libavcodec/jpeglsdec.c

   1 /*
   2  * JPEG-LS decoder
   3  * Copyright (c) 2003 Michael Niedermayer
   4  * Copyright (c) 2006 Konstantin Shishkov
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file jpeglsdec.c
  25  * JPEG-LS decoder.
  26  */
  27
  28 #include "avcodec.h"
  29 #include "bitstream.h"
  30 #include "golomb.h"
  31 #include "mjpeg.h"
  32 #include "mjpegdec.h"
  33 #include "jpegls.h"
  34 #include "jpeglsdec.h"
  35
  36
  37 /*
  38 * Uncomment this to significantly speed up decoding of broken JPEG-LS
  39 * (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.
  40 *
  41 * There is no Golomb code with length >= 32 bits possible, so check and
  42 * avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow
  43 * on this errors.
  44 */
  45 //#define JLS_BROKEN
  46
  47
  48 /**
  49  * Decode LSE block with initialization parameters
  50  */
  51 int ff_jpegls_decode_lse(MJpegDecodeContext *s)
  52 {
  53     int len, id;
  54
  55     /* XXX: verify len field validity */
  56     len = get_bits(&s->gb, 16);
  57     id = get_bits(&s->gb, 8);
  58
  59     switch(id){
  60     case 1:
  61         s->maxval= get_bits(&s->gb, 16);
  62         s->t1= get_bits(&s->gb, 16);
  63         s->t2= get_bits(&s->gb, 16);
  64         s->t3= get_bits(&s->gb, 16);
  65         s->reset= get_bits(&s->gb, 16);
  66
  67 //        ff_jpegls_reset_coding_parameters(s, 0);
  68         //FIXME quant table?
  69         break;
  70     case 2:
  71     case 3:
  72         av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");
  73         return -1;
  74     case 4:
  75         av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");
  76         return -1;
  77     default:
  78         av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);
  79         return -1;
  80     }
  81 //    av_log(s->avctx, AV_LOG_DEBUG, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);
  82
  83     return 0;
  84 }
  85
  86 /**
  87  * Get context-dependent Golomb code, decode it and update context
  88  */
  89 static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q){
  90     int k, ret;
  91
  92     for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
  93
  94 #ifdef JLS_BROKEN
  95     if(!show_bits_long(gb, 32))return -1;
  96 #endif
  97     ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);
  98
  99     /* decode mapped error */
 100     if(ret & 1)
 101         ret = -((ret + 1) >> 1);
 102     else
 103         ret >>= 1;
 104
 105     /* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */
 106     if(!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))
 107         ret = -(ret + 1);
 108
 109     ret= ff_jpegls_update_state_regular(state, Q, ret);
 110
 111     return ret;
 112 }
 113
 114 /**
 115  * Get Golomb code, decode it and update state for run termination
 116  */
 117 static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state, int RItype, int limit_add){
 118     int k, ret, temp, map;
 119     int Q = 365 + RItype;
 120
 121     temp=  state->A[Q];
 122     if(RItype)
 123         temp += state->N[Q] >> 1;
 124
 125     for(k = 0; (state->N[Q] << k) < temp; k++);
 126
 127 #ifdef JLS_BROKEN
 128     if(!show_bits_long(gb, 32))return -1;
 129 #endif
 130     ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1, state->qbpp);
 131
 132     /* decode mapped error */
 133     map = 0;
 134     if(!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))
 135         map = 1;
 136     ret += RItype + map;
 137
 138     if(ret & 1){
 139         ret = map - ((ret + 1) >> 1);
 140         state->B[Q]++;
 141     } else {
 142         ret = ret >> 1;
 143     }
 144
 145     /* update state */
 146     state->A[Q] += FFABS(ret) - RItype;
 147     ret *= state->twonear;
 148     ff_jpegls_downscale_state(state, Q);
 149
 150     return ret;
 151 }
 152
 153 /**
 154  * Decode one line of image
 155  */
 156 static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s, void *last, void *dst, int last2, int w, int stride, int comp, int bits){
 157     int i, x = 0;
 158     int Ra, Rb, Rc, Rd;
 159     int D0, D1, D2;
 160
 161     while(x < w) {
 162         int err, pred;
 163
 164         /* compute gradients */
 165         Ra = x ? R(dst, x - stride) : R(last, x);
 166         Rb = R(last, x);
 167         Rc = x ? R(last, x - stride) : last2;
 168         Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
 169         D0 = Rd - Rb;
 170         D1 = Rb - Rc;
 171         D2 = Rc - Ra;
 172         /* run mode */
 173         if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
 174             int r;
 175             int RItype;
 176
 177             /* decode full runs while available */
 178             while(get_bits1(&s->gb)) {
 179                 int r;
 180                 r = 1 << ff_log2_run[state->run_index[comp]];
 181                 if(x + r * stride > w) {
 182                     r = (w - x) / stride;
 183                 }
 184                 for(i = 0; i < r; i++) {
 185                     W(dst, x, Ra);
 186                     x += stride;
 187                 }
 188                 /* if EOL reached, we stop decoding */
 189                 if(r != (1 << ff_log2_run[state->run_index[comp]]))
 190                     return;
 191                 if(state->run_index[comp] < 31)
 192                     state->run_index[comp]++;
 193                 if(x + stride > w)
 194                     return;
 195             }
 196             /* decode aborted run */
 197             r = ff_log2_run[state->run_index[comp]];
 198             if(r)
 199                 r = get_bits_long(&s->gb, r);
 200             for(i = 0; i < r; i++) {
 201                 W(dst, x, Ra);
 202                 x += stride;
 203             }
 204
 205             /* decode run termination value */
 206             Rb = R(last, x);
 207             RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;
 208             err = ls_get_code_runterm(&s->gb, state, RItype, ff_log2_run[state->run_index[comp]]);
 209             if(state->run_index[comp])
 210                 state->run_index[comp]--;
 211
 212             if(state->near && RItype){
 213                 pred = Ra + err;
 214             } else {
 215                 if(Rb < Ra)
 216                     pred = Rb - err;
 217                 else
 218                     pred = Rb + err;
 219             }
 220         } else { /* regular mode */
 221             int context, sign;
 222
 223             context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
 224             pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
 225
 226             if(context < 0){
 227                 context = -context;
 228                 sign = 1;
 229             }else{
 230                 sign = 0;
 231             }
 232
 233             if(sign){
 234                 pred = av_clip(pred - state->C[context], 0, state->maxval);
 235                 err = -ls_get_code_regular(&s->gb, state, context);
 236             } else {
 237                 pred = av_clip(pred + state->C[context], 0, state->maxval);
 238                 err = ls_get_code_regular(&s->gb, state, context);
 239             }
 240
 241             /* we have to do something more for near-lossless coding */
 242             pred += err;
 243         }
 244         if(state->near){
 245             if(pred < -state->near)
 246                 pred += state->range * state->twonear;
 247             else if(pred > state->maxval + state->near)
 248                 pred -= state->range * state->twonear;
 249             pred = av_clip(pred, 0, state->maxval);
 250         }
 251
 252         pred &= state->maxval;
 253         W(dst, x, pred);
 254         x += stride;
 255     }
 256 }
 257
 258 int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transform, int ilv){
 259     int i, t = 0;
 260     uint8_t *zero, *last, *cur;
 261     JLSState *state;
 262     int off = 0, stride = 1, width, shift;
 263
 264     zero = av_mallocz(s->picture.linesize[0]);
 265     last = zero;
 266     cur = s->picture.data[0];
 267
 268     state = av_mallocz(sizeof(JLSState));
 269     /* initialize JPEG-LS state from JPEG parameters */
 270     state->near = near;
 271     state->bpp = (s->bits < 2) ? 2 : s->bits;
 272     state->maxval = s->maxval;
 273     state->T1 = s->t1;
 274     state->T2 = s->t2;
 275     state->T3 = s->t3;
 276     state->reset = s->reset;
 277     ff_jpegls_reset_coding_parameters(state, 0);
 278     ff_jpegls_init_state(state);
 279
 280     if(s->bits <= 8)
 281         shift = point_transform + (8 - s->bits);
 282     else
 283         shift = point_transform + (16 - s->bits);
 284
 285 //    av_log(s->avctx, AV_LOG_DEBUG, "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",s->width,s->height,state->near,state->maxval,state->T1,state->T2,state->T3,state->reset,state->limit,state->qbpp, state->range);
 286 //    av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n", ilv, point_transform, s->bits, s->cur_scan);
 287     if(ilv == 0) { /* separate planes */
 288         off = s->cur_scan - 1;
 289         stride = (s->nb_components > 1) ? 3 : 1;
 290         width = s->width * stride;
 291         cur += off;
 292         for(i = 0; i < s->height; i++) {
 293             if(s->bits <= 8){
 294                 ls_decode_line(state, s, last, cur, t, width, stride, off,  8);
 295                 t = last[0];
 296             }else{
 297                 ls_decode_line(state, s, last, cur, t, width, stride, off, 16);
 298                 t = *((uint16_t*)last);
 299             }
 300             last = cur;
 301             cur += s->picture.linesize[0];
 302
 303             if (s->restart_interval && !--s->restart_count) {
 304                 align_get_bits(&s->gb);
 305                 skip_bits(&s->gb, 16); /* skip RSTn */
 306             }
 307         }
 308     } else if(ilv == 1) { /* line interleaving */
 309         int j;
 310         int Rc[3] = {0, 0, 0};
 311         memset(cur, 0, s->picture.linesize[0]);
 312         width = s->width * 3;
 313         for(i = 0; i < s->height; i++) {
 314             for(j = 0; j < 3; j++) {
 315                 ls_decode_line(state, s, last + j, cur + j, Rc[j], width, 3, j, 8);
 316                 Rc[j] = last[j];
 317
 318                 if (s->restart_interval && !--s->restart_count) {
 319                     align_get_bits(&s->gb);
 320                     skip_bits(&s->gb, 16); /* skip RSTn */
 321                 }
 322             }
 323             last = cur;
 324             cur += s->picture.linesize[0];
 325         }
 326     } else if(ilv == 2) { /* sample interleaving */
 327         av_log(s->avctx, AV_LOG_ERROR, "Sample interleaved images are not supported.\n");
 328         av_free(state);
 329         av_free(zero);
 330         return -1;
 331     }
 332
 333     if(shift){ /* we need to do point transform or normalize samples */
 334         int x, w;
 335
 336         w = s->width * s->nb_components;
 337
 338         if(s->bits <= 8){
 339             uint8_t *src = s->picture.data[0];
 340
 341             for(i = 0; i < s->height; i++){
 342                 for(x = off; x < w; x+= stride){
 343                     src[x] <<= shift;
 344                 }
 345                 src += s->picture.linesize[0];
 346             }
 347         }else{
 348             uint16_t *src = (uint16_t*) s->picture.data[0];
 349
 350             for(i = 0; i < s->height; i++){
 351                 for(x = 0; x < w; x++){
 352                     src[x] <<= shift;
 353                 }
 354                 src += s->picture.linesize[0]/2;
 355             }
 356         }
 357     }
 358     av_free(state);
 359     av_free(zero);
 360
 361     return 0;
 362 }
 363
 364
 365 AVCodec jpegls_decoder = {
 366     "jpegls",
 367     CODEC_TYPE_VIDEO,
 368     CODEC_ID_JPEGLS,
 369     sizeof(MJpegDecodeContext),
 370     ff_mjpeg_decode_init,
 371     NULL,
 372     ff_mjpeg_decode_end,
 373     ff_mjpeg_decode_frame,
 374     CODEC_CAP_DR1,
 375     .long_name = "JPEG-LS",
 376 };