19f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 29f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * jchuff.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 encoding routines. 99f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Much of the complexity here has to do with supporting output suspension. 119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * If the data destination module demands suspension, we want to be able to 129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * back up to the start of the current MCU. To do this, we copy state 139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * variables into local working storage, and update them back to the 149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * permanent JPEG objects 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 "jchuff.h" /* Declarations shared with jcphuff.c */ 219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Expanded entropy encoder object for Huffman encoding. 249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The savable_state subrecord contains fields that change within an MCU, 269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but must not be updated permanently until we complete the MCU. 279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef struct { 309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project INT32 put_buffer; /* current bit-accumulation buffer */ 319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int put_bits; /* # of bits now in it */ 329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ 339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} savable_state; 349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* This macro is to work around compilers with missing or broken 369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * structure assignment. You'll need to fix this code if you have 379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * such a compiler and you change MAX_COMPS_IN_SCAN. 389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifndef NO_STRUCT_ASSIGN 419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define ASSIGN_STATE(dest,src) ((dest) = (src)) 429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#else 439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#if MAX_COMPS_IN_SCAN == 4 449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define ASSIGN_STATE(dest,src) \ 459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ((dest).put_buffer = (src).put_buffer, \ 469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).put_bits = (src).put_bits, \ 479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[0] = (src).last_dc_val[0], \ 489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[1] = (src).last_dc_val[1], \ 499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[2] = (src).last_dc_val[2], \ 509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (dest).last_dc_val[3] = (src).last_dc_val[3]) 519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef struct { 569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project struct jpeg_entropy_encoder pub; /* public fields */ 579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project savable_state saved; /* Bit buffer & DC state at start of MCU */ 599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* These fields are NOT loaded into local working state. */ 619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int restarts_to_go; /* MCUs left in this restart interval */ 629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int next_restart_num; /* next restart number to write (0-7) */ 639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Pointers to derived tables (these workspaces have image lifespan) */ 659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS]; 669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS]; 679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED /* Statistics tables for optimization */ 699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project long * dc_count_ptrs[NUM_HUFF_TBLS]; 709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project long * ac_count_ptrs[NUM_HUFF_TBLS]; 719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} huff_entropy_encoder; 739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef huff_entropy_encoder * huff_entropy_ptr; 759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Working state while writing an MCU. 779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This struct contains all the fields that are needed by subroutines. 789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecttypedef struct { 819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JOCTET * next_output_byte; /* => next byte to write in buffer */ 829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project savable_state cur; /* Current bit buffer & DC state */ 849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project j_compress_ptr cinfo; /* dump_buffer needs access to this */ 859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} working_state; 869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Forward declarations */ 899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(boolean) encode_mcu_huff JPP((j_compress_ptr cinfo, 909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JBLOCKROW *MCU_data)); 919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) finish_pass_huff JPP((j_compress_ptr cinfo)); 929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED 939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(boolean) encode_mcu_gather JPP((j_compress_ptr cinfo, 949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JBLOCKROW *MCU_data)); 959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) finish_pass_gather JPP((j_compress_ptr cinfo)); 969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 1009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Initialize for a Huffman-compressed scan. 1019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * If gather_statistics is TRUE, we do not output anything during the scan, 1029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * just count the Huffman symbols used and generate Huffman code tables. 1039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 1049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) 1069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectstart_pass_huff (j_compress_ptr cinfo, boolean gather_statistics) 1079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 1089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 1099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci, dctbl, actbl; 1109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_component_info * compptr; 1119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (gather_statistics) { 1139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED 1149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.encode_mcu = encode_mcu_gather; 1159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.finish_pass = finish_pass_gather; 1169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#else 1179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_NOT_COMPILED); 1189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 1199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 1209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.encode_mcu = encode_mcu_huff; 1219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.finish_pass = finish_pass_huff; 1229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 1259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 1269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dctbl = compptr->dc_tbl_no; 1279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project actbl = compptr->ac_tbl_no; 1289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (gather_statistics) { 1299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED 1309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check for invalid table indexes */ 1319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* (make_c_derived_tbl does this in the other path) */ 1329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (dctbl < 0 || dctbl >= NUM_HUFF_TBLS) 1339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, dctbl); 1349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (actbl < 0 || actbl >= NUM_HUFF_TBLS) 1359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, actbl); 1369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Allocate and zero the statistics tables */ 1379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */ 1389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->dc_count_ptrs[dctbl] == NULL) 1399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_count_ptrs[dctbl] = (long *) 1409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 1419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 257 * SIZEOF(long)); 1429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(entropy->dc_count_ptrs[dctbl], 257 * SIZEOF(long)); 1439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->ac_count_ptrs[actbl] == NULL) 1449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->ac_count_ptrs[actbl] = (long *) 1459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 1469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 257 * SIZEOF(long)); 1479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(entropy->ac_count_ptrs[actbl], 257 * SIZEOF(long)); 1489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 1499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 1509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Compute derived values for Huffman tables */ 1519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We may do this more than once for a table, but it's not expensive */ 1529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_make_c_derived_tbl(cinfo, TRUE, dctbl, 1539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project & entropy->dc_derived_tbls[dctbl]); 1549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_make_c_derived_tbl(cinfo, FALSE, actbl, 1559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project & entropy->ac_derived_tbls[actbl]); 1569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize DC predictions to 0 */ 1589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.last_dc_val[ci] = 0; 1599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 1609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize bit buffer to empty */ 1629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.put_buffer = 0; 1639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.put_bits = 0; 1649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Initialize restart stuff */ 1669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go = cinfo->restart_interval; 1679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->next_restart_num = 0; 1689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 1699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 1729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Compute the derived values for a Huffman table. 1739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * This routine also performs some validation checks on the table. 1749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 1759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Note this is also used by jcphuff.c. 1769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 1779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(void) 1799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjpeg_make_c_derived_tbl (j_compress_ptr cinfo, boolean isDC, int tblno, 1809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c_derived_tbl ** pdtbl) 1819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 1829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JHUFF_TBL *htbl; 1839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c_derived_tbl *dtbl; 1849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int p, i, l, lastp, si, maxsymbol; 1859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project char huffsize[257]; 1869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int huffcode[257]; 1879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project unsigned int code; 1889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Note that huffsize[] and huffcode[] are filled in code-length order, 1909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * paralleling the order of the symbols themselves in htbl->huffval[]. 1919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 1929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 1939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the input Huffman table */ 1949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (tblno < 0 || tblno >= NUM_HUFF_TBLS) 1959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 1969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htbl = 1979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno]; 1989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (htbl == NULL) 1999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); 2009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Allocate a workspace if we haven't already done so. */ 2029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (*pdtbl == NULL) 2039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project *pdtbl = (c_derived_tbl *) 2049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 2059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project SIZEOF(c_derived_tbl)); 2069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl = *pdtbl; 2079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure C.1: make table of Huffman code length for each symbol */ 2099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 2119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (l = 1; l <= 16; l++) { 2129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project i = (int) htbl->bits[l]; 2139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (i < 0 || p + i > 256) /* protect against table overrun */ 2149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 2159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (i--) 2169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffsize[p++] = (char) l; 2179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffsize[p] = 0; 2199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project lastp = p; 2209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure C.2: generate the codes themselves */ 2229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* We also validate that the counts represent a legal Huffman code tree. */ 2239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code = 0; 2259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project si = huffsize[0]; 2269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 2279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (huffsize[p]) { 2289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (((int) huffsize[p]) == si) { 2299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huffcode[p++] = code; 2309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code++; 2319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* code is now 1 more than the last code used for codelength si; but 2339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * it must still fit in si bits, since no code is allowed to be all ones. 2349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (((INT32) code) >= (((INT32) 1) << si)) 2369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 2379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project code <<= 1; 2389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project si++; 2399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Figure C.3: generate encoding tables */ 2429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* These are code and size indexed by symbol value */ 2439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Set all codeless symbols to have code length 0; 2459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * this lets us detect duplicate VAL entries here, and later 2469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * allows emit_bits to detect any attempt to emit such symbols. 2479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(dtbl->ehufsi, SIZEOF(dtbl->ehufsi)); 2499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This is also a convenient place to check for out-of-range 2519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * and duplicated VAL entries. We allow 0..255 for AC symbols 2529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * but only 0..15 for DC. (We could constrain them further 2539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * based on data depth and mode, but this seems enough.) 2549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project maxsymbol = isDC ? 15 : 255; 2569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (p = 0; p < lastp; p++) { 2589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project i = htbl->huffval[p]; 2599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (i < 0 || i > maxsymbol || dtbl->ehufsi[i]) 2609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 2619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->ehufco[i] = huffcode[p]; 2629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dtbl->ehufsi[i] = huffsize[p]; 2639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 2649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 2659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Outputting bytes to the file */ 2689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Emit a byte, taking 'action' if must suspend. */ 2709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define emit_byte(state,val,action) \ 2719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project { *(state)->next_output_byte++ = (JOCTET) (val); \ 2729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (--(state)->free_in_buffer == 0) \ 2739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! dump_buffer(state)) \ 2749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project { action; } } 2759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 2789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectdump_buffer (working_state * state) 2799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Empty the output buffer; return TRUE if successful, FALSE if must suspend */ 2809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 2819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project struct jpeg_destination_mgr * dest = state->cinfo->dest; 2829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! (*dest->empty_output_buffer) (state->cinfo)) 2849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 2859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* After a successful buffer dump, must reset buffer pointers */ 2869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->next_output_byte = dest->next_output_byte; 2879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->free_in_buffer = dest->free_in_buffer; 2889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 2899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 2909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Outputting bits to the file */ 2939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 2949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Only the right 24 bits of put_buffer are used; the valid bits are 2959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * left-justified in this part. At most 16 bits can be passed to emit_bits 2969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * in one call, and we never retain more than 7 bits in put_buffer 2979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * between calls, so 24 bits are sufficient. 2989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 2999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectINLINE 3019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 3029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectemit_bits (working_state * state, unsigned int code, int size) 3039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Emit some bits; return TRUE if successful, FALSE if must suspend */ 3049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 3059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This routine is heavily used, so it's worth coding tightly. */ 3069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register INT32 put_buffer = (INT32) code; 3079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int put_bits = state->cur.put_bits; 3089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* if size is 0, caller used an invalid Huffman table entry */ 3109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (size == 0) 3119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(state->cinfo, JERR_HUFF_MISSING_CODE); 3129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ 3149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_bits += size; /* new number of bits in buffer */ 3169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_buffer <<= 24 - put_bits; /* align incoming bits */ 3189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_buffer |= state->cur.put_buffer; /* and merge with old buffer contents */ 3209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (put_bits >= 8) { 3229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int c = (int) ((put_buffer >> 16) & 0xFF); 3239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project emit_byte(state, c, return FALSE); 3259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (c == 0xFF) { /* need to stuff a zero byte? */ 3269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project emit_byte(state, 0, return FALSE); 3279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_buffer <<= 8; 3299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project put_bits -= 8; 3309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->cur.put_buffer = put_buffer; /* update state variables */ 3339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->cur.put_bits = put_bits; 3349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 3369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 3379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 3409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectflush_bits (working_state * state) 3419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 3429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, 0x7F, 7)) /* fill any partial byte with ones */ 3439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 3449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->cur.put_buffer = 0; /* and reset bit-buffer to empty */ 3459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->cur.put_bits = 0; 3469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 3479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 3489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Encode a single block's worth of coefficients */ 3519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 3539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectencode_one_block (working_state * state, JCOEFPTR block, int last_dc_val, 3549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c_derived_tbl *dctbl, c_derived_tbl *actbl) 3559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 3569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int temp, temp2; 3579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int nbits; 3589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int k, r, i; 3599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Encode the DC coefficient difference per section F.1.2.1 */ 3619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = temp2 = block[0] - last_dc_val; 3639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (temp < 0) { 3659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = -temp; /* temp is abs value of input */ 3669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* For a negative input, want temp2 = bitwise complement of abs(input) */ 3679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This code assumes we are on a two's complement machine */ 3689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp2--; 3699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the number of bits needed for the magnitude of the coefficient */ 3729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits = 0; 3739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (temp) { 3749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits++; 3759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp >>= 1; 3769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 3779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check for out-of-range coefficient values. 3789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Since we're encoding a difference, the range limit is twice as much. 3799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 3809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits > MAX_COEF_BITS+1) 3819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(state->cinfo, JERR_BAD_DCT_COEF); 3829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Emit the Huffman-coded symbol for the number of bits */ 3849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits])) 3859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 3869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Emit that number of bits of the value, if positive, */ 3889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* or the complement of its magnitude, if negative. */ 3899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits) /* emit_bits rejects calls with size 0 */ 3909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, (unsigned int) temp2, nbits)) 3919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 3929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Encode the AC coefficients per section F.1.2.2 */ 3949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = 0; /* r = run length of zeros */ 3969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 3979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (k = 1; k < DCTSIZE2; k++) { 3989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if ((temp = block[jpeg_natural_order[k]]) == 0) { 3999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r++; 4009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 4019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* if run length > 15, must emit special run-length-16 codes (0xF0) */ 4029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (r > 15) { 4039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0])) 4049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r -= 16; 4069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp2 = temp; 4099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (temp < 0) { 4109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = -temp; /* temp is abs value of input */ 4119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This code assumes we are on a two's complement machine */ 4129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp2--; 4139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the number of bits needed for the magnitude of the coefficient */ 4169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits = 1; /* there must be at least one 1 bit */ 4179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while ((temp >>= 1)) 4189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits++; 4199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check for out-of-range coefficient values */ 4209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits > MAX_COEF_BITS) 4219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(state->cinfo, JERR_BAD_DCT_COEF); 4229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Emit Huffman symbol for run length / number of bits */ 4249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project i = (r << 4) + nbits; 4259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, actbl->ehufco[i], actbl->ehufsi[i])) 4269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Emit that number of bits of the value, if positive, */ 4299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* or the complement of its magnitude, if negative. */ 4309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, (unsigned int) temp2, nbits)) 4319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = 0; 4349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* If the last coef(s) were zero, emit an end-of-block code */ 4389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (r > 0) 4399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_bits(state, actbl->ehufco[0], actbl->ehufsi[0])) 4409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 4439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 4449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 4479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Emit a restart marker & resynchronize predictions. 4489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 4499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(boolean) 4519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectemit_restart (working_state * state, int restart_num) 4529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 4539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci; 4549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! flush_bits(state)) 4569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project emit_byte(state, 0xFF, return FALSE); 4599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project emit_byte(state, JPEG_RST0 + restart_num, return FALSE); 4609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Re-initialize DC predictions to 0 */ 4629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < state->cinfo->comps_in_scan; ci++) 4639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state->cur.last_dc_val[ci] = 0; 4649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* The restart counter is not updated until we successfully write the MCU. */ 4669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 4689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 4699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 4729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Encode and output one MCU's worth of Huffman-compressed coefficients. 4739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 4749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(boolean) 4769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectencode_mcu_huff (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 4779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 4789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 4799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project working_state state; 4809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int blkn, ci; 4819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_component_info * compptr; 4829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Load up working state */ 4849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.next_output_byte = cinfo->dest->next_output_byte; 4859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.free_in_buffer = cinfo->dest->free_in_buffer; 4869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(state.cur, entropy->saved); 4879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.cinfo = cinfo; 4889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Emit restart marker if needed */ 4909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->restart_interval) { 4919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->restarts_to_go == 0) 4929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! emit_restart(&state, entropy->next_restart_num)) 4939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 4949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 4959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 4969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Encode the MCU data blocks */ 4979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 4989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ci = cinfo->MCU_membership[blkn]; 4999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 5009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! encode_one_block(&state, 5019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MCU_data[blkn][0], state.cur.last_dc_val[ci], 5029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_derived_tbls[compptr->dc_tbl_no], 5039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->ac_derived_tbls[compptr->ac_tbl_no])) 5049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return FALSE; 5059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Update last_dc_val */ 5069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.cur.last_dc_val[ci] = MCU_data[blkn][0][0]; 5079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 5089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Completed MCU, so update state */ 5109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->dest->next_output_byte = state.next_output_byte; 5119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->dest->free_in_buffer = state.free_in_buffer; 5129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(entropy->saved, state.cur); 5139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Update restart-interval state too */ 5159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->restart_interval) { 5169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->restarts_to_go == 0) { 5179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go = cinfo->restart_interval; 5189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->next_restart_num++; 5199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->next_restart_num &= 7; 5209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 5219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go--; 5229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 5239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 5259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 5269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 5299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Finish up at the end of a Huffman-compressed scan. 5309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 5319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) 5339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectfinish_pass_huff (j_compress_ptr cinfo) 5349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 5359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 5369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project working_state state; 5379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Load up working state ... flush_bits needs it */ 5399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.next_output_byte = cinfo->dest->next_output_byte; 5409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.free_in_buffer = cinfo->dest->free_in_buffer; 5419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(state.cur, entropy->saved); 5429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project state.cinfo = cinfo; 5439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Flush out the last data */ 5459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! flush_bits(&state)) 5469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_CANT_SUSPEND); 5479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Update state */ 5499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->dest->next_output_byte = state.next_output_byte; 5509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->dest->free_in_buffer = state.free_in_buffer; 5519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ASSIGN_STATE(entropy->saved, state.cur); 5529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 5539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 5569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Huffman coding optimization. 5579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 5589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * We first scan the supplied data and count the number of uses of each symbol 5599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * that is to be Huffman-coded. (This process MUST agree with the code above.) 5609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Then we build a Huffman coding tree for the observed counts. 5619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Symbols which are not needed at all for the particular image are not 5629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * assigned any code, which saves space in the DHT marker as well as in 5639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * the compressed data. 5649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 5659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED 5679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* Process a single block's worth of coefficients */ 5709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectLOCAL(void) 5729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projecthtest_one_block (j_compress_ptr cinfo, JCOEFPTR block, int last_dc_val, 5739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project long dc_counts[], long ac_counts[]) 5749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 5759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int temp; 5769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int nbits; 5779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project register int k, r; 5789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Encode the DC coefficient difference per section F.1.2.1 */ 5809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = block[0] - last_dc_val; 5829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (temp < 0) 5839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = -temp; 5849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the number of bits needed for the magnitude of the coefficient */ 5869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits = 0; 5879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (temp) { 5889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits++; 5899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp >>= 1; 5909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 5919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check for out-of-range coefficient values. 5929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Since we're encoding a difference, the range limit is twice as much. 5939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 5949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits > MAX_COEF_BITS+1) 5959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_DCT_COEF); 5969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 5979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Count the Huffman symbol for the number of bits */ 5989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dc_counts[nbits]++; 5999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Encode the AC coefficients per section F.1.2.2 */ 6019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = 0; /* r = run length of zeros */ 6039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (k = 1; k < DCTSIZE2; k++) { 6059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if ((temp = block[jpeg_natural_order[k]]) == 0) { 6069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r++; 6079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } else { 6089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* if run length > 15, must emit special run-length-16 codes (0xF0) */ 6099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (r > 15) { 6109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ac_counts[0xF0]++; 6119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r -= 16; 6129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the number of bits needed for the magnitude of the coefficient */ 6159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (temp < 0) 6169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project temp = -temp; 6179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the number of bits needed for the magnitude of the coefficient */ 6199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits = 1; /* there must be at least one 1 bit */ 6209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while ((temp >>= 1)) 6219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project nbits++; 6229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Check for out-of-range coefficient values */ 6239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (nbits > MAX_COEF_BITS) 6249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_BAD_DCT_COEF); 6259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Count Huffman symbol for run length / number of bits */ 6279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ac_counts[(r << 4) + nbits]++; 6289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project r = 0; 6309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* If the last coef(s) were zero, emit an end-of-block code */ 6349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (r > 0) 6359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ac_counts[0]++; 6369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 6379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 6409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Trial-encode one MCU's worth of Huffman-compressed coefficients. 6419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * No data is actually output, so no suspension return is possible. 6429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 6439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(boolean) 6459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectencode_mcu_gather (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 6469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 6479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 6489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int blkn, ci; 6499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_component_info * compptr; 6509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Take care of restart intervals if needed */ 6529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (cinfo->restart_interval) { 6539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (entropy->restarts_to_go == 0) { 6549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Re-initialize DC predictions to 0 */ 6559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < cinfo->comps_in_scan; ci++) 6569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.last_dc_val[ci] = 0; 6579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Update restart state */ 6589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go = cinfo->restart_interval; 6599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->restarts_to_go--; 6619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 6649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ci = cinfo->MCU_membership[blkn]; 6659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 6669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htest_one_block(cinfo, MCU_data[blkn][0], entropy->saved.last_dc_val[ci], 6679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_count_ptrs[compptr->dc_tbl_no], 6689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->ac_count_ptrs[compptr->ac_tbl_no]); 6699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->saved.last_dc_val[ci] = MCU_data[blkn][0][0]; 6709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 6719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project return TRUE; 6739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 6749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 6769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 6779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Generate the best Huffman code table for the given counts, fill htbl. 6789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Note this is also used by jcphuff.c. 6799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 6809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The JPEG standard requires that no symbol be assigned a codeword of all 6819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * one bits (so that padding bits added at the end of a compressed segment 6829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * can't look like a valid code). Because of the canonical ordering of 6839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * codewords, this just means that there must be an unused slot in the 6849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * longest codeword length category. Section K.2 of the JPEG spec suggests 6859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * reserving such a slot by pretending that symbol 256 is a valid symbol 6869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * with count 1. In theory that's not optimal; giving it count zero but 6879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * including it in the symbol set anyway should give a better Huffman code. 6889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * But the theoretically better code actually seems to come out worse in 6899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * practice, because it produces more all-ones bytes (which incur stuffed 6909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * zero bytes in the final file). In any case the difference is tiny. 6919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * 6929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * The JPEG standard requires Huffman codes to be no more than 16 bits long. 6939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * If some symbols have a very small but nonzero probability, the Huffman tree 6949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * must be adjusted to meet the code length restriction. We currently use 6959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * the adjustment method suggested in JPEG section K.2. This method is *not* 6969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * optimal; it may not choose the best possible limited-length code. But 6979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * typically only very-low-frequency symbols will be given less-than-optimal 6989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * lengths, so the code is almost optimal. Experimental comparisons against 6999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * an optimal limited-length-code algorithm indicate that the difference is 7009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * microscopic --- usually less than a hundredth of a percent of total size. 7019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * So the extra complexity of an optimal algorithm doesn't seem worthwhile. 7029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 7039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(void) 7059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjpeg_gen_optimal_table (j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[]) 7069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 7079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#define MAX_CLEN 32 /* assumed maximum initial code length */ 7089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project UINT8 bits[MAX_CLEN+1]; /* bits[k] = # of symbols with code length k */ 7099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int codesize[257]; /* codesize[k] = code length of symbol k */ 7109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int others[257]; /* next symbol in current branch of tree */ 7119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int c1, c2; 7129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int p, i, j; 7139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project long v; 7149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* This algorithm is explained in section K.2 of the JPEG standard */ 7169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(bits, SIZEOF(bits)); 7189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(codesize, SIZEOF(codesize)); 7199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i < 257; i++) 7209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project others[i] = -1; /* init links to empty */ 7219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project freq[256] = 1; /* make sure 256 has a nonzero count */ 7239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Including the pseudo-symbol 256 in the Huffman procedure guarantees 7249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * that no real symbol is given code-value of all ones, because 256 7259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * will be placed last in the largest codeword category. 7269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 7279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Huffman's basic algorithm to assign optimal code lengths to symbols */ 7299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (;;) { 7319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the smallest nonzero frequency, set c1 = its symbol */ 7329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* In case of ties, take the larger symbol number */ 7339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c1 = -1; 7349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project v = 1000000000L; 7359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i <= 256; i++) { 7369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (freq[i] && freq[i] <= v) { 7379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project v = freq[i]; 7389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c1 = i; 7399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Find the next smallest nonzero frequency, set c2 = its symbol */ 7439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* In case of ties, take the larger symbol number */ 7449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c2 = -1; 7459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project v = 1000000000L; 7469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i <= 256; i++) { 7479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (freq[i] && freq[i] <= v && i != c1) { 7489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project v = freq[i]; 7499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c2 = i; 7509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Done if we've merged everything into one frequency */ 7549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (c2 < 0) 7559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project break; 7569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Else merge the two counts/trees */ 7589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project freq[c1] += freq[c2]; 7599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project freq[c2] = 0; 7609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Increment the codesize of everything in c1's tree branch */ 7629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project codesize[c1]++; 7639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (others[c1] >= 0) { 7649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c1 = others[c1]; 7659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project codesize[c1]++; 7669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project others[c1] = c2; /* chain c2 onto c1's tree branch */ 7699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Increment the codesize of everything in c2's tree branch */ 7719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project codesize[c2]++; 7729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (others[c2] >= 0) { 7739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project c2 = others[c2]; 7749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project codesize[c2]++; 7759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Now count the number of symbols of each code length */ 7799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i <= 256; i++) { 7809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (codesize[i]) { 7819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* The JPEG standard seems to think that this can't happen, */ 7829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* but I'm paranoid... */ 7839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (codesize[i] > MAX_CLEN) 7849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project ERREXIT(cinfo, JERR_HUFF_CLEN_OVERFLOW); 7859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[codesize[i]]++; 7879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 7899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 7909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* JPEG doesn't allow symbols with code lengths over 16 bits, so if the pure 7919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Huffman procedure assigned any such lengths, we must adjust the coding. 7929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Here is what the JPEG spec says about how this next bit works: 7939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Since symbols are paired for the longest Huffman code, the symbols are 7949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * removed from this length category two at a time. The prefix for the pair 7959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * (which is one bit shorter) is allocated to one of the pair; then, 7969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * skipping the BITS entry for that prefix length, a code word from the next 7979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * shortest nonzero BITS entry is converted into a prefix for two code words 7989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * one bit longer. 7999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 8009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = MAX_CLEN; i > 16; i--) { 8029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (bits[i] > 0) { 8039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project j = i - 2; /* find length of new prefix to be used */ 8049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (bits[j] == 0) 8059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project j--; 8069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[i] -= 2; /* remove two symbols */ 8089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[i-1]++; /* one goes in this length */ 8099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[j+1] += 2; /* two new symbols in this length */ 8109f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[j]--; /* symbol of this length is now a prefix */ 8119f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8129f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8139f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8149f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Remove the count for the pseudo-symbol 256 from the largest codelength */ 8159f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project while (bits[i] == 0) /* find largest codelength still in use */ 8169f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project i--; 8179f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project bits[i]--; 8189f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8199f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Return final symbol counts (only for lengths 0..16) */ 8209f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMCOPY(htbl->bits, bits, SIZEOF(htbl->bits)); 8219f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8229f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Return a list of the symbols sorted by code length */ 8239f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* It's not real clear to me why we don't need to consider the codelength 8249f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * changes made above, but the JPEG spec seems to think this works. 8259f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 8269f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p = 0; 8279f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 1; i <= MAX_CLEN; i++) { 8289f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (j = 0; j <= 255; j++) { 8299f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (codesize[j] == i) { 8309f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htbl->huffval[p] = (UINT8) j; 8319f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project p++; 8329f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8339f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8349f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8359f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8369f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Set sent_table FALSE so updated table will be written to JPEG file. */ 8379f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htbl->sent_table = FALSE; 8389f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 8399f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8409f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8419f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 8429f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Finish up a statistics-gathering pass and create the new Huffman tables. 8439f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 8449f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8459f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectMETHODDEF(void) 8469f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectfinish_pass_gather (j_compress_ptr cinfo) 8479f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 8489f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy; 8499f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int ci, dctbl, actbl; 8509f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_component_info * compptr; 8519f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project JHUFF_TBL **htblptr; 8529f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project boolean did_dc[NUM_HUFF_TBLS]; 8539f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project boolean did_ac[NUM_HUFF_TBLS]; 8549f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8559f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* It's important not to apply jpeg_gen_optimal_table more than once 8569f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * per table, because it clobbers the input frequency counts! 8579f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 8589f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(did_dc, SIZEOF(did_dc)); 8599f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project MEMZERO(did_ac, SIZEOF(did_ac)); 8609f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8619f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 8629f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project compptr = cinfo->cur_comp_info[ci]; 8639f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project dctbl = compptr->dc_tbl_no; 8649f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project actbl = compptr->ac_tbl_no; 8659f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! did_dc[dctbl]) { 8669f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htblptr = & cinfo->dc_huff_tbl_ptrs[dctbl]; 8679f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (*htblptr == NULL) 8689f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); 8699f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[dctbl]); 8709f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project did_dc[dctbl] = TRUE; 8719f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8729f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (! did_ac[actbl]) { 8739f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project htblptr = & cinfo->ac_huff_tbl_ptrs[actbl]; 8749f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project if (*htblptr == NULL) 8759f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); 8769f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[actbl]); 8779f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project did_ac[actbl] = TRUE; 8789f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8799f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 8809f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 8819f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8829f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8839f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif /* ENTROPY_OPT_SUPPORTED */ 8849f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8859f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8869f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project/* 8879f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project * Module initialization routine for Huffman entropy encoding. 8889f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project */ 8899f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8909f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source ProjectGLOBAL(void) 8919f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Projectjinit_huff_encoder (j_compress_ptr cinfo) 8929f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project{ 8939f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project huff_entropy_ptr entropy; 8949f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project int i; 8959f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 8969f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy = (huff_entropy_ptr) 8979f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 8989f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project SIZEOF(huff_entropy_encoder)); 8999f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; 9009f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->pub.start_pass = start_pass_huff; 9019f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project 9029f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project /* Mark tables unallocated */ 9039f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project for (i = 0; i < NUM_HUFF_TBLS; i++) { 9049f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; 9059f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#ifdef ENTROPY_OPT_SUPPORTED 9069f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL; 9079f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project#endif 9089f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project } 9099f5d49a1588e438ae7ceabd0c94172117e3303aaThe Android Open Source Project} 910