/*
* jdhuff.c
*
+ * This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
- * Copyright (C) 2009-2011, D. R. Commander.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2009-2011, 2016, 2018, D. R. Commander.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
*
* This file contains Huffman entropy decoding routines.
*
* 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.
+ *
+ * NOTE: All referenced figures are from
+ * Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
-#include "jdhuff.h" /* Declarations shared with jdphuff.c */
+#include "jdhuff.h" /* Declarations shared with jdphuff.c */
#include "jpegcomp.h"
+#include "jstdhuff.c"
/*
*/
#ifndef NO_STRUCT_ASSIGN
-#define ASSIGN_STATE(dest,src) ((dest) = (src))
+#define ASSIGN_STATE(dest, src) ((dest) = (src))
#else
#if MAX_COMPS_IN_SCAN == 4
-#define ASSIGN_STATE(dest,src) \
- ((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])
+#define ASSIGN_STATE(dest, src) \
+ ((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
/* 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 */
+ 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 */
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
/* Pointers to derived tables (these workspaces have image lifespan) */
- d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
- d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+ d_derived_tbl *dc_derived_tbls[NUM_HUFF_TBLS];
+ d_derived_tbl *ac_derived_tbls[NUM_HUFF_TBLS];
/* Precalculated info set up by start_pass for use in decode_mcu: */
/* Pointers to derived tables to be used for each block within an MCU */
- d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
- d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
+ d_derived_tbl *dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
+ d_derived_tbl *ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
/* Whether we care about the DC and AC coefficient values for each block */
boolean dc_needed[D_MAX_BLOCKS_IN_MCU];
boolean ac_needed[D_MAX_BLOCKS_IN_MCU];
} huff_entropy_decoder;
-typedef huff_entropy_decoder * huff_entropy_ptr;
+typedef huff_entropy_decoder *huff_entropy_ptr;
/*
*/
METHODDEF(void)
-start_pass_huff_decoder (j_decompress_ptr cinfo)
+start_pass_huff_decoder(j_decompress_ptr cinfo)
{
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
int ci, blkn, dctbl, actbl;
- jpeg_component_info * compptr;
+ d_derived_tbl **pdtbl;
+ jpeg_component_info *compptr;
/* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG.
* This ought to be an error condition, but we make it a warning because
* there are some baseline files out there with all zeroes in these bytes.
*/
- if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2-1 ||
+ if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2 - 1 ||
cinfo->Ah != 0 || cinfo->Al != 0)
WARNMS(cinfo, JWRN_NOT_SEQUENTIAL);
actbl = compptr->ac_tbl_no;
/* Compute derived values for Huffman tables */
/* We may do this more than once for a table, but it's not expensive */
- jpeg_make_d_derived_tbl(cinfo, TRUE, dctbl,
- & entropy->dc_derived_tbls[dctbl]);
- jpeg_make_d_derived_tbl(cinfo, FALSE, actbl,
- & entropy->ac_derived_tbls[actbl]);
+ pdtbl = (d_derived_tbl **)(entropy->dc_derived_tbls) + dctbl;
+ jpeg_make_d_derived_tbl(cinfo, TRUE, dctbl, pdtbl);
+ pdtbl = (d_derived_tbl **)(entropy->ac_derived_tbls) + actbl;
+ jpeg_make_d_derived_tbl(cinfo, FALSE, actbl, pdtbl);
/* Initialize DC predictions to 0 */
entropy->saved.last_dc_val[ci] = 0;
}
*/
GLOBAL(void)
-jpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno,
- d_derived_tbl ** pdtbl)
+jpeg_make_d_derived_tbl(j_decompress_ptr cinfo, boolean isDC, int tblno,
+ d_derived_tbl **pdtbl)
{
JHUFF_TBL *htbl;
d_derived_tbl *dtbl;
/* Allocate a workspace if we haven't already done so. */
if (*pdtbl == NULL)
*pdtbl = (d_derived_tbl *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(d_derived_tbl));
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ sizeof(d_derived_tbl));
dtbl = *pdtbl;
- dtbl->pub = htbl; /* fill in back link */
-
+ dtbl->pub = htbl; /* fill in back link */
+
/* Figure C.1: make table of Huffman code length for each symbol */
p = 0;
for (l = 1; l <= 16; l++) {
- i = (int) htbl->bits[l];
- if (i < 0 || p + i > 256) /* protect against table overrun */
+ i = (int)htbl->bits[l];
+ if (i < 0 || p + i > 256) /* protect against table overrun */
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
while (i--)
- huffsize[p++] = (char) l;
+ huffsize[p++] = (char)l;
}
huffsize[p] = 0;
numsymbols = p;
-
+
/* Figure C.2: generate the codes themselves */
/* We also validate that the counts represent a legal Huffman code tree. */
-
+
code = 0;
si = huffsize[0];
p = 0;
while (huffsize[p]) {
- while (((int) huffsize[p]) == si) {
+ while (((int)huffsize[p]) == si) {
huffcode[p++] = code;
code++;
}
/* code is now 1 more than the last code used for codelength si; but
* it must still fit in si bits, since no code is allowed to be all ones.
*/
- if (((INT32) code) >= (((INT32) 1) << si))
+ if (((JLONG)code) >= (((JLONG)1) << si))
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
code <<= 1;
si++;
/* valoffset[l] = huffval[] index of 1st symbol of code length l,
* minus the minimum code of length l
*/
- dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p];
+ dtbl->valoffset[l] = (JLONG)p - (JLONG)huffcode[p];
p += htbl->bits[l];
- dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
+ dtbl->maxcode[l] = huffcode[p - 1]; /* maximum code of length l */
} else {
- dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
+ dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
}
}
dtbl->valoffset[17] = 0;
* with that code.
*/
- for (i = 0; i < (1 << HUFF_LOOKAHEAD); i++)
- dtbl->lookup[i] = (HUFF_LOOKAHEAD + 1) << HUFF_LOOKAHEAD;
+ for (i = 0; i < (1 << HUFF_LOOKAHEAD); i++)
+ dtbl->lookup[i] = (HUFF_LOOKAHEAD + 1) << HUFF_LOOKAHEAD;
p = 0;
for (l = 1; l <= HUFF_LOOKAHEAD; l++) {
- for (i = 1; i <= (int) htbl->bits[l]; i++, p++) {
+ for (i = 1; i <= (int)htbl->bits[l]; i++, p++) {
/* l = current code's length, p = its index in huffcode[] & huffval[]. */
/* Generate left-justified code followed by all possible bit sequences */
- lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
- for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) {
- dtbl->lookup[lookbits] = (l << HUFF_LOOKAHEAD) | htbl->huffval[p];
- lookbits++;
+ lookbits = huffcode[p] << (HUFF_LOOKAHEAD - l);
+ for (ctr = 1 << (HUFF_LOOKAHEAD - l); ctr > 0; ctr--) {
+ dtbl->lookup[lookbits] = (l << HUFF_LOOKAHEAD) | htbl->huffval[p];
+ lookbits++;
}
}
}
for (i = 0; i < numsymbols; i++) {
int sym = htbl->huffval[i];
if (sym < 0 || sym > 15)
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
}
}
}
*/
#ifdef SLOW_SHIFT_32
-#define MIN_GET_BITS 15 /* minimum allowable value */
+#define MIN_GET_BITS 15 /* minimum allowable value */
#else
-#define MIN_GET_BITS (BIT_BUF_SIZE-7)
+#define MIN_GET_BITS (BIT_BUF_SIZE - 7)
#endif
GLOBAL(boolean)
-jpeg_fill_bit_buffer (bitread_working_state * state,
- register bit_buf_type get_buffer, register int bits_left,
- int nbits)
+jpeg_fill_bit_buffer(bitread_working_state *state,
+ register bit_buf_type get_buffer, register int bits_left,
+ int nbits)
/* Load up the bit buffer to a depth of at least nbits */
{
/* Copy heavily used state fields into locals (hopefully registers) */
- register const JOCTET * next_input_byte = state->next_input_byte;
+ register const JOCTET *next_input_byte = state->next_input_byte;
register size_t bytes_in_buffer = state->bytes_in_buffer;
j_decompress_ptr cinfo = state->cinfo;
/* (It is assumed that no request will be for more than that many bits.) */
/* We fail to do so only if we hit a marker or are forced to suspend. */
- if (cinfo->unread_marker == 0) { /* cannot advance past a marker */
+ if (cinfo->unread_marker == 0) { /* cannot advance past a marker */
while (bits_left < MIN_GET_BITS) {
register int c;
/* Attempt to read a byte */
if (bytes_in_buffer == 0) {
- if (! (*cinfo->src->fill_input_buffer) (cinfo))
- return FALSE;
- next_input_byte = cinfo->src->next_input_byte;
- bytes_in_buffer = cinfo->src->bytes_in_buffer;
+ if (!(*cinfo->src->fill_input_buffer) (cinfo))
+ return FALSE;
+ next_input_byte = cinfo->src->next_input_byte;
+ bytes_in_buffer = cinfo->src->bytes_in_buffer;
}
bytes_in_buffer--;
c = GETJOCTET(*next_input_byte++);
/* If it's 0xFF, check and discard stuffed zero byte */
if (c == 0xFF) {
- /* Loop here to discard any padding FF's on terminating marker,
- * so that we can save a valid unread_marker value. NOTE: we will
- * accept multiple FF's followed by a 0 as meaning a single FF data
- * byte. This data pattern is not valid according to the standard.
- */
- do {
- if (bytes_in_buffer == 0) {
- if (! (*cinfo->src->fill_input_buffer) (cinfo))
- return FALSE;
- next_input_byte = cinfo->src->next_input_byte;
- bytes_in_buffer = cinfo->src->bytes_in_buffer;
- }
- bytes_in_buffer--;
- c = GETJOCTET(*next_input_byte++);
- } while (c == 0xFF);
-
- if (c == 0) {
- /* Found FF/00, which represents an FF data byte */
- c = 0xFF;
- } else {
- /* Oops, it's actually a marker indicating end of compressed data.
- * Save the marker code for later use.
- * Fine point: it might appear that we should save the marker into
- * bitread working state, not straight into permanent state. But
- * once we have hit a marker, we cannot need to suspend within the
- * current MCU, because we will read no more bytes from the data
- * source. So it is OK to update permanent state right away.
- */
- cinfo->unread_marker = c;
- /* See if we need to insert some fake zero bits. */
- goto no_more_bytes;
- }
+ /* Loop here to discard any padding FF's on terminating marker,
+ * so that we can save a valid unread_marker value. NOTE: we will
+ * accept multiple FF's followed by a 0 as meaning a single FF data
+ * byte. This data pattern is not valid according to the standard.
+ */
+ do {
+ if (bytes_in_buffer == 0) {
+ if (!(*cinfo->src->fill_input_buffer) (cinfo))
+ return FALSE;
+ next_input_byte = cinfo->src->next_input_byte;
+ bytes_in_buffer = cinfo->src->bytes_in_buffer;
+ }
+ bytes_in_buffer--;
+ c = GETJOCTET(*next_input_byte++);
+ } while (c == 0xFF);
+
+ if (c == 0) {
+ /* Found FF/00, which represents an FF data byte */
+ c = 0xFF;
+ } else {
+ /* Oops, it's actually a marker indicating end of compressed data.
+ * Save the marker code for later use.
+ * Fine point: it might appear that we should save the marker into
+ * bitread working state, not straight into permanent state. But
+ * once we have hit a marker, we cannot need to suspend within the
+ * current MCU, because we will read no more bytes from the data
+ * source. So it is OK to update permanent state right away.
+ */
+ cinfo->unread_marker = c;
+ /* See if we need to insert some fake zero bits. */
+ goto no_more_bytes;
+ }
}
/* OK, load c into get_buffer */
bits_left += 8;
} /* end while */
} else {
- no_more_bytes:
+no_more_bytes:
/* We get here if we've read the marker that terminates the compressed
* data segment. There should be enough bits in the buffer register
* to satisfy the request; if so, no problem.
* We use a nonvolatile flag to ensure that only one warning message
* appears per data segment.
*/
- if (! cinfo->entropy->insufficient_data) {
- WARNMS(cinfo, JWRN_HIT_MARKER);
- cinfo->entropy->insufficient_data = TRUE;
+ if (!cinfo->entropy->insufficient_data) {
+ WARNMS(cinfo, JWRN_HIT_MARKER);
+ cinfo->entropy->insufficient_data = TRUE;
}
/* Fill the buffer with zero bits */
get_buffer <<= MIN_GET_BITS - bits_left;
handle markers. We have to hand off any blocks with markers to the
slower routines. */
-#define GET_BYTE \
-{ \
+#define GET_BYTE { \
register int c0, c1; \
c0 = GETJOCTET(*buffer++); \
c1 = GETJOCTET(*buffer); \
} \
}
-#if __WORDSIZE == 64 || defined(_WIN64)
+#if SIZEOF_SIZE_T == 8 || defined(_WIN64)
/* Pre-fetch 48 bytes, because the holding register is 64-bit */
#define FILL_BIT_BUFFER_FAST \
- if (bits_left < 16) { \
+ if (bits_left <= 16) { \
GET_BYTE GET_BYTE GET_BYTE GET_BYTE GET_BYTE GET_BYTE \
}
/* Pre-fetch 16 bytes, because the holding register is 32-bit */
#define FILL_BIT_BUFFER_FAST \
- if (bits_left < 16) { \
+ if (bits_left <= 16) { \
GET_BYTE GET_BYTE \
}
*/
GLOBAL(int)
-jpeg_huff_decode (bitread_working_state * state,
- register bit_buf_type get_buffer, register int bits_left,
- d_derived_tbl * htbl, int min_bits)
+jpeg_huff_decode(bitread_working_state *state,
+ register bit_buf_type get_buffer, register int bits_left,
+ d_derived_tbl *htbl, int min_bits)
{
register int l = min_bits;
- register INT32 code;
+ register JLONG code;
/* HUFF_DECODE has determined that the code is at least min_bits */
/* bits long, so fetch that many bits in one swoop. */
code = GET_BITS(l);
/* Collect the rest of the Huffman code one bit at a time. */
- /* This is per Figure F.16 in the JPEG spec. */
+ /* This is per Figure F.16. */
while (code > htbl->maxcode[l]) {
code <<= 1;
if (l > 16) {
WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE);
- return 0; /* fake a zero as the safest result */
+ return 0; /* fake a zero as the safest result */
}
- return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ];
+ return htbl->pub->huffval[(int)(code + htbl->valoffset[l])];
}
#define AVOID_TABLES
#ifdef AVOID_TABLES
-#define HUFF_EXTEND(x,s) ((x) + ((((x) - (1<<((s)-1))) >> 31) & (((-1)<<(s)) + 1)))
+#define NEG_1 ((unsigned int)-1)
+#define HUFF_EXTEND(x, s) \
+ ((x) + ((((x) - (1 << ((s) - 1))) >> 31) & (((NEG_1) << (s)) + 1)))
#else
-#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
+#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_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 };
+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 */
*/
LOCAL(boolean)
-process_restart (j_decompress_ptr cinfo)
+process_restart(j_decompress_ptr cinfo)
{
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
int ci;
/* Throw away any unused bits remaining in bit buffer; */
entropy->bitstate.bits_left = 0;
/* Advance past the RSTn marker */
- if (! (*cinfo->marker->read_restart_marker) (cinfo))
+ if (!(*cinfo->marker->read_restart_marker) (cinfo))
return FALSE;
/* Re-initialize DC predictions to 0 */
LOCAL(boolean)
-decode_mcu_slow (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+decode_mcu_slow(j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
BITREAD_STATE_VARS;
int blkn;
savable_state state;
/* Outer loop handles each block in the MCU */
/* Load up working state */
- BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+ BITREAD_LOAD_STATE(cinfo, entropy->bitstate);
ASSIGN_STATE(state, entropy->saved);
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
- JBLOCKROW block = MCU_data[blkn];
- d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn];
- d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn];
+ JBLOCKROW block = MCU_data ? MCU_data[blkn] : NULL;
+ d_derived_tbl *dctbl = entropy->dc_cur_tbls[blkn];
+ d_derived_tbl *actbl = entropy->ac_cur_tbls[blkn];
register int s, k, r;
/* Decode a single block's worth of coefficients */
int ci = cinfo->MCU_membership[blkn];
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
- /* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
- (*block)[0] = (JCOEF) s;
+ if (block) {
+ /* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
+ (*block)[0] = (JCOEF)s;
+ }
}
- if (entropy->ac_needed[blkn]) {
+ if (entropy->ac_needed[blkn] && block) {
/* Section F.2.2.2: decode the AC coefficients */
/* Since zeroes are skipped, output area must be cleared beforehand */
r = s >> 4;
s &= 15;
-
+
if (s) {
k += r;
CHECK_BIT_BUFFER(br_state, s, return FALSE);
* Note: the extra entries in jpeg_natural_order[] will save us
* if k >= DCTSIZE2, which could happen if the data is corrupted.
*/
- (*block)[jpeg_natural_order[k]] = (JCOEF) s;
+ (*block)[jpeg_natural_order[k]] = (JCOEF)s;
} else {
if (r != 15)
break;
}
/* Completed MCU, so update state */
- BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ BITREAD_SAVE_STATE(cinfo, entropy->bitstate);
ASSIGN_STATE(entropy->saved, state);
return TRUE;
}
LOCAL(boolean)
-decode_mcu_fast (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+decode_mcu_fast(j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
BITREAD_STATE_VARS;
JOCTET *buffer;
int blkn;
/* Outer loop handles each block in the MCU */
/* Load up working state */
- BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
- buffer = (JOCTET *) br_state.next_input_byte;
+ BITREAD_LOAD_STATE(cinfo, entropy->bitstate);
+ buffer = (JOCTET *)br_state.next_input_byte;
ASSIGN_STATE(state, entropy->saved);
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
- JBLOCKROW block = MCU_data[blkn];
- d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn];
- d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn];
+ JBLOCKROW block = MCU_data ? MCU_data[blkn] : NULL;
+ d_derived_tbl *dctbl = entropy->dc_cur_tbls[blkn];
+ d_derived_tbl *actbl = entropy->ac_cur_tbls[blkn];
register int s, k, r, l;
HUFF_DECODE_FAST(s, l, dctbl);
int ci = cinfo->MCU_membership[blkn];
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
- (*block)[0] = (JCOEF) s;
+ if (block)
+ (*block)[0] = (JCOEF)s;
}
- if (entropy->ac_needed[blkn]) {
+ if (entropy->ac_needed[blkn] && block) {
for (k = 1; k < DCTSIZE2; k++) {
HUFF_DECODE_FAST(s, l, actbl);
r = s >> 4;
s &= 15;
-
+
if (s) {
k += r;
FILL_BIT_BUFFER_FAST
r = GET_BITS(s);
s = HUFF_EXTEND(r, s);
- (*block)[jpeg_natural_order[k]] = (JCOEF) s;
+ (*block)[jpeg_natural_order[k]] = (JCOEF)s;
} else {
if (r != 15) break;
k += 15;
br_state.bytes_in_buffer -= (buffer - br_state.next_input_byte);
br_state.next_input_byte = buffer;
- BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ BITREAD_SAVE_STATE(cinfo, entropy->bitstate);
ASSIGN_STATE(entropy->saved, state);
return TRUE;
}
* this module, since we'll just re-assign them on the next call.)
*/
-#define BUFSIZE (DCTSIZE2 * 2)
+#define BUFSIZE (DCTSIZE2 * 8)
METHODDEF(boolean)
-decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+decode_mcu(j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
int usefast = 1;
/* 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 (!process_restart(cinfo))
+ return FALSE;
usefast = 0;
}
- if (cinfo->src->bytes_in_buffer < BUFSIZE * (size_t)cinfo->blocks_in_MCU
- || cinfo->unread_marker != 0)
+ if (cinfo->src->bytes_in_buffer < BUFSIZE * (size_t)cinfo->blocks_in_MCU ||
+ cinfo->unread_marker != 0)
usefast = 0;
/* 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) {
+ if (!entropy->pub.insufficient_data) {
if (usefast) {
if (!decode_mcu_fast(cinfo, MCU_data)) goto use_slow;
- }
- else {
- use_slow:
+ } else {
+use_slow:
if (!decode_mcu_slow(cinfo, MCU_data)) return FALSE;
}
*/
GLOBAL(void)
-jinit_huff_decoder (j_decompress_ptr cinfo)
+jinit_huff_decoder(j_decompress_ptr cinfo)
{
huff_entropy_ptr entropy;
int i;
+ /* Motion JPEG frames typically do not include the Huffman tables if they
+ are the default tables. Thus, if the tables are not set by the time
+ the Huffman decoder is initialized (usually within the body of
+ jpeg_start_decompress()), we set them to default values. */
+ std_huff_tables((j_common_ptr)cinfo);
+
entropy = (huff_entropy_ptr)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(huff_entropy_decoder));
- cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ sizeof(huff_entropy_decoder));
+ cinfo->entropy = (struct jpeg_entropy_decoder *)entropy;
entropy->pub.start_pass = start_pass_huff_decoder;
entropy->pub.decode_mcu = decode_mcu;
projects / platform / upstream / libjpeg-turbo.git / blobdiff