1/*
2 * JPEG-LS encoder
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/jpeglsenc.c
25 * JPEG-LS encoder.
26 */
27
28#include "avcodec.h"
29#include "bitstream.h"
30#include "golomb.h"
31#include "mathops.h"
32#include "dsputil.h"
33#include "mjpeg.h"
34#include "jpegls.h"
35
36
37/**
38 * Encode error from regular symbol
39 */
40static inline void ls_encode_regular(JLSState *state, PutBitContext *pb, int Q, int err){
41    int k;
42    int val;
43    int map;
44
45    for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
46
47    map = !state->near && !k && (2 * state->B[Q] <= -state->N[Q]);
48
49    if(err < 0)
50        err += state->range;
51    if(err >= ((state->range + 1) >> 1)) {
52        err -= state->range;
53        val = 2 * FFABS(err) - 1 - map;
54    } else
55        val = 2 * err + map;
56
57    set_ur_golomb_jpegls(pb, val, k, state->limit, state->qbpp);
58
59    ff_jpegls_update_state_regular(state, Q, err);
60}
61
62/**
63 * Encode error from run termination
64 */
65static inline void ls_encode_runterm(JLSState *state, PutBitContext *pb, int RItype, int err, int limit_add){
66    int k;
67    int val, map;
68    int Q = 365 + RItype;
69    int temp;
70
71    temp = state->A[Q];
72    if(RItype)
73        temp += state->N[Q] >> 1;
74    for(k = 0; (state->N[Q] << k) < temp; k++);
75    map = 0;
76    if(!k && err && (2 * state->B[Q] < state->N[Q]))
77        map = 1;
78
79    if(err < 0)
80        val = - (2 * err) - 1 - RItype + map;
81    else
82        val = 2 * err - RItype - map;
83    set_ur_golomb_jpegls(pb, val, k, state->limit - limit_add - 1, state->qbpp);
84
85    if(err < 0)
86        state->B[Q]++;
87    state->A[Q] += (val + 1 - RItype) >> 1;
88
89    ff_jpegls_downscale_state(state, Q);
90}
91
92/**
93 * Encode run value as specified by JPEG-LS standard
94 */
95static inline void ls_encode_run(JLSState *state, PutBitContext *pb, int run, int comp, int trail){
96    while(run >= (1 << ff_log2_run[state->run_index[comp]])){
97        put_bits(pb, 1, 1);
98        run -= 1 << ff_log2_run[state->run_index[comp]];
99        if(state->run_index[comp] < 31)
100            state->run_index[comp]++;
101    }
102    /* if hit EOL, encode another full run, else encode aborted run */
103    if(!trail && run) {
104        put_bits(pb, 1, 1);
105    }else if(trail){
106        put_bits(pb, 1, 0);
107        if(ff_log2_run[state->run_index[comp]])
108            put_bits(pb, ff_log2_run[state->run_index[comp]], run);
109    }
110}
111
112/**
113 * Encode one line of image
114 */
115static inline void ls_encode_line(JLSState *state, PutBitContext *pb, void *last, void *cur, int last2, int w, int stride, int comp, int bits){
116    int x = 0;
117    int Ra, Rb, Rc, Rd;
118    int D0, D1, D2;
119
120    while(x < w) {
121        int err, pred, sign;
122
123        /* compute gradients */
124        Ra = x ? R(cur, x - stride) : R(last, x);
125        Rb = R(last, x);
126        Rc = x ? R(last, x - stride) : last2;
127        Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
128        D0 = Rd - Rb;
129        D1 = Rb - Rc;
130        D2 = Rc - Ra;
131
132        /* run mode */
133        if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
134            int RUNval, RItype, run;
135
136            run = 0;
137            RUNval = Ra;
138            while(x < w && (FFABS(R(cur, x) - RUNval) <= state->near)){
139                run++;
140                W(cur, x, Ra);
141                x += stride;
142            }
143            ls_encode_run(state, pb, run, comp, x < w);
144            if(x >= w)
145                return;
146            Rb = R(last, x);
147            RItype = (FFABS(Ra - Rb) <= state->near);
148            pred = RItype ? Ra : Rb;
149            err = R(cur, x) - pred;
150
151            if(!RItype && Ra > Rb)
152                err = -err;
153
154            if(state->near){
155                if(err > 0)
156                    err = (state->near + err) / state->twonear;
157                else
158                    err = -(state->near - err) / state->twonear;
159
160                if(RItype || (Rb >= Ra))
161                    Ra = av_clip(pred + err * state->twonear, 0, state->maxval);
162                else
163                    Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
164                W(cur, x, Ra);
165            }
166            if(err < 0)
167                err += state->range;
168            if(err >= ((state->range + 1) >> 1))
169                err -= state->range;
170
171            ls_encode_runterm(state, pb, RItype, err, ff_log2_run[state->run_index[comp]]);
172
173            if(state->run_index[comp] > 0)
174                state->run_index[comp]--;
175        } else { /* regular mode */
176            int context;
177
178            context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
179            pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
180
181            if(context < 0){
182                context = -context;
183                sign = 1;
184                pred = av_clip(pred - state->C[context], 0, state->maxval);
185                err = pred - R(cur, x);
186            }else{
187                sign = 0;
188                pred = av_clip(pred + state->C[context], 0, state->maxval);
189                err = R(cur, x) - pred;
190            }
191
192            if(state->near){
193                if(err > 0)
194                    err = (state->near + err) / state->twonear;
195                else
196                    err = -(state->near - err) / state->twonear;
197                if(!sign)
198                    Ra = av_clip(pred + err * state->twonear, 0, state->maxval);
199                else
200                    Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
201                W(cur, x, Ra);
202            }
203
204            ls_encode_regular(state, pb, context, err);
205        }
206        x += stride;
207    }
208}
209
210static void ls_store_lse(JLSState *state, PutBitContext *pb){
211    /* Test if we have default params and don't need to store LSE */
212    JLSState state2;
213    memset(&state2, 0, sizeof(JLSState));
214    state2.bpp = state->bpp;
215    state2.near = state->near;
216    ff_jpegls_reset_coding_parameters(&state2, 1);
217    if(state->T1 == state2.T1 && state->T2 == state2.T2 && state->T3 == state2.T3 && state->reset == state2.reset)
218        return;
219    /* store LSE type 1 */
220    put_marker(pb, LSE);
221    put_bits(pb, 16, 13);
222    put_bits(pb, 8,   1);
223    put_bits(pb, 16, state->maxval);
224    put_bits(pb, 16, state->T1);
225    put_bits(pb, 16, state->T2);
226    put_bits(pb, 16, state->T3);
227    put_bits(pb, 16, state->reset);
228}
229
230static int encode_picture_ls(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
231    JpeglsContext * const s = avctx->priv_data;
232    AVFrame *pict = data;
233    AVFrame * const p= (AVFrame*)&s->picture;
234    const int near = avctx->prediction_method;
235    PutBitContext pb, pb2;
236    GetBitContext gb;
237    uint8_t *buf2, *zero, *cur, *last;
238    JLSState *state;
239    int i, size;
240    int comps;
241
242    buf2 = av_malloc(buf_size);
243
244    init_put_bits(&pb, buf, buf_size);
245    init_put_bits(&pb2, buf2, buf_size);
246
247    *p = *pict;
248    p->pict_type= FF_I_TYPE;
249    p->key_frame= 1;
250
251    if(avctx->pix_fmt == PIX_FMT_GRAY8 || avctx->pix_fmt == PIX_FMT_GRAY16)
252        comps = 1;
253    else
254        comps = 3;
255
256    /* write our own JPEG header, can't use mjpeg_picture_header */
257    put_marker(&pb, SOI);
258    put_marker(&pb, SOF48);
259    put_bits(&pb, 16, 8 + comps * 3); // header size depends on components
260    put_bits(&pb,  8, (avctx->pix_fmt == PIX_FMT_GRAY16) ? 16 : 8); // bpp
261    put_bits(&pb, 16, avctx->height);
262    put_bits(&pb, 16, avctx->width);
263    put_bits(&pb,  8, comps);         // components
264    for(i = 1; i <= comps; i++) {
265        put_bits(&pb,  8, i);    // component ID
266        put_bits(&pb,  8, 0x11); // subsampling: none
267        put_bits(&pb,  8, 0);    // Tiq, used by JPEG-LS ext
268    }
269
270    put_marker(&pb, SOS);
271    put_bits(&pb, 16, 6 + comps * 2);
272    put_bits(&pb,  8, comps);
273    for(i = 1; i <= comps; i++) {
274        put_bits(&pb,  8, i);  // component ID
275        put_bits(&pb,  8, 0);  // mapping index: none
276    }
277    put_bits(&pb,  8, near);
278    put_bits(&pb,  8, (comps > 1) ? 1 : 0); // interleaving: 0 - plane, 1 - line
279    put_bits(&pb,  8, 0); // point transform: none
280
281    state = av_mallocz(sizeof(JLSState));
282    /* initialize JPEG-LS state from JPEG parameters */
283    state->near = near;
284    state->bpp = (avctx->pix_fmt == PIX_FMT_GRAY16) ? 16 : 8;
285    ff_jpegls_reset_coding_parameters(state, 0);
286    ff_jpegls_init_state(state);
287
288    ls_store_lse(state, &pb);
289
290    zero = av_mallocz(p->linesize[0]);
291    last = zero;
292    cur = p->data[0];
293    if(avctx->pix_fmt == PIX_FMT_GRAY8){
294        int t = 0;
295
296        for(i = 0; i < avctx->height; i++) {
297            ls_encode_line(state, &pb2, last, cur, t, avctx->width, 1, 0,  8);
298            t = last[0];
299            last = cur;
300            cur += p->linesize[0];
301        }
302    }else if(avctx->pix_fmt == PIX_FMT_GRAY16){
303        int t = 0;
304
305        for(i = 0; i < avctx->height; i++) {
306            ls_encode_line(state, &pb2, last, cur, t, avctx->width, 1, 0, 16);
307            t = *((uint16_t*)last);
308            last = cur;
309            cur += p->linesize[0];
310        }
311    }else if(avctx->pix_fmt == PIX_FMT_RGB24){
312        int j, width;
313        int Rc[3] = {0, 0, 0};
314
315        width = avctx->width * 3;
316        for(i = 0; i < avctx->height; i++) {
317            for(j = 0; j < 3; j++) {
318                ls_encode_line(state, &pb2, last + j, cur + j, Rc[j], width, 3, j, 8);
319                Rc[j] = last[j];
320            }
321            last = cur;
322            cur += s->picture.linesize[0];
323        }
324    }else if(avctx->pix_fmt == PIX_FMT_BGR24){
325        int j, width;
326        int Rc[3] = {0, 0, 0};
327
328        width = avctx->width * 3;
329        for(i = 0; i < avctx->height; i++) {
330            for(j = 2; j >= 0; j--) {
331                ls_encode_line(state, &pb2, last + j, cur + j, Rc[j], width, 3, j, 8);
332                Rc[j] = last[j];
333            }
334            last = cur;
335            cur += s->picture.linesize[0];
336        }
337    }
338
339    av_free(zero);
340    av_free(state);
341
342    // the specification says that after doing 0xff escaping unused bits in the
343    // last byte must be set to 0, so just append 7 "optional" zero-bits to
344    // avoid special-casing.
345    put_bits(&pb2, 7, 0);
346    size = put_bits_count(&pb2);
347    flush_put_bits(&pb2);
348    /* do escape coding */
349    init_get_bits(&gb, buf2, size);
350    size -= 7;
351    while(get_bits_count(&gb) < size){
352        int v;
353        v = get_bits(&gb, 8);
354        put_bits(&pb, 8, v);
355        if(v == 0xFF){
356            v = get_bits(&gb, 7);
357            put_bits(&pb, 8, v);
358        }
359    }
360    align_put_bits(&pb);
361    av_free(buf2);
362
363    /* End of image */
364    put_marker(&pb, EOI);
365    flush_put_bits(&pb);
366
367    emms_c();
368
369    return put_bits_count(&pb) >> 3;
370}
371
372static av_cold int encode_init_ls(AVCodecContext *ctx) {
373    JpeglsContext *c = (JpeglsContext*)ctx->priv_data;
374
375    c->avctx = ctx;
376    ctx->coded_frame = &c->picture;
377
378    if(ctx->pix_fmt != PIX_FMT_GRAY8 && ctx->pix_fmt != PIX_FMT_GRAY16 && ctx->pix_fmt != PIX_FMT_RGB24 && ctx->pix_fmt != PIX_FMT_BGR24){
379        av_log(ctx, AV_LOG_ERROR, "Only grayscale and RGB24/BGR24 images are supported\n");
380        return -1;
381    }
382    return 0;
383}
384
385AVCodec jpegls_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them
386    "jpegls",
387    CODEC_TYPE_VIDEO,
388    CODEC_ID_JPEGLS,
389    sizeof(JpeglsContext),
390    encode_init_ls,
391    encode_picture_ls,
392    NULL,
393    .pix_fmts= (enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB24, PIX_FMT_GRAY8, PIX_FMT_GRAY16, PIX_FMT_NONE},
394    .long_name= NULL_IF_CONFIG_SMALL("JPEG-LS"),
395};
396