1e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 2e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * jcphuff.c 3e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 4e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Copyright (C) 1995-1997, Thomas G. Lane. 5e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file is part of the Independent JPEG Group's software. 6e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * For conditions of distribution and use, see the accompanying README file. 7e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 8e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file contains Huffman entropy encoding routines for progressive JPEG. 9e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 10e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * We do not support output suspension in this module, since the library 11e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * currently does not allow multiple-scan files to be written with output 12e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * suspension. 13e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 14e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 15e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define JPEG_INTERNALS 16e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jinclude.h" 17e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jpeglib.h" 18e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jchuff.h" /* Declarations shared with jchuff.c */ 19e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 20e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef C_PROGRESSIVE_SUPPORTED 21e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 22e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Expanded entropy encoder object for progressive Huffman encoding. */ 23e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 24e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef struct { 25e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov struct jpeg_entropy_encoder pub; /* public fields */ 26e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 27e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Mode flag: TRUE for optimization, FALSE for actual data output */ 28e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean gather_statistics; 29e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 30e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Bit-level coding status. 31e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * next_output_byte/free_in_buffer are local copies of cinfo->dest fields. 32e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 33e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JOCTET * next_output_byte; /* => next byte to write in buffer */ 34e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov size_t free_in_buffer; /* # of byte spaces remaining in buffer */ 35e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov INT32 put_buffer; /* current bit-accumulation buffer */ 36e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int put_bits; /* # of bits now in it */ 37e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov j_compress_ptr cinfo; /* link to cinfo (needed for dump_buffer) */ 38e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 39e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Coding status for DC components */ 40e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ 41e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 42e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Coding status for AC components */ 43e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ac_tbl_no; /* the table number of the single component */ 44e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov unsigned int EOBRUN; /* run length of EOBs */ 45e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov unsigned int BE; /* # of buffered correction bits before MCU */ 46e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov char * bit_buffer; /* buffer for correction bits (1 per char) */ 47e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* packing correction bits tightly would save some space but cost time... */ 48e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 49e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov unsigned int restarts_to_go; /* MCUs left in this restart interval */ 50e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int next_restart_num; /* next restart number to write (0-7) */ 51e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 52e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Pointers to derived tables (these workspaces have image lifespan). 53e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Since any one scan codes only DC or only AC, we only need one set 54e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * of tables, not one for DC and one for AC. 55e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 56e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov c_derived_tbl * derived_tbls[NUM_HUFF_TBLS]; 57e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 58e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Statistics tables for optimization; again, one set is enough */ 59e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov long * count_ptrs[NUM_HUFF_TBLS]; 60e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} phuff_entropy_encoder; 61e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 62e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef phuff_entropy_encoder * phuff_entropy_ptr; 63e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 64e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit 65e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * buffer can hold. Larger sizes may slightly improve compression, but 66e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 1000 is already well into the realm of overkill. 67e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The minimum safe size is 64 bits. 68e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 69e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 70e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define MAX_CORR_BITS 1000 /* Max # of correction bits I can buffer */ 71e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 72e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. 73e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * We assume that int right shift is unsigned if INT32 right shift is, 74e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * which should be safe. 75e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 76e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 77e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#ifdef RIGHT_SHIFT_IS_UNSIGNED 78e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define ISHIFT_TEMPS int ishift_temp; 79e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define IRIGHT_SHIFT(x,shft) \ 80e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ((ishift_temp = (x)) < 0 ? \ 81e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ 82e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (ishift_temp >> (shft))) 83e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#else 84e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define ISHIFT_TEMPS 85e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) 86e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif 87e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 88e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Forward declarations */ 89e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) encode_mcu_DC_first JPP((j_compress_ptr cinfo, 90e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW *MCU_data)); 91e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) encode_mcu_AC_first JPP((j_compress_ptr cinfo, 92e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW *MCU_data)); 93e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) encode_mcu_DC_refine JPP((j_compress_ptr cinfo, 94e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW *MCU_data)); 95e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) encode_mcu_AC_refine JPP((j_compress_ptr cinfo, 96e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW *MCU_data)); 97e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) finish_pass_phuff JPP((j_compress_ptr cinfo)); 98e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) finish_pass_gather_phuff JPP((j_compress_ptr cinfo)); 99e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 100e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 101e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 102e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Initialize for a Huffman-compressed scan using progressive JPEG. 103e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 104e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 105e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 106e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovstart_pass_phuff (j_compress_ptr cinfo, boolean gather_statistics) 107e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 108e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 109e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean is_DC_band; 110e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci, tbl; 111e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info * compptr; 112e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 113e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->cinfo = cinfo; 114e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->gather_statistics = gather_statistics; 115e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 116e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov is_DC_band = (cinfo->Ss == 0); 117e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 118e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We assume jcmaster.c already validated the scan parameters. */ 119e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 120e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Select execution routines */ 121e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->Ah == 0) { 122e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (is_DC_band) 123e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.encode_mcu = encode_mcu_DC_first; 124e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else 125e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.encode_mcu = encode_mcu_AC_first; 126e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 127e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (is_DC_band) 128e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.encode_mcu = encode_mcu_DC_refine; 129e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else { 130e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.encode_mcu = encode_mcu_AC_refine; 131e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* AC refinement needs a correction bit buffer */ 132e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->bit_buffer == NULL) 133e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->bit_buffer = (char *) 134e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 135e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MAX_CORR_BITS * SIZEOF(char)); 136e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 137e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 138e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (gather_statistics) 139e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.finish_pass = finish_pass_gather_phuff; 140e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else 141e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.finish_pass = finish_pass_phuff; 142e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 143e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Only DC coefficients may be interleaved, so cinfo->comps_in_scan = 1 144e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * for AC coefficients. 145e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 146e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 147e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[ci]; 148e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize DC predictions to 0 */ 149e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->last_dc_val[ci] = 0; 150e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Get table index */ 151e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (is_DC_band) { 152e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->Ah != 0) /* DC refinement needs no table */ 153e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 154e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tbl = compptr->dc_tbl_no; 155e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 156e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->ac_tbl_no = tbl = compptr->ac_tbl_no; 157e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 158e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (gather_statistics) { 159e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Check for invalid table index */ 160e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* (make_c_derived_tbl does this in the other path) */ 161e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (tbl < 0 || tbl >= NUM_HUFF_TBLS) 162e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl); 163e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Allocate and zero the statistics tables */ 164e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */ 165e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->count_ptrs[tbl] == NULL) 166e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->count_ptrs[tbl] = (long *) 167e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 168e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 257 * SIZEOF(long)); 169e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MEMZERO(entropy->count_ptrs[tbl], 257 * SIZEOF(long)); 170e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 171e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Compute derived values for Huffman table */ 172e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We may do this more than once for a table, but it's not expensive */ 173e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_make_c_derived_tbl(cinfo, is_DC_band, tbl, 174e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov & entropy->derived_tbls[tbl]); 175e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 176e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 177e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 178e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize AC stuff */ 179e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->EOBRUN = 0; 180e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->BE = 0; 181e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 182e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize bit buffer to empty */ 183e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_buffer = 0; 184e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_bits = 0; 185e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 186e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize restart stuff */ 187e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go = cinfo->restart_interval; 188e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num = 0; 189e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 190e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 191e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 192e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Outputting bytes to the file. 193e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * NB: these must be called only when actually outputting, 194e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * that is, entropy->gather_statistics == FALSE. 195e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 196e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 197e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Emit a byte */ 198e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define emit_byte(entropy,val) \ 199e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov { *(entropy)->next_output_byte++ = (JOCTET) (val); \ 200e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (--(entropy)->free_in_buffer == 0) \ 201e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov dump_buffer(entropy); } 202e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 203e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 204e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 205e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovdump_buffer (phuff_entropy_ptr entropy) 206e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Empty the output buffer; we do not support suspension in this module. */ 207e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 208e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov struct jpeg_destination_mgr * dest = entropy->cinfo->dest; 209e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 210e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (! (*dest->empty_output_buffer) (entropy->cinfo)) 211e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND); 212e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* After a successful buffer dump, must reset buffer pointers */ 213e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = dest->next_output_byte; 214e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = dest->free_in_buffer; 215e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 216e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 217e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 218e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Outputting bits to the file */ 219e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 220e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Only the right 24 bits of put_buffer are used; the valid bits are 221e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * left-justified in this part. At most 16 bits can be passed to emit_bits 222e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * in one call, and we never retain more than 7 bits in put_buffer 223e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * between calls, so 24 bits are sufficient. 224e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 225e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 226e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovINLINE 227e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 228e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovemit_bits (phuff_entropy_ptr entropy, unsigned int code, int size) 229e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Emit some bits, unless we are in gather mode */ 230e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 231e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* This routine is heavily used, so it's worth coding tightly. */ 232e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register INT32 put_buffer = (INT32) code; 233e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int put_bits = entropy->put_bits; 234e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 235e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* if size is 0, caller used an invalid Huffman table entry */ 236e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (size == 0) 237e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); 238e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 239e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->gather_statistics) 240e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return; /* do nothing if we're only getting stats */ 241e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 242e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ 243e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 244e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_bits += size; /* new number of bits in buffer */ 245e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 246e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_buffer <<= 24 - put_bits; /* align incoming bits */ 247e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 248e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_buffer |= entropy->put_buffer; /* and merge with old buffer contents */ 249e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 250e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (put_bits >= 8) { 251e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int c = (int) ((put_buffer >> 16) & 0xFF); 252e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 253e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_byte(entropy, c); 254e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (c == 0xFF) { /* need to stuff a zero byte? */ 255e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_byte(entropy, 0); 256e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 257e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_buffer <<= 8; 258e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov put_bits -= 8; 259e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 260e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 261e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_buffer = put_buffer; /* update variables */ 262e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_bits = put_bits; 263e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 264e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 265e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 266e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 267e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovflush_bits (phuff_entropy_ptr entropy) 268e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 269e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, 0x7F, 7); /* fill any partial byte with ones */ 270e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_buffer = 0; /* and reset bit-buffer to empty */ 271e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->put_bits = 0; 272e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 273e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 274e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 275e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 276e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Emit (or just count) a Huffman symbol. 277e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 278e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 279e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovINLINE 280e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 281e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovemit_symbol (phuff_entropy_ptr entropy, int tbl_no, int symbol) 282e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 283e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->gather_statistics) 284e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->count_ptrs[tbl_no][symbol]++; 285e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else { 286e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov c_derived_tbl * tbl = entropy->derived_tbls[tbl_no]; 287e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]); 288e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 289e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 290e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 291e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 292e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 293e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Emit bits from a correction bit buffer. 294e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 295e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 296e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 297e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovemit_buffered_bits (phuff_entropy_ptr entropy, char * bufstart, 298e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov unsigned int nbits) 299e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 300e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->gather_statistics) 301e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return; /* no real work */ 302e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 303e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (nbits > 0) { 304e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, (unsigned int) (*bufstart), 1); 305e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov bufstart++; 306e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits--; 307e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 308e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 309e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 310e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 311e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 312e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Emit any pending EOBRUN symbol. 313e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 314e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 315e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 316e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovemit_eobrun (phuff_entropy_ptr entropy) 317e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 318e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int temp, nbits; 319e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 320e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->EOBRUN > 0) { /* if there is any pending EOBRUN */ 321e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = entropy->EOBRUN; 322e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits = 0; 323e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while ((temp >>= 1)) 324e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits++; 325e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* safety check: shouldn't happen given limited correction-bit buffer */ 326e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (nbits > 14) 327e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); 328e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 329e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, entropy->ac_tbl_no, nbits << 4); 330e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (nbits) 331e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, entropy->EOBRUN, nbits); 332e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 333e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->EOBRUN = 0; 334e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 335e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit any buffered correction bits */ 336e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE); 337e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->BE = 0; 338e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 339e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 340e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 341e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 342e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 343e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Emit a restart marker & resynchronize predictions. 344e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 345e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 346e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 347e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovemit_restart (phuff_entropy_ptr entropy, int restart_num) 348e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 349e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci; 350e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 351e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 352e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 353e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (! entropy->gather_statistics) { 354e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov flush_bits(entropy); 355e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_byte(entropy, 0xFF); 356e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_byte(entropy, JPEG_RST0 + restart_num); 357e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 358e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 359e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->cinfo->Ss == 0) { 360e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Re-initialize DC predictions to 0 */ 361e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++) 362e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->last_dc_val[ci] = 0; 363e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 364e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Re-initialize all AC-related fields to 0 */ 365e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->EOBRUN = 0; 366e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->BE = 0; 367e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 368e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 369e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 370e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 371e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 372e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * MCU encoding for DC initial scan (either spectral selection, 373e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * or first pass of successive approximation). 374e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 375e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 376e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) 377e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovencode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 378e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 379e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 380e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int temp, temp2; 381e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int nbits; 382e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int blkn, ci; 383e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Al = cinfo->Al; 384e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW block; 385e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info * compptr; 386e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ISHIFT_TEMPS 387e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 388e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = cinfo->dest->next_output_byte; 389e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = cinfo->dest->free_in_buffer; 390e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 391e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit restart marker if needed */ 392e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) 393e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) 394e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_restart(entropy, entropy->next_restart_num); 395e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 396e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the MCU data blocks */ 397e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 398e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov block = MCU_data[blkn]; 399e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ci = cinfo->MCU_membership[blkn]; 400e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[ci]; 401e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 402e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Compute the DC value after the required point transform by Al. 403e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This is simply an arithmetic right shift. 404e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 405e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp2 = IRIGHT_SHIFT((int) ((*block)[0]), Al); 406e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 407e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* DC differences are figured on the point-transformed values. */ 408e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = temp2 - entropy->last_dc_val[ci]; 409e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->last_dc_val[ci] = temp2; 410e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 411e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the DC coefficient difference per section G.1.2.1 */ 412e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp2 = temp; 413e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp < 0) { 414e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = -temp; /* temp is abs value of input */ 415e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* For a negative input, want temp2 = bitwise complement of abs(input) */ 416e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* This code assumes we are on a two's complement machine */ 417e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp2--; 418e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 419e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 420e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Find the number of bits needed for the magnitude of the coefficient */ 421e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits = 0; 422e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (temp) { 423e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits++; 424e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp >>= 1; 425e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 426e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Check for out-of-range coefficient values. 427e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Since we're encoding a difference, the range limit is twice as much. 428e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 429e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (nbits > MAX_COEF_BITS+1) 430e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_BAD_DCT_COEF); 431e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 432e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Count/emit the Huffman-coded symbol for the number of bits */ 433e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, compptr->dc_tbl_no, nbits); 434e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 435e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit that number of bits of the value, if positive, */ 436e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* or the complement of its magnitude, if negative. */ 437e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (nbits) /* emit_bits rejects calls with size 0 */ 438e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, (unsigned int) temp2, nbits); 439e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 440e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 441e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->next_output_byte = entropy->next_output_byte; 442e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->free_in_buffer = entropy->free_in_buffer; 443e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 444e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Update restart-interval state too */ 445e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) { 446e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) { 447e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go = cinfo->restart_interval; 448e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num++; 449e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num &= 7; 450e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 451e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go--; 452e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 453e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 454e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return TRUE; 455e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 456e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 457e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 458e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 459e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * MCU encoding for AC initial scan (either spectral selection, 460e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * or first pass of successive approximation). 461e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 462e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 463e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) 464e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovencode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 465e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 466e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 467e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int temp, temp2; 468e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int nbits; 469e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int r, k; 470e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Se = cinfo->Se; 471e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Al = cinfo->Al; 472e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW block; 473e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 474e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = cinfo->dest->next_output_byte; 475e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = cinfo->dest->free_in_buffer; 476e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 477e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit restart marker if needed */ 478e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) 479e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) 480e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_restart(entropy, entropy->next_restart_num); 481e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 482e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the MCU data block */ 483e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov block = MCU_data[0]; 484e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 485e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */ 486e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 487e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r = 0; /* r = run length of zeros */ 488e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 489e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (k = cinfo->Ss; k <= Se; k++) { 490e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if ((temp = (*block)[jpeg_natural_order[k]]) == 0) { 491e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r++; 492e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 493e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 494e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We must apply the point transform by Al. For AC coefficients this 495e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * is an integer division with rounding towards 0. To do this portably 496e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * in C, we shift after obtaining the absolute value; so the code is 497e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * interwoven with finding the abs value (temp) and output bits (temp2). 498e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 499e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp < 0) { 500e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = -temp; /* temp is abs value of input */ 501e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp >>= Al; /* apply the point transform */ 502e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* For a negative coef, want temp2 = bitwise complement of abs(coef) */ 503e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp2 = ~temp; 504e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 505e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp >>= Al; /* apply the point transform */ 506e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp2 = temp; 507e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 508e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Watch out for case that nonzero coef is zero after point transform */ 509e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp == 0) { 510e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r++; 511e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 512e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 513e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 514e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit any pending EOBRUN */ 515e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->EOBRUN > 0) 516e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 517e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* if run length > 15, must emit special run-length-16 codes (0xF0) */ 518e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (r > 15) { 519e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); 520e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r -= 16; 521e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 522e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 523e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Find the number of bits needed for the magnitude of the coefficient */ 524e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits = 1; /* there must be at least one 1 bit */ 525e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while ((temp >>= 1)) 526e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov nbits++; 527e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Check for out-of-range coefficient values */ 528e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (nbits > MAX_COEF_BITS) 529e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_BAD_DCT_COEF); 530e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 531e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Count/emit Huffman symbol for run length / number of bits */ 532e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits); 533e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 534e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit that number of bits of the value, if positive, */ 535e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* or the complement of its magnitude, if negative. */ 536e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, (unsigned int) temp2, nbits); 537e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 538e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r = 0; /* reset zero run length */ 539e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 540e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 541e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (r > 0) { /* If there are trailing zeroes, */ 542e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->EOBRUN++; /* count an EOB */ 543e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->EOBRUN == 0x7FFF) 544e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); /* force it out to avoid overflow */ 545e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 546e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 547e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->next_output_byte = entropy->next_output_byte; 548e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->free_in_buffer = entropy->free_in_buffer; 549e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 550e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Update restart-interval state too */ 551e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) { 552e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) { 553e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go = cinfo->restart_interval; 554e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num++; 555e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num &= 7; 556e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 557e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go--; 558e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 559e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 560e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return TRUE; 561e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 562e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 563e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 564e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 565e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * MCU encoding for DC successive approximation refinement scan. 566e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Note: we assume such scans can be multi-component, although the spec 567e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * is not very clear on the point. 568e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 569e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 570e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) 571e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovencode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 572e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 573e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 574e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int temp; 575e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int blkn; 576e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Al = cinfo->Al; 577e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW block; 578e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 579e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = cinfo->dest->next_output_byte; 580e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = cinfo->dest->free_in_buffer; 581e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 582e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit restart marker if needed */ 583e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) 584e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) 585e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_restart(entropy, entropy->next_restart_num); 586e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 587e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the MCU data blocks */ 588e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { 589e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov block = MCU_data[blkn]; 590e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 591e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We simply emit the Al'th bit of the DC coefficient value. */ 592e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = (*block)[0]; 593e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, (unsigned int) (temp >> Al), 1); 594e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 595e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 596e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->next_output_byte = entropy->next_output_byte; 597e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->free_in_buffer = entropy->free_in_buffer; 598e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 599e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Update restart-interval state too */ 600e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) { 601e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) { 602e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go = cinfo->restart_interval; 603e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num++; 604e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num &= 7; 605e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 606e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go--; 607e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 608e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 609e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return TRUE; 610e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 611e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 612e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 613e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 614e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * MCU encoding for AC successive approximation refinement scan. 615e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 616e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 617e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(boolean) 618e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovencode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) 619e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 620e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 621e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int temp; 622e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov register int r, k; 623e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int EOB; 624e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov char *BR_buffer; 625e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov unsigned int BR; 626e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Se = cinfo->Se; 627e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int Al = cinfo->Al; 628e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JBLOCKROW block; 629e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int absvalues[DCTSIZE2]; 630e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 631e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = cinfo->dest->next_output_byte; 632e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = cinfo->dest->free_in_buffer; 633e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 634e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit restart marker if needed */ 635e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) 636e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) 637e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_restart(entropy, entropy->next_restart_num); 638e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 639e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the MCU data block */ 640e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov block = MCU_data[0]; 641e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 642e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* It is convenient to make a pre-pass to determine the transformed 643e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * coefficients' absolute values and the EOB position. 644e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 645e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov EOB = 0; 646e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (k = cinfo->Ss; k <= Se; k++) { 647e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = (*block)[jpeg_natural_order[k]]; 648e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We must apply the point transform by Al. For AC coefficients this 649e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * is an integer division with rounding towards 0. To do this portably 650e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * in C, we shift after obtaining the absolute value. 651e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 652e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp < 0) 653e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = -temp; /* temp is abs value of input */ 654e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp >>= Al; /* apply the point transform */ 655e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov absvalues[k] = temp; /* save abs value for main pass */ 656e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp == 1) 657e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov EOB = k; /* EOB = index of last newly-nonzero coef */ 658e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 659e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 660e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */ 661e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 662e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r = 0; /* r = run length of zeros */ 663e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR = 0; /* BR = count of buffered bits added now */ 664e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */ 665e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 666e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (k = cinfo->Ss; k <= Se; k++) { 667e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if ((temp = absvalues[k]) == 0) { 668e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r++; 669e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 670e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 671e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 672e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit any required ZRLs, but not if they can be folded into EOB */ 673e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (r > 15 && k <= EOB) { 674e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* emit any pending EOBRUN and the BE correction bits */ 675e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 676e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit ZRL */ 677e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); 678e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r -= 16; 679e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit buffered correction bits that must be associated with ZRL */ 680e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_buffered_bits(entropy, BR_buffer, BR); 681e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ 682e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR = 0; 683e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 684e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 685e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* If the coef was previously nonzero, it only needs a correction bit. 686e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * NOTE: a straight translation of the spec's figure G.7 would suggest 687e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * that we also need to test r > 15. But if r > 15, we can only get here 688e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * if k > EOB, which implies that this coefficient is not 1. 689e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 690e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (temp > 1) { 691e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* The correction bit is the next bit of the absolute value. */ 692e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR_buffer[BR++] = (char) (temp & 1); 693e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 694e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 695e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 696e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit any pending EOBRUN and the BE correction bits */ 697e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 698e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 699e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Count/emit Huffman symbol for run length / number of bits */ 700e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1); 701e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 702e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit output bit for newly-nonzero coef */ 703e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov temp = ((*block)[jpeg_natural_order[k]] < 0) ? 0 : 1; 704e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_bits(entropy, (unsigned int) temp, 1); 705e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 706e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Emit buffered correction bits that must be associated with this code */ 707e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_buffered_bits(entropy, BR_buffer, BR); 708e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ 709e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov BR = 0; 710e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov r = 0; /* reset zero run length */ 711e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 712e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 713e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (r > 0 || BR > 0) { /* If there are trailing zeroes, */ 714e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->EOBRUN++; /* count an EOB */ 715e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->BE += BR; /* concat my correction bits to older ones */ 716e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We force out the EOB if we risk either: 717e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 1. overflow of the EOB counter; 718e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 2. overflow of the correction bit buffer during the next MCU. 719e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 720e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->EOBRUN == 0x7FFF || entropy->BE > (MAX_CORR_BITS-DCTSIZE2+1)) 721e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 722e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 723e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 724e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->next_output_byte = entropy->next_output_byte; 725e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->free_in_buffer = entropy->free_in_buffer; 726e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 727e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Update restart-interval state too */ 728e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->restart_interval) { 729e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (entropy->restarts_to_go == 0) { 730e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go = cinfo->restart_interval; 731e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num++; 732e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_restart_num &= 7; 733e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 734e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->restarts_to_go--; 735e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 736e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 737e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return TRUE; 738e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 739e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 740e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 741e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 742e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Finish up at the end of a Huffman-compressed progressive scan. 743e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 744e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 745e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 746e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovfinish_pass_phuff (j_compress_ptr cinfo) 747e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 748e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 749e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 750e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->next_output_byte = cinfo->dest->next_output_byte; 751e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->free_in_buffer = cinfo->dest->free_in_buffer; 752e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 753e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Flush out any buffered data */ 754e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 755e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov flush_bits(entropy); 756e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 757e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->next_output_byte = entropy->next_output_byte; 758e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->dest->free_in_buffer = entropy->free_in_buffer; 759e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 760e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 761e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 762e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 763e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Finish up a statistics-gathering pass and create the new Huffman tables. 764e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 765e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 766e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 767e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovfinish_pass_gather_phuff (j_compress_ptr cinfo) 768e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 769e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; 770e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean is_DC_band; 771e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci, tbl; 772e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info * compptr; 773e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JHUFF_TBL **htblptr; 774e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean did[NUM_HUFF_TBLS]; 775e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 776e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Flush out buffered data (all we care about is counting the EOB symbol) */ 777e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov emit_eobrun(entropy); 778e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 779e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov is_DC_band = (cinfo->Ss == 0); 780e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 781e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* It's important not to apply jpeg_gen_optimal_table more than once 782e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * per table, because it clobbers the input frequency counts! 783e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 784e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MEMZERO(did, SIZEOF(did)); 785e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 786e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 787e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[ci]; 788e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (is_DC_band) { 789e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->Ah != 0) /* DC refinement needs no table */ 790e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 791e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tbl = compptr->dc_tbl_no; 792e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 793e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tbl = compptr->ac_tbl_no; 794e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 795e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (! did[tbl]) { 796e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (is_DC_band) 797e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov htblptr = & cinfo->dc_huff_tbl_ptrs[tbl]; 798e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else 799e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov htblptr = & cinfo->ac_huff_tbl_ptrs[tbl]; 800e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (*htblptr == NULL) 801e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); 802e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_gen_optimal_table(cinfo, *htblptr, entropy->count_ptrs[tbl]); 803e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov did[tbl] = TRUE; 804e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 805e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 806e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 807e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 808e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 809e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 810e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Module initialization routine for progressive Huffman entropy encoding. 811e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 812e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 813e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovGLOBAL(void) 814e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovjinit_phuff_encoder (j_compress_ptr cinfo) 815e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 816e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov phuff_entropy_ptr entropy; 817e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int i; 818e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 819e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy = (phuff_entropy_ptr) 820e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 821e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov SIZEOF(phuff_entropy_encoder)); 822e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; 823e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->pub.start_pass = start_pass_phuff; 824e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 825e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Mark tables unallocated */ 826e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (i = 0; i < NUM_HUFF_TBLS; i++) { 827e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->derived_tbls[i] = NULL; 828e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->count_ptrs[i] = NULL; 829e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 830e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov entropy->bit_buffer = NULL; /* needed only in AC refinement scan */ 831e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 832e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 833e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#endif /* C_PROGRESSIVE_SUPPORTED */ 834