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
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 */
52int 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 */
90static 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 */
118static 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 */
157static 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
259int 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
366AVCodec jpegls_decoder = {
367    "jpegls",
368    AVMEDIA_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};
378