Final 350 project
Dependencies: uzair Camera_LS_Y201 F7_Ethernet LCD_DISCO_F746NG NetworkAPI SDFileSystem mbed
includes/jcarith.c@0:791a779d6220, 2017-07-31 (annotated)
- Committer:
- shoaib_ahmed
- Date:
- Mon Jul 31 09:16:35 2017 +0000
- Revision:
- 0:791a779d6220
final project;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
shoaib_ahmed | 0:791a779d6220 | 1 | /* |
shoaib_ahmed | 0:791a779d6220 | 2 | * jcarith.c |
shoaib_ahmed | 0:791a779d6220 | 3 | * |
shoaib_ahmed | 0:791a779d6220 | 4 | * Developed 1997-2013 by Guido Vollbeding. |
shoaib_ahmed | 0:791a779d6220 | 5 | * This file is part of the Independent JPEG Group's software. |
shoaib_ahmed | 0:791a779d6220 | 6 | * For conditions of distribution and use, see the accompanying README file. |
shoaib_ahmed | 0:791a779d6220 | 7 | * |
shoaib_ahmed | 0:791a779d6220 | 8 | * This file contains portable arithmetic entropy encoding routines for JPEG |
shoaib_ahmed | 0:791a779d6220 | 9 | * (implementing the ISO/IEC IS 10918-1 and CCITT Recommendation ITU-T T.81). |
shoaib_ahmed | 0:791a779d6220 | 10 | * |
shoaib_ahmed | 0:791a779d6220 | 11 | * Both sequential and progressive modes are supported in this single module. |
shoaib_ahmed | 0:791a779d6220 | 12 | * |
shoaib_ahmed | 0:791a779d6220 | 13 | * Suspension is not currently supported in this module. |
shoaib_ahmed | 0:791a779d6220 | 14 | */ |
shoaib_ahmed | 0:791a779d6220 | 15 | |
shoaib_ahmed | 0:791a779d6220 | 16 | #define JPEG_INTERNALS |
shoaib_ahmed | 0:791a779d6220 | 17 | #include "jinclude.h" |
shoaib_ahmed | 0:791a779d6220 | 18 | #include "jpeglib.h" |
shoaib_ahmed | 0:791a779d6220 | 19 | |
shoaib_ahmed | 0:791a779d6220 | 20 | |
shoaib_ahmed | 0:791a779d6220 | 21 | /* Expanded entropy encoder object for arithmetic encoding. */ |
shoaib_ahmed | 0:791a779d6220 | 22 | |
shoaib_ahmed | 0:791a779d6220 | 23 | typedef struct { |
shoaib_ahmed | 0:791a779d6220 | 24 | struct jpeg_entropy_encoder pub; /* public fields */ |
shoaib_ahmed | 0:791a779d6220 | 25 | |
shoaib_ahmed | 0:791a779d6220 | 26 | INT32 c; /* C register, base of coding interval, layout as in sec. D.1.3 */ |
shoaib_ahmed | 0:791a779d6220 | 27 | INT32 a; /* A register, normalized size of coding interval */ |
shoaib_ahmed | 0:791a779d6220 | 28 | INT32 sc; /* counter for stacked 0xFF values which might overflow */ |
shoaib_ahmed | 0:791a779d6220 | 29 | INT32 zc; /* counter for pending 0x00 output values which might * |
shoaib_ahmed | 0:791a779d6220 | 30 | * be discarded at the end ("Pacman" termination) */ |
shoaib_ahmed | 0:791a779d6220 | 31 | int ct; /* bit shift counter, determines when next byte will be written */ |
shoaib_ahmed | 0:791a779d6220 | 32 | int buffer; /* buffer for most recent output byte != 0xFF */ |
shoaib_ahmed | 0:791a779d6220 | 33 | |
shoaib_ahmed | 0:791a779d6220 | 34 | int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ |
shoaib_ahmed | 0:791a779d6220 | 35 | int dc_context[MAX_COMPS_IN_SCAN]; /* context index for DC conditioning */ |
shoaib_ahmed | 0:791a779d6220 | 36 | |
shoaib_ahmed | 0:791a779d6220 | 37 | unsigned int restarts_to_go; /* MCUs left in this restart interval */ |
shoaib_ahmed | 0:791a779d6220 | 38 | int next_restart_num; /* next restart number to write (0-7) */ |
shoaib_ahmed | 0:791a779d6220 | 39 | |
shoaib_ahmed | 0:791a779d6220 | 40 | /* Pointers to statistics areas (these workspaces have image lifespan) */ |
shoaib_ahmed | 0:791a779d6220 | 41 | unsigned char * dc_stats[NUM_ARITH_TBLS]; |
shoaib_ahmed | 0:791a779d6220 | 42 | unsigned char * ac_stats[NUM_ARITH_TBLS]; |
shoaib_ahmed | 0:791a779d6220 | 43 | |
shoaib_ahmed | 0:791a779d6220 | 44 | /* Statistics bin for coding with fixed probability 0.5 */ |
shoaib_ahmed | 0:791a779d6220 | 45 | unsigned char fixed_bin[4]; |
shoaib_ahmed | 0:791a779d6220 | 46 | } arith_entropy_encoder; |
shoaib_ahmed | 0:791a779d6220 | 47 | |
shoaib_ahmed | 0:791a779d6220 | 48 | typedef arith_entropy_encoder * arith_entropy_ptr; |
shoaib_ahmed | 0:791a779d6220 | 49 | |
shoaib_ahmed | 0:791a779d6220 | 50 | /* The following two definitions specify the allocation chunk size |
shoaib_ahmed | 0:791a779d6220 | 51 | * for the statistics area. |
shoaib_ahmed | 0:791a779d6220 | 52 | * According to sections F.1.4.4.1.3 and F.1.4.4.2, we need at least |
shoaib_ahmed | 0:791a779d6220 | 53 | * 49 statistics bins for DC, and 245 statistics bins for AC coding. |
shoaib_ahmed | 0:791a779d6220 | 54 | * |
shoaib_ahmed | 0:791a779d6220 | 55 | * We use a compact representation with 1 byte per statistics bin, |
shoaib_ahmed | 0:791a779d6220 | 56 | * thus the numbers directly represent byte sizes. |
shoaib_ahmed | 0:791a779d6220 | 57 | * This 1 byte per statistics bin contains the meaning of the MPS |
shoaib_ahmed | 0:791a779d6220 | 58 | * (more probable symbol) in the highest bit (mask 0x80), and the |
shoaib_ahmed | 0:791a779d6220 | 59 | * index into the probability estimation state machine table |
shoaib_ahmed | 0:791a779d6220 | 60 | * in the lower bits (mask 0x7F). |
shoaib_ahmed | 0:791a779d6220 | 61 | */ |
shoaib_ahmed | 0:791a779d6220 | 62 | |
shoaib_ahmed | 0:791a779d6220 | 63 | #define DC_STAT_BINS 64 |
shoaib_ahmed | 0:791a779d6220 | 64 | #define AC_STAT_BINS 256 |
shoaib_ahmed | 0:791a779d6220 | 65 | |
shoaib_ahmed | 0:791a779d6220 | 66 | /* NOTE: Uncomment the following #define if you want to use the |
shoaib_ahmed | 0:791a779d6220 | 67 | * given formula for calculating the AC conditioning parameter Kx |
shoaib_ahmed | 0:791a779d6220 | 68 | * for spectral selection progressive coding in section G.1.3.2 |
shoaib_ahmed | 0:791a779d6220 | 69 | * of the spec (Kx = Kmin + SRL (8 + Se - Kmin) 4). |
shoaib_ahmed | 0:791a779d6220 | 70 | * Although the spec and P&M authors claim that this "has proven |
shoaib_ahmed | 0:791a779d6220 | 71 | * to give good results for 8 bit precision samples", I'm not |
shoaib_ahmed | 0:791a779d6220 | 72 | * convinced yet that this is really beneficial. |
shoaib_ahmed | 0:791a779d6220 | 73 | * Early tests gave only very marginal compression enhancements |
shoaib_ahmed | 0:791a779d6220 | 74 | * (a few - around 5 or so - bytes even for very large files), |
shoaib_ahmed | 0:791a779d6220 | 75 | * which would turn out rather negative if we'd suppress the |
shoaib_ahmed | 0:791a779d6220 | 76 | * DAC (Define Arithmetic Conditioning) marker segments for |
shoaib_ahmed | 0:791a779d6220 | 77 | * the default parameters in the future. |
shoaib_ahmed | 0:791a779d6220 | 78 | * Note that currently the marker writing module emits 12-byte |
shoaib_ahmed | 0:791a779d6220 | 79 | * DAC segments for a full-component scan in a color image. |
shoaib_ahmed | 0:791a779d6220 | 80 | * This is not worth worrying about IMHO. However, since the |
shoaib_ahmed | 0:791a779d6220 | 81 | * spec defines the default values to be used if the tables |
shoaib_ahmed | 0:791a779d6220 | 82 | * are omitted (unlike Huffman tables, which are required |
shoaib_ahmed | 0:791a779d6220 | 83 | * anyway), one might optimize this behaviour in the future, |
shoaib_ahmed | 0:791a779d6220 | 84 | * and then it would be disadvantageous to use custom tables if |
shoaib_ahmed | 0:791a779d6220 | 85 | * they don't provide sufficient gain to exceed the DAC size. |
shoaib_ahmed | 0:791a779d6220 | 86 | * |
shoaib_ahmed | 0:791a779d6220 | 87 | * On the other hand, I'd consider it as a reasonable result |
shoaib_ahmed | 0:791a779d6220 | 88 | * that the conditioning has no significant influence on the |
shoaib_ahmed | 0:791a779d6220 | 89 | * compression performance. This means that the basic |
shoaib_ahmed | 0:791a779d6220 | 90 | * statistical model is already rather stable. |
shoaib_ahmed | 0:791a779d6220 | 91 | * |
shoaib_ahmed | 0:791a779d6220 | 92 | * Thus, at the moment, we use the default conditioning values |
shoaib_ahmed | 0:791a779d6220 | 93 | * anyway, and do not use the custom formula. |
shoaib_ahmed | 0:791a779d6220 | 94 | * |
shoaib_ahmed | 0:791a779d6220 | 95 | #define CALCULATE_SPECTRAL_CONDITIONING |
shoaib_ahmed | 0:791a779d6220 | 96 | */ |
shoaib_ahmed | 0:791a779d6220 | 97 | |
shoaib_ahmed | 0:791a779d6220 | 98 | /* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. |
shoaib_ahmed | 0:791a779d6220 | 99 | * We assume that int right shift is unsigned if INT32 right shift is, |
shoaib_ahmed | 0:791a779d6220 | 100 | * which should be safe. |
shoaib_ahmed | 0:791a779d6220 | 101 | */ |
shoaib_ahmed | 0:791a779d6220 | 102 | |
shoaib_ahmed | 0:791a779d6220 | 103 | #ifdef RIGHT_SHIFT_IS_UNSIGNED |
shoaib_ahmed | 0:791a779d6220 | 104 | #define ISHIFT_TEMPS int ishift_temp; |
shoaib_ahmed | 0:791a779d6220 | 105 | #define IRIGHT_SHIFT(x,shft) \ |
shoaib_ahmed | 0:791a779d6220 | 106 | ((ishift_temp = (x)) < 0 ? \ |
shoaib_ahmed | 0:791a779d6220 | 107 | (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ |
shoaib_ahmed | 0:791a779d6220 | 108 | (ishift_temp >> (shft))) |
shoaib_ahmed | 0:791a779d6220 | 109 | #else |
shoaib_ahmed | 0:791a779d6220 | 110 | #define ISHIFT_TEMPS |
shoaib_ahmed | 0:791a779d6220 | 111 | #define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) |
shoaib_ahmed | 0:791a779d6220 | 112 | #endif |
shoaib_ahmed | 0:791a779d6220 | 113 | |
shoaib_ahmed | 0:791a779d6220 | 114 | |
shoaib_ahmed | 0:791a779d6220 | 115 | LOCAL(void) |
shoaib_ahmed | 0:791a779d6220 | 116 | emit_byte (int val, j_compress_ptr cinfo) |
shoaib_ahmed | 0:791a779d6220 | 117 | /* Write next output byte; we do not support suspension in this module. */ |
shoaib_ahmed | 0:791a779d6220 | 118 | { |
shoaib_ahmed | 0:791a779d6220 | 119 | struct jpeg_destination_mgr * dest = cinfo->dest; |
shoaib_ahmed | 0:791a779d6220 | 120 | |
shoaib_ahmed | 0:791a779d6220 | 121 | *dest->next_output_byte++ = (JOCTET) val; |
shoaib_ahmed | 0:791a779d6220 | 122 | if (--dest->free_in_buffer == 0) |
shoaib_ahmed | 0:791a779d6220 | 123 | if (! (*dest->empty_output_buffer) (cinfo)) |
shoaib_ahmed | 0:791a779d6220 | 124 | ERREXIT(cinfo, JERR_CANT_SUSPEND); |
shoaib_ahmed | 0:791a779d6220 | 125 | } |
shoaib_ahmed | 0:791a779d6220 | 126 | |
shoaib_ahmed | 0:791a779d6220 | 127 | |
shoaib_ahmed | 0:791a779d6220 | 128 | /* |
shoaib_ahmed | 0:791a779d6220 | 129 | * Finish up at the end of an arithmetic-compressed scan. |
shoaib_ahmed | 0:791a779d6220 | 130 | */ |
shoaib_ahmed | 0:791a779d6220 | 131 | |
shoaib_ahmed | 0:791a779d6220 | 132 | METHODDEF(void) |
shoaib_ahmed | 0:791a779d6220 | 133 | finish_pass (j_compress_ptr cinfo) |
shoaib_ahmed | 0:791a779d6220 | 134 | { |
shoaib_ahmed | 0:791a779d6220 | 135 | arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 136 | INT32 temp; |
shoaib_ahmed | 0:791a779d6220 | 137 | |
shoaib_ahmed | 0:791a779d6220 | 138 | /* Section D.1.8: Termination of encoding */ |
shoaib_ahmed | 0:791a779d6220 | 139 | |
shoaib_ahmed | 0:791a779d6220 | 140 | /* Find the e->c in the coding interval with the largest |
shoaib_ahmed | 0:791a779d6220 | 141 | * number of trailing zero bits */ |
shoaib_ahmed | 0:791a779d6220 | 142 | if ((temp = (e->a - 1 + e->c) & 0xFFFF0000L) < e->c) |
shoaib_ahmed | 0:791a779d6220 | 143 | e->c = temp + 0x8000L; |
shoaib_ahmed | 0:791a779d6220 | 144 | else |
shoaib_ahmed | 0:791a779d6220 | 145 | e->c = temp; |
shoaib_ahmed | 0:791a779d6220 | 146 | /* Send remaining bytes to output */ |
shoaib_ahmed | 0:791a779d6220 | 147 | e->c <<= e->ct; |
shoaib_ahmed | 0:791a779d6220 | 148 | if (e->c & 0xF8000000L) { |
shoaib_ahmed | 0:791a779d6220 | 149 | /* One final overflow has to be handled */ |
shoaib_ahmed | 0:791a779d6220 | 150 | if (e->buffer >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 151 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 152 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 153 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 154 | emit_byte(e->buffer + 1, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 155 | if (e->buffer + 1 == 0xFF) |
shoaib_ahmed | 0:791a779d6220 | 156 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 157 | } |
shoaib_ahmed | 0:791a779d6220 | 158 | e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ |
shoaib_ahmed | 0:791a779d6220 | 159 | e->sc = 0; |
shoaib_ahmed | 0:791a779d6220 | 160 | } else { |
shoaib_ahmed | 0:791a779d6220 | 161 | if (e->buffer == 0) |
shoaib_ahmed | 0:791a779d6220 | 162 | ++e->zc; |
shoaib_ahmed | 0:791a779d6220 | 163 | else if (e->buffer >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 164 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 165 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 166 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 167 | emit_byte(e->buffer, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 168 | } |
shoaib_ahmed | 0:791a779d6220 | 169 | if (e->sc) { |
shoaib_ahmed | 0:791a779d6220 | 170 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 171 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 172 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 173 | do { |
shoaib_ahmed | 0:791a779d6220 | 174 | emit_byte(0xFF, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 175 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 176 | } while (--e->sc); |
shoaib_ahmed | 0:791a779d6220 | 177 | } |
shoaib_ahmed | 0:791a779d6220 | 178 | } |
shoaib_ahmed | 0:791a779d6220 | 179 | /* Output final bytes only if they are not 0x00 */ |
shoaib_ahmed | 0:791a779d6220 | 180 | if (e->c & 0x7FFF800L) { |
shoaib_ahmed | 0:791a779d6220 | 181 | if (e->zc) /* output final pending zero bytes */ |
shoaib_ahmed | 0:791a779d6220 | 182 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 183 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 184 | emit_byte((e->c >> 19) & 0xFF, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 185 | if (((e->c >> 19) & 0xFF) == 0xFF) |
shoaib_ahmed | 0:791a779d6220 | 186 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 187 | if (e->c & 0x7F800L) { |
shoaib_ahmed | 0:791a779d6220 | 188 | emit_byte((e->c >> 11) & 0xFF, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 189 | if (((e->c >> 11) & 0xFF) == 0xFF) |
shoaib_ahmed | 0:791a779d6220 | 190 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 191 | } |
shoaib_ahmed | 0:791a779d6220 | 192 | } |
shoaib_ahmed | 0:791a779d6220 | 193 | } |
shoaib_ahmed | 0:791a779d6220 | 194 | |
shoaib_ahmed | 0:791a779d6220 | 195 | |
shoaib_ahmed | 0:791a779d6220 | 196 | /* |
shoaib_ahmed | 0:791a779d6220 | 197 | * The core arithmetic encoding routine (common in JPEG and JBIG). |
shoaib_ahmed | 0:791a779d6220 | 198 | * This needs to go as fast as possible. |
shoaib_ahmed | 0:791a779d6220 | 199 | * Machine-dependent optimization facilities |
shoaib_ahmed | 0:791a779d6220 | 200 | * are not utilized in this portable implementation. |
shoaib_ahmed | 0:791a779d6220 | 201 | * However, this code should be fairly efficient and |
shoaib_ahmed | 0:791a779d6220 | 202 | * may be a good base for further optimizations anyway. |
shoaib_ahmed | 0:791a779d6220 | 203 | * |
shoaib_ahmed | 0:791a779d6220 | 204 | * Parameter 'val' to be encoded may be 0 or 1 (binary decision). |
shoaib_ahmed | 0:791a779d6220 | 205 | * |
shoaib_ahmed | 0:791a779d6220 | 206 | * Note: I've added full "Pacman" termination support to the |
shoaib_ahmed | 0:791a779d6220 | 207 | * byte output routines, which is equivalent to the optional |
shoaib_ahmed | 0:791a779d6220 | 208 | * Discard_final_zeros procedure (Figure D.15) in the spec. |
shoaib_ahmed | 0:791a779d6220 | 209 | * Thus, we always produce the shortest possible output |
shoaib_ahmed | 0:791a779d6220 | 210 | * stream compliant to the spec (no trailing zero bytes, |
shoaib_ahmed | 0:791a779d6220 | 211 | * except for FF stuffing). |
shoaib_ahmed | 0:791a779d6220 | 212 | * |
shoaib_ahmed | 0:791a779d6220 | 213 | * I've also introduced a new scheme for accessing |
shoaib_ahmed | 0:791a779d6220 | 214 | * the probability estimation state machine table, |
shoaib_ahmed | 0:791a779d6220 | 215 | * derived from Markus Kuhn's JBIG implementation. |
shoaib_ahmed | 0:791a779d6220 | 216 | */ |
shoaib_ahmed | 0:791a779d6220 | 217 | |
shoaib_ahmed | 0:791a779d6220 | 218 | LOCAL(void) |
shoaib_ahmed | 0:791a779d6220 | 219 | arith_encode (j_compress_ptr cinfo, unsigned char *st, int val) |
shoaib_ahmed | 0:791a779d6220 | 220 | { |
shoaib_ahmed | 0:791a779d6220 | 221 | register arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 222 | register unsigned char nl, nm; |
shoaib_ahmed | 0:791a779d6220 | 223 | register INT32 qe, temp; |
shoaib_ahmed | 0:791a779d6220 | 224 | register int sv; |
shoaib_ahmed | 0:791a779d6220 | 225 | |
shoaib_ahmed | 0:791a779d6220 | 226 | /* Fetch values from our compact representation of Table D.3(D.2): |
shoaib_ahmed | 0:791a779d6220 | 227 | * Qe values and probability estimation state machine |
shoaib_ahmed | 0:791a779d6220 | 228 | */ |
shoaib_ahmed | 0:791a779d6220 | 229 | sv = *st; |
shoaib_ahmed | 0:791a779d6220 | 230 | qe = jpeg_aritab[sv & 0x7F]; /* => Qe_Value */ |
shoaib_ahmed | 0:791a779d6220 | 231 | nl = qe & 0xFF; qe >>= 8; /* Next_Index_LPS + Switch_MPS */ |
shoaib_ahmed | 0:791a779d6220 | 232 | nm = qe & 0xFF; qe >>= 8; /* Next_Index_MPS */ |
shoaib_ahmed | 0:791a779d6220 | 233 | |
shoaib_ahmed | 0:791a779d6220 | 234 | /* Encode & estimation procedures per sections D.1.4 & D.1.5 */ |
shoaib_ahmed | 0:791a779d6220 | 235 | e->a -= qe; |
shoaib_ahmed | 0:791a779d6220 | 236 | if (val != (sv >> 7)) { |
shoaib_ahmed | 0:791a779d6220 | 237 | /* Encode the less probable symbol */ |
shoaib_ahmed | 0:791a779d6220 | 238 | if (e->a >= qe) { |
shoaib_ahmed | 0:791a779d6220 | 239 | /* If the interval size (qe) for the less probable symbol (LPS) |
shoaib_ahmed | 0:791a779d6220 | 240 | * is larger than the interval size for the MPS, then exchange |
shoaib_ahmed | 0:791a779d6220 | 241 | * the two symbols for coding efficiency, otherwise code the LPS |
shoaib_ahmed | 0:791a779d6220 | 242 | * as usual: */ |
shoaib_ahmed | 0:791a779d6220 | 243 | e->c += e->a; |
shoaib_ahmed | 0:791a779d6220 | 244 | e->a = qe; |
shoaib_ahmed | 0:791a779d6220 | 245 | } |
shoaib_ahmed | 0:791a779d6220 | 246 | *st = (sv & 0x80) ^ nl; /* Estimate_after_LPS */ |
shoaib_ahmed | 0:791a779d6220 | 247 | } else { |
shoaib_ahmed | 0:791a779d6220 | 248 | /* Encode the more probable symbol */ |
shoaib_ahmed | 0:791a779d6220 | 249 | if (e->a >= 0x8000L) |
shoaib_ahmed | 0:791a779d6220 | 250 | return; /* A >= 0x8000 -> ready, no renormalization required */ |
shoaib_ahmed | 0:791a779d6220 | 251 | if (e->a < qe) { |
shoaib_ahmed | 0:791a779d6220 | 252 | /* If the interval size (qe) for the less probable symbol (LPS) |
shoaib_ahmed | 0:791a779d6220 | 253 | * is larger than the interval size for the MPS, then exchange |
shoaib_ahmed | 0:791a779d6220 | 254 | * the two symbols for coding efficiency: */ |
shoaib_ahmed | 0:791a779d6220 | 255 | e->c += e->a; |
shoaib_ahmed | 0:791a779d6220 | 256 | e->a = qe; |
shoaib_ahmed | 0:791a779d6220 | 257 | } |
shoaib_ahmed | 0:791a779d6220 | 258 | *st = (sv & 0x80) ^ nm; /* Estimate_after_MPS */ |
shoaib_ahmed | 0:791a779d6220 | 259 | } |
shoaib_ahmed | 0:791a779d6220 | 260 | |
shoaib_ahmed | 0:791a779d6220 | 261 | /* Renormalization & data output per section D.1.6 */ |
shoaib_ahmed | 0:791a779d6220 | 262 | do { |
shoaib_ahmed | 0:791a779d6220 | 263 | e->a <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 264 | e->c <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 265 | if (--e->ct == 0) { |
shoaib_ahmed | 0:791a779d6220 | 266 | /* Another byte is ready for output */ |
shoaib_ahmed | 0:791a779d6220 | 267 | temp = e->c >> 19; |
shoaib_ahmed | 0:791a779d6220 | 268 | if (temp > 0xFF) { |
shoaib_ahmed | 0:791a779d6220 | 269 | /* Handle overflow over all stacked 0xFF bytes */ |
shoaib_ahmed | 0:791a779d6220 | 270 | if (e->buffer >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 271 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 272 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 273 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 274 | emit_byte(e->buffer + 1, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 275 | if (e->buffer + 1 == 0xFF) |
shoaib_ahmed | 0:791a779d6220 | 276 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 277 | } |
shoaib_ahmed | 0:791a779d6220 | 278 | e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ |
shoaib_ahmed | 0:791a779d6220 | 279 | e->sc = 0; |
shoaib_ahmed | 0:791a779d6220 | 280 | /* Note: The 3 spacer bits in the C register guarantee |
shoaib_ahmed | 0:791a779d6220 | 281 | * that the new buffer byte can't be 0xFF here |
shoaib_ahmed | 0:791a779d6220 | 282 | * (see page 160 in the P&M JPEG book). */ |
shoaib_ahmed | 0:791a779d6220 | 283 | e->buffer = temp & 0xFF; /* new output byte, might overflow later */ |
shoaib_ahmed | 0:791a779d6220 | 284 | } else if (temp == 0xFF) { |
shoaib_ahmed | 0:791a779d6220 | 285 | ++e->sc; /* stack 0xFF byte (which might overflow later) */ |
shoaib_ahmed | 0:791a779d6220 | 286 | } else { |
shoaib_ahmed | 0:791a779d6220 | 287 | /* Output all stacked 0xFF bytes, they will not overflow any more */ |
shoaib_ahmed | 0:791a779d6220 | 288 | if (e->buffer == 0) |
shoaib_ahmed | 0:791a779d6220 | 289 | ++e->zc; |
shoaib_ahmed | 0:791a779d6220 | 290 | else if (e->buffer >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 291 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 292 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 293 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 294 | emit_byte(e->buffer, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 295 | } |
shoaib_ahmed | 0:791a779d6220 | 296 | if (e->sc) { |
shoaib_ahmed | 0:791a779d6220 | 297 | if (e->zc) |
shoaib_ahmed | 0:791a779d6220 | 298 | do emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 299 | while (--e->zc); |
shoaib_ahmed | 0:791a779d6220 | 300 | do { |
shoaib_ahmed | 0:791a779d6220 | 301 | emit_byte(0xFF, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 302 | emit_byte(0x00, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 303 | } while (--e->sc); |
shoaib_ahmed | 0:791a779d6220 | 304 | } |
shoaib_ahmed | 0:791a779d6220 | 305 | e->buffer = temp & 0xFF; /* new output byte (can still overflow) */ |
shoaib_ahmed | 0:791a779d6220 | 306 | } |
shoaib_ahmed | 0:791a779d6220 | 307 | e->c &= 0x7FFFFL; |
shoaib_ahmed | 0:791a779d6220 | 308 | e->ct += 8; |
shoaib_ahmed | 0:791a779d6220 | 309 | } |
shoaib_ahmed | 0:791a779d6220 | 310 | } while (e->a < 0x8000L); |
shoaib_ahmed | 0:791a779d6220 | 311 | } |
shoaib_ahmed | 0:791a779d6220 | 312 | |
shoaib_ahmed | 0:791a779d6220 | 313 | |
shoaib_ahmed | 0:791a779d6220 | 314 | /* |
shoaib_ahmed | 0:791a779d6220 | 315 | * Emit a restart marker & resynchronize predictions. |
shoaib_ahmed | 0:791a779d6220 | 316 | */ |
shoaib_ahmed | 0:791a779d6220 | 317 | |
shoaib_ahmed | 0:791a779d6220 | 318 | LOCAL(void) |
shoaib_ahmed | 0:791a779d6220 | 319 | emit_restart (j_compress_ptr cinfo, int restart_num) |
shoaib_ahmed | 0:791a779d6220 | 320 | { |
shoaib_ahmed | 0:791a779d6220 | 321 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 322 | int ci; |
shoaib_ahmed | 0:791a779d6220 | 323 | jpeg_component_info * compptr; |
shoaib_ahmed | 0:791a779d6220 | 324 | |
shoaib_ahmed | 0:791a779d6220 | 325 | finish_pass(cinfo); |
shoaib_ahmed | 0:791a779d6220 | 326 | |
shoaib_ahmed | 0:791a779d6220 | 327 | emit_byte(0xFF, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 328 | emit_byte(JPEG_RST0 + restart_num, cinfo); |
shoaib_ahmed | 0:791a779d6220 | 329 | |
shoaib_ahmed | 0:791a779d6220 | 330 | /* Re-initialize statistics areas */ |
shoaib_ahmed | 0:791a779d6220 | 331 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
shoaib_ahmed | 0:791a779d6220 | 332 | compptr = cinfo->cur_comp_info[ci]; |
shoaib_ahmed | 0:791a779d6220 | 333 | /* DC needs no table for refinement scan */ |
shoaib_ahmed | 0:791a779d6220 | 334 | if (cinfo->Ss == 0 && cinfo->Ah == 0) { |
shoaib_ahmed | 0:791a779d6220 | 335 | MEMZERO(entropy->dc_stats[compptr->dc_tbl_no], DC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 336 | /* Reset DC predictions to 0 */ |
shoaib_ahmed | 0:791a779d6220 | 337 | entropy->last_dc_val[ci] = 0; |
shoaib_ahmed | 0:791a779d6220 | 338 | entropy->dc_context[ci] = 0; |
shoaib_ahmed | 0:791a779d6220 | 339 | } |
shoaib_ahmed | 0:791a779d6220 | 340 | /* AC needs no table when not present */ |
shoaib_ahmed | 0:791a779d6220 | 341 | if (cinfo->Se) { |
shoaib_ahmed | 0:791a779d6220 | 342 | MEMZERO(entropy->ac_stats[compptr->ac_tbl_no], AC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 343 | } |
shoaib_ahmed | 0:791a779d6220 | 344 | } |
shoaib_ahmed | 0:791a779d6220 | 345 | |
shoaib_ahmed | 0:791a779d6220 | 346 | /* Reset arithmetic encoding variables */ |
shoaib_ahmed | 0:791a779d6220 | 347 | entropy->c = 0; |
shoaib_ahmed | 0:791a779d6220 | 348 | entropy->a = 0x10000L; |
shoaib_ahmed | 0:791a779d6220 | 349 | entropy->sc = 0; |
shoaib_ahmed | 0:791a779d6220 | 350 | entropy->zc = 0; |
shoaib_ahmed | 0:791a779d6220 | 351 | entropy->ct = 11; |
shoaib_ahmed | 0:791a779d6220 | 352 | entropy->buffer = -1; /* empty */ |
shoaib_ahmed | 0:791a779d6220 | 353 | } |
shoaib_ahmed | 0:791a779d6220 | 354 | |
shoaib_ahmed | 0:791a779d6220 | 355 | |
shoaib_ahmed | 0:791a779d6220 | 356 | /* |
shoaib_ahmed | 0:791a779d6220 | 357 | * MCU encoding for DC initial scan (either spectral selection, |
shoaib_ahmed | 0:791a779d6220 | 358 | * or first pass of successive approximation). |
shoaib_ahmed | 0:791a779d6220 | 359 | */ |
shoaib_ahmed | 0:791a779d6220 | 360 | |
shoaib_ahmed | 0:791a779d6220 | 361 | METHODDEF(boolean) |
shoaib_ahmed | 0:791a779d6220 | 362 | encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
shoaib_ahmed | 0:791a779d6220 | 363 | { |
shoaib_ahmed | 0:791a779d6220 | 364 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 365 | unsigned char *st; |
shoaib_ahmed | 0:791a779d6220 | 366 | int blkn, ci, tbl; |
shoaib_ahmed | 0:791a779d6220 | 367 | int v, v2, m; |
shoaib_ahmed | 0:791a779d6220 | 368 | ISHIFT_TEMPS |
shoaib_ahmed | 0:791a779d6220 | 369 | |
shoaib_ahmed | 0:791a779d6220 | 370 | /* Emit restart marker if needed */ |
shoaib_ahmed | 0:791a779d6220 | 371 | if (cinfo->restart_interval) { |
shoaib_ahmed | 0:791a779d6220 | 372 | if (entropy->restarts_to_go == 0) { |
shoaib_ahmed | 0:791a779d6220 | 373 | emit_restart(cinfo, entropy->next_restart_num); |
shoaib_ahmed | 0:791a779d6220 | 374 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 375 | entropy->next_restart_num++; |
shoaib_ahmed | 0:791a779d6220 | 376 | entropy->next_restart_num &= 7; |
shoaib_ahmed | 0:791a779d6220 | 377 | } |
shoaib_ahmed | 0:791a779d6220 | 378 | entropy->restarts_to_go--; |
shoaib_ahmed | 0:791a779d6220 | 379 | } |
shoaib_ahmed | 0:791a779d6220 | 380 | |
shoaib_ahmed | 0:791a779d6220 | 381 | /* Encode the MCU data blocks */ |
shoaib_ahmed | 0:791a779d6220 | 382 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
shoaib_ahmed | 0:791a779d6220 | 383 | ci = cinfo->MCU_membership[blkn]; |
shoaib_ahmed | 0:791a779d6220 | 384 | tbl = cinfo->cur_comp_info[ci]->dc_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 385 | |
shoaib_ahmed | 0:791a779d6220 | 386 | /* Compute the DC value after the required point transform by Al. |
shoaib_ahmed | 0:791a779d6220 | 387 | * This is simply an arithmetic right shift. |
shoaib_ahmed | 0:791a779d6220 | 388 | */ |
shoaib_ahmed | 0:791a779d6220 | 389 | m = IRIGHT_SHIFT((int) (MCU_data[blkn][0][0]), cinfo->Al); |
shoaib_ahmed | 0:791a779d6220 | 390 | |
shoaib_ahmed | 0:791a779d6220 | 391 | /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 392 | |
shoaib_ahmed | 0:791a779d6220 | 393 | /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ |
shoaib_ahmed | 0:791a779d6220 | 394 | st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; |
shoaib_ahmed | 0:791a779d6220 | 395 | |
shoaib_ahmed | 0:791a779d6220 | 396 | /* Figure F.4: Encode_DC_DIFF */ |
shoaib_ahmed | 0:791a779d6220 | 397 | if ((v = m - entropy->last_dc_val[ci]) == 0) { |
shoaib_ahmed | 0:791a779d6220 | 398 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 399 | entropy->dc_context[ci] = 0; /* zero diff category */ |
shoaib_ahmed | 0:791a779d6220 | 400 | } else { |
shoaib_ahmed | 0:791a779d6220 | 401 | entropy->last_dc_val[ci] = m; |
shoaib_ahmed | 0:791a779d6220 | 402 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 403 | /* Figure F.6: Encoding nonzero value v */ |
shoaib_ahmed | 0:791a779d6220 | 404 | /* Figure F.7: Encoding the sign of v */ |
shoaib_ahmed | 0:791a779d6220 | 405 | if (v > 0) { |
shoaib_ahmed | 0:791a779d6220 | 406 | arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ |
shoaib_ahmed | 0:791a779d6220 | 407 | st += 2; /* Table F.4: SP = S0 + 2 */ |
shoaib_ahmed | 0:791a779d6220 | 408 | entropy->dc_context[ci] = 4; /* small positive diff category */ |
shoaib_ahmed | 0:791a779d6220 | 409 | } else { |
shoaib_ahmed | 0:791a779d6220 | 410 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 411 | arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ |
shoaib_ahmed | 0:791a779d6220 | 412 | st += 3; /* Table F.4: SN = S0 + 3 */ |
shoaib_ahmed | 0:791a779d6220 | 413 | entropy->dc_context[ci] = 8; /* small negative diff category */ |
shoaib_ahmed | 0:791a779d6220 | 414 | } |
shoaib_ahmed | 0:791a779d6220 | 415 | /* Figure F.8: Encoding the magnitude category of v */ |
shoaib_ahmed | 0:791a779d6220 | 416 | m = 0; |
shoaib_ahmed | 0:791a779d6220 | 417 | if (v -= 1) { |
shoaib_ahmed | 0:791a779d6220 | 418 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 419 | m = 1; |
shoaib_ahmed | 0:791a779d6220 | 420 | v2 = v; |
shoaib_ahmed | 0:791a779d6220 | 421 | st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ |
shoaib_ahmed | 0:791a779d6220 | 422 | while (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 423 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 424 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 425 | st += 1; |
shoaib_ahmed | 0:791a779d6220 | 426 | } |
shoaib_ahmed | 0:791a779d6220 | 427 | } |
shoaib_ahmed | 0:791a779d6220 | 428 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 429 | /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ |
shoaib_ahmed | 0:791a779d6220 | 430 | if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) |
shoaib_ahmed | 0:791a779d6220 | 431 | entropy->dc_context[ci] = 0; /* zero diff category */ |
shoaib_ahmed | 0:791a779d6220 | 432 | else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) |
shoaib_ahmed | 0:791a779d6220 | 433 | entropy->dc_context[ci] += 8; /* large diff category */ |
shoaib_ahmed | 0:791a779d6220 | 434 | /* Figure F.9: Encoding the magnitude bit pattern of v */ |
shoaib_ahmed | 0:791a779d6220 | 435 | st += 14; |
shoaib_ahmed | 0:791a779d6220 | 436 | while (m >>= 1) |
shoaib_ahmed | 0:791a779d6220 | 437 | arith_encode(cinfo, st, (m & v) ? 1 : 0); |
shoaib_ahmed | 0:791a779d6220 | 438 | } |
shoaib_ahmed | 0:791a779d6220 | 439 | } |
shoaib_ahmed | 0:791a779d6220 | 440 | |
shoaib_ahmed | 0:791a779d6220 | 441 | return TRUE; |
shoaib_ahmed | 0:791a779d6220 | 442 | } |
shoaib_ahmed | 0:791a779d6220 | 443 | |
shoaib_ahmed | 0:791a779d6220 | 444 | |
shoaib_ahmed | 0:791a779d6220 | 445 | /* |
shoaib_ahmed | 0:791a779d6220 | 446 | * MCU encoding for AC initial scan (either spectral selection, |
shoaib_ahmed | 0:791a779d6220 | 447 | * or first pass of successive approximation). |
shoaib_ahmed | 0:791a779d6220 | 448 | */ |
shoaib_ahmed | 0:791a779d6220 | 449 | |
shoaib_ahmed | 0:791a779d6220 | 450 | METHODDEF(boolean) |
shoaib_ahmed | 0:791a779d6220 | 451 | encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
shoaib_ahmed | 0:791a779d6220 | 452 | { |
shoaib_ahmed | 0:791a779d6220 | 453 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 454 | const int * natural_order; |
shoaib_ahmed | 0:791a779d6220 | 455 | JBLOCKROW block; |
shoaib_ahmed | 0:791a779d6220 | 456 | unsigned char *st; |
shoaib_ahmed | 0:791a779d6220 | 457 | int tbl, k, ke; |
shoaib_ahmed | 0:791a779d6220 | 458 | int v, v2, m; |
shoaib_ahmed | 0:791a779d6220 | 459 | |
shoaib_ahmed | 0:791a779d6220 | 460 | /* Emit restart marker if needed */ |
shoaib_ahmed | 0:791a779d6220 | 461 | if (cinfo->restart_interval) { |
shoaib_ahmed | 0:791a779d6220 | 462 | if (entropy->restarts_to_go == 0) { |
shoaib_ahmed | 0:791a779d6220 | 463 | emit_restart(cinfo, entropy->next_restart_num); |
shoaib_ahmed | 0:791a779d6220 | 464 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 465 | entropy->next_restart_num++; |
shoaib_ahmed | 0:791a779d6220 | 466 | entropy->next_restart_num &= 7; |
shoaib_ahmed | 0:791a779d6220 | 467 | } |
shoaib_ahmed | 0:791a779d6220 | 468 | entropy->restarts_to_go--; |
shoaib_ahmed | 0:791a779d6220 | 469 | } |
shoaib_ahmed | 0:791a779d6220 | 470 | |
shoaib_ahmed | 0:791a779d6220 | 471 | natural_order = cinfo->natural_order; |
shoaib_ahmed | 0:791a779d6220 | 472 | |
shoaib_ahmed | 0:791a779d6220 | 473 | /* Encode the MCU data block */ |
shoaib_ahmed | 0:791a779d6220 | 474 | block = MCU_data[0]; |
shoaib_ahmed | 0:791a779d6220 | 475 | tbl = cinfo->cur_comp_info[0]->ac_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 476 | |
shoaib_ahmed | 0:791a779d6220 | 477 | /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 478 | |
shoaib_ahmed | 0:791a779d6220 | 479 | /* Establish EOB (end-of-block) index */ |
shoaib_ahmed | 0:791a779d6220 | 480 | ke = cinfo->Se; |
shoaib_ahmed | 0:791a779d6220 | 481 | do { |
shoaib_ahmed | 0:791a779d6220 | 482 | /* We must apply the point transform by Al. For AC coefficients this |
shoaib_ahmed | 0:791a779d6220 | 483 | * is an integer division with rounding towards 0. To do this portably |
shoaib_ahmed | 0:791a779d6220 | 484 | * in C, we shift after obtaining the absolute value. |
shoaib_ahmed | 0:791a779d6220 | 485 | */ |
shoaib_ahmed | 0:791a779d6220 | 486 | if ((v = (*block)[natural_order[ke]]) >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 487 | if (v >>= cinfo->Al) break; |
shoaib_ahmed | 0:791a779d6220 | 488 | } else { |
shoaib_ahmed | 0:791a779d6220 | 489 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 490 | if (v >>= cinfo->Al) break; |
shoaib_ahmed | 0:791a779d6220 | 491 | } |
shoaib_ahmed | 0:791a779d6220 | 492 | } while (--ke); |
shoaib_ahmed | 0:791a779d6220 | 493 | |
shoaib_ahmed | 0:791a779d6220 | 494 | /* Figure F.5: Encode_AC_Coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 495 | for (k = cinfo->Ss - 1; k < ke;) { |
shoaib_ahmed | 0:791a779d6220 | 496 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 497 | arith_encode(cinfo, st, 0); /* EOB decision */ |
shoaib_ahmed | 0:791a779d6220 | 498 | for (;;) { |
shoaib_ahmed | 0:791a779d6220 | 499 | if ((v = (*block)[natural_order[++k]]) >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 500 | if (v >>= cinfo->Al) { |
shoaib_ahmed | 0:791a779d6220 | 501 | arith_encode(cinfo, st + 1, 1); |
shoaib_ahmed | 0:791a779d6220 | 502 | arith_encode(cinfo, entropy->fixed_bin, 0); |
shoaib_ahmed | 0:791a779d6220 | 503 | break; |
shoaib_ahmed | 0:791a779d6220 | 504 | } |
shoaib_ahmed | 0:791a779d6220 | 505 | } else { |
shoaib_ahmed | 0:791a779d6220 | 506 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 507 | if (v >>= cinfo->Al) { |
shoaib_ahmed | 0:791a779d6220 | 508 | arith_encode(cinfo, st + 1, 1); |
shoaib_ahmed | 0:791a779d6220 | 509 | arith_encode(cinfo, entropy->fixed_bin, 1); |
shoaib_ahmed | 0:791a779d6220 | 510 | break; |
shoaib_ahmed | 0:791a779d6220 | 511 | } |
shoaib_ahmed | 0:791a779d6220 | 512 | } |
shoaib_ahmed | 0:791a779d6220 | 513 | arith_encode(cinfo, st + 1, 0); |
shoaib_ahmed | 0:791a779d6220 | 514 | st += 3; |
shoaib_ahmed | 0:791a779d6220 | 515 | } |
shoaib_ahmed | 0:791a779d6220 | 516 | st += 2; |
shoaib_ahmed | 0:791a779d6220 | 517 | /* Figure F.8: Encoding the magnitude category of v */ |
shoaib_ahmed | 0:791a779d6220 | 518 | m = 0; |
shoaib_ahmed | 0:791a779d6220 | 519 | if (v -= 1) { |
shoaib_ahmed | 0:791a779d6220 | 520 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 521 | m = 1; |
shoaib_ahmed | 0:791a779d6220 | 522 | v2 = v; |
shoaib_ahmed | 0:791a779d6220 | 523 | if (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 524 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 525 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 526 | st = entropy->ac_stats[tbl] + |
shoaib_ahmed | 0:791a779d6220 | 527 | (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); |
shoaib_ahmed | 0:791a779d6220 | 528 | while (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 529 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 530 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 531 | st += 1; |
shoaib_ahmed | 0:791a779d6220 | 532 | } |
shoaib_ahmed | 0:791a779d6220 | 533 | } |
shoaib_ahmed | 0:791a779d6220 | 534 | } |
shoaib_ahmed | 0:791a779d6220 | 535 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 536 | /* Figure F.9: Encoding the magnitude bit pattern of v */ |
shoaib_ahmed | 0:791a779d6220 | 537 | st += 14; |
shoaib_ahmed | 0:791a779d6220 | 538 | while (m >>= 1) |
shoaib_ahmed | 0:791a779d6220 | 539 | arith_encode(cinfo, st, (m & v) ? 1 : 0); |
shoaib_ahmed | 0:791a779d6220 | 540 | } |
shoaib_ahmed | 0:791a779d6220 | 541 | /* Encode EOB decision only if k < cinfo->Se */ |
shoaib_ahmed | 0:791a779d6220 | 542 | if (k < cinfo->Se) { |
shoaib_ahmed | 0:791a779d6220 | 543 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 544 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 545 | } |
shoaib_ahmed | 0:791a779d6220 | 546 | |
shoaib_ahmed | 0:791a779d6220 | 547 | return TRUE; |
shoaib_ahmed | 0:791a779d6220 | 548 | } |
shoaib_ahmed | 0:791a779d6220 | 549 | |
shoaib_ahmed | 0:791a779d6220 | 550 | |
shoaib_ahmed | 0:791a779d6220 | 551 | /* |
shoaib_ahmed | 0:791a779d6220 | 552 | * MCU encoding for DC successive approximation refinement scan. |
shoaib_ahmed | 0:791a779d6220 | 553 | * Note: we assume such scans can be multi-component, |
shoaib_ahmed | 0:791a779d6220 | 554 | * although the spec is not very clear on the point. |
shoaib_ahmed | 0:791a779d6220 | 555 | */ |
shoaib_ahmed | 0:791a779d6220 | 556 | |
shoaib_ahmed | 0:791a779d6220 | 557 | METHODDEF(boolean) |
shoaib_ahmed | 0:791a779d6220 | 558 | encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
shoaib_ahmed | 0:791a779d6220 | 559 | { |
shoaib_ahmed | 0:791a779d6220 | 560 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 561 | unsigned char *st; |
shoaib_ahmed | 0:791a779d6220 | 562 | int Al, blkn; |
shoaib_ahmed | 0:791a779d6220 | 563 | |
shoaib_ahmed | 0:791a779d6220 | 564 | /* Emit restart marker if needed */ |
shoaib_ahmed | 0:791a779d6220 | 565 | if (cinfo->restart_interval) { |
shoaib_ahmed | 0:791a779d6220 | 566 | if (entropy->restarts_to_go == 0) { |
shoaib_ahmed | 0:791a779d6220 | 567 | emit_restart(cinfo, entropy->next_restart_num); |
shoaib_ahmed | 0:791a779d6220 | 568 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 569 | entropy->next_restart_num++; |
shoaib_ahmed | 0:791a779d6220 | 570 | entropy->next_restart_num &= 7; |
shoaib_ahmed | 0:791a779d6220 | 571 | } |
shoaib_ahmed | 0:791a779d6220 | 572 | entropy->restarts_to_go--; |
shoaib_ahmed | 0:791a779d6220 | 573 | } |
shoaib_ahmed | 0:791a779d6220 | 574 | |
shoaib_ahmed | 0:791a779d6220 | 575 | st = entropy->fixed_bin; /* use fixed probability estimation */ |
shoaib_ahmed | 0:791a779d6220 | 576 | Al = cinfo->Al; |
shoaib_ahmed | 0:791a779d6220 | 577 | |
shoaib_ahmed | 0:791a779d6220 | 578 | /* Encode the MCU data blocks */ |
shoaib_ahmed | 0:791a779d6220 | 579 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
shoaib_ahmed | 0:791a779d6220 | 580 | /* We simply emit the Al'th bit of the DC coefficient value. */ |
shoaib_ahmed | 0:791a779d6220 | 581 | arith_encode(cinfo, st, (MCU_data[blkn][0][0] >> Al) & 1); |
shoaib_ahmed | 0:791a779d6220 | 582 | } |
shoaib_ahmed | 0:791a779d6220 | 583 | |
shoaib_ahmed | 0:791a779d6220 | 584 | return TRUE; |
shoaib_ahmed | 0:791a779d6220 | 585 | } |
shoaib_ahmed | 0:791a779d6220 | 586 | |
shoaib_ahmed | 0:791a779d6220 | 587 | |
shoaib_ahmed | 0:791a779d6220 | 588 | /* |
shoaib_ahmed | 0:791a779d6220 | 589 | * MCU encoding for AC successive approximation refinement scan. |
shoaib_ahmed | 0:791a779d6220 | 590 | */ |
shoaib_ahmed | 0:791a779d6220 | 591 | |
shoaib_ahmed | 0:791a779d6220 | 592 | METHODDEF(boolean) |
shoaib_ahmed | 0:791a779d6220 | 593 | encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
shoaib_ahmed | 0:791a779d6220 | 594 | { |
shoaib_ahmed | 0:791a779d6220 | 595 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 596 | const int * natural_order; |
shoaib_ahmed | 0:791a779d6220 | 597 | JBLOCKROW block; |
shoaib_ahmed | 0:791a779d6220 | 598 | unsigned char *st; |
shoaib_ahmed | 0:791a779d6220 | 599 | int tbl, k, ke, kex; |
shoaib_ahmed | 0:791a779d6220 | 600 | int v; |
shoaib_ahmed | 0:791a779d6220 | 601 | |
shoaib_ahmed | 0:791a779d6220 | 602 | /* Emit restart marker if needed */ |
shoaib_ahmed | 0:791a779d6220 | 603 | if (cinfo->restart_interval) { |
shoaib_ahmed | 0:791a779d6220 | 604 | if (entropy->restarts_to_go == 0) { |
shoaib_ahmed | 0:791a779d6220 | 605 | emit_restart(cinfo, entropy->next_restart_num); |
shoaib_ahmed | 0:791a779d6220 | 606 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 607 | entropy->next_restart_num++; |
shoaib_ahmed | 0:791a779d6220 | 608 | entropy->next_restart_num &= 7; |
shoaib_ahmed | 0:791a779d6220 | 609 | } |
shoaib_ahmed | 0:791a779d6220 | 610 | entropy->restarts_to_go--; |
shoaib_ahmed | 0:791a779d6220 | 611 | } |
shoaib_ahmed | 0:791a779d6220 | 612 | |
shoaib_ahmed | 0:791a779d6220 | 613 | natural_order = cinfo->natural_order; |
shoaib_ahmed | 0:791a779d6220 | 614 | |
shoaib_ahmed | 0:791a779d6220 | 615 | /* Encode the MCU data block */ |
shoaib_ahmed | 0:791a779d6220 | 616 | block = MCU_data[0]; |
shoaib_ahmed | 0:791a779d6220 | 617 | tbl = cinfo->cur_comp_info[0]->ac_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 618 | |
shoaib_ahmed | 0:791a779d6220 | 619 | /* Section G.1.3.3: Encoding of AC coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 620 | |
shoaib_ahmed | 0:791a779d6220 | 621 | /* Establish EOB (end-of-block) index */ |
shoaib_ahmed | 0:791a779d6220 | 622 | ke = cinfo->Se; |
shoaib_ahmed | 0:791a779d6220 | 623 | do { |
shoaib_ahmed | 0:791a779d6220 | 624 | /* We must apply the point transform by Al. For AC coefficients this |
shoaib_ahmed | 0:791a779d6220 | 625 | * is an integer division with rounding towards 0. To do this portably |
shoaib_ahmed | 0:791a779d6220 | 626 | * in C, we shift after obtaining the absolute value. |
shoaib_ahmed | 0:791a779d6220 | 627 | */ |
shoaib_ahmed | 0:791a779d6220 | 628 | if ((v = (*block)[natural_order[ke]]) >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 629 | if (v >>= cinfo->Al) break; |
shoaib_ahmed | 0:791a779d6220 | 630 | } else { |
shoaib_ahmed | 0:791a779d6220 | 631 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 632 | if (v >>= cinfo->Al) break; |
shoaib_ahmed | 0:791a779d6220 | 633 | } |
shoaib_ahmed | 0:791a779d6220 | 634 | } while (--ke); |
shoaib_ahmed | 0:791a779d6220 | 635 | |
shoaib_ahmed | 0:791a779d6220 | 636 | /* Establish EOBx (previous stage end-of-block) index */ |
shoaib_ahmed | 0:791a779d6220 | 637 | for (kex = ke; kex > 0; kex--) |
shoaib_ahmed | 0:791a779d6220 | 638 | if ((v = (*block)[natural_order[kex]]) >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 639 | if (v >>= cinfo->Ah) break; |
shoaib_ahmed | 0:791a779d6220 | 640 | } else { |
shoaib_ahmed | 0:791a779d6220 | 641 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 642 | if (v >>= cinfo->Ah) break; |
shoaib_ahmed | 0:791a779d6220 | 643 | } |
shoaib_ahmed | 0:791a779d6220 | 644 | |
shoaib_ahmed | 0:791a779d6220 | 645 | /* Figure G.10: Encode_AC_Coefficients_SA */ |
shoaib_ahmed | 0:791a779d6220 | 646 | for (k = cinfo->Ss - 1; k < ke;) { |
shoaib_ahmed | 0:791a779d6220 | 647 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 648 | if (k >= kex) |
shoaib_ahmed | 0:791a779d6220 | 649 | arith_encode(cinfo, st, 0); /* EOB decision */ |
shoaib_ahmed | 0:791a779d6220 | 650 | for (;;) { |
shoaib_ahmed | 0:791a779d6220 | 651 | if ((v = (*block)[natural_order[++k]]) >= 0) { |
shoaib_ahmed | 0:791a779d6220 | 652 | if (v >>= cinfo->Al) { |
shoaib_ahmed | 0:791a779d6220 | 653 | if (v >> 1) /* previously nonzero coef */ |
shoaib_ahmed | 0:791a779d6220 | 654 | arith_encode(cinfo, st + 2, (v & 1)); |
shoaib_ahmed | 0:791a779d6220 | 655 | else { /* newly nonzero coef */ |
shoaib_ahmed | 0:791a779d6220 | 656 | arith_encode(cinfo, st + 1, 1); |
shoaib_ahmed | 0:791a779d6220 | 657 | arith_encode(cinfo, entropy->fixed_bin, 0); |
shoaib_ahmed | 0:791a779d6220 | 658 | } |
shoaib_ahmed | 0:791a779d6220 | 659 | break; |
shoaib_ahmed | 0:791a779d6220 | 660 | } |
shoaib_ahmed | 0:791a779d6220 | 661 | } else { |
shoaib_ahmed | 0:791a779d6220 | 662 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 663 | if (v >>= cinfo->Al) { |
shoaib_ahmed | 0:791a779d6220 | 664 | if (v >> 1) /* previously nonzero coef */ |
shoaib_ahmed | 0:791a779d6220 | 665 | arith_encode(cinfo, st + 2, (v & 1)); |
shoaib_ahmed | 0:791a779d6220 | 666 | else { /* newly nonzero coef */ |
shoaib_ahmed | 0:791a779d6220 | 667 | arith_encode(cinfo, st + 1, 1); |
shoaib_ahmed | 0:791a779d6220 | 668 | arith_encode(cinfo, entropy->fixed_bin, 1); |
shoaib_ahmed | 0:791a779d6220 | 669 | } |
shoaib_ahmed | 0:791a779d6220 | 670 | break; |
shoaib_ahmed | 0:791a779d6220 | 671 | } |
shoaib_ahmed | 0:791a779d6220 | 672 | } |
shoaib_ahmed | 0:791a779d6220 | 673 | arith_encode(cinfo, st + 1, 0); |
shoaib_ahmed | 0:791a779d6220 | 674 | st += 3; |
shoaib_ahmed | 0:791a779d6220 | 675 | } |
shoaib_ahmed | 0:791a779d6220 | 676 | } |
shoaib_ahmed | 0:791a779d6220 | 677 | /* Encode EOB decision only if k < cinfo->Se */ |
shoaib_ahmed | 0:791a779d6220 | 678 | if (k < cinfo->Se) { |
shoaib_ahmed | 0:791a779d6220 | 679 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 680 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 681 | } |
shoaib_ahmed | 0:791a779d6220 | 682 | |
shoaib_ahmed | 0:791a779d6220 | 683 | return TRUE; |
shoaib_ahmed | 0:791a779d6220 | 684 | } |
shoaib_ahmed | 0:791a779d6220 | 685 | |
shoaib_ahmed | 0:791a779d6220 | 686 | |
shoaib_ahmed | 0:791a779d6220 | 687 | /* |
shoaib_ahmed | 0:791a779d6220 | 688 | * Encode and output one MCU's worth of arithmetic-compressed coefficients. |
shoaib_ahmed | 0:791a779d6220 | 689 | */ |
shoaib_ahmed | 0:791a779d6220 | 690 | |
shoaib_ahmed | 0:791a779d6220 | 691 | METHODDEF(boolean) |
shoaib_ahmed | 0:791a779d6220 | 692 | encode_mcu (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
shoaib_ahmed | 0:791a779d6220 | 693 | { |
shoaib_ahmed | 0:791a779d6220 | 694 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 695 | const int * natural_order; |
shoaib_ahmed | 0:791a779d6220 | 696 | JBLOCKROW block; |
shoaib_ahmed | 0:791a779d6220 | 697 | unsigned char *st; |
shoaib_ahmed | 0:791a779d6220 | 698 | int tbl, k, ke; |
shoaib_ahmed | 0:791a779d6220 | 699 | int v, v2, m; |
shoaib_ahmed | 0:791a779d6220 | 700 | int blkn, ci; |
shoaib_ahmed | 0:791a779d6220 | 701 | jpeg_component_info * compptr; |
shoaib_ahmed | 0:791a779d6220 | 702 | |
shoaib_ahmed | 0:791a779d6220 | 703 | /* Emit restart marker if needed */ |
shoaib_ahmed | 0:791a779d6220 | 704 | if (cinfo->restart_interval) { |
shoaib_ahmed | 0:791a779d6220 | 705 | if (entropy->restarts_to_go == 0) { |
shoaib_ahmed | 0:791a779d6220 | 706 | emit_restart(cinfo, entropy->next_restart_num); |
shoaib_ahmed | 0:791a779d6220 | 707 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 708 | entropy->next_restart_num++; |
shoaib_ahmed | 0:791a779d6220 | 709 | entropy->next_restart_num &= 7; |
shoaib_ahmed | 0:791a779d6220 | 710 | } |
shoaib_ahmed | 0:791a779d6220 | 711 | entropy->restarts_to_go--; |
shoaib_ahmed | 0:791a779d6220 | 712 | } |
shoaib_ahmed | 0:791a779d6220 | 713 | |
shoaib_ahmed | 0:791a779d6220 | 714 | natural_order = cinfo->natural_order; |
shoaib_ahmed | 0:791a779d6220 | 715 | |
shoaib_ahmed | 0:791a779d6220 | 716 | /* Encode the MCU data blocks */ |
shoaib_ahmed | 0:791a779d6220 | 717 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
shoaib_ahmed | 0:791a779d6220 | 718 | block = MCU_data[blkn]; |
shoaib_ahmed | 0:791a779d6220 | 719 | ci = cinfo->MCU_membership[blkn]; |
shoaib_ahmed | 0:791a779d6220 | 720 | compptr = cinfo->cur_comp_info[ci]; |
shoaib_ahmed | 0:791a779d6220 | 721 | |
shoaib_ahmed | 0:791a779d6220 | 722 | /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 723 | |
shoaib_ahmed | 0:791a779d6220 | 724 | tbl = compptr->dc_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 725 | |
shoaib_ahmed | 0:791a779d6220 | 726 | /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ |
shoaib_ahmed | 0:791a779d6220 | 727 | st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; |
shoaib_ahmed | 0:791a779d6220 | 728 | |
shoaib_ahmed | 0:791a779d6220 | 729 | /* Figure F.4: Encode_DC_DIFF */ |
shoaib_ahmed | 0:791a779d6220 | 730 | if ((v = (*block)[0] - entropy->last_dc_val[ci]) == 0) { |
shoaib_ahmed | 0:791a779d6220 | 731 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 732 | entropy->dc_context[ci] = 0; /* zero diff category */ |
shoaib_ahmed | 0:791a779d6220 | 733 | } else { |
shoaib_ahmed | 0:791a779d6220 | 734 | entropy->last_dc_val[ci] = (*block)[0]; |
shoaib_ahmed | 0:791a779d6220 | 735 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 736 | /* Figure F.6: Encoding nonzero value v */ |
shoaib_ahmed | 0:791a779d6220 | 737 | /* Figure F.7: Encoding the sign of v */ |
shoaib_ahmed | 0:791a779d6220 | 738 | if (v > 0) { |
shoaib_ahmed | 0:791a779d6220 | 739 | arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ |
shoaib_ahmed | 0:791a779d6220 | 740 | st += 2; /* Table F.4: SP = S0 + 2 */ |
shoaib_ahmed | 0:791a779d6220 | 741 | entropy->dc_context[ci] = 4; /* small positive diff category */ |
shoaib_ahmed | 0:791a779d6220 | 742 | } else { |
shoaib_ahmed | 0:791a779d6220 | 743 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 744 | arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ |
shoaib_ahmed | 0:791a779d6220 | 745 | st += 3; /* Table F.4: SN = S0 + 3 */ |
shoaib_ahmed | 0:791a779d6220 | 746 | entropy->dc_context[ci] = 8; /* small negative diff category */ |
shoaib_ahmed | 0:791a779d6220 | 747 | } |
shoaib_ahmed | 0:791a779d6220 | 748 | /* Figure F.8: Encoding the magnitude category of v */ |
shoaib_ahmed | 0:791a779d6220 | 749 | m = 0; |
shoaib_ahmed | 0:791a779d6220 | 750 | if (v -= 1) { |
shoaib_ahmed | 0:791a779d6220 | 751 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 752 | m = 1; |
shoaib_ahmed | 0:791a779d6220 | 753 | v2 = v; |
shoaib_ahmed | 0:791a779d6220 | 754 | st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ |
shoaib_ahmed | 0:791a779d6220 | 755 | while (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 756 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 757 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 758 | st += 1; |
shoaib_ahmed | 0:791a779d6220 | 759 | } |
shoaib_ahmed | 0:791a779d6220 | 760 | } |
shoaib_ahmed | 0:791a779d6220 | 761 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 762 | /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ |
shoaib_ahmed | 0:791a779d6220 | 763 | if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) |
shoaib_ahmed | 0:791a779d6220 | 764 | entropy->dc_context[ci] = 0; /* zero diff category */ |
shoaib_ahmed | 0:791a779d6220 | 765 | else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) |
shoaib_ahmed | 0:791a779d6220 | 766 | entropy->dc_context[ci] += 8; /* large diff category */ |
shoaib_ahmed | 0:791a779d6220 | 767 | /* Figure F.9: Encoding the magnitude bit pattern of v */ |
shoaib_ahmed | 0:791a779d6220 | 768 | st += 14; |
shoaib_ahmed | 0:791a779d6220 | 769 | while (m >>= 1) |
shoaib_ahmed | 0:791a779d6220 | 770 | arith_encode(cinfo, st, (m & v) ? 1 : 0); |
shoaib_ahmed | 0:791a779d6220 | 771 | } |
shoaib_ahmed | 0:791a779d6220 | 772 | |
shoaib_ahmed | 0:791a779d6220 | 773 | /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 774 | |
shoaib_ahmed | 0:791a779d6220 | 775 | if ((ke = cinfo->lim_Se) == 0) continue; |
shoaib_ahmed | 0:791a779d6220 | 776 | tbl = compptr->ac_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 777 | |
shoaib_ahmed | 0:791a779d6220 | 778 | /* Establish EOB (end-of-block) index */ |
shoaib_ahmed | 0:791a779d6220 | 779 | do { |
shoaib_ahmed | 0:791a779d6220 | 780 | if ((*block)[natural_order[ke]]) break; |
shoaib_ahmed | 0:791a779d6220 | 781 | } while (--ke); |
shoaib_ahmed | 0:791a779d6220 | 782 | |
shoaib_ahmed | 0:791a779d6220 | 783 | /* Figure F.5: Encode_AC_Coefficients */ |
shoaib_ahmed | 0:791a779d6220 | 784 | for (k = 0; k < ke;) { |
shoaib_ahmed | 0:791a779d6220 | 785 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 786 | arith_encode(cinfo, st, 0); /* EOB decision */ |
shoaib_ahmed | 0:791a779d6220 | 787 | while ((v = (*block)[natural_order[++k]]) == 0) { |
shoaib_ahmed | 0:791a779d6220 | 788 | arith_encode(cinfo, st + 1, 0); |
shoaib_ahmed | 0:791a779d6220 | 789 | st += 3; |
shoaib_ahmed | 0:791a779d6220 | 790 | } |
shoaib_ahmed | 0:791a779d6220 | 791 | arith_encode(cinfo, st + 1, 1); |
shoaib_ahmed | 0:791a779d6220 | 792 | /* Figure F.6: Encoding nonzero value v */ |
shoaib_ahmed | 0:791a779d6220 | 793 | /* Figure F.7: Encoding the sign of v */ |
shoaib_ahmed | 0:791a779d6220 | 794 | if (v > 0) { |
shoaib_ahmed | 0:791a779d6220 | 795 | arith_encode(cinfo, entropy->fixed_bin, 0); |
shoaib_ahmed | 0:791a779d6220 | 796 | } else { |
shoaib_ahmed | 0:791a779d6220 | 797 | v = -v; |
shoaib_ahmed | 0:791a779d6220 | 798 | arith_encode(cinfo, entropy->fixed_bin, 1); |
shoaib_ahmed | 0:791a779d6220 | 799 | } |
shoaib_ahmed | 0:791a779d6220 | 800 | st += 2; |
shoaib_ahmed | 0:791a779d6220 | 801 | /* Figure F.8: Encoding the magnitude category of v */ |
shoaib_ahmed | 0:791a779d6220 | 802 | m = 0; |
shoaib_ahmed | 0:791a779d6220 | 803 | if (v -= 1) { |
shoaib_ahmed | 0:791a779d6220 | 804 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 805 | m = 1; |
shoaib_ahmed | 0:791a779d6220 | 806 | v2 = v; |
shoaib_ahmed | 0:791a779d6220 | 807 | if (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 808 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 809 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 810 | st = entropy->ac_stats[tbl] + |
shoaib_ahmed | 0:791a779d6220 | 811 | (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); |
shoaib_ahmed | 0:791a779d6220 | 812 | while (v2 >>= 1) { |
shoaib_ahmed | 0:791a779d6220 | 813 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 814 | m <<= 1; |
shoaib_ahmed | 0:791a779d6220 | 815 | st += 1; |
shoaib_ahmed | 0:791a779d6220 | 816 | } |
shoaib_ahmed | 0:791a779d6220 | 817 | } |
shoaib_ahmed | 0:791a779d6220 | 818 | } |
shoaib_ahmed | 0:791a779d6220 | 819 | arith_encode(cinfo, st, 0); |
shoaib_ahmed | 0:791a779d6220 | 820 | /* Figure F.9: Encoding the magnitude bit pattern of v */ |
shoaib_ahmed | 0:791a779d6220 | 821 | st += 14; |
shoaib_ahmed | 0:791a779d6220 | 822 | while (m >>= 1) |
shoaib_ahmed | 0:791a779d6220 | 823 | arith_encode(cinfo, st, (m & v) ? 1 : 0); |
shoaib_ahmed | 0:791a779d6220 | 824 | } |
shoaib_ahmed | 0:791a779d6220 | 825 | /* Encode EOB decision only if k < cinfo->lim_Se */ |
shoaib_ahmed | 0:791a779d6220 | 826 | if (k < cinfo->lim_Se) { |
shoaib_ahmed | 0:791a779d6220 | 827 | st = entropy->ac_stats[tbl] + 3 * k; |
shoaib_ahmed | 0:791a779d6220 | 828 | arith_encode(cinfo, st, 1); |
shoaib_ahmed | 0:791a779d6220 | 829 | } |
shoaib_ahmed | 0:791a779d6220 | 830 | } |
shoaib_ahmed | 0:791a779d6220 | 831 | |
shoaib_ahmed | 0:791a779d6220 | 832 | return TRUE; |
shoaib_ahmed | 0:791a779d6220 | 833 | } |
shoaib_ahmed | 0:791a779d6220 | 834 | |
shoaib_ahmed | 0:791a779d6220 | 835 | |
shoaib_ahmed | 0:791a779d6220 | 836 | /* |
shoaib_ahmed | 0:791a779d6220 | 837 | * Initialize for an arithmetic-compressed scan. |
shoaib_ahmed | 0:791a779d6220 | 838 | */ |
shoaib_ahmed | 0:791a779d6220 | 839 | |
shoaib_ahmed | 0:791a779d6220 | 840 | METHODDEF(void) |
shoaib_ahmed | 0:791a779d6220 | 841 | start_pass (j_compress_ptr cinfo, boolean gather_statistics) |
shoaib_ahmed | 0:791a779d6220 | 842 | { |
shoaib_ahmed | 0:791a779d6220 | 843 | arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
shoaib_ahmed | 0:791a779d6220 | 844 | int ci, tbl; |
shoaib_ahmed | 0:791a779d6220 | 845 | jpeg_component_info * compptr; |
shoaib_ahmed | 0:791a779d6220 | 846 | |
shoaib_ahmed | 0:791a779d6220 | 847 | if (gather_statistics) |
shoaib_ahmed | 0:791a779d6220 | 848 | /* Make sure to avoid that in the master control logic! |
shoaib_ahmed | 0:791a779d6220 | 849 | * We are fully adaptive here and need no extra |
shoaib_ahmed | 0:791a779d6220 | 850 | * statistics gathering pass! |
shoaib_ahmed | 0:791a779d6220 | 851 | */ |
shoaib_ahmed | 0:791a779d6220 | 852 | ERREXIT(cinfo, JERR_NOT_COMPILED); |
shoaib_ahmed | 0:791a779d6220 | 853 | |
shoaib_ahmed | 0:791a779d6220 | 854 | /* We assume jcmaster.c already validated the progressive scan parameters. */ |
shoaib_ahmed | 0:791a779d6220 | 855 | |
shoaib_ahmed | 0:791a779d6220 | 856 | /* Select execution routines */ |
shoaib_ahmed | 0:791a779d6220 | 857 | if (cinfo->progressive_mode) { |
shoaib_ahmed | 0:791a779d6220 | 858 | if (cinfo->Ah == 0) { |
shoaib_ahmed | 0:791a779d6220 | 859 | if (cinfo->Ss == 0) |
shoaib_ahmed | 0:791a779d6220 | 860 | entropy->pub.encode_mcu = encode_mcu_DC_first; |
shoaib_ahmed | 0:791a779d6220 | 861 | else |
shoaib_ahmed | 0:791a779d6220 | 862 | entropy->pub.encode_mcu = encode_mcu_AC_first; |
shoaib_ahmed | 0:791a779d6220 | 863 | } else { |
shoaib_ahmed | 0:791a779d6220 | 864 | if (cinfo->Ss == 0) |
shoaib_ahmed | 0:791a779d6220 | 865 | entropy->pub.encode_mcu = encode_mcu_DC_refine; |
shoaib_ahmed | 0:791a779d6220 | 866 | else |
shoaib_ahmed | 0:791a779d6220 | 867 | entropy->pub.encode_mcu = encode_mcu_AC_refine; |
shoaib_ahmed | 0:791a779d6220 | 868 | } |
shoaib_ahmed | 0:791a779d6220 | 869 | } else |
shoaib_ahmed | 0:791a779d6220 | 870 | entropy->pub.encode_mcu = encode_mcu; |
shoaib_ahmed | 0:791a779d6220 | 871 | |
shoaib_ahmed | 0:791a779d6220 | 872 | /* Allocate & initialize requested statistics areas */ |
shoaib_ahmed | 0:791a779d6220 | 873 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
shoaib_ahmed | 0:791a779d6220 | 874 | compptr = cinfo->cur_comp_info[ci]; |
shoaib_ahmed | 0:791a779d6220 | 875 | /* DC needs no table for refinement scan */ |
shoaib_ahmed | 0:791a779d6220 | 876 | if (cinfo->Ss == 0 && cinfo->Ah == 0) { |
shoaib_ahmed | 0:791a779d6220 | 877 | tbl = compptr->dc_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 878 | if (tbl < 0 || tbl >= NUM_ARITH_TBLS) |
shoaib_ahmed | 0:791a779d6220 | 879 | ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); |
shoaib_ahmed | 0:791a779d6220 | 880 | if (entropy->dc_stats[tbl] == NULL) |
shoaib_ahmed | 0:791a779d6220 | 881 | entropy->dc_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) |
shoaib_ahmed | 0:791a779d6220 | 882 | ((j_common_ptr) cinfo, JPOOL_IMAGE, DC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 883 | MEMZERO(entropy->dc_stats[tbl], DC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 884 | /* Initialize DC predictions to 0 */ |
shoaib_ahmed | 0:791a779d6220 | 885 | entropy->last_dc_val[ci] = 0; |
shoaib_ahmed | 0:791a779d6220 | 886 | entropy->dc_context[ci] = 0; |
shoaib_ahmed | 0:791a779d6220 | 887 | } |
shoaib_ahmed | 0:791a779d6220 | 888 | /* AC needs no table when not present */ |
shoaib_ahmed | 0:791a779d6220 | 889 | if (cinfo->Se) { |
shoaib_ahmed | 0:791a779d6220 | 890 | tbl = compptr->ac_tbl_no; |
shoaib_ahmed | 0:791a779d6220 | 891 | if (tbl < 0 || tbl >= NUM_ARITH_TBLS) |
shoaib_ahmed | 0:791a779d6220 | 892 | ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); |
shoaib_ahmed | 0:791a779d6220 | 893 | if (entropy->ac_stats[tbl] == NULL) |
shoaib_ahmed | 0:791a779d6220 | 894 | entropy->ac_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) |
shoaib_ahmed | 0:791a779d6220 | 895 | ((j_common_ptr) cinfo, JPOOL_IMAGE, AC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 896 | MEMZERO(entropy->ac_stats[tbl], AC_STAT_BINS); |
shoaib_ahmed | 0:791a779d6220 | 897 | #ifdef CALCULATE_SPECTRAL_CONDITIONING |
shoaib_ahmed | 0:791a779d6220 | 898 | if (cinfo->progressive_mode) |
shoaib_ahmed | 0:791a779d6220 | 899 | /* Section G.1.3.2: Set appropriate arithmetic conditioning value Kx */ |
shoaib_ahmed | 0:791a779d6220 | 900 | cinfo->arith_ac_K[tbl] = cinfo->Ss + ((8 + cinfo->Se - cinfo->Ss) >> 4); |
shoaib_ahmed | 0:791a779d6220 | 901 | #endif |
shoaib_ahmed | 0:791a779d6220 | 902 | } |
shoaib_ahmed | 0:791a779d6220 | 903 | } |
shoaib_ahmed | 0:791a779d6220 | 904 | |
shoaib_ahmed | 0:791a779d6220 | 905 | /* Initialize arithmetic encoding variables */ |
shoaib_ahmed | 0:791a779d6220 | 906 | entropy->c = 0; |
shoaib_ahmed | 0:791a779d6220 | 907 | entropy->a = 0x10000L; |
shoaib_ahmed | 0:791a779d6220 | 908 | entropy->sc = 0; |
shoaib_ahmed | 0:791a779d6220 | 909 | entropy->zc = 0; |
shoaib_ahmed | 0:791a779d6220 | 910 | entropy->ct = 11; |
shoaib_ahmed | 0:791a779d6220 | 911 | entropy->buffer = -1; /* empty */ |
shoaib_ahmed | 0:791a779d6220 | 912 | |
shoaib_ahmed | 0:791a779d6220 | 913 | /* Initialize restart stuff */ |
shoaib_ahmed | 0:791a779d6220 | 914 | entropy->restarts_to_go = cinfo->restart_interval; |
shoaib_ahmed | 0:791a779d6220 | 915 | entropy->next_restart_num = 0; |
shoaib_ahmed | 0:791a779d6220 | 916 | } |
shoaib_ahmed | 0:791a779d6220 | 917 | |
shoaib_ahmed | 0:791a779d6220 | 918 | |
shoaib_ahmed | 0:791a779d6220 | 919 | /* |
shoaib_ahmed | 0:791a779d6220 | 920 | * Module initialization routine for arithmetic entropy encoding. |
shoaib_ahmed | 0:791a779d6220 | 921 | */ |
shoaib_ahmed | 0:791a779d6220 | 922 | |
shoaib_ahmed | 0:791a779d6220 | 923 | GLOBAL(void) |
shoaib_ahmed | 0:791a779d6220 | 924 | jinit_arith_encoder (j_compress_ptr cinfo) |
shoaib_ahmed | 0:791a779d6220 | 925 | { |
shoaib_ahmed | 0:791a779d6220 | 926 | arith_entropy_ptr entropy; |
shoaib_ahmed | 0:791a779d6220 | 927 | int i; |
shoaib_ahmed | 0:791a779d6220 | 928 | |
shoaib_ahmed | 0:791a779d6220 | 929 | entropy = (arith_entropy_ptr) |
shoaib_ahmed | 0:791a779d6220 | 930 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
shoaib_ahmed | 0:791a779d6220 | 931 | SIZEOF(arith_entropy_encoder)); |
shoaib_ahmed | 0:791a779d6220 | 932 | cinfo->entropy = &entropy->pub; |
shoaib_ahmed | 0:791a779d6220 | 933 | entropy->pub.start_pass = start_pass; |
shoaib_ahmed | 0:791a779d6220 | 934 | entropy->pub.finish_pass = finish_pass; |
shoaib_ahmed | 0:791a779d6220 | 935 | |
shoaib_ahmed | 0:791a779d6220 | 936 | /* Mark tables unallocated */ |
shoaib_ahmed | 0:791a779d6220 | 937 | for (i = 0; i < NUM_ARITH_TBLS; i++) { |
shoaib_ahmed | 0:791a779d6220 | 938 | entropy->dc_stats[i] = NULL; |
shoaib_ahmed | 0:791a779d6220 | 939 | entropy->ac_stats[i] = NULL; |
shoaib_ahmed | 0:791a779d6220 | 940 | } |
shoaib_ahmed | 0:791a779d6220 | 941 | |
shoaib_ahmed | 0:791a779d6220 | 942 | /* Initialize index for fixed probability estimation */ |
shoaib_ahmed | 0:791a779d6220 | 943 | entropy->fixed_bin[0] = 113; |
shoaib_ahmed | 0:791a779d6220 | 944 | } |