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- #define JPEG_INTERNALS
- #include "jinclude.h"
- #include "jpeglib.h"
- #include "jdhuff.h"
- #include "jpegcomp.h"
- #include "jstdhuff.c"
- typedef struct {
- int last_dc_val[MAX_COMPS_IN_SCAN];
- } savable_state;
- #ifndef NO_STRUCT_ASSIGN
- #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])
- #endif
- #endif
- typedef struct {
- struct jpeg_entropy_decoder pub;
-
- bitread_perm_state bitstate;
- savable_state saved;
-
- unsigned int restarts_to_go;
-
- d_derived_tbl *dc_derived_tbls[NUM_HUFF_TBLS];
- d_derived_tbl *ac_derived_tbls[NUM_HUFF_TBLS];
-
-
- d_derived_tbl *dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
- d_derived_tbl *ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
-
- 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;
- METHODDEF(void)
- start_pass_huff_decoder(j_decompress_ptr cinfo)
- {
- huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
- int ci, blkn, dctbl, actbl;
- d_derived_tbl **pdtbl;
- jpeg_component_info *compptr;
-
- if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2 - 1 ||
- cinfo->Ah != 0 || cinfo->Al != 0)
- WARNMS(cinfo, JWRN_NOT_SEQUENTIAL);
- 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;
-
-
- 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);
-
- entropy->saved.last_dc_val[ci] = 0;
- }
-
- for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
- ci = cinfo->MCU_membership[blkn];
- compptr = cinfo->cur_comp_info[ci];
-
- entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no];
- entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no];
-
- if (compptr->component_needed) {
- entropy->dc_needed[blkn] = TRUE;
-
- entropy->ac_needed[blkn] = (compptr->_DCT_scaled_size > 1);
- } else {
- entropy->dc_needed[blkn] = entropy->ac_needed[blkn] = FALSE;
- }
- }
-
- entropy->bitstate.bits_left = 0;
- entropy->bitstate.get_buffer = 0;
- entropy->pub.insufficient_data = FALSE;
-
- entropy->restarts_to_go = cinfo->restart_interval;
- }
- GLOBAL(void)
- jpeg_make_d_derived_tbl(j_decompress_ptr cinfo, boolean isDC, int tblno,
- d_derived_tbl **pdtbl)
- {
- JHUFF_TBL *htbl;
- d_derived_tbl *dtbl;
- int p, i, l, si, numsymbols;
- int lookbits, ctr;
- char huffsize[257];
- unsigned int huffcode[257];
- unsigned int code;
-
-
- if (tblno < 0 || tblno >= NUM_HUFF_TBLS)
- ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
- htbl =
- isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno];
- if (htbl == NULL)
- ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
-
- if (*pdtbl == NULL)
- *pdtbl = (d_derived_tbl *)
- (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
- sizeof(d_derived_tbl));
- dtbl = *pdtbl;
- dtbl->pub = htbl;
-
- p = 0;
- for (l = 1; l <= 16; l++) {
- i = (int)htbl->bits[l];
- if (i < 0 || p + i > 256)
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
- while (i--)
- huffsize[p++] = (char)l;
- }
- huffsize[p] = 0;
- numsymbols = p;
-
-
- code = 0;
- si = huffsize[0];
- p = 0;
- while (huffsize[p]) {
- while (((int)huffsize[p]) == si) {
- huffcode[p++] = code;
- code++;
- }
-
- if (((JLONG)code) >= (((JLONG)1) << si))
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
- code <<= 1;
- si++;
- }
-
- p = 0;
- for (l = 1; l <= 16; l++) {
- if (htbl->bits[l]) {
-
- dtbl->valoffset[l] = (JLONG)p - (JLONG)huffcode[p];
- p += htbl->bits[l];
- dtbl->maxcode[l] = huffcode[p - 1];
- } else {
- dtbl->maxcode[l] = -1;
- }
- }
- dtbl->valoffset[17] = 0;
- dtbl->maxcode[17] = 0xFFFFFL;
-
- 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++) {
-
-
- 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++;
- }
- }
- }
-
- if (isDC) {
- for (i = 0; i < numsymbols; i++) {
- int sym = htbl->huffval[i];
- if (sym < 0 || sym > 15)
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
- }
- }
- }
- #ifdef SLOW_SHIFT_32
- #define MIN_GET_BITS 15
- #else
- #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)
- {
-
- 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;
-
-
-
- if (cinfo->unread_marker == 0) {
- while (bits_left < MIN_GET_BITS) {
- register int c;
-
- 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++);
-
- if (c == 0xFF) {
-
- 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) {
-
- c = 0xFF;
- } else {
-
- cinfo->unread_marker = c;
-
- goto no_more_bytes;
- }
- }
-
- get_buffer = (get_buffer << 8) | c;
- bits_left += 8;
- }
- } else {
- no_more_bytes:
-
- if (nbits > bits_left) {
-
- if (!cinfo->entropy->insufficient_data) {
- WARNMS(cinfo, JWRN_HIT_MARKER);
- cinfo->entropy->insufficient_data = TRUE;
- }
-
- get_buffer <<= MIN_GET_BITS - bits_left;
- bits_left = MIN_GET_BITS;
- }
- }
-
- state->next_input_byte = next_input_byte;
- state->bytes_in_buffer = bytes_in_buffer;
- state->get_buffer = get_buffer;
- state->bits_left = bits_left;
- return TRUE;
- }
- #define GET_BYTE { \
- register int c0, c1; \
- c0 = GETJOCTET(*buffer++); \
- c1 = GETJOCTET(*buffer); \
- \
- get_buffer = (get_buffer << 8) | c0; \
- bits_left += 8; \
- if (c0 == 0xFF) { \
- \
- buffer++; \
- if (c1 != 0) { \
- \
- cinfo->unread_marker = c1; \
- \
- buffer -= 2; \
- get_buffer &= ~0xFF; \
- } \
- } \
- }
- #if SIZEOF_SIZE_T == 8 || defined(_WIN64)
- #define FILL_BIT_BUFFER_FAST \
- if (bits_left <= 16) { \
- GET_BYTE GET_BYTE GET_BYTE GET_BYTE GET_BYTE GET_BYTE \
- }
- #else
- #define FILL_BIT_BUFFER_FAST \
- if (bits_left <= 16) { \
- GET_BYTE GET_BYTE \
- }
- #endif
- 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)
- {
- register int l = min_bits;
- register JLONG code;
-
-
- CHECK_BIT_BUFFER(*state, l, return -1);
- code = GET_BITS(l);
-
-
- while (code > htbl->maxcode[l]) {
- code <<= 1;
- CHECK_BIT_BUFFER(*state, 1, return -1);
- code |= GET_BITS(1);
- l++;
- }
-
- state->get_buffer = get_buffer;
- state->bits_left = bits_left;
-
- if (l > 16) {
- WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE);
- return 0;
- }
- return htbl->pub->huffval[(int)(code + htbl->valoffset[l])];
- }
- #define AVOID_TABLES
- #ifdef AVOID_TABLES
- #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))
- static const int extend_test[16] = {
- 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
- 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000
- };
- static const int extend_offset[16] = {
- 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
- LOCAL(boolean)
- process_restart(j_decompress_ptr cinfo)
- {
- huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
- int ci;
-
-
- cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
- entropy->bitstate.bits_left = 0;
-
- if (!(*cinfo->marker->read_restart_marker) (cinfo))
- return FALSE;
-
- for (ci = 0; ci < cinfo->comps_in_scan; ci++)
- entropy->saved.last_dc_val[ci] = 0;
-
- entropy->restarts_to_go = cinfo->restart_interval;
-
- if (cinfo->unread_marker == 0)
- entropy->pub.insufficient_data = FALSE;
- return TRUE;
- }
- LOCAL(boolean)
- decode_mcu_slow(j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
- {
- huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
- BITREAD_STATE_VARS;
- int blkn;
- savable_state state;
-
-
- BITREAD_LOAD_STATE(cinfo, entropy->bitstate);
- ASSIGN_STATE(state, entropy->saved);
- for (blkn = 0; blkn < cinfo->blocks_in_MCU; 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;
-
-
- HUFF_DECODE(s, br_state, dctbl, return FALSE, label1);
- if (s) {
- CHECK_BIT_BUFFER(br_state, s, return FALSE);
- r = GET_BITS(s);
- s = HUFF_EXTEND(r, s);
- }
- if (entropy->dc_needed[blkn]) {
-
- int ci = cinfo->MCU_membership[blkn];
-
- s = (int)((unsigned int)s + (unsigned int)state.last_dc_val[ci]);
- state.last_dc_val[ci] = s;
- if (block) {
-
- (*block)[0] = (JCOEF)s;
- }
- }
- if (entropy->ac_needed[blkn] && block) {
-
-
- for (k = 1; k < DCTSIZE2; k++) {
- HUFF_DECODE(s, br_state, actbl, 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);
-
- (*block)[jpeg_natural_order[k]] = (JCOEF)s;
- } else {
- if (r != 15)
- break;
- k += 15;
- }
- }
- } else {
-
-
- for (k = 1; k < DCTSIZE2; k++) {
- HUFF_DECODE(s, br_state, actbl, return FALSE, label3);
- r = s >> 4;
- s &= 15;
- if (s) {
- k += r;
- CHECK_BIT_BUFFER(br_state, s, return FALSE);
- DROP_BITS(s);
- } else {
- if (r != 15)
- break;
- k += 15;
- }
- }
- }
- }
-
- 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)
- {
- huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
- BITREAD_STATE_VARS;
- JOCTET *buffer;
- int blkn;
- savable_state state;
-
-
- 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 ? 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);
- if (s) {
- FILL_BIT_BUFFER_FAST
- r = GET_BITS(s);
- s = HUFF_EXTEND(r, s);
- }
- if (entropy->dc_needed[blkn]) {
- int ci = cinfo->MCU_membership[blkn];
- s = (int)((unsigned int)s + (unsigned int)state.last_dc_val[ci]);
- state.last_dc_val[ci] = s;
- if (block)
- (*block)[0] = (JCOEF)s;
- }
- 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;
- } else {
- if (r != 15) break;
- k += 15;
- }
- }
- } else {
- 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
- DROP_BITS(s);
- } else {
- if (r != 15) break;
- k += 15;
- }
- }
- }
- }
- if (cinfo->unread_marker != 0) {
- cinfo->unread_marker = 0;
- return FALSE;
- }
- br_state.bytes_in_buffer -= (buffer - br_state.next_input_byte);
- br_state.next_input_byte = buffer;
- BITREAD_SAVE_STATE(cinfo, entropy->bitstate);
- ASSIGN_STATE(entropy->saved, state);
- return TRUE;
- }
- #define BUFSIZE (DCTSIZE2 * 8)
- METHODDEF(boolean)
- decode_mcu(j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
- {
- huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy;
- int usefast = 1;
-
- if (cinfo->restart_interval) {
- if (entropy->restarts_to_go == 0)
- 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)
- usefast = 0;
-
- if (!entropy->pub.insufficient_data) {
- if (usefast) {
- if (!decode_mcu_fast(cinfo, MCU_data)) goto use_slow;
- } else {
- use_slow:
- if (!decode_mcu_slow(cinfo, MCU_data)) return FALSE;
- }
- }
-
- entropy->restarts_to_go--;
- return TRUE;
- }
- GLOBAL(void)
- jinit_huff_decoder(j_decompress_ptr cinfo)
- {
- huff_entropy_ptr entropy;
- int i;
-
- 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;
- entropy->pub.start_pass = start_pass_huff_decoder;
- entropy->pub.decode_mcu = decode_mcu;
-
- for (i = 0; i < NUM_HUFF_TBLS; i++) {
- entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
- }
- }
|