT coefficient is
+*  -1024 .. +1023  for 8-bit data;
+* -16384 .. +16383 for 12-bit data.
+* Hence the magnitude should always fit in 10 or 14 bits respectively.
+*/
+#if BITS_IN_JSAMPLE == 8
+#define MAX_COEF_BITS 10
+#else
+#define MAX_COEF_BITS 14
+#endif
+/* Derived data constructed for each Huffman table */
+typedef struct {
+unsigned int ehufco[256];	/* code for each symbol */
+char ehufsi[256];		/* length of code for each symbol */
+/* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
+} c_derived_tbl;
 /* Expanded entropy encoder object for Huffman encoding.
 *
 * The savable_state subrecord contains fields that change within an MCU,
 /* Pointers to derived tables (these workspaces have image lifespan) */
 c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
 c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
-#ifdef ENTROPY_OPT_SUPPORTED	/* Statistics tables for optimization */
+/* Statistics tables for optimization */
 long * dc_count_ptrs[NUM_HUFF_TBLS];
 long * ac_count_ptrs[NUM_HUFF_TBLS];
-#endif
+/* Following fields used only in progressive mode */
+/* Mode flag: TRUE for optimization, FALSE for actual data output */
+boolean gather_statistics;
+/* next_output_byte/free_in_buffer are local copies of cinfo->dest fields.
+*/
+JOCTET * next_output_byte;	/* => next byte to write in buffer */
+size_t free_in_buffer;	/* # of byte spaces remaining in buffer */
+j_compress_ptr cinfo;		/* link to cinfo (needed for dump_buffer) */
+/* Coding status for AC components */
+int ac_tbl_no;		/* the table number of the single component */
+unsigned int EOBRUN;		/* run length of EOBs */
+unsigned int BE;		/* # of buffered correction bits before MCU */
+char * bit_buffer;		/* buffer for correction bits (1 per char) */
+/* packing correction bits tightly would save some space but cost time... */
 } huff_entropy_encoder;
 typedef huff_entropy_encoder * huff_entropy_ptr;
-/* Working state while writing an MCU.
+/* Working state while writing an MCU (sequential mode).
 * This struct contains all the fields that are needed by subroutines.
 */
 typedef struct {
 JOCTET * next_output_byte;	/* => next byte to write in buffer */
 size_t free_in_buffer;	/* # of byte spaces remaining in buffer */
 savable_state cur;		/* Current bit buffer & DC state */
 j_compress_ptr cinfo;		/* dump_buffer needs access to this */
 } working_state;
+/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit
-/* Forward declarations */
+* buffer can hold.  Larger sizes may slightly improve compression, but
-METHODDEF(boolean) encode_mcu_huff JPP((j_compress_ptr cinfo,
+* 1000 is already well into the realm of overkill.
-					JBLOCKROW *MCU_data));
+* The minimum safe size is 64 bits.
-METHODDEF(void) finish_pass_huff JPP((j_compress_ptr cinfo));
+*/
-#ifdef ENTROPY_OPT_SUPPORTED
-METHODDEF(boolean) encode_mcu_gather JPP((j_compress_ptr cinfo,
+#define MAX_CORR_BITS  1000	/* Max # of correction bits I can buffer */
-					  JBLOCKROW *MCU_data));
-METHODDEF(void) finish_pass_gather JPP((j_compress_ptr cinfo));
+/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32.
+* We assume that int right shift is unsigned if INT32 right shift is,
+* which should be safe.
+*/
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS	int ishift_temp;
+#define IRIGHT_SHIFT(x,shft)  \
+	((ishift_temp = (x)) < 0 ? \
+	 (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \
+	 (ishift_temp >> (shft)))
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT(x,shft)	((x) >> (shft))
 #endif
-/*
-* Initialize for a Huffman-compressed scan.
-* If gather_statistics is TRUE, we do not output anything during the scan,
-* just count the Huffman symbols used and generate Huffman code tables.
-*/
-METHODDEF(void)
-start_pass_huff (j_compress_ptr cinfo, boolean gather_statistics)
-{
-huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
-int ci, dctbl, actbl;
-jpeg_component_info * compptr;
-if (gather_statistics) {
-#ifdef ENTROPY_OPT_SUPPORTED
-entropy->pub.encode_mcu = encode_mcu_gather;
-entropy->pub.finish_pass = finish_pass_gather;
-#else
-ERREXIT(cinfo, JERR_NOT_COMPILED);
-#endif
-} else {
-entropy->pub.encode_mcu = encode_mcu_huff;
-entropy->pub.finish_pass = finish_pass_huff;
-}
-for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
-compptr = cinfo->cur_comp_info[ci];
-dctbl = compptr->dc_tbl_no;
-actbl = compptr->ac_tbl_no;
-if (gather_statistics) {
-#ifdef ENTROPY_OPT_SUPPORTED
-/* Check for invalid table indexes */
-/* (make_c_derived_tbl does this in the other path) */
-if (dctbl < 0 || dctbl >= NUM_HUFF_TBLS)
-	ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, dctbl);
-if (actbl < 0 || actbl >= NUM_HUFF_TBLS)
-	ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, actbl);
-/* Allocate and zero the statistics tables */
-/* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
-if (entropy->dc_count_ptrs[dctbl] == NULL)
-	entropy->dc_count_ptrs[dctbl] = (long *)
-	  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
-				      257 * SIZEOF(long));
-MEMZERO(entropy->dc_count_ptrs[dctbl], 257 * SIZEOF(long));
-if (entropy->ac_count_ptrs[actbl] == NULL)
-	entropy->ac_count_ptrs[actbl] = (long *)
-	  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
-				      257 * SIZEOF(long));
-MEMZERO(entropy->ac_count_ptrs[actbl], 257 * SIZEOF(long));
-#endif
-} else {
-/* Compute derived values for Huffman tables */
-/* We may do this more than once for a table, but it's not expensive */
-jpeg_make_c_derived_tbl(cinfo, TRUE, dctbl,
-			      & entropy->dc_derived_tbls[dctbl]);
-jpeg_make_c_derived_tbl(cinfo, FALSE, actbl,
-			      & entropy->ac_derived_tbls[actbl]);
-}
-/* Initialize DC predictions to 0 */
-entropy->saved.last_dc_val[ci] = 0;
-}
-/* Initialize bit buffer to empty */
-entropy->saved.put_buffer = 0;
-entropy->saved.put_bits = 0;
-/* Initialize restart stuff */
-entropy->restarts_to_go = cinfo->restart_interval;
-entropy->next_restart_num = 0;
-}
 /*
 * Compute the derived values for a Huffman table.
 * This routine also performs some validation checks on the table.
-*
+*/
-* Note this is also used by jcphuff.c.
-*/
+LOCAL(void)
-GLOBAL(void)
 jpeg_make_c_derived_tbl (j_compress_ptr cinfo, boolean isDC, int tblno,
 			 c_derived_tbl ** pdtbl)
 {
 JHUFF_TBL *htbl;
 c_derived_tbl *dtbl;
 dtbl->ehufsi[i] = huffsize[p];
 }
 }
-/* Outputting bytes to the file */
+/* Outputting bytes to the file.
+* NB: these must be called only when actually outputting,
+* that is, entropy->gather_statistics == FALSE.
+*/
 /* Emit a byte, taking 'action' if must suspend. */
-#define emit_byte(state,val,action)  \
+#define emit_byte_s(state,val,action)  \
 	{ *(state)->next_output_byte++ = (JOCTET) (val);  \
 	  if (--(state)->free_in_buffer == 0)  \
-	    if (! dump_buffer(state))  \
+	    if (! dump_buffer_s(state))  \
 	      { action; } }
+/* Emit a byte */
+#define emit_byte_e(entropy,val)  \
+	{ *(entropy)->next_output_byte++ = (JOCTET) (val);  \
+	  if (--(entropy)->free_in_buffer == 0)  \
+	    dump_buffer_e(entropy); }
 LOCAL(boolean)
-dump_buffer (working_state * state)
+dump_buffer_s (working_state * state)
 /* Empty the output buffer; return TRUE if successful, FALSE if must suspend */
 {
 struct jpeg_destination_mgr * dest = state->cinfo->dest;
 if (! (*dest->empty_output_buffer) (state->cinfo))
 state->free_in_buffer = dest->free_in_buffer;
 return TRUE;
 }
+LOCAL(void)
+dump_buffer_e (huff_entropy_ptr entropy)
+/* Empty the output buffer; we do not support suspension in this case. */
+{
+struct jpeg_destination_mgr * dest = entropy->cinfo->dest;
+if (! (*dest->empty_output_buffer) (entropy->cinfo))
+ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND);
+/* After a successful buffer dump, must reset buffer pointers */
+entropy->next_output_byte = dest->next_output_byte;
+entropy->free_in_buffer = dest->free_in_buffer;
+}
 /* Outputting bits to the file */
 /* Only the right 24 bits of put_buffer are used; the valid bits are
 * left-justified in this part.  At most 16 bits can be passed to emit_bits
 * in one call, and we never retain more than 7 bits in put_buffer
 * between calls, so 24 bits are sufficient.
 */
 INLINE
 LOCAL(boolean)
-emit_bits (working_state * state, unsigned int code, int size)
+emit_bits_s (working_state * state, unsigned int code, int size)
 /* Emit some bits; return TRUE if successful, FALSE if must suspend */
 {
 /* This routine is heavily used, so it's worth coding tightly. */
 register INT32 put_buffer = (INT32) code;
 register int put_bits = state->cur.put_bits;
 put_buffer |= state->cur.put_buffer; /* and merge with old buffer contents */
 while (put_bits >= 8) {
 int c = (int) ((put_buffer >> 16) & 0xFF);
-emit_byte(state, c, return FALSE);
+emit_byte_s(state, c, return FALSE);
 if (c == 0xFF) {		/* need to stuff a zero byte? */
-emit_byte(state, 0, return FALSE);
+emit_byte_s(state, 0, return FALSE);
 }
 put_buffer <<= 8;
 put_bits -= 8;
 }
 return TRUE;
 }
+INLINE
+LOCAL(void)
+emit_bits_e (huff_entropy_ptr entropy, unsigned int code, int size)
+/* Emit some bits, unless we are in gather mode */
+{
+/* This routine is heavily used, so it's worth coding tightly. */
+register INT32 put_buffer = (INT32) code;
+register int put_bits = entropy->saved.put_bits;
+/* if size is 0, caller used an invalid Huffman table entry */
+if (size == 0)
+ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+if (entropy->gather_statistics)
+return;			/* do nothing if we're only getting stats */
+put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */
+put_bits += size;		/* new number of bits in buffer */
+put_buffer <<= 24 - put_bits; /* align incoming bits */
+/* and merge with old buffer contents */
+put_buffer |= entropy->saved.put_buffer;
+while (put_bits >= 8) {
+int c = (int) ((put_buffer >> 16) & 0xFF);
+emit_byte_e(entropy, c);
+if (c == 0xFF) {		/* need to stuff a zero byte? */
+emit_byte_e(entropy, 0);
+}
+put_buffer <<= 8;
+put_bits -= 8;
+}
+entropy->saved.put_buffer = put_buffer; /* update variables */
+entropy->saved.put_bits = put_bits;
+}
 LOCAL(boolean)
-flush_bits (working_state * state)
+flush_bits_s (working_state * state)
 {
-if (! emit_bits(state, 0x7F, 7)) /* fill any partial byte with ones */
+if (! emit_bits_s(state, 0x7F, 7)) /* fill any partial byte with ones */
 return FALSE;
-state->cur.put_buffer = 0;	/* and reset bit-buffer to empty */
+state->cur.put_buffer = 0;	     /* and reset bit-buffer to empty */
 state->cur.put_bits = 0;
+return TRUE;
+}
+LOCAL(void)
+flush_bits_e (huff_entropy_ptr entropy)
+{
+emit_bits_e(entropy, 0x7F, 7); /* fill any partial byte with ones */
+entropy->saved.put_buffer = 0; /* and reset bit-buffer to empty */
+entropy->saved.put_bits = 0;
+}
+/*
+* Emit (or just count) a Huffman symbol.
+*/
+INLINE
+LOCAL(void)
+emit_dc_symbol (huff_entropy_ptr entropy, int tbl_no, int symbol)
+{
+if (entropy->gather_statistics)
+entropy->dc_count_ptrs[tbl_no][symbol]++;
+else {
+c_derived_tbl * tbl = entropy->dc_derived_tbls[tbl_no];
+emit_bits_e(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]);
+}
+}
+INLINE
+LOCAL(void)
+emit_ac_symbol (huff_entropy_ptr entropy, int tbl_no, int symbol)
+{
+if (entropy->gather_statistics)
+entropy->ac_count_ptrs[tbl_no][symbol]++;
+else {
+c_derived_tbl * tbl = entropy->ac_derived_tbls[tbl_no];
+emit_bits_e(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]);
+}
+}
+/*
+* Emit bits from a correction bit buffer.
+*/
+LOCAL(void)
+emit_buffered_bits (huff_entropy_ptr entropy, char * bufstart,
+		    unsigned int nbits)
+{
+if (entropy->gather_statistics)
+return;			/* no real work */
+while (nbits > 0) {
+emit_bits_e(entropy, (unsigned int) (*bufstart), 1);
+bufstart++;
+nbits--;
+}
+}
+/*
+* Emit any pending EOBRUN symbol.
+*/
+LOCAL(void)
+emit_eobrun (huff_entropy_ptr entropy)
+{
+register int temp, nbits;
+if (entropy->EOBRUN > 0) {	/* if there is any pending EOBRUN */
+temp = entropy->EOBRUN;
+nbits = 0;
+while ((temp >>= 1))
+nbits++;
+/* safety check: shouldn't happen given limited correction-bit buffer */
+if (nbits > 14)
+ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+emit_ac_symbol(entropy, entropy->ac_tbl_no, nbits << 4);
+if (nbits)
+emit_bits_e(entropy, entropy->EOBRUN, nbits);
+entropy->EOBRUN = 0;
+/* Emit any buffered correction bits */
+emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE);
+entropy->BE = 0;
+}
+}
+/*
+* Emit a restart marker & resynchronize predictions.
+*/
+LOCAL(boolean)
+emit_restart_s (working_state * state, int restart_num)
+{
+int ci;
+if (! flush_bits_s(state))
+return FALSE;
+emit_byte_s(state, 0xFF, return FALSE);
+emit_byte_s(state, JPEG_RST0 + restart_num, return FALSE);
+/* Re-initialize DC predictions to 0 */
+for (ci = 0; ci < state->cinfo->comps_in_scan; ci++)
+state->cur.last_dc_val[ci] = 0;
+/* The restart counter is not updated until we successfully write the MCU. */
+return TRUE;
+}
+LOCAL(void)
+emit_restart_e (huff_entropy_ptr entropy, int restart_num)
+{
+int ci;
+emit_eobrun(entropy);
+if (! entropy->gather_statistics) {
+flush_bits_e(entropy);
+emit_byte_e(entropy, 0xFF);
+emit_byte_e(entropy, JPEG_RST0 + restart_num);
+}
+if (entropy->cinfo->Ss == 0) {
+/* Re-initialize DC predictions to 0 */
+for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++)
+entropy->saved.last_dc_val[ci] = 0;
+} else {
+/* Re-initialize all AC-related fields to 0 */
+entropy->EOBRUN = 0;
+entropy->BE = 0;
+}
+}
+/*
+* MCU encoding for DC initial scan (either spectral selection,
+* or first pass of successive approximation).
+*/
+METHODDEF(boolean)
+encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+register int temp, temp2;
+register int nbits;
+int blkn, ci;
+int Al = cinfo->Al;
+JBLOCKROW block;
+jpeg_component_info * compptr;
+ISHIFT_TEMPS
+entropy->next_output_byte = cinfo->dest->next_output_byte;
+entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+/* Emit restart marker if needed */
+if (cinfo->restart_interval)
+if (entropy->restarts_to_go == 0)
+emit_restart_e(entropy, entropy->next_restart_num);
+/* Encode the MCU data blocks */
+for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+block = MCU_data[blkn];
+ci = cinfo->MCU_membership[blkn];
+compptr = cinfo->cur_comp_info[ci];
+/* Compute the DC value after the required point transform by Al.
+* This is simply an arithmetic right shift.
+*/
+temp2 = IRIGHT_SHIFT((int) ((*block)[0]), Al);
+/* DC differences are figured on the point-transformed values. */
+temp = temp2 - entropy->saved.last_dc_val[ci];
+entropy->saved.last_dc_val[ci] = temp2;
+/* Encode the DC coefficient difference per section G.1.2.1 */
+temp2 = temp;
+if (temp < 0) {
+temp = -temp;		/* temp is abs value of input */
+/* For a negative input, want temp2 = bitwise complement of abs(input) */
+/* This code assumes we are on a two's complement machine */
+temp2--;
+}
+/* Find the number of bits needed for the magnitude of the coefficient */
+nbits = 0;
+while (temp) {
+nbits++;
+temp >>= 1;
+}
+/* Check for out-of-range coefficient values.
+* Since we're encoding a difference, the range limit is twice as much.
+*/
+if (nbits > MAX_COEF_BITS+1)
+ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+/* Count/emit the Huffman-coded symbol for the number of bits */
+emit_dc_symbol(entropy, compptr->dc_tbl_no, nbits);
+/* Emit that number of bits of the value, if positive, */
+/* or the complement of its magnitude, if negative. */
+if (nbits)			/* emit_bits rejects calls with size 0 */
+emit_bits_e(entropy, (unsigned int) temp2, nbits);
+}
+cinfo->dest->next_output_byte = entropy->next_output_byte;
+cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+/* Update restart-interval state too */
+if (cinfo->restart_interval) {
+if (entropy->restarts_to_go == 0) {
+entropy->restarts_to_go = cinfo->restart_interval;
+entropy->next_restart_num++;
+entropy->next_restart_num &= 7;
+}
+entropy->restarts_to_go--;
+}
+return TRUE;
+}
+/*
+* MCU encoding for AC initial scan (either spectral selection,
+* or first pass of successive approximation).
+*/
+METHODDEF(boolean)
+encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+register int temp, temp2;
+register int nbits;
+register int r, k;
+int Se, Al;
+const int * natural_order;
+JBLOCKROW block;
+entropy->next_output_byte = cinfo->dest->next_output_byte;
+entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+/* Emit restart marker if needed */
+if (cinfo->restart_interval)
+if (entropy->restarts_to_go == 0)
+emit_restart_e(entropy, entropy->next_restart_num);
+Se = cinfo->Se;
+Al = cinfo->Al;
+natural_order = cinfo->natural_order;
+/* Encode the MCU data block */
+block = MCU_data[0];
+/* Encode the AC coefficients per section G.1.2.2, fig. G.3 */
+r = 0;			/* r = run length of zeros */
+for (k = cinfo->Ss; k <= Se; k++) {
+if ((temp = (*block)[natural_order[k]]) == 0) {
+r++;
+continue;
+}
+/* We must apply the point transform by Al.  For AC coefficients this
+* is an integer division with rounding towards 0.  To do this portably
+* in C, we shift after obtaining the absolute value; so the code is
+* interwoven with finding the abs value (temp) and output bits (temp2).
+*/
+if (temp < 0) {
+temp = -temp;		/* temp is abs value of input */
+temp >>= Al;		/* apply the point transform */
+/* For a negative coef, want temp2 = bitwise complement of abs(coef) */
+temp2 = ~temp;
+} else {
+temp >>= Al;		/* apply the point transform */
+temp2 = temp;
+}
+/* Watch out for case that nonzero coef is zero after point transform */
+if (temp == 0) {
+r++;
+continue;
+}
+/* Emit any pending EOBRUN */
+if (entropy->EOBRUN > 0)
+emit_eobrun(entropy);
+/* if run length > 15, must emit special run-length-16 codes (0xF0) */
+while (r > 15) {
+emit_ac_symbol(entropy, entropy->ac_tbl_no, 0xF0);
+r -= 16;
+}
+/* Find the number of bits needed for the magnitude of the coefficient */
+nbits = 1;			/* there must be at least one 1 bit */
+while ((temp >>= 1))
+nbits++;
+/* Check for out-of-range coefficient values */
+if (nbits > MAX_COEF_BITS)
+ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+/* Count/emit Huffman symbol for run length / number of bits */
+emit_ac_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits);
+/* Emit that number of bits of the value, if positive, */
+/* or the complement of its magnitude, if negative. */
+emit_bits_e(entropy, (unsigned int) temp2, nbits);
+r = 0;			/* reset zero run length */
+}
+if (r > 0) {			/* If there are trailing zeroes, */
+entropy->EOBRUN++;		/* count an EOB */
+if (entropy->EOBRUN == 0x7FFF)
+emit_eobrun(entropy);	/* force it out to avoid overflow */
+}
+cinfo->dest->next_output_byte = entropy->next_output_byte;
+cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+/* Update restart-interval state too */
+if (cinfo->restart_interval) {
+if (entropy->restarts_to_go == 0) {
+entropy->restarts_to_go = cinfo->restart_interval;
+entropy->next_restart_num++;
+entropy->next_restart_num &= 7;
+}
+entropy->restarts_to_go--;
+}
+return TRUE;
+}
+/*
+* MCU encoding 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)
+encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+register int temp;
+int blkn;
+int Al = cinfo->Al;
+JBLOCKROW block;
+entropy->next_output_byte = cinfo->dest->next_output_byte;
+entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+/* Emit restart marker if needed */
+if (cinfo->restart_interval)
+if (entropy->restarts_to_go == 0)
+emit_restart_e(entropy, entropy->next_restart_num);
+/* Encode the MCU data blocks */
+for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+block = MCU_data[blkn];
+/* We simply emit the Al'th bit of the DC coefficient value. */
+temp = (*block)[0];
+emit_bits_e(entropy, (unsigned int) (temp >> Al), 1);
+}
+cinfo->dest->next_output_byte = entropy->next_output_byte;
+cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+/* Update restart-interval state too */
+if (cinfo->restart_interval) {
+if (entropy->restarts_to_go == 0) {
+entropy->restarts_to_go = cinfo->restart_interval;
+entropy->next_restart_num++;
+entropy->next_restart_num &= 7;
+}
+entropy->restarts_to_go--;
+}
+return TRUE;
+}
+/*
+* MCU encoding for AC successive approximation refinement scan.
+*/
+METHODDEF(boolean)
+encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+register int temp;
+register int r, k;
+int EOB;
+char *BR_buffer;
+unsigned int BR;
+int Se, Al;
+const int * natural_order;
+JBLOCKROW block;
+int absvalues[DCTSIZE2];
+entropy->next_output_byte = cinfo->dest->next_output_byte;
+entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+/* Emit restart marker if needed */
+if (cinfo->restart_interval)
+if (entropy->restarts_to_go == 0)
+emit_restart_e(entropy, entropy->next_restart_num);
+Se = cinfo->Se;
+Al = cinfo->Al;
+natural_order = cinfo->natural_order;
+/* Encode the MCU data block */
+block = MCU_data[0];
+/* It is convenient to make a pre-pass to determine the transformed
+* coefficients' absolute values and the EOB position.
+*/
+EOB = 0;
+for (k = cinfo->Ss; k <= Se; k++) {
+temp = (*block)[natural_order[k]];
+/* We must apply the point transform by Al.  For AC coefficients this
+* is an integer division with rounding towards 0.  To do this portably
+* in C, we shift after obtaining the absolute value.
+*/
+if (temp < 0)
+temp = -temp;		/* temp is abs value of input */
+temp >>= Al;		/* apply the point transform */
+absvalues[k] = temp;	/* save abs value for main pass */
+if (temp == 1)
+EOB = k;			/* EOB = index of last newly-nonzero coef */
+}
+/* Encode the AC coefficients per section G.1.2.3, fig. G.7 */
+r = 0;			/* r = run length of zeros */
+BR = 0;			/* BR = count of buffered bits added now */
+BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */
+for (k = cinfo->Ss; k <= Se; k++) {
+if ((temp = absvalues[k]) == 0) {
+r++;
+continue;
+}
+/* Emit any required ZRLs, but not if they can be folded into EOB */
+while (r > 15 && k <= EOB) {
+/* emit any pending EOBRUN and the BE correction bits */
+emit_eobrun(entropy);
+/* Emit ZRL */
+emit_ac_symbol(entropy, entropy->ac_tbl_no, 0xF0);
+r -= 16;
+/* Emit buffered correction bits that must be associated with ZRL */
+emit_buffered_bits(entropy, BR_buffer, BR);
+BR_buffer = entropy->bit_buffer; /* BE bits are gone now */
+BR = 0;
+}
+/* If the coef was previously nonzero, it only needs a correction bit.
+* NOTE: a straight translation of the spec's figure G.7 would suggest
+* that we also need to test r > 15.  But if r > 15, we can only get here
+* if k > EOB, which implies that this coefficient is not 1.
+*/
+if (temp > 1) {
+/* The correction bit is the next bit of the absolute value. */
+BR_buffer[BR++] = (char) (temp & 1);
+continue;
+}
+/* Emit any pending EOBRUN and the BE correction bits */
+emit_eobrun(entropy);
+/* Count/emit Huffman symbol for run length / number of bits */
+emit_ac_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1);
+/* Emit output bit for newly-nonzero coef */
+temp = ((*block)[natural_order[k]] < 0) ? 0 : 1;
+emit_bits_e(entropy, (unsigned int) temp, 1);
+/* Emit buffered correction bits that must be associated with this code */
+emit_buffered_bits(entropy, BR_buffer, BR);
+BR_buffer = entropy->bit_buffer; /* BE bits are gone now */
+BR = 0;
+r = 0;			/* reset zero run length */
+}
+if (r > 0 || BR > 0) {	/* If there are trailing zeroes, */
+entropy->EOBRUN++;		/* count an EOB */
+entropy->BE += BR;		/* concat my correction bits to older ones */
+/* We force out the EOB if we risk either:
+* 1. overflow of the EOB counter;
+* 2. overflow of the correction bit buffer during the next MCU.
+*/
+if (entropy->EOBRUN == 0x7FFF || entropy->BE > (MAX_CORR_BITS-DCTSIZE2+1))
+emit_eobrun(entropy);
+}
+cinfo->dest->next_output_byte = entropy->next_output_byte;
+cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+/* Update restart-interval state too */
+if (cinfo->restart_interval) {
+if (entropy->restarts_to_go == 0) {
+entropy->restarts_to_go = cinfo->restart_interval;
+entropy->next_restart_num++;
+entropy->next_restart_num &= 7;
+}
+entropy->restarts_to_go--;
+}
 return TRUE;
 }
 /* Encode a single block's worth of coefficients */
 		  c_derived_tbl *dctbl, c_derived_tbl *actbl)
 {
 register int temp, temp2;
 register int nbits;
 register int k, r, i;
+int Se = state->cinfo->lim_Se;
+const int * natural_order = state->cinfo->natural_order;
 /* Encode the DC coefficient difference per section F.1.2.1 */
 temp = temp2 = block[0] - last_dc_val;
 if (temp < 0) {
 temp = -temp;		/* temp is abs value of input */
 /* For a negative input, want temp2 = bitwise complement of abs(input) */
 /* This code assumes we are on a two's complement machine */
 temp2--;
 }
 /* Find the number of bits needed for the magnitude of the coefficient */
 nbits = 0;
 while (temp) {
 nbits++;
 temp >>= 1;
 /* Check for out-of-range coefficient values.
 * Since we're encoding a difference, the range limit is twice as much.
 */
 if (nbits > MAX_COEF_BITS+1)
 ERREXIT(state->cinfo, JERR_BAD_DCT_COEF);
 /* Emit the Huffman-coded symbol for the number of bits */
-if (! emit_bits(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits]))
+if (! emit_bits_s(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits]))
 return FALSE;
 /* Emit that number of bits of the value, if positive, */
 /* or the complement of its magnitude, if negative. */
 if (nbits)			/* emit_bits rejects calls with size 0 */
-if (! emit_bits(state, (unsigned int) temp2, nbits))
+if (! emit_bits_s(state, (unsigned int) temp2, nbits))
 return FALSE;
 /* Encode the AC coefficients per section F.1.2.2 */
 r = 0;			/* r = run length of zeros */
-for (k = 1; k < DCTSIZE2; k++) {
+for (k = 1; k <= Se; k++) {
-if ((temp = block[jpeg_natural_order[k]]) == 0) {
+if ((temp = block[natural_order[k]]) == 0) {
 r++;
 } else {
 /* if run length > 15, must emit special run-length-16 codes (0xF0) */
 while (r > 15) {
-	if (! emit_bits(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0]))
+	if (! emit_bits_s(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0]))
 	  return FALSE;
 	r -= 16;
 }
 temp2 = temp;
 if (temp < 0) {
 	temp = -temp;		/* temp is abs value of input */
 	/* This code assumes we are on a two's complement machine */
 	temp2--;
 }
 /* Find the number of bits needed for the magnitude of the coefficient */
 nbits = 1;		/* there must be at least one 1 bit */
 while ((temp >>= 1))
 	nbits++;
 /* Check for out-of-range coefficient values */
 if (nbits > MAX_COEF_BITS)
 	ERREXIT(state->cinfo, JERR_BAD_DCT_COEF);
 /* Emit Huffman symbol for run length / number of bits */
 i = (r << 4) + nbits;
-if (! emit_bits(state, actbl->ehufco[i], actbl->ehufsi[i]))
+if (! emit_bits_s(state, actbl->ehufco[i], actbl->ehufsi[i]))
 	return FALSE;
 /* Emit that number of bits of the value, if positive, */
 /* or the complement of its magnitude, if negative. */
-if (! emit_bits(state, (unsigned int) temp2, nbits))
+if (! emit_bits_s(state, (unsigned int) temp2, nbits))
 	return FALSE;
 r = 0;
 }
 }
 /* If the last coef(s) were zero, emit an end-of-block code */
 if (r > 0)
-if (! emit_bits(state, actbl->ehufco[0], actbl->ehufsi[0]))
+if (! emit_bits_s(state, actbl->ehufco[0], actbl->ehufsi[0]))
 return FALSE;
-return TRUE;
-}
-/*
-* Emit a restart marker & resynchronize predictions.
-*/
-LOCAL(boolean)
-emit_restart (working_state * state, int restart_num)
-{
-int ci;
-if (! flush_bits(state))
-return FALSE;
-emit_byte(state, 0xFF, return FALSE);
-emit_byte(state, JPEG_RST0 + restart_num, return FALSE);
-/* Re-initialize DC predictions to 0 */
-for (ci = 0; ci < state->cinfo->comps_in_scan; ci++)
-state->cur.last_dc_val[ci] = 0;
-/* The restart counter is not updated until we successfully write the MCU. */
 return TRUE;
 }
 state.cinfo = cinfo;
 /* Emit restart marker if needed */
 if (cinfo->restart_interval) {
 if (entropy->restarts_to_go == 0)
-if (! emit_restart(&state, entropy->next_restart_num))
+if (! emit_restart_s(&state, entropy->next_restart_num))
 	return FALSE;
 }
 /* Encode the MCU data blocks */
 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
 finish_pass_huff (j_compress_ptr cinfo)
 {
 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
 working_state state;
-/* Load up working state ... flush_bits needs it */
+if (cinfo->progressive_mode) {
-state.next_output_byte = cinfo->dest->next_output_byte;
+entropy->next_output_byte = cinfo->dest->next_output_byte;
-state.free_in_buffer = cinfo->dest->free_in_buffer;
+entropy->free_in_buffer = cinfo->dest->free_in_buffer;
-ASSIGN_STATE(state.cur, entropy->saved);
-state.cinfo = cinfo;
+/* Flush out any buffered data */
+emit_eobrun(entropy);
-/* Flush out the last data */
+flush_bits_e(entropy);
-if (! flush_bits(&state))
-ERREXIT(cinfo, JERR_CANT_SUSPEND);
+cinfo->dest->next_output_byte = entropy->next_output_byte;
+cinfo->dest->free_in_buffer = entropy->free_in_buffer;
-/* Update state */
+} else {
-cinfo->dest->next_output_byte = state.next_output_byte;
+/* Load up working state ... flush_bits needs it */
-cinfo->dest->free_in_buffer = state.free_in_buffer;
+state.next_output_byte = cinfo->dest->next_output_byte;
-ASSIGN_STATE(entropy->saved, state.cur);
+state.free_in_buffer = cinfo->dest->free_in_buffer;
+ASSIGN_STATE(state.cur, entropy->saved);
+state.cinfo = cinfo;
+/* Flush out the last data */
+if (! flush_bits_s(&state))
+ERREXIT(cinfo, JERR_CANT_SUSPEND);
+/* Update state */
+cinfo->dest->next_output_byte = state.next_output_byte;
+cinfo->dest->free_in_buffer = state.free_in_buffer;
+ASSIGN_STATE(entropy->saved, state.cur);
+}
 }
 /*
 * Huffman coding optimization.
 * Symbols which are not needed at all for the particular image are not
 * assigned any code, which saves space in the DHT marker as well as in
 * the compressed data.
 */
-#ifdef ENTROPY_OPT_SUPPORTED
 /* Process a single block's worth of coefficients */
 LOCAL(void)
 htest_one_block (j_compress_ptr cinfo, JCOEFPTR block, int last_dc_val,
 		 long dc_counts[], long ac_counts[])
 {
 register int temp;
 register int nbits;
 register int k, r;
+int Se = cinfo->lim_Se;
+const int * natural_order = cinfo->natural_order;
 /* Encode the DC coefficient difference per section F.1.2.1 */
 temp = block[0] - last_dc_val;
 if (temp < 0)
 /* Encode the AC coefficients per section F.1.2.2 */
 r = 0;			/* r = run length of zeros */
-for (k = 1; k < DCTSIZE2; k++) {
+for (k = 1; k <= Se; k++) {
-if ((temp = block[jpeg_natural_order[k]]) == 0) {
+if ((temp = block[natural_order[k]]) == 0) {
 r++;
 } else {
 /* if run length > 15, must emit special run-length-16 codes (0xF0) */
 while (r > 15) {
 	ac_counts[0xF0]++;
 }
 /*
 * Generate the best Huffman code table for the given counts, fill htbl.
-* Note this is also used by jcphuff.c.
 *
 * The JPEG standard requires that no symbol be assigned a codeword of all
 * one bits (so that padding bits added at the end of a compressed segment
 * can't look like a valid code).  Because of the canonical ordering of
 * codewords, this just means that there must be an unused slot in the
 * an optimal limited-length-code algorithm indicate that the difference is
 * microscopic --- usually less than a hundredth of a percent of total size.
 * So the extra complexity of an optimal algorithm doesn't seem worthwhile.
 */
-GLOBAL(void)
+LOCAL(void)
 jpeg_gen_optimal_table (j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[])
 {
 #define MAX_CLEN 32		/* assumed maximum initial code length */
 UINT8 bits[MAX_CLEN+1];	/* bits[k] = # of symbols with code length k */
 int codesize[257];		/* codesize[k] = code length of symbol k */
 METHODDEF(void)
 finish_pass_gather (j_compress_ptr cinfo)
 {
 huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
-int ci, dctbl, actbl;
+int ci, tbl;
 jpeg_component_info * compptr;
 JHUFF_TBL **htblptr;
 boolean did_dc[NUM_HUFF_TBLS];
 boolean did_ac[NUM_HUFF_TBLS];
 /* It's important not to apply jpeg_gen_optimal_table more than once
 * per table, because it clobbers the input frequency counts!
 */
+if (cinfo->progressive_mode)
+/* Flush out buffered data (all we care about is counting the EOB symbol) */
+emit_eobrun(entropy);
 MEMZERO(did_dc, SIZEOF(did_dc));
 MEMZERO(did_ac, SIZEOF(did_ac));
 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
 compptr = cinfo->cur_comp_info[ci];
-dctbl = compptr->dc_tbl_no;
+/* DC needs no table for refinement scan */
-actbl = compptr->ac_tbl_no;
+if (cinfo->Ss == 0 && cinfo->Ah == 0) {
-if (! did_dc[dctbl]) {
+tbl = compptr->dc_tbl_no;
-htblptr = & cinfo->dc_huff_tbl_ptrs[dctbl];
+if (! did_dc[tbl]) {
-if (*htblptr == NULL)
+	htblptr = & cinfo->dc_huff_tbl_ptrs[tbl];
-	*htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+	if (*htblptr == NULL)
-jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[dctbl]);
+	  *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
-did_dc[dctbl] = TRUE;
+	jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[tbl]);
-}
+	did_dc[tbl] = TRUE;
-if (! did_ac[actbl]) {
+}
-htblptr = & cinfo->ac_huff_tbl_ptrs[actbl];
+}
-if (*htblptr == NULL)
+/* AC needs no table when not present */
-	*htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+if (cinfo->Se) {
-jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[actbl]);
+tbl = compptr->ac_tbl_no;
-did_ac[actbl] = TRUE;
+if (! did_ac[tbl]) {
-}
+	htblptr = & cinfo->ac_huff_tbl_ptrs[tbl];
-}
+	if (*htblptr == NULL)
-}
+	  *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+	jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[tbl]);
+	did_ac[tbl] = TRUE;
-#endif /* ENTROPY_OPT_SUPPORTED */
+}
+}
+}
+}
+/*
+* Initialize for a Huffman-compressed scan.
+* If gather_statistics is TRUE, we do not output anything during the scan,
+* just count the Huffman symbols used and generate Huffman code tables.
+*/
+METHODDEF(void)
+start_pass_huff (j_compress_ptr cinfo, boolean gather_statistics)
+{
+huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+int ci, tbl;
+jpeg_component_info * compptr;
+if (gather_statistics)
+entropy->pub.finish_pass = finish_pass_gather;
+else
+entropy->pub.finish_pass = finish_pass_huff;
+if (cinfo->progressive_mode) {
+entropy->cinfo = cinfo;
+entropy->gather_statistics = gather_statistics;
+/* We assume jcmaster.c already validated the scan parameters. */
+/* Select execution routine */
+if (cinfo->Ah == 0) {
+if (cinfo->Ss == 0)
+	entropy->pub.encode_mcu = encode_mcu_DC_first;
+else
+	entropy->pub.encode_mcu = encode_mcu_AC_first;
+} else {
+if (cinfo->Ss == 0)
+	entropy->pub.encode_mcu = encode_mcu_DC_refine;
+else {
+	entropy->pub.encode_mcu = encode_mcu_AC_refine;
+	/* AC refinement needs a correction bit buffer */
+	if (entropy->bit_buffer == NULL)
+	  entropy->bit_buffer = (char *)
+	    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+					MAX_CORR_BITS * SIZEOF(char));
+}
+}
+/* Initialize AC stuff */
+entropy->ac_tbl_no = cinfo->cur_comp_info[0]->ac_tbl_no;
+entropy->EOBRUN = 0;
+entropy->BE = 0;
+} else {
+if (gather_statistics)
+entropy->pub.encode_mcu = encode_mcu_gather;
+else
+entropy->pub.encode_mcu = encode_mcu_huff;
+}
+for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+compptr = cinfo->cur_comp_info[ci];
+/* DC needs no table for refinement scan */
+if (cinfo->Ss == 0 && cinfo->Ah == 0) {
+tbl = compptr->dc_tbl_no;
+if (gather_statistics) {
+	/* Check for invalid table index */
+	/* (make_c_derived_tbl does this in the other path) */
+	if (tbl < 0 || tbl >= NUM_HUFF_TBLS)
+	  ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl);
+	/* Allocate and zero the statistics tables */
+	/* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+	if (entropy->dc_count_ptrs[tbl] == NULL)
+	  entropy->dc_count_ptrs[tbl] = (long *)
+	    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+					257 * SIZEOF(long));
+	MEMZERO(entropy->dc_count_ptrs[tbl], 257 * SIZEOF(long));
+} else {
+	/* Compute derived values for Huffman tables */
+	/* We may do this more than once for a table, but it's not expensive */
+	jpeg_make_c_derived_tbl(cinfo, TRUE, tbl,
+				& entropy->dc_derived_tbls[tbl]);
+}
+/* Initialize DC predictions to 0 */
+entropy->saved.last_dc_val[ci] = 0;
+}
+/* AC needs no table when not present */
+if (cinfo->Se) {
+tbl = compptr->ac_tbl_no;
+if (gather_statistics) {
+	if (tbl < 0 || tbl >= NUM_HUFF_TBLS)
+	  ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl);
+	if (entropy->ac_count_ptrs[tbl] == NULL)
+	  entropy->ac_count_ptrs[tbl] = (long *)
+	    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+					257 * SIZEOF(long));
+	MEMZERO(entropy->ac_count_ptrs[tbl], 257 * SIZEOF(long));
+} else {
+	jpeg_make_c_derived_tbl(cinfo, FALSE, tbl,
+				& entropy->ac_derived_tbls[tbl]);
+}
+}
+}
+/* Initialize bit buffer to empty */
+entropy->saved.put_buffer = 0;
+entropy->saved.put_bits = 0;
+/* Initialize restart stuff */
+entropy->restarts_to_go = cinfo->restart_interval;
+entropy->next_restart_num = 0;
+}
 /*
 * Module initialization routine for Huffman entropy encoding.
 */
 entropy->pub.start_pass = start_pass_huff;
 /* Mark tables unallocated */
 for (i = 0; i < NUM_HUFF_TBLS; i++) {
 entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
-#ifdef ENTROPY_OPT_SUPPORTED
 entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL;
-#endif
+}
-}
-}
+if (cinfo->progressive_mode)
+entropy->bit_buffer = NULL;	/* needed only in AC refinement scan */
+}

changeset 30	5dc02b23752f
parent 0	1918ee327afb