170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jdphuff.c 370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Copyright (C) 1995-1997, Thomas G. Lane. 570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file is part of the Independent JPEG Group's software. 670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * For conditions of distribution and use, see the accompanying README file. 770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file contains Huffman entropy decoding routines for progressive JPEG. 970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 1070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Much of the complexity here has to do with supporting input suspension. 1170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * If the data source module demands suspension, we want to be able to back 1270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * up to the start of the current MCU. To do this, we copy state variables 1370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * into local working storage, and update them back to the permanent 1470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * storage only upon successful completion of an MCU. 1570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 1670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 1770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define JPEG_INTERNALS 1870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include "jinclude.h" 1970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include "jpeglib.h" 2070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include "jdhuff.h" /* Declarations shared with jdhuff.c */ 2170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef D_PROGRESSIVE_SUPPORTED 2470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 2670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Expanded entropy decoder object for progressive Huffman decoding. 2770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 2870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The savable_state subrecord contains fields that change within an MCU, 2970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * but must not be updated permanently until we complete the MCU. 3070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 3170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 3270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef struct { 3370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int EOBRUN; /* remaining EOBs in EOBRUN */ 3470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ 3570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} savable_state; 3670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 3770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* This macro is to work around compilers with missing or broken 3870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * structure assignment. You'll need to fix this code if you have 3970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * such a compiler and you change MAX_COMPS_IN_SCAN. 4070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 4170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 4270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifndef NO_STRUCT_ASSIGN 4370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define ASSIGN_STATE(dest,src) ((dest) = (src)) 4470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#else 4570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#if MAX_COMPS_IN_SCAN == 4 4670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define ASSIGN_STATE(dest,src) \ 4770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ((dest).EOBRUN = (src).EOBRUN, \ 4870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (dest).last_dc_val[0] = (src).last_dc_val[0], \ 4970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (dest).last_dc_val[1] = (src).last_dc_val[1], \ 5070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (dest).last_dc_val[2] = (src).last_dc_val[2], \ 5170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (dest).last_dc_val[3] = (src).last_dc_val[3]) 5270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 5370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 5470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 5570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 5670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef struct { 5770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine struct jpeg_entropy_decoder pub; /* public fields */ 5870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 5970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* These fields are loaded into local variables at start of each MCU. 6070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * In case of suspension, we exit WITHOUT updating them. 6170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 6270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bitread_perm_state bitstate; /* Bit buffer at start of MCU */ 6370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine savable_state saved; /* Other state at start of MCU */ 6470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 6570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* These fields are NOT loaded into local working state. */ 6670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int restarts_to_go; /* MCUs left in this restart interval */ 6770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 6870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Pointers to derived tables (these workspaces have image lifespan) */ 6970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine d_derived_tbl * derived_tbls[NUM_HUFF_TBLS]; 7070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 7170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */ 7270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} phuff_entropy_decoder; 7370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 7470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef phuff_entropy_decoder * phuff_entropy_ptr; 7570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 7670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Forward declarations */ 7770a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) decode_mcu_DC_first JPP((j_decompress_ptr cinfo, 7870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW *MCU_data)); 7970a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) decode_mcu_AC_first JPP((j_decompress_ptr cinfo, 8070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW *MCU_data)); 8170a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) decode_mcu_DC_refine JPP((j_decompress_ptr cinfo, 8270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW *MCU_data)); 8370a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) decode_mcu_AC_refine JPP((j_decompress_ptr cinfo, 8470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW *MCU_data)); 85349beb3f9b2a10a9a5cc001c115c2f742a833d6fAl SuttonGLOBAL(void) jpeg_configure_huffman_decoder_progressive( 86349beb3f9b2a10a9a5cc001c115c2f742a833d6fAl Sutton j_decompress_ptr cinfo, huffman_offset_data offset); 87349beb3f9b2a10a9a5cc001c115c2f742a833d6fAl SuttonGLOBAL(void) jpeg_get_huffman_decoder_configuration_progressive( 88349beb3f9b2a10a9a5cc001c115c2f742a833d6fAl Sutton j_decompress_ptr cinfo, huffman_offset_data *offset); 8970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 9070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 9170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Initialize for a Huffman-compressed scan. 9270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 9370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 9470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 9570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinestart_pass_phuff_decoder (j_decompress_ptr cinfo) 9670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 9770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 9870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine boolean is_DC_band, bad; 9970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, coefi, tbl; 10070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int *coef_bit_ptr; 10170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info * compptr; 10270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 10370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine is_DC_band = (cinfo->Ss == 0); 10470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 10570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Validate scan parameters */ 10670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = FALSE; 10770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (is_DC_band) { 10870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Se != 0) 10970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = TRUE; 11070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 11170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* need not check Ss/Se < 0 since they came from unsigned bytes */ 11270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Ss > cinfo->Se || cinfo->Se >= DCTSIZE2) 11370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = TRUE; 11470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* AC scans may have only one component */ 11570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->comps_in_scan != 1) 11670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = TRUE; 11770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 11870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Ah != 0) { 11970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Successive approximation refinement scan: must have Al = Ah-1. */ 12070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Al != cinfo->Ah-1) 12170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = TRUE; 12270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 12370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Al > 13) /* need not check for < 0 */ 12470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bad = TRUE; 12570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Arguably the maximum Al value should be less than 13 for 8-bit precision, 12670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * but the spec doesn't say so, and we try to be liberal about what we 12770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * accept. Note: large Al values could result in out-of-range DC 12870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * coefficients during early scans, leading to bizarre displays due to 12970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * overflows in the IDCT math. But we won't crash. 13070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 13170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (bad) 13270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ERREXIT4(cinfo, JERR_BAD_PROGRESSION, 13370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al); 13470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Update progression status, and verify that scan order is legal. 13570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Note that inter-scan inconsistencies are treated as warnings 13670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * not fatal errors ... not clear if this is right way to behave. 13770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 13870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 13970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int cindex = cinfo->cur_comp_info[ci]->component_index; 14070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine coef_bit_ptr = & cinfo->coef_bits[cindex][0]; 14170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */ 14270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0); 14370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) { 14470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi]; 14570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Ah != expected) 14670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi); 14770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine coef_bit_ptr[coefi] = cinfo->Al; 14870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 14970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 15070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 15170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Select MCU decoding routine */ 15270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Ah == 0) { 15370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (is_DC_band) 15470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.decode_mcu = decode_mcu_DC_first; 15570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else 15670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.decode_mcu = decode_mcu_AC_first; 15770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 15870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (is_DC_band) 15970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.decode_mcu = decode_mcu_DC_refine; 16070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else 16170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.decode_mcu = decode_mcu_AC_refine; 16270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 16370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 16470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 16570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine compptr = cinfo->cur_comp_info[ci]; 16670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Make sure requested tables are present, and compute derived tables. 16770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We may build same derived table more than once, but it's not expensive. 16870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 16970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (is_DC_band) { 17070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->Ah == 0) { /* DC refinement needs no table */ 17170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine tbl = compptr->dc_tbl_no; 17270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_make_d_derived_tbl(cinfo, TRUE, tbl, 17370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine & entropy->derived_tbls[tbl]); 17470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 17570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 17670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine tbl = compptr->ac_tbl_no; 17770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_make_d_derived_tbl(cinfo, FALSE, tbl, 17870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine & entropy->derived_tbls[tbl]); 17970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* remember the single active table */ 18070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->ac_derived_tbl = entropy->derived_tbls[tbl]; 18170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 18270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Initialize DC predictions to 0 */ 18370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.last_dc_val[ci] = 0; 18470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 18570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 18670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Initialize bitread state variables */ 18770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->bitstate.bits_left = 0; 18870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */ 18970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.insufficient_data = FALSE; 19070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Initialize private state variables */ 19270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.EOBRUN = 0; 19370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Initialize restart counter */ 19570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go = cinfo->restart_interval; 19670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 19770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 20070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Figure F.12: extend sign bit. 20170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * On some machines, a shift and add will be faster than a table lookup. 20270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 20370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 20470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef AVOID_TABLES 20570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 20670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x)) 20770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 20870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#else 20970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 21070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x)) 21170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 21270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinestatic const int extend_test[16] = /* entry n is 2**(n-1) */ 21370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, 21470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 }; 21570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 21670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinestatic const int extend_offset[16] = /* entry n is (-1 << n) + 1 */ 21770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1, 21870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1, 21970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1, 22070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 }; 22170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 22270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* AVOID_TABLES */ 22370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 22470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 22570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 22670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Check for a restart marker & resynchronize decoder. 22770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Returns FALSE if must suspend. 22870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 22970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 23070a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineLOCAL(boolean) 23170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineprocess_restart (j_decompress_ptr cinfo) 23270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 23370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 23470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci; 23570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 23670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Throw away any unused bits remaining in bit buffer; */ 23770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* include any full bytes in next_marker's count of discarded bytes */ 23870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8; 23970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->bitstate.bits_left = 0; 24070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 24170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Advance past the RSTn marker */ 24270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! (*cinfo->marker->read_restart_marker) (cinfo)) 24370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 24470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 24570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Re-initialize DC predictions to 0 */ 24670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0; ci < cinfo->comps_in_scan; ci++) 24770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.last_dc_val[ci] = 0; 24870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Re-init EOB run count, too */ 24970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.EOBRUN = 0; 25070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 25170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Reset restart counter */ 25270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go = cinfo->restart_interval; 25370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 25470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Reset out-of-data flag, unless read_restart_marker left us smack up 25570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * against a marker. In that case we will end up treating the next data 25670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * segment as empty, and we can avoid producing bogus output pixels by 25770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * leaving the flag set. 25870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 25970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->unread_marker == 0) 26070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.insufficient_data = FALSE; 26170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 26270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return TRUE; 26370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 26470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 26570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 26670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 26770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Huffman MCU decoding. 26870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Each of these routines decodes and returns one MCU's worth of 26970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Huffman-compressed coefficients. 27070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The coefficients are reordered from zigzag order into natural array order, 27170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * but are not dequantized. 27270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 27370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The i'th block of the MCU is stored into the block pointed to by 27470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER. 27570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 27670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We return FALSE if data source requested suspension. In that case no 27770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * changes have been made to permanent state. (Exception: some output 27870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * coefficients may already have been assigned. This is harmless for 27970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * spectral selection, since we'll just re-assign them on the next call. 28070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Successive approximation AC refinement has to be more careful, however.) 28170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 28270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 28370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 28470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * MCU decoding for DC initial scan (either spectral selection, 28570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * or first pass of successive approximation). 28670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 28770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 28870a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) 28970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinedecode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 29070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 29170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 29270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int Al = cinfo->Al; 29370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine register int s, r; 29470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int blkn, ci; 29570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW block; 29670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_STATE_VARS; 29770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine savable_state state; 29870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine d_derived_tbl * tbl; 29970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info * compptr; 30070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 30170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Process restart marker if needed; may have to suspend */ 30270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->restart_interval) { 30370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (entropy->restarts_to_go == 0) 30470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! process_restart(cinfo)) 30570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 30670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 30770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 30870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* If we've run out of data, just leave the MCU set to zeroes. 30970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This way, we return uniform gray for the remainder of the segment. 31070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 31170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! entropy->pub.insufficient_data) { 31270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 31370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Load up working state */ 31470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 31570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ASSIGN_STATE(state, entropy->saved); 31670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 31770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Outer loop handles each block in the MCU */ 31870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 31970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 32070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine block = MCU_data[blkn]; 32170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci = cinfo->MCU_membership[blkn]; 32270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine compptr = cinfo->cur_comp_info[ci]; 32370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine tbl = entropy->derived_tbls[compptr->dc_tbl_no]; 32470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 32570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Decode a single block's worth of coefficients */ 32670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 32770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Section F.2.2.1: decode the DC coefficient difference */ 32870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine HUFF_DECODE(s, br_state, tbl, return FALSE, label1); 32970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (s) { 33070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, s, return FALSE); 33170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = GET_BITS(s); 33270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s = HUFF_EXTEND(r, s); 33370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 33470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 33570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Convert DC difference to actual value, update last_dc_val */ 33670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s += state.last_dc_val[ci]; 33770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine state.last_dc_val[ci] = s; 33870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */ 33970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*block)[0] = (JCOEF) (s << Al); 34070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 34170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 34270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Completed MCU, so update state */ 34370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 34470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ASSIGN_STATE(entropy->saved, state); 34570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 34670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 34770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Account for restart interval (no-op if not using restarts) */ 34870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go--; 34970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return TRUE; 35170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 35270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 35570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * MCU decoding for AC initial scan (either spectral selection, 35670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * or first pass of successive approximation). 35770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 35870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35970a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) 36070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinedecode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 36170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 36270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 36370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int Se = cinfo->Se; 36470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int Al = cinfo->Al; 36570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine register int s, k, r; 36670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int EOBRUN; 36770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW block; 36870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_STATE_VARS; 36970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine d_derived_tbl * tbl; 37070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 37170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Process restart marker if needed; may have to suspend */ 37270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->restart_interval) { 37370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (entropy->restarts_to_go == 0) 37470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! process_restart(cinfo)) 37570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 37670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 37770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 37870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* If we've run out of data, just leave the MCU set to zeroes. 37970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This way, we return uniform gray for the remainder of the segment. 38070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 38170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! entropy->pub.insufficient_data) { 38270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 38370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Load up working state. 38470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We can avoid loading/saving bitread state if in an EOB run. 38570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 38670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */ 38770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 38870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* There is always only one block per MCU */ 38970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 39070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (EOBRUN > 0) /* if it's a band of zeroes... */ 39170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN--; /* ...process it now (we do nothing) */ 39270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else { 39370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 39470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine block = MCU_data[0]; 39570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine tbl = entropy->ac_derived_tbl; 39670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 39770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (k = cinfo->Ss; k <= Se; k++) { 39870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine HUFF_DECODE(s, br_state, tbl, return FALSE, label2); 39970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = s >> 4; 40070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s &= 15; 40170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (s) { 40270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine k += r; 40370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, s, return FALSE); 40470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = GET_BITS(s); 40570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s = HUFF_EXTEND(r, s); 40670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Scale and output coefficient in natural (dezigzagged) order */ 40770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*block)[jpeg_natural_order[k]] = (JCOEF) (s << Al); 40870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 40970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (r == 15) { /* ZRL */ 41070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine k += 15; /* skip 15 zeroes in band */ 41170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { /* EOBr, run length is 2^r + appended bits */ 41270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN = 1 << r; 41370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (r) { /* EOBr, r > 0 */ 41470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, r, return FALSE); 41570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = GET_BITS(r); 41670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN += r; 41770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 41870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN--; /* this band is processed at this moment */ 41970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; /* force end-of-band */ 42070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 42170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 42270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 42370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 42470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 42570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 42670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 42770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Completed MCU, so update state */ 42870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */ 42970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 43070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 43170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Account for restart interval (no-op if not using restarts) */ 43270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go--; 43370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 43470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return TRUE; 43570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 43670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 43770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 43870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 43970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * MCU decoding for DC successive approximation refinement scan. 44070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Note: we assume such scans can be multi-component, although the spec 44170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * is not very clear on the point. 44270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 44370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 44470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) 44570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinedecode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 44670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 44770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 44870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ 44970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int blkn; 45070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW block; 45170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_STATE_VARS; 45270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 45370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Process restart marker if needed; may have to suspend */ 45470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->restart_interval) { 45570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (entropy->restarts_to_go == 0) 45670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! process_restart(cinfo)) 45770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 45870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 45970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 46070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Not worth the cycles to check insufficient_data here, 46170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * since we will not change the data anyway if we read zeroes. 46270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 46370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 46470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Load up working state */ 46570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 46670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 46770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Outer loop handles each block in the MCU */ 46870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 46970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 47070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine block = MCU_data[blkn]; 47170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 47270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Encoded data is simply the next bit of the two's-complement DC value */ 47370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, 1, return FALSE); 47470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (GET_BITS(1)) 47570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*block)[0] |= p1; 47670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Note: since we use |=, repeating the assignment later is safe */ 47770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 47870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 47970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Completed MCU, so update state */ 48070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 48170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Account for restart interval (no-op if not using restarts) */ 48370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go--; 48470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return TRUE; 48670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 48770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 49070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * MCU decoding for AC successive approximation refinement scan. 49170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 49270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 49370a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(boolean) 49470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinedecode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) 49570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 49670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 49770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int Se = cinfo->Se; 49870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ 49970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */ 50070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine register int s, k, r; 50170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int EOBRUN; 50270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JBLOCKROW block; 50370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JCOEFPTR thiscoef; 50470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_STATE_VARS; 50570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine d_derived_tbl * tbl; 50670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int num_newnz; 50770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int newnz_pos[DCTSIZE2]; 50870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 50970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Process restart marker if needed; may have to suspend */ 51070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->restart_interval) { 51170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (entropy->restarts_to_go == 0) 51270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! process_restart(cinfo)) 51370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 51470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 51570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 51670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* If we've run out of data, don't modify the MCU. 51770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 51870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! entropy->pub.insufficient_data) { 51970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 52070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Load up working state */ 52170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_LOAD_STATE(cinfo,entropy->bitstate); 52270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */ 52370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 52470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* There is always only one block per MCU */ 52570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine block = MCU_data[0]; 52670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine tbl = entropy->ac_derived_tbl; 52770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 52870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* If we are forced to suspend, we must undo the assignments to any newly 52970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * nonzero coefficients in the block, because otherwise we'd get confused 53070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * next time about which coefficients were already nonzero. 53170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * But we need not undo addition of bits to already-nonzero coefficients; 53270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * instead, we can test the current bit to see if we already did it. 53370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 53470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine num_newnz = 0; 53570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 53670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* initialize coefficient loop counter to start of band */ 53770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine k = cinfo->Ss; 53870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 53970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (EOBRUN == 0) { 54070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (; k <= Se; k++) { 54170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine HUFF_DECODE(s, br_state, tbl, goto undoit, label3); 54270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = s >> 4; 54370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s &= 15; 54470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (s) { 54570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (s != 1) /* size of new coef should always be 1 */ 54670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine WARNMS(cinfo, JWRN_HUFF_BAD_CODE); 54770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, 1, goto undoit); 54870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (GET_BITS(1)) 54970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s = p1; /* newly nonzero coef is positive */ 55070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else 55170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine s = m1; /* newly nonzero coef is negative */ 55270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 55370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (r != 15) { 55470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */ 55570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (r) { 55670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, r, goto undoit); 55770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine r = GET_BITS(r); 55870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN += r; 55970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 56070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; /* rest of block is handled by EOB logic */ 56170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 56270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* note s = 0 for processing ZRL */ 56370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 56470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Advance over already-nonzero coefs and r still-zero coefs, 56570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * appending correction bits to the nonzeroes. A correction bit is 1 56670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * if the absolute value of the coefficient must be increased. 56770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 56870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine do { 56970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine thiscoef = *block + jpeg_natural_order[k]; 57070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (*thiscoef != 0) { 57170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, 1, goto undoit); 57270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (GET_BITS(1)) { 57370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if ((*thiscoef & p1) == 0) { /* do nothing if already set it */ 57470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (*thiscoef >= 0) 57570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine *thiscoef += p1; 57670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else 57770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine *thiscoef += m1; 57870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 57970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 58070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 58170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (--r < 0) 58270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; /* reached target zero coefficient */ 58370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 58470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine k++; 58570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } while (k <= Se); 58670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (s) { 58770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int pos = jpeg_natural_order[k]; 58870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Output newly nonzero coefficient */ 58970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*block)[pos] = (JCOEF) s; 59070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Remember its position in case we have to suspend */ 59170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine newnz_pos[num_newnz++] = pos; 59270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 59370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 59470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 59570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 59670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (EOBRUN > 0) { 59770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Scan any remaining coefficient positions after the end-of-band 59870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (the last newly nonzero coefficient, if any). Append a correction 59970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * bit to each already-nonzero coefficient. A correction bit is 1 60070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * if the absolute value of the coefficient must be increased. 60170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 60270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (; k <= Se; k++) { 60370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine thiscoef = *block + jpeg_natural_order[k]; 60470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (*thiscoef != 0) { 60570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine CHECK_BIT_BUFFER(br_state, 1, goto undoit); 60670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (GET_BITS(1)) { 60770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */ 60870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (*thiscoef >= 0) 60970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine *thiscoef += p1; 61070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine else 61170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine *thiscoef += m1; 61270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 61370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 61470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 61570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 61670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Count one block completed in EOB run */ 61770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine EOBRUN--; 61870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 61970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 62070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Completed MCU, so update state */ 62170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine BITREAD_SAVE_STATE(cinfo,entropy->bitstate); 62270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */ 62370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 62470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 62570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Account for restart interval (no-op if not using restarts) */ 62670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go--; 62770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 62870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return TRUE; 62970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 63070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineundoit: 63170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Re-zero any output coefficients that we made newly nonzero */ 63270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine while (num_newnz > 0) 63370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*block)[newnz_pos[--num_newnz]] = 0; 63470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 63570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return FALSE; 63670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 63770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 63870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 63970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Save the current Huffman deocde position and the DC coefficients 64070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * for each component into bitstream_offset and dc_info[], respectively. 64170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 64270a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 64370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineget_huffman_decoder_configuration(j_decompress_ptr cinfo, 64470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine huffman_offset_data *offset) 64570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 64670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int i; 64770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 64870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_get_huffman_decoder_configuration_progressive(cinfo, offset); 64970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->EOBRUN = entropy->saved.EOBRUN; 65070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < cinfo->comps_in_scan; i++) 65170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->prev_dc[i] = entropy->saved.last_dc_val[i]; 65270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 65370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 65470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 65570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 65670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Save the current Huffman decoder position and the bit buffer 65770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * into bitstream_offset and get_buffer, respectively. 65870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 65970a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineGLOBAL(void) 66070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinejpeg_get_huffman_decoder_configuration_progressive(j_decompress_ptr cinfo, 66170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine huffman_offset_data *offset) 66270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 66370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 66470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 66570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->restart_interval) { 66670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine // We are at the end of a data segment 66770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (entropy->restarts_to_go == 0) 66870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! process_restart(cinfo)) 66970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; 67070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 67170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 67270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine // Save restarts_to_go and next_restart_num. 67370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->restarts_to_go = (unsigned short) entropy->restarts_to_go; 67470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->next_restart_num = cinfo->marker->next_restart_num; 67570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 67670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->bitstream_offset = 67770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (jget_input_stream_position(cinfo) << LOG_TWO_BIT_BUF_SIZE) 67870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine + entropy->bitstate.bits_left; 67970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 68070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine offset->get_buffer = entropy->bitstate.get_buffer; 68170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 68270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 68370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 68470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 68570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Configure the Huffman decoder to decode the image 68670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * starting from (iMCU_row_offset, iMCU_col_offset). 68770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 68870a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 68970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineconfigure_huffman_decoder(j_decompress_ptr cinfo, huffman_offset_data offset) 69070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 69170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int i; 69270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 69370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_configure_huffman_decoder_progressive(cinfo, offset); 69470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.EOBRUN = offset.EOBRUN; 69570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < cinfo->comps_in_scan; i++) 69670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->saved.last_dc_val[i] = offset.prev_dc[i]; 69770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 69870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 69970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 70070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Configure the Huffman decoder reader position and bit buffer. 70170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 70270a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineGLOBAL(void) 70370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinejpeg_configure_huffman_decoder_progressive(j_decompress_ptr cinfo, 70470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine huffman_offset_data offset) 70570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 70670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 70770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 70870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine // Restore restarts_to_go and next_restart_num 70970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->unread_marker = 0; 71070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->restarts_to_go = offset.restarts_to_go; 71170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->marker->next_restart_num = offset.next_restart_num; 71270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 71370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int bitstream_offset = offset.bitstream_offset; 71470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int blkn, i; 71570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 71670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int byte_offset = bitstream_offset >> LOG_TWO_BIT_BUF_SIZE; 71770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine unsigned int bit_in_bit_buffer = 71870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bitstream_offset & ((1 << LOG_TWO_BIT_BUF_SIZE) - 1); 71970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 72070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jset_input_stream_position_bit(cinfo, byte_offset, 72170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine bit_in_bit_buffer, offset.get_buffer); 72270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 72370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 72470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineGLOBAL(void) 72570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinejpeg_configure_huffman_index_scan(j_decompress_ptr cinfo, 72670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine huffman_index *index, int scan_no, int offset) 72770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 72870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 72970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (scan_no >= index->scan_count) { 73070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine index->scan = realloc(index->scan, 73170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (scan_no + 1) * sizeof(huffman_scan_header)); 73270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine index->mem_used += (scan_no - index->scan_count + 1) 73370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (sizeof(huffman_scan_header) + cinfo->total_iMCU_rows 73470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * sizeof(huffman_offset_data*)); 73570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine index->scan_count = scan_no + 1; 73670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 73770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine index->scan[scan_no].offset = (huffman_offset_data**)malloc( 73870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->total_iMCU_rows * sizeof(huffman_offset_data*)); 73970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine index->scan[scan_no].bitstream_offset = offset; 74070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 74170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 74270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 74370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Module initialization routine for progressive Huffman entropy decoding. 74470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 74570a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineGLOBAL(void) 74670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinejinit_phuff_decoder (j_decompress_ptr cinfo) 74770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 74870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine phuff_entropy_ptr entropy; 74970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int *coef_bit_ptr; 75070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, i; 75170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 75270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy = (phuff_entropy_ptr) 75370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 75470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine SIZEOF(phuff_entropy_decoder)); 75570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->entropy = (struct jpeg_entropy_decoder *) entropy; 75670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.start_pass = start_pass_phuff_decoder; 75770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.configure_huffman_decoder = configure_huffman_decoder; 75870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->pub.get_huffman_decoder_configuration = 75970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine get_huffman_decoder_configuration; 76070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 76170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Mark derived tables unallocated */ 76270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < NUM_HUFF_TBLS; i++) { 76370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine entropy->derived_tbls[i] = NULL; 76470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 76570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 76670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Create progression status table */ 76770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->coef_bits = (int (*)[DCTSIZE2]) 76870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 76970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->num_components*DCTSIZE2*SIZEOF(int)); 77070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine coef_bit_ptr = & cinfo->coef_bits[0][0]; 77170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0; ci < cinfo->num_components; ci++) 77270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < DCTSIZE2; i++) 77370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine *coef_bit_ptr++ = -1; 77470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 77570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 77670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* D_PROGRESSIVE_SUPPORTED */ 777