19f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 29f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * jdhuff.c 39f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 49f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Copyright (C) 1991-1997, Thomas G. Lane. 59f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This file is part of the Independent JPEG Group's software. 69f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * For conditions of distribution and use, see the accompanying README file. 79f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 89f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This file contains Huffman entropy decoding routines. 99f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Much of the complexity here has to do with supporting input suspension. 119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * If the data source module demands suspension, we want to be able to back 129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * up to the start of the current MCU. To do this, we copy state variables 139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * into local working storage, and update them back to the permanent 149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * storage only upon successful completion of an MCU. 159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define JPEG_INTERNALS 189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#include "jinclude.h" 199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#include "jpeglib.h" 209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#include "jdhuff.h" /* Declarations shared with jdphuff.c */ 219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 22f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenLOCAL(boolean) process_restart (j_decompress_ptr cinfo); 23f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Expanded entropy decoder object for Huffman decoding. 279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The savable_state subrecord contains fields that change within an MCU, 299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but must not be updated permanently until we complete the MCU. 309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef struct { 339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ 349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} savable_state; 359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* This macro is to work around compilers with missing or broken 379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * structure assignment. You'll need to fix this code if you have 389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * such a compiler and you change MAX_COMPS_IN_SCAN. 399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifndef NO_STRUCT_ASSIGN 429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define ASSIGN_STATE(dest,src) ((dest) = (src)) 439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#else 449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#if MAX_COMPS_IN_SCAN == 4 459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define ASSIGN_STATE(dest,src) \ 469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ((dest).last_dc_val[0] = (src).last_dc_val[0], \ 479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[1] = (src).last_dc_val[1], \ 489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[2] = (src).last_dc_val[2], \ 499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[3] = (src).last_dc_val[3]) 509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef struct { 559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project struct jpeg_entropy_decoder pub; /* public fields */ 569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* These fields are loaded into local variables at start of each MCU. 589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * In case of suspension, we exit WITHOUT updating them. 599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bitread_perm_state bitstate; /* Bit buffer at start of MCU */ 619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project savable_state saved; /* Other state at start of MCU */ 629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* These fields are NOT loaded into local working state. */ 649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int restarts_to_go; /* MCUs left in this restart interval */ 659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Pointers to derived tables (these workspaces have image lifespan) */ 679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS]; 689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS]; 699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Precalculated info set up by start_pass for use in decode_mcu: */ 719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Pointers to derived tables to be used for each block within an MCU */ 739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU]; 749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU]; 759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Whether we care about the DC and AC coefficient values for each block */ 769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project boolean dc_needed[D_MAX_BLOCKS_IN_MCU]; 779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project boolean ac_needed[D_MAX_BLOCKS_IN_MCU]; 789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} huff_entropy_decoder; 799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef huff_entropy_decoder * huff_entropy_ptr; 819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Initialize for a Huffman-compressed scan. 849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) 879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectstart_pass_huff_decoder (j_decompress_ptr cinfo) 889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci, blkn, dctbl, actbl; 919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_component_info * compptr; 929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG. 949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This ought to be an error condition, but we make it a warning because 959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * there are some baseline files out there with all zeroes in these bytes. 969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2-1 || 989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->Ah != 0 || cinfo->Al != 0) 999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project WARNMS(cinfo, JWRN_NOT_SEQUENTIAL); 1009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 1029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 1039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dctbl = compptr->dc_tbl_no; 1049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project actbl = compptr->ac_tbl_no; 1059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Compute derived values for Huffman tables */ 1069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We may do this more than once for a table, but it's not expensive */ 1079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_make_d_derived_tbl(cinfo, TRUE, dctbl, 1089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project & entropy->dc_derived_tbls[dctbl]); 1099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_make_d_derived_tbl(cinfo, FALSE, actbl, 1109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project & entropy->ac_derived_tbls[actbl]); 1119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize DC predictions to 0 */ 1129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.last_dc_val[ci] = 0; 1139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Precalculate decoding info for each block in an MCU of this scan */ 1169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 1179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ci = cinfo->MCU_membership[blkn]; 1189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 1199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Precalculate which table to use for each block */ 1209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no]; 1219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no]; 1229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Decide whether we really care about the coefficient values */ 1239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (compptr->component_needed) { 1249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_needed[blkn] = TRUE; 1259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* we don't need the ACs if producing a 1/8th-size image */ 1269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->ac_needed[blkn] = (compptr->DCT_scaled_size > 1); 1279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 1289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_needed[blkn] = entropy->ac_needed[blkn] = FALSE; 1299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize bitread state variables */ 1339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->bitstate.bits_left = 0; 1349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */ 1359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.insufficient_data = FALSE; 1369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize restart counter */ 1389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go = cinfo->restart_interval; 1399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 1409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 1439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Compute the derived values for a Huffman table. 1449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This routine also performs some validation checks on the table. 1459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 1469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Note this is also used by jdphuff.c. 1479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 1489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(void) 1509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno, 1519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl ** pdtbl) 1529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 1539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JHUFF_TBL *htbl; 1549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl *dtbl; 1559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int p, i, l, si, numsymbols; 1569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int lookbits, ctr; 1579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project char huffsize[257]; 1589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int huffcode[257]; 1599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int code; 1609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Note that huffsize[] and huffcode[] are filled in code-length order, 1629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * paralleling the order of the symbols themselves in htbl->huffval[]. 1639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 1649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the input Huffman table */ 1669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (tblno < 0 || tblno >= NUM_HUFF_TBLS) 1679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 1689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htbl = 1699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno]; 1709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (htbl == NULL) 1719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 1729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Allocate a workspace if we haven't already done so. */ 1749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (*pdtbl == NULL) 1759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project *pdtbl = (d_derived_tbl *) 1769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 1779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project SIZEOF(d_derived_tbl)); 1789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl = *pdtbl; 1799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->pub = htbl; /* fill in back link */ 1809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure C.1: make table of Huffman code length for each symbol */ 1829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 1849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (l = 1; l <= 16; l++) { 1859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project i = (int) htbl->bits[l]; 1869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (i < 0 || p + i > 256) /* protect against table overrun */ 1879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 1889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (i--) 1899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffsize[p++] = (char) l; 1909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffsize[p] = 0; 1929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project numsymbols = p; 1939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure C.2: generate the codes themselves */ 1959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We also validate that the counts represent a legal Huffman code tree. */ 1969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code = 0; 1989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project si = huffsize[0]; 1999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 2009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (huffsize[p]) { 2019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (((int) huffsize[p]) == si) { 2029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffcode[p++] = code; 2039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code++; 2049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* code is now 1 more than the last code used for codelength si; but 2069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * it must still fit in si bits, since no code is allowed to be all ones. 2079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (((INT32) code) >= (((INT32) 1) << si)) 2099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 2109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code <<= 1; 2119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project si++; 2129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure F.15: generate decoding tables for bit-sequential decoding */ 2159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 2179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (l = 1; l <= 16; l++) { 2189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (htbl->bits[l]) { 2199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* valoffset[l] = huffval[] index of 1st symbol of code length l, 2209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * minus the minimum code of length l 2219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p]; 2239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p += htbl->bits[l]; 2249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */ 2259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 2269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->maxcode[l] = -1; /* -1 if no codes of this length */ 2279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->maxcode[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */ 2309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Compute lookahead tables to speed up decoding. 2329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * First we set all the table entries to 0, indicating "too long"; 2339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * then we iterate through the Huffman codes that are short enough and 2349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * fill in all the entries that correspond to bit sequences starting 2359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * with that code. 2369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits)); 2399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 2419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (l = 1; l <= HUFF_LOOKAHEAD; l++) { 2429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 1; i <= (int) htbl->bits[l]; i++, p++) { 2439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* l = current code's length, p = its index in huffcode[] & huffval[]. */ 2449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Generate left-justified code followed by all possible bit sequences */ 2459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l); 2469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) { 2479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->look_nbits[lookbits] = l; 2489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->look_sym[lookbits] = htbl->huffval[p]; 2499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project lookbits++; 2509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Validate symbols as being reasonable. 2559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * For AC tables, we make no check, but accept all byte values 0..255. 2569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * For DC tables, we require the symbols to be in range 0..15. 2579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * (Tighter bounds could be applied depending on the data depth and mode, 2589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but this is sufficient to ensure safe decoding.) 2599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (isDC) { 2619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i < numsymbols; i++) { 2629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int sym = htbl->huffval[i]; 2639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (sym < 0 || sym > 15) 2649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 2659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 2689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 2719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Out-of-line code for bit fetching (shared with jdphuff.c). 2729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * See jdhuff.h for info about usage. 2739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Note: current values of get_buffer and bits_left are passed as parameters, 2749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but are returned in the corresponding fields of the state struct. 2759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 2769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width 2779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * of get_buffer to be used. (On machines with wider words, an even larger 2789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * buffer could be used.) However, on some machines 32-bit shifts are 2799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * quite slow and take time proportional to the number of places shifted. 2809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * (This is true with most PC compilers, for instance.) In this case it may 2819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the 2829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * average shift distance at the cost of more calls to jpeg_fill_bit_buffer. 2839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef SLOW_SHIFT_32 2869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define MIN_GET_BITS 15 /* minimum allowable value */ 2879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#else 2889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define MIN_GET_BITS (BIT_BUF_SIZE-7) 2899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 2909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(boolean) 2939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjpeg_fill_bit_buffer (bitread_working_state * state, 2949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register bit_buf_type get_buffer, register int bits_left, 2959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int nbits) 2969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Load up the bit buffer to a depth of at least nbits */ 2979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 2989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Copy heavily used state fields into locals (hopefully registers) */ 2999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register const JOCTET * next_input_byte = state->next_input_byte; 3009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register size_t bytes_in_buffer = state->bytes_in_buffer; 30127c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen j_decompress_ptr cinfo = state->cinfo; 3029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */ 3049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* (It is assumed that no request will be for more than that many bits.) */ 3059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We fail to do so only if we hit a marker or are forced to suspend. */ 3069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->unread_marker == 0) { /* cannot advance past a marker */ 3089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (bits_left < MIN_GET_BITS) { 3099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int c; 3109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Attempt to read a byte */ 3129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (bytes_in_buffer == 0) { 3139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! (*cinfo->src->fill_input_buffer) (cinfo)) 3149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 3159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project next_input_byte = cinfo->src->next_input_byte; 3169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bytes_in_buffer = cinfo->src->bytes_in_buffer; 3179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bytes_in_buffer--; 3199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c = GETJOCTET(*next_input_byte++); 3209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* If it's 0xFF, check and discard stuffed zero byte */ 3229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (c == 0xFF) { 3239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Loop here to discard any padding FF's on terminating marker, 3249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * so that we can save a valid unread_marker value. NOTE: we will 3259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * accept multiple FF's followed by a 0 as meaning a single FF data 3269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * byte. This data pattern is not valid according to the standard. 3279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project do { 3299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (bytes_in_buffer == 0) { 3309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! (*cinfo->src->fill_input_buffer) (cinfo)) 3319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 3329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project next_input_byte = cinfo->src->next_input_byte; 3339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bytes_in_buffer = cinfo->src->bytes_in_buffer; 3349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bytes_in_buffer--; 3369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c = GETJOCTET(*next_input_byte++); 3379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } while (c == 0xFF); 3389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (c == 0) { 3409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Found FF/00, which represents an FF data byte */ 3419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c = 0xFF; 3429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 3439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Oops, it's actually a marker indicating end of compressed data. 3449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Save the marker code for later use. 3459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Fine point: it might appear that we should save the marker into 3469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * bitread working state, not straight into permanent state. But 3479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * once we have hit a marker, we cannot need to suspend within the 3489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * current MCU, because we will read no more bytes from the data 3499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * source. So it is OK to update permanent state right away. 3509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->unread_marker = c; 3529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* See if we need to insert some fake zero bits. */ 3539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project goto no_more_bytes; 3549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* OK, load c into get_buffer */ 3589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project get_buffer = (get_buffer << 8) | c; 3599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits_left += 8; 3609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } /* end while */ 3619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 3629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project no_more_bytes: 3639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We get here if we've read the marker that terminates the compressed 3649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * data segment. There should be enough bits in the buffer register 3659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * to satisfy the request; if so, no problem. 3669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits > bits_left) { 3689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Uh-oh. Report corrupted data to user and stuff zeroes into 3699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * the data stream, so that we can produce some kind of image. 3709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * We use a nonvolatile flag to ensure that only one warning message 3719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * appears per data segment. 3729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! cinfo->entropy->insufficient_data) { 3749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project WARNMS(cinfo, JWRN_HIT_MARKER); 3759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->entropy->insufficient_data = TRUE; 3769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Fill the buffer with zero bits */ 3789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project get_buffer <<= MIN_GET_BITS - bits_left; 3799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits_left = MIN_GET_BITS; 3809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Unload the local registers */ 3849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->next_input_byte = next_input_byte; 3859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->bytes_in_buffer = bytes_in_buffer; 3869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->get_buffer = get_buffer; 3879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->bits_left = bits_left; 3889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 3909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 3919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 3949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Out-of-line code for Huffman code decoding. 3959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * See jdhuff.h for info about usage. 3969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(int) 3999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjpeg_huff_decode (bitread_working_state * state, 4009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register bit_buf_type get_buffer, register int bits_left, 4019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * htbl, int min_bits) 4029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 4039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int l = min_bits; 4049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register INT32 code; 4059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* HUFF_DECODE has determined that the code is at least min_bits */ 4079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* bits long, so fetch that many bits in one swoop. */ 4089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project CHECK_BIT_BUFFER(*state, l, return -1); 4109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code = GET_BITS(l); 4119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Collect the rest of the Huffman code one bit at a time. */ 4139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This is per Figure F.16 in the JPEG spec. */ 4149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (code > htbl->maxcode[l]) { 4169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code <<= 1; 4179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project CHECK_BIT_BUFFER(*state, 1, return -1); 4189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code |= GET_BITS(1); 4199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project l++; 4209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Unload the local registers */ 4239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->get_buffer = get_buffer; 4249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->bits_left = bits_left; 4259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* With garbage input we may reach the sentinel value l = 17. */ 4279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (l > 16) { 4299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE); 4309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return 0; /* fake a zero as the safest result */ 4319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ]; 4349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 4359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 4389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Figure F.12: extend sign bit. 4399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * On some machines, a shift and add will be faster than a table lookup. 4409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 4419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef AVOID_TABLES 4439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x)) 4459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#else 4479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x)) 4499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectstatic const int extend_test[16] = /* entry n is 2**(n-1) */ 4519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, 4529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 }; 4539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectstatic const int extend_offset[16] = /* entry n is (-1 << n) + 1 */ 4559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1, 4569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1, 4579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1, 4589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 }; 4599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif /* AVOID_TABLES */ 4619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 4649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Check for a restart marker & resynchronize decoder. 4659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Returns FALSE if must suspend. 4669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 4679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 4699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectprocess_restart (j_decompress_ptr cinfo) 4709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 4719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 4729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci; 4739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Throw away any unused bits remaining in bit buffer; */ 4759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* include any full bytes in next_marker's count of discarded bytes */ 4769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8; 4779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->bitstate.bits_left = 0; 4789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Advance past the RSTn marker */ 4809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! (*cinfo->marker->read_restart_marker) (cinfo)) 4819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Re-initialize DC predictions to 0 */ 4849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < cinfo->comps_in_scan; ci++) 4859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.last_dc_val[ci] = 0; 4869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Reset restart counter */ 4889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go = cinfo->restart_interval; 4899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Reset out-of-data flag, unless read_restart_marker left us smack up 4919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * against a marker. In that case we will end up treating the next data 4929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * segment as empty, and we can avoid producing bogus output pixels by 4939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * leaving the flag set. 4949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 4959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->unread_marker == 0) 4969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.insufficient_data = FALSE; 4979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 4999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 5009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5013147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen/* 50227c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen * Save the current Huffman deocde position and the DC coefficients 50327c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen * for each component into bitstream_offset and dc_info[], respectively. 5043147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen */ 50527c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta ChenMETHODDEF(void) 50627c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chenget_huffman_decoder_configuration(j_decompress_ptr cinfo, 50727c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen huffman_offset_data *offset) 5083147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen{ 50927c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 51027c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen short int *dc_info = offset->prev_dc; 51127c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen int i; 51227c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen jpeg_get_huffman_decoder_configuration(cinfo, offset); 51327c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen for (i = 0; i < cinfo->comps_in_scan; i++) { 51427c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen dc_info[i] = entropy->saved.last_dc_val[i]; 51527c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen } 516f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen} 5173147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 518f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen/* 519f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * Save the current Huffman decoder position and the bit buffer 520f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * into bitstream_offset and get_buffer, respectively. 521f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen */ 522f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenGLOBAL(void) 523f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wenjpeg_get_huffman_decoder_configuration(j_decompress_ptr cinfo, 524f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen huffman_offset_data *offset) 525f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen{ 526f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 5273147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 528f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen if (cinfo->restart_interval) { 529f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen // We are at the end of a data segment 530f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen if (entropy->restarts_to_go == 0) 531f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen if (! process_restart(cinfo)) 532f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen return; 5333147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 5343147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 53527c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen // Save restarts_to_go and next_restart_num 53627c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen offset->restarts_to_go = (unsigned short) entropy->restarts_to_go; 53727c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen offset->next_restart_num = cinfo->marker->next_restart_num; 53827c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen 539f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen offset->bitstream_offset = 540f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen (jget_input_stream_position(cinfo) << LOG_TWO_BIT_BUF_SIZE) 541f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen + entropy->bitstate.bits_left; 542f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 543f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen offset->get_buffer = entropy->bitstate.get_buffer; 544f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen} 5453147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 546f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen/* 547f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * Configure the Huffman decoder to decode the image 548f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * starting from the bitstream position recorded in offset. 549f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen */ 550f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenMETHODDEF(void) 551f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wenconfigure_huffman_decoder(j_decompress_ptr cinfo, huffman_offset_data offset) 552f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen{ 553f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 554f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen short int *dc_info = offset.prev_dc; 555f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen int i; 556f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen jpeg_configure_huffman_decoder(cinfo, offset); 5573147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for (i = 0; i < cinfo->comps_in_scan; i++) { 5583147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen entropy->saved.last_dc_val[i] = dc_info[i]; 5593147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 5603147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 5613147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 5623147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen/* 56327c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen * Configure the Huffman decoder reader position and bit buffer. 5643147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen */ 56527c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta ChenGLOBAL(void) 56627c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chenjpeg_configure_huffman_decoder(j_decompress_ptr cinfo, 56727c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen huffman_offset_data offset) 5683147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen{ 5693147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 57027c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen 57127c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen // Restore restarts_to_go and next_restart_num 57227c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen cinfo->unread_marker = 0; 57327c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen entropy->restarts_to_go = offset.restarts_to_go; 57427c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen cinfo->marker->next_restart_num = offset.next_restart_num; 57527c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen 57627c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen unsigned int bitstream_offset = offset.bitstream_offset; 57727c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen int blkn, i; 57827c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen 57927c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen unsigned int byte_offset = bitstream_offset >> LOG_TWO_BIT_BUF_SIZE; 58027c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen unsigned int bit_in_bit_buffer = 58127c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen bitstream_offset & ((1 << LOG_TWO_BIT_BUF_SIZE) - 1); 58227c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen 58327c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen jset_input_stream_position_bit(cinfo, byte_offset, 58427c2e1a63730561332f4d3c406c7e9b7c36963d2Wei-Ta Chen bit_in_bit_buffer, offset.get_buffer); 5853147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 5869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 5889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Decode and return one MCU's worth of Huffman-compressed coefficients. 5899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The coefficients are reordered from zigzag order into natural array order, 5909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but are not dequantized. 5919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 5929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The i'th block of the MCU is stored into the block pointed to by 5939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * MCU_data[i]. WE ASSUME THIS AREA HAS BEEN ZEROED BY THE CALLER. 5949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * (Wholesale zeroing is usually a little faster than retail...) 5959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 5969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Returns FALSE if data source requested suspension. In that case no 5979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * changes have been made to permanent state. (Exception: some output 5989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * coefficients may already have been assigned. This is harmless for 5999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * this module, since we'll just re-assign them on the next call.) 6009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 6019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(boolean) 6039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectdecode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 6049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 6059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 6069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int blkn; 6079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project BITREAD_STATE_VARS; 6089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project savable_state state; 6099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Process restart marker if needed; may have to suspend */ 6119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->restart_interval) { 6129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->restarts_to_go == 0) 6139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! process_restart(cinfo)) 6149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 6159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* If we've run out of data, just leave the MCU set to zeroes. 6189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This way, we return uniform gray for the remainder of the segment. 6199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 6209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! entropy->pub.insufficient_data) { 6219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Load up working state */ 6229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 6239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(state, entropy->saved); 6249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Outer loop handles each block in the MCU */ 6269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 6289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JBLOCKROW block = MCU_data[blkn]; 6299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn]; 6309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn]; 6319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int s, k, r; 6329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Decode a single block's worth of coefficients */ 6349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Section F.2.2.1: decode the DC coefficient difference */ 6369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project HUFF_DECODE(s, br_state, dctbl, return FALSE, label1); 6379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (s) { 6389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project CHECK_BIT_BUFFER(br_state, s, return FALSE); 6399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = GET_BITS(s); 6409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project s = HUFF_EXTEND(r, s); 6419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->dc_needed[blkn]) { 6449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Convert DC difference to actual value, update last_dc_val */ 6459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci = cinfo->MCU_membership[blkn]; 6469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project s += state.last_dc_val[ci]; 6479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.last_dc_val[ci] = s; 6489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */ 6499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*block)[0] = (JCOEF) s; 6509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->ac_needed[blkn]) { 6539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Section F.2.2.2: decode the AC coefficients */ 6559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Since zeroes are skipped, output area must be cleared beforehand */ 6569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (k = 1; k < DCTSIZE2; k++) { 6579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project HUFF_DECODE(s, br_state, actbl, return FALSE, label2); 6589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = s >> 4; 6609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project s &= 15; 6619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (s) { 6639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project k += r; 6649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project CHECK_BIT_BUFFER(br_state, s, return FALSE); 6659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = GET_BITS(s); 6669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project s = HUFF_EXTEND(r, s); 6679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Output coefficient in natural (dezigzagged) order. 6689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Note: the extra entries in jpeg_natural_order[] will save us 6699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * if k >= DCTSIZE2, which could happen if the data is corrupted. 6709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 6719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*block)[jpeg_natural_order[k]] = (JCOEF) s; 6729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 6739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (r != 15) 6749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project break; 6759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project k += 15; 6769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 6809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Section F.2.2.2: decode the AC coefficients */ 6829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* In this path we just discard the values */ 6839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (k = 1; k < DCTSIZE2; k++) { 6849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project HUFF_DECODE(s, br_state, actbl, return FALSE, label3); 6859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = s >> 4; 6879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project s &= 15; 6889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (s) { 6909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project k += r; 6919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project CHECK_BIT_BUFFER(br_state, s, return FALSE); 6929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project DROP_BITS(s); 6939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 6949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (r != 15) 6959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project break; 6969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project k += 15; 6979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Completed MCU, so update state */ 7049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 7059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(entropy->saved, state); 7069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Account for restart interval (no-op if not using restarts) */ 7099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go--; 7109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 7129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 7139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7143147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen/* 7153147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * Decode one MCU's worth of Huffman-compressed coefficients. 7163147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * The propose of this method is to calculate the 7173147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * data length of one MCU in Huffman-coded format. 7183147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * Therefore, all coefficients are discarded. 7193147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen */ 7203147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7213147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph WenMETHODDEF(boolean) 7223147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wendecode_mcu_discard_coef (j_decompress_ptr cinfo) 7233147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen{ 7243147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 7253147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen int blkn; 7263147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen BITREAD_STATE_VARS; 7273147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen savable_state state; 7283147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7293147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Process restart marker if needed; may have to suspend */ 7303147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (cinfo->restart_interval) { 7313147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (entropy->restarts_to_go == 0) 7323147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (! process_restart(cinfo)) 7333147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen return FALSE; 7343147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7353147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7363147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (! entropy->pub.insufficient_data) { 7373147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7383147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Load up working state */ 7393147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 7403147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen ASSIGN_STATE(state, entropy->saved); 7413147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7423147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Outer loop handles each block in the MCU */ 7433147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7443147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 7453147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn]; 7463147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn]; 7473147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen register int s, k, r; 7483147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7493147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Decode a single block's worth of coefficients */ 7503147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7513147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Section F.2.2.1: decode the DC coefficient difference */ 7523147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen HUFF_DECODE(s, br_state, dctbl, return FALSE, label1); 7533147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (s) { 7543147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen CHECK_BIT_BUFFER(br_state, s, return FALSE); 7553147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen r = GET_BITS(s); 7563147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen s = HUFF_EXTEND(r, s); 7573147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7583147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7593147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* discard all coefficients */ 7603147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (entropy->dc_needed[blkn]) { 7613147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Convert DC difference to actual value, update last_dc_val */ 7623147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen int ci = cinfo->MCU_membership[blkn]; 7633147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen s += state.last_dc_val[ci]; 7643147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen state.last_dc_val[ci] = s; 7653147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7663147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for (k = 1; k < DCTSIZE2; k++) { 7673147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen HUFF_DECODE(s, br_state, actbl, return FALSE, label3); 7683147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7693147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen r = s >> 4; 7703147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen s &= 15; 7713147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7723147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (s) { 7733147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen k += r; 7743147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen CHECK_BIT_BUFFER(br_state, s, return FALSE); 7753147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen DROP_BITS(s); 7763147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } else { 7773147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen if (r != 15) 7783147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen break; 7793147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen k += 15; 7803147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7813147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7823147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7833147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7843147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Completed MCU, so update state */ 7853147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 7863147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen ASSIGN_STATE(entropy->saved, state); 7873147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 7883147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7893147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Account for restart interval (no-op if not using restarts) */ 7903147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen entropy->restarts_to_go--; 7913147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7923147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen return TRUE; 7933147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 7943147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 7959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 7979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Module initialization routine for Huffman entropy decoding. 7989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 7999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(void) 8019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjinit_huff_decoder (j_decompress_ptr cinfo) 8029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 8039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy; 8049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int i; 8059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy = (huff_entropy_ptr) 8079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 8089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project SIZEOF(huff_entropy_decoder)); 8099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->entropy = (struct jpeg_entropy_decoder *) entropy; 8109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.start_pass = start_pass_huff_decoder; 8119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.decode_mcu = decode_mcu; 8123147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen entropy->pub.decode_mcu_discard_coef = decode_mcu_discard_coef; 813f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen entropy->pub.configure_huffman_decoder = configure_huffman_decoder; 814f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen entropy->pub.get_huffman_decoder_configuration = 815f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen get_huffman_decoder_configuration; 816f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen entropy->pub.index = NULL; 8173147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 8183147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen /* Mark tables unallocated */ 8193147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for (i = 0; i < NUM_HUFF_TBLS; i++) { 8203147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; 8213147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 8223147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 8233147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 8243147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen/* 8253147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * Call after jpeg_read_header 8263147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen */ 8273147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph WenGLOBAL(void) 8283147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wenjpeg_create_huffman_index(j_decompress_ptr cinfo, huffman_index *index) 8293147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen{ 8303147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen int i, s; 8313147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen index->scan_count = 1; 832f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen index->total_iMCU_rows = cinfo->total_iMCU_rows; 8333147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen index->scan = (huffman_scan_header*)malloc(index->scan_count 8343147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * sizeof(huffman_scan_header)); 8353147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen index->scan[0].offset = (huffman_offset_data**)malloc(cinfo->total_iMCU_rows 8363147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen * sizeof(huffman_offset_data*)); 837f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen index->scan[0].prev_MCU_offset.bitstream_offset = 0; 8383147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen index->MCU_sample_size = DEFAULT_MCU_SAMPLE_SIZE; 8393147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 8403147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen index->mem_used = sizeof(huffman_scan_header) 841f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen + cinfo->total_iMCU_rows * sizeof(huffman_offset_data*); 8423147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 8433147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen 8443147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph WenGLOBAL(void) 8453147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wenjpeg_destroy_huffman_index(huffman_index *index) 8463147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen{ 8473147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen int i, j; 8483147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for (i = 0; i < index->scan_count; i++) { 8493147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen for(j = 0; j < index->total_iMCU_rows; j++) { 8503147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen free(index->scan[i].offset[j]); 8513147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 8523147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen free(index->scan[i].offset); 8533147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen } 8543147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen free(index->scan); 8553147fbe7688fc353e6ae03825a37cf101a4ee01dJoseph Wen} 856f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 857f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen/* 858f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * Set the reader byte position to offset 859f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen */ 860f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenGLOBAL(void) 861f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wenjset_input_stream_position(j_decompress_ptr cinfo, int offset) 862f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen{ 863f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen if (cinfo->src->seek_input_data) { 864f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen cinfo->src->seek_input_data(cinfo, offset); 865f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen } else { 866f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen cinfo->src->bytes_in_buffer = cinfo->src->current_offset - offset; 867f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen cinfo->src->next_input_byte = cinfo->src->start_input_byte + offset; 868f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen } 869f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen} 870f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 871f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen/* 872f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * Set the reader byte position to offset and bit position to bit_left 873f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * with bit buffer set to buf. 874f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen */ 875f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenGLOBAL(void) 876f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wenjset_input_stream_position_bit(j_decompress_ptr cinfo, 877f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen int byte_offset, int bit_left, INT32 buf) 878f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen{ 879f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 880f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 881f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen entropy->bitstate.bits_left = bit_left; 882f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen entropy->bitstate.get_buffer = buf; 883f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 884f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen jset_input_stream_position(cinfo, byte_offset); 885f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen} 886f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen 887f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen/* 888f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen * Get the current reader byte position. 889f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen */ 890f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph WenGLOBAL(int) 891f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wenjget_input_stream_position(j_decompress_ptr cinfo) 892f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen{ 893f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen return cinfo->src->current_offset - cinfo->src->bytes_in_buffer; 894f5b94eebe742df1a9bb3941fc0a0ec0137e936efJoseph Wen} 895