Index: third_party/libjpeg/jdhuff.c |
diff --git a/third_party/libjpeg/jdhuff.c b/third_party/libjpeg/jdhuff.c |
deleted file mode 100644 |
index b5ba39f736a7ae4f059d4b0594f4cc8ff854e1f4..0000000000000000000000000000000000000000 |
--- a/third_party/libjpeg/jdhuff.c |
+++ /dev/null |
@@ -1,651 +0,0 @@ |
-/* |
- * jdhuff.c |
- * |
- * Copyright (C) 1991-1997, 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. |
- * |
- * 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 jdphuff.c */ |
- |
- |
-/* |
- * Expanded entropy decoder object for 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 { |
- 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).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 * 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]; |
- /* 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; |
- |
- |
-/* |
- * Initialize for a Huffman-compressed scan. |
- */ |
- |
-METHODDEF(void) |
-start_pass_huff_decoder (j_decompress_ptr cinfo) |
-{ |
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; |
- int ci, blkn, dctbl, actbl; |
- 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 || |
- 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; |
- /* 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]); |
- /* Initialize DC predictions to 0 */ |
- entropy->saved.last_dc_val[ci] = 0; |
- } |
- |
- /* Precalculate decoding info for each block in an MCU of this scan */ |
- for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
- ci = cinfo->MCU_membership[blkn]; |
- compptr = cinfo->cur_comp_info[ci]; |
- /* Precalculate which table to use for each block */ |
- 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]; |
- /* Decide whether we really care about the coefficient values */ |
- if (compptr->component_needed) { |
- entropy->dc_needed[blkn] = TRUE; |
- /* we don't need the ACs if producing a 1/8th-size image */ |
- entropy->ac_needed[blkn] = (compptr->DCT_scaled_size > 1); |
- } else { |
- entropy->dc_needed[blkn] = entropy->ac_needed[blkn] = FALSE; |
- } |
- } |
- |
- /* 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 restart counter */ |
- entropy->restarts_to_go = cinfo->restart_interval; |
-} |
- |
- |
-/* |
- * Compute the derived values for a Huffman table. |
- * This routine also performs some validation checks on the table. |
- * |
- * Note this is also used by jdphuff.c. |
- */ |
- |
-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; |
- |
- /* Note that huffsize[] and huffcode[] are filled in code-length order, |
- * paralleling the order of the symbols themselves in htbl->huffval[]. |
- */ |
- |
- /* Find the input Huffman table */ |
- 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); |
- |
- /* 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)); |
- dtbl = *pdtbl; |
- 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 */ |
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
- while (i--) |
- 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) { |
- 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)) |
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
- code <<= 1; |
- si++; |
- } |
- |
- /* Figure F.15: generate decoding tables for bit-sequential decoding */ |
- |
- p = 0; |
- for (l = 1; l <= 16; l++) { |
- if (htbl->bits[l]) { |
- /* 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]; |
- p += htbl->bits[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[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */ |
- |
- /* Compute lookahead tables to speed up decoding. |
- * First we set all the table entries to 0, indicating "too long"; |
- * then we iterate through the Huffman codes that are short enough and |
- * fill in all the entries that correspond to bit sequences starting |
- * with that code. |
- */ |
- |
- MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits)); |
- |
- p = 0; |
- for (l = 1; l <= HUFF_LOOKAHEAD; l++) { |
- 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->look_nbits[lookbits] = l; |
- dtbl->look_sym[lookbits] = htbl->huffval[p]; |
- lookbits++; |
- } |
- } |
- } |
- |
- /* Validate symbols as being reasonable. |
- * For AC tables, we make no check, but accept all byte values 0..255. |
- * For DC tables, we require the symbols to be in range 0..15. |
- * (Tighter bounds could be applied depending on the data depth and mode, |
- * but this is sufficient to ensure safe decoding.) |
- */ |
- if (isDC) { |
- for (i = 0; i < numsymbols; i++) { |
- int sym = htbl->huffval[i]; |
- if (sym < 0 || sym > 15) |
- ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
- } |
- } |
-} |
- |
- |
-/* |
- * Out-of-line code for bit fetching (shared with jdphuff.c). |
- * See jdhuff.h for info about usage. |
- * Note: current values of get_buffer and bits_left are passed as parameters, |
- * but are returned in the corresponding fields of the state struct. |
- * |
- * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width |
- * of get_buffer to be used. (On machines with wider words, an even larger |
- * buffer could be used.) However, on some machines 32-bit shifts are |
- * quite slow and take time proportional to the number of places shifted. |
- * (This is true with most PC compilers, for instance.) In this case it may |
- * be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the |
- * average shift distance at the cost of more calls to jpeg_fill_bit_buffer. |
- */ |
- |
-#ifdef SLOW_SHIFT_32 |
-#define MIN_GET_BITS 15 /* minimum allowable value */ |
-#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) |
-/* 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 size_t bytes_in_buffer = state->bytes_in_buffer; |
- j_decompress_ptr cinfo = state->cinfo; |
- |
- /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */ |
- /* (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 */ |
- 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; |
- } |
- 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; |
- } |
- } |
- |
- /* OK, load c into get_buffer */ |
- get_buffer = (get_buffer << 8) | c; |
- bits_left += 8; |
- } /* end while */ |
- } else { |
- 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. |
- */ |
- if (nbits > bits_left) { |
- /* Uh-oh. Report corrupted data to user and stuff zeroes into |
- * the data stream, so that we can produce some kind of image. |
- * 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; |
- } |
- /* Fill the buffer with zero bits */ |
- get_buffer <<= MIN_GET_BITS - bits_left; |
- bits_left = MIN_GET_BITS; |
- } |
- } |
- |
- /* Unload the local registers */ |
- 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; |
-} |
- |
- |
-/* |
- * Out-of-line code for Huffman code decoding. |
- * See jdhuff.h for info about usage. |
- */ |
- |
-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 INT32 code; |
- |
- /* HUFF_DECODE has determined that the code is at least min_bits */ |
- /* bits long, so fetch that many bits in one swoop. */ |
- |
- CHECK_BIT_BUFFER(*state, l, return -1); |
- 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. */ |
- |
- while (code > htbl->maxcode[l]) { |
- code <<= 1; |
- CHECK_BIT_BUFFER(*state, 1, return -1); |
- code |= GET_BITS(1); |
- l++; |
- } |
- |
- /* Unload the local registers */ |
- state->get_buffer = get_buffer; |
- state->bits_left = bits_left; |
- |
- /* With garbage input we may reach the sentinel value l = 17. */ |
- |
- if (l > 16) { |
- WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE); |
- return 0; /* fake a zero as the safest result */ |
- } |
- |
- return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ]; |
-} |
- |
- |
-/* |
- * 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) |
-{ |
- huff_entropy_ptr entropy = (huff_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; |
- |
- /* 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; |
-} |
- |
- |
-/* |
- * Decode and return 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 HAS BEEN ZEROED BY THE CALLER. |
- * (Wholesale zeroing is usually a little faster than retail...) |
- * |
- * Returns 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 |
- * this module, since we'll just re-assign them on the next call.) |
- */ |
- |
-METHODDEF(boolean) |
-decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) |
-{ |
- huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; |
- int blkn; |
- BITREAD_STATE_VARS; |
- savable_state state; |
- |
- /* 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++) { |
- JBLOCKROW block = MCU_data[blkn]; |
- 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 */ |
- |
- /* Section F.2.2.1: decode the DC coefficient difference */ |
- 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]) { |
- /* Convert DC difference to actual value, update last_dc_val */ |
- 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 (entropy->ac_needed[blkn]) { |
- |
- /* Section F.2.2.2: decode the AC coefficients */ |
- /* Since zeroes are skipped, output area must be cleared beforehand */ |
- 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); |
- /* Output coefficient in natural (dezigzagged) order. |
- * 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; |
- } else { |
- if (r != 15) |
- break; |
- k += 15; |
- } |
- } |
- |
- } else { |
- |
- /* Section F.2.2.2: decode the AC coefficients */ |
- /* In this path we just discard the values */ |
- 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; |
- } |
- } |
- |
- } |
- } |
- |
- /* 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; |
-} |
- |
- |
-/* |
- * Module initialization routine for Huffman entropy decoding. |
- */ |
- |
-GLOBAL(void) |
-jinit_huff_decoder (j_decompress_ptr cinfo) |
-{ |
- huff_entropy_ptr entropy; |
- int i; |
- |
- 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; |
- |
- /* Mark tables unallocated */ |
- for (i = 0; i < NUM_HUFF_TBLS; i++) { |
- entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; |
- } |
-} |