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 libavcodec/jpeglsdec.c
  25  * JPEG-LS decoder.
  26  */
  27
  28 #include "avcodec.h"
  29 #include "get_bits.h"
  30 #include "golomb.h"
  31 #include "mathops.h"
  32 #include "mjpeg.h"
  33 #include "mjpegdec.h"
  34 #include "jpegls.h"
  35 #include "jpeglsdec.h"
  36
  37
  38 /*
  39 * Uncomment this to significantly speed up decoding of broken JPEG-LS
  40 * (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.
  41 *
  42 * There is no Golomb code with length >= 32 bits possible, so check and
  43 * avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow
  44 * on this errors.
  45 */
  46 //#define JLS_BROKEN
  47
  48
  49 /**
  50  * Decode LSE block with initialization parameters
  51  */
  52 int ff_jpegls_decode_lse(MJpegDecodeContext *s)
  53 {
  54     int len, id;
  55
  56     /* XXX: verify len field validity */
  57     len = get_bits(&s->gb, 16);
  58     id = get_bits(&s->gb, 8);
  59
  60     switch(id){
  61     case 1:
  62         s->maxval= get_bits(&s->gb, 16);
  63         s->t1= get_bits(&s->gb, 16);
  64         s->t2= get_bits(&s->gb, 16);
  65         s->t3= get_bits(&s->gb, 16);
  66         s->reset= get_bits(&s->gb, 16);
  67
  68 //        ff_jpegls_reset_coding_parameters(s, 0);
  69         //FIXME quant table?
  70         break;
  71     case 2:
  72     case 3:
  73         av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");
  74         return -1;
  75     case 4:
  76         av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");
  77         return -1;
  78     default:
  79         av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);
  80         return -1;
  81     }
  82 //    av_log(s->avctx, AV_LOG_DEBUG, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);
  83
  84     return 0;
  85 }
  86
  87 /**
  88  * Get context-dependent Golomb code, decode it and update context
  89  */
  90 static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q){
  91     int k, ret;
  92
  93     for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
  94
  95 #ifdef JLS_BROKEN
  96     if(!show_bits_long(gb, 32))return -1;
  97 #endif
  98     ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);
  99
 100     /* decode mapped error */
 101     if(ret & 1)
 102         ret = -((ret + 1) >> 1);
 103     else
 104         ret >>= 1;
 105
 106     /* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */
 107     if(!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))
 108         ret = -(ret + 1);
 109
 110     ret= ff_jpegls_update_state_regular(state, Q, ret);
 111
 112     return ret;
 113 }
 114
 115 /**
 116  * Get Golomb code, decode it and update state for run termination
 117  */
 118 static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state, int RItype, int limit_add){
 119     int k, ret, temp, map;
 120     int Q = 365 + RItype;
 121
 122     temp=  state->A[Q];
 123     if(RItype)
 124         temp += state->N[Q] >> 1;
 125
 126     for(k = 0; (state->N[Q] << k) < temp; k++);
 127
 128 #ifdef JLS_BROKEN
 129     if(!show_bits_long(gb, 32))return -1;
 130 #endif
 131     ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1, state->qbpp);
 132
 133     /* decode mapped error */
 134     map = 0;
 135     if(!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))
 136         map = 1;
 137     ret += RItype + map;
 138
 139     if(ret & 1){
 140         ret = map - ((ret + 1) >> 1);
 141         state->B[Q]++;
 142     } else {
 143         ret = ret >> 1;
 144     }
 145
 146     /* update state */
 147     state->A[Q] += FFABS(ret) - RItype;
 148     ret *= state->twonear;
 149     ff_jpegls_downscale_state(state, Q);
 150
 151     return ret;
 152 }
 153
 154 /**
 155  * Decode one line of image
 156  */
 157 static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s, void *last, void *dst, int last2, int w, int stride, int comp, int bits){
 158     int i, x = 0;
 159     int Ra, Rb, Rc, Rd;
 160     int D0, D1, D2;
 161
 162     while(x < w) {
 163         int err, pred;
 164
 165         /* compute gradients */
 166         Ra = x ? R(dst, x - stride) : R(last, x);
 167         Rb = R(last, x);
 168         Rc = x ? R(last, x - stride) : last2;
 169         Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
 170         D0 = Rd - Rb;
 171         D1 = Rb - Rc;
 172         D2 = Rc - Ra;
 173         /* run mode */
 174         if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
 175             int r;
 176             int RItype;
 177
 178             /* decode full runs while available */
 179             while(get_bits1(&s->gb)) {
 180                 int r;
 181                 r = 1 << ff_log2_run[state->run_index[comp]];
 182                 if(x + r * stride > w) {
 183                     r = (w - x) / stride;
 184                 }
 185                 for(i = 0; i < r; i++) {
 186                     W(dst, x, Ra);
 187                     x += stride;
 188                 }
 189                 /* if EOL reached, we stop decoding */
 190                 if(r != (1 << ff_log2_run[state->run_index[comp]]))
 191                     return;
 192                 if(state->run_index[comp] < 31)
 193                     state->run_index[comp]++;
 194                 if(x + stride > w)
 195                     return;
 196             }
 197             /* decode aborted run */
 198             r = ff_log2_run[state->run_index[comp]];
 199             if(r)
 200                 r = get_bits_long(&s->gb, r);
 201             for(i = 0; i < r; i++) {
 202                 W(dst, x, Ra);
 203                 x += stride;
 204             }
 205
 206             /* decode run termination value */
 207             Rb = R(last, x);
 208             RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;
 209             err = ls_get_code_runterm(&s->gb, state, RItype, ff_log2_run[state->run_index[comp]]);
 210             if(state->run_index[comp])
 211                 state->run_index[comp]--;
 212
 213             if(state->near && RItype){
 214                 pred = Ra + err;
 215             } else {
 216                 if(Rb < Ra)
 217                     pred = Rb - err;
 218                 else
 219                     pred = Rb + err;
 220             }
 221         } else { /* regular mode */
 222             int context, sign;
 223
 224             context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
 225             pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
 226
 227             if(context < 0){
 228                 context = -context;
 229                 sign = 1;
 230             }else{
 231                 sign = 0;
 232             }
 233
 234             if(sign){
 235                 pred = av_clip(pred - state->C[context], 0, state->maxval);
 236                 err = -ls_get_code_regular(&s->gb, state, context);
 237             } else {
 238                 pred = av_clip(pred + state->C[context], 0, state->maxval);
 239                 err = ls_get_code_regular(&s->gb, state, context);
 240             }
 241
 242             /* we have to do something more for near-lossless coding */
 243             pred += err;
 244         }
 245         if(state->near){
 246             if(pred < -state->near)
 247                 pred += state->range * state->twonear;
 248             else if(pred > state->maxval + state->near)
 249                 pred -= state->range * state->twonear;
 250             pred = av_clip(pred, 0, state->maxval);
 251         }
 252
 253         pred &= state->maxval;
 254         W(dst, x, pred);
 255         x += stride;
 256     }
 257 }
 258
 259 int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transform, int ilv){
 260     int i, t = 0;
 261     uint8_t *zero, *last, *cur;
 262     JLSState *state;
 263     int off = 0, stride = 1, width, shift;
 264
 265     zero = av_mallocz(s->picture.linesize[0]);
 266     last = zero;
 267     cur = s->picture.data[0];
 268
 269     state = av_mallocz(sizeof(JLSState));
 270     /* initialize JPEG-LS state from JPEG parameters */
 271     state->near = near;
 272     state->bpp = (s->bits < 2) ? 2 : s->bits;
 273     state->maxval = s->maxval;
 274     state->T1 = s->t1;
 275     state->T2 = s->t2;
 276     state->T3 = s->t3;
 277     state->reset = s->reset;
 278     ff_jpegls_reset_coding_parameters(state, 0);
 279     ff_jpegls_init_state(state);
 280
 281     if(s->bits <= 8)
 282         shift = point_transform + (8 - s->bits);
 283     else
 284         shift = point_transform + (16 - s->bits);
 285
 286 //    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);
 287 //    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);
 288     if(ilv == 0) { /* separate planes */
 289         off = s->cur_scan - 1;
 290         stride = (s->nb_components > 1) ? 3 : 1;
 291         width = s->width * stride;
 292         cur += off;
 293         for(i = 0; i < s->height; i++) {
 294             if(s->bits <= 8){
 295                 ls_decode_line(state, s, last, cur, t, width, stride, off,  8);
 296                 t = last[0];
 297             }else{
 298                 ls_decode_line(state, s, last, cur, t, width, stride, off, 16);
 299                 t = *((uint16_t*)last);
 300             }
 301             last = cur;
 302             cur += s->picture.linesize[0];
 303
 304             if (s->restart_interval && !--s->restart_count) {
 305                 align_get_bits(&s->gb);
 306                 skip_bits(&s->gb, 16); /* skip RSTn */
 307             }
 308         }
 309     } else if(ilv == 1) { /* line interleaving */
 310         int j;
 311         int Rc[3] = {0, 0, 0};
 312         memset(cur, 0, s->picture.linesize[0]);
 313         width = s->width * 3;
 314         for(i = 0; i < s->height; i++) {
 315             for(j = 0; j < 3; j++) {
 316                 ls_decode_line(state, s, last + j, cur + j, Rc[j], width, 3, j, 8);
 317                 Rc[j] = last[j];
 318
 319                 if (s->restart_interval && !--s->restart_count) {
 320                     align_get_bits(&s->gb);
 321                     skip_bits(&s->gb, 16); /* skip RSTn */
 322                 }
 323             }
 324             last = cur;
 325             cur += s->picture.linesize[0];
 326         }
 327     } else if(ilv == 2) { /* sample interleaving */
 328         av_log(s->avctx, AV_LOG_ERROR, "Sample interleaved images are not supported.\n");
 329         av_free(state);
 330         av_free(zero);
 331         return -1;
 332     }
 333
 334     if(shift){ /* we need to do point transform or normalize samples */
 335         int x, w;
 336
 337         w = s->width * s->nb_components;
 338
 339         if(s->bits <= 8){
 340             uint8_t *src = s->picture.data[0];
 341
 342             for(i = 0; i < s->height; i++){
 343                 for(x = off; x < w; x+= stride){
 344                     src[x] <<= shift;
 345                 }
 346                 src += s->picture.linesize[0];
 347             }
 348         }else{
 349             uint16_t *src = (uint16_t*) s->picture.data[0];
 350
 351             for(i = 0; i < s->height; i++){
 352                 for(x = 0; x < w; x++){
 353                     src[x] <<= shift;
 354                 }
 355                 src += s->picture.linesize[0]/2;
 356             }
 357         }
 358     }
 359     av_free(state);
 360     av_free(zero);
 361
 362     return 0;
 363 }
 364
 365
 366 AVCodec jpegls_decoder = {
 367     "jpegls",
 368     CODEC_TYPE_VIDEO,
 369     CODEC_ID_JPEGLS,
 370     sizeof(MJpegDecodeContext),
 371     ff_mjpeg_decode_init,
 372     NULL,
 373     ff_mjpeg_decode_end,
 374     ff_mjpeg_decode_frame,
 375     CODEC_CAP_DR1,
 376     .long_name = NULL_IF_CONFIG_SMALL("JPEG-LS"),
 377 };