diff options
| author | git perforce import user <a@b> | 2016-10-25 12:29:14 -0600 |
|---|---|---|
| committer | Sheikh Dawood Abdul Ajees <Sheikh Dawood Abdul Ajees> | 2016-10-25 18:56:37 -0500 |
| commit | 3dfe2108cfab31ba3ee5527e217d0d8e99a51162 (patch) | |
| tree | fa6485c169e50d7415a651bf838f5bcd0fd3bfbd /KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp | |
| download | physx-3.4-3dfe2108cfab31ba3ee5527e217d0d8e99a51162.tar.xz physx-3.4-3dfe2108cfab31ba3ee5527e217d0d8e99a51162.zip | |
Initial commit:
PhysX 3.4.0 Update @ 21294896
APEX 1.4.0 Update @ 21275617
[CL 21300167]
Diffstat (limited to 'KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp')
| -rw-r--r-- | KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp b/KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp new file mode 100644 index 00000000..a5e0696f --- /dev/null +++ b/KaplaDemo/samples/sampleViewer3/IJGWin32/jdshuff.cpp @@ -0,0 +1,361 @@ +/* + * jdshuff.c + * + * Copyright (C) 1991-1998, Thomas G. Lane. + * This file is part of the Independent JPEG Group's software. + * For conditions of distribution and use, see the accompanying README file. + * + * This file contains Huffman entropy decoding routines for sequential JPEG. + * + * Much of the complexity here has to do with supporting input suspension. + * If the data source module demands suspension, we want to be able to back + * up to the start of the current MCU. To do this, we copy state variables + * into local working storage, and update them back to the permanent + * storage only upon successful completion of an MCU. + */ +#include "stdafx.h" + +#define JPEG_INTERNALS +//#include "jinclude.h" +//#include "jpeglib.h" +//#include "jlossy.h" /* Private declarations for lossy codec */ +//#include "jdhuff.h" /* Declarations shared with jd*huff.c */ + + +/* + * Private 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 { + huffd_common_fields; /* Fields shared with other entropy decoders */ + + /* These fields are loaded into local variables at start of each MCU. + * In case of suspension, we exit WITHOUT updating them. + */ + 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_DATA_UNITS_IN_MCU]; + d_derived_tbl * ac_cur_tbls[D_MAX_DATA_UNITS_IN_MCU]; + /* Whether we care about the DC and AC coefficient values for each block */ + boolean dc_needed[D_MAX_DATA_UNITS_IN_MCU]; + boolean ac_needed[D_MAX_DATA_UNITS_IN_MCU]; +} shuff_entropy_decoder; + +typedef shuff_entropy_decoder * shuff_entropy_ptr; + + +/* + * Initialize for a Huffman-compressed scan. + */ + +METHODDEF(void) +start_pass_huff_decoder (j_decompress_ptr cinfo) +{ + j_lossy_d_ptr lossyd = (j_lossy_d_ptr) cinfo->codec; + shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyd->entropy_private; + 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->data_units_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->codec_data_unit > 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->insufficient_data = FALSE; + + /* Initialize restart counter */ + entropy->restarts_to_go = cinfo->restart_interval; +} + + +/* + * Figure F.12: extend sign bit. + * On some machines, a shift and add will be faster than a table lookup. + */ + +#ifdef AVOID_TABLES + +#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x)) + +#else + +#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x)) + +static const int extend_test[16] = /* entry n is 2**(n-1) */ + { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, + 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 }; + +static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */ + { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1, + ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1, + ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1, + ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 }; + +#endif /* AVOID_TABLES */ + + +/* + * Check for a restart marker & resynchronize decoder. + * Returns FALSE if must suspend. + */ + +LOCAL(boolean) +process_restart (j_decompress_ptr cinfo) +{ + j_lossy_d_ptr lossyd = (j_lossy_d_ptr) cinfo->codec; + shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyd->entropy_private; + 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->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) +{ + j_lossy_d_ptr lossyd = (j_lossy_d_ptr) cinfo->codec; + shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyd->entropy_private; + 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->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->data_units_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_shuff_decoder (j_decompress_ptr cinfo) +{ + j_lossy_d_ptr lossyd = (j_lossy_d_ptr) cinfo->codec; + shuff_entropy_ptr entropy; + int i; + + entropy = (shuff_entropy_ptr) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + SIZEOF(shuff_entropy_decoder)); + lossyd->entropy_private = (void *) entropy; + lossyd->entropy_start_pass = start_pass_huff_decoder; + lossyd->entropy_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; + } +} |