1/*
2 * LOCO codec
3 * Copyright (c) 2005 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file libavcodec/loco.c
24 * LOCO codec.
25 */
26
27#include "avcodec.h"
28#include "bitstream.h"
29#include "golomb.h"
30#include "mathops.h"
31
32enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CRGBA=-3, LOCO_CYV12=-4,
33 LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
34
35typedef struct LOCOContext{
36    AVCodecContext *avctx;
37    AVFrame pic;
38    int lossy;
39    int mode;
40} LOCOContext;
41
42typedef struct RICEContext{
43    GetBitContext gb;
44    int save, run, run2; /* internal rice decoder state */
45    int sum, count; /* sum and count for getting rice parameter */
46    int lossy;
47}RICEContext;
48
49static int loco_get_rice_param(RICEContext *r)
50{
51    int cnt = 0;
52    int val = r->count;
53
54    while(r->sum > val && cnt < 9) {
55        val <<= 1;
56        cnt++;
57    }
58
59    return cnt;
60}
61
62static inline void loco_update_rice_param(RICEContext *r, int val)
63{
64    r->sum += val;
65    r->count++;
66
67    if(r->count == 16) {
68        r->sum >>= 1;
69        r->count >>= 1;
70    }
71}
72
73static inline int loco_get_rice(RICEContext *r)
74{
75    int v;
76    if (r->run > 0) { /* we have zero run */
77        r->run--;
78        loco_update_rice_param(r, 0);
79        return 0;
80    }
81    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
82    loco_update_rice_param(r, (v+1)>>1);
83    if (!v) {
84        if (r->save >= 0) {
85            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
86            if(r->run > 1)
87                r->save += r->run + 1;
88            else
89                r->save -= 3;
90        }
91        else
92            r->run2++;
93    } else {
94        v = ((v>>1) + r->lossy) ^ -(v&1);
95        if (r->run2 > 0) {
96            if (r->run2 > 2)
97                r->save += r->run2;
98            else
99                r->save -= 3;
100            r->run2 = 0;
101        }
102    }
103
104    return v;
105}
106
107/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
108static inline int loco_predict(uint8_t* data, int stride, int step)
109{
110    int a, b, c;
111
112    a = data[-stride];
113    b = data[-step];
114    c = data[-stride - step];
115
116    return mid_pred(a, a + b - c, b);
117}
118
119static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
120                             int stride, const uint8_t *buf, int buf_size, int step)
121{
122    RICEContext rc;
123    int val;
124    int i, j;
125
126    init_get_bits(&rc.gb, buf, buf_size*8);
127    rc.save = 0;
128    rc.run = 0;
129    rc.run2 = 0;
130    rc.lossy = l->lossy;
131
132    rc.sum = 8;
133    rc.count = 1;
134
135    /* restore top left pixel */
136    val = loco_get_rice(&rc);
137    data[0] = 128 + val;
138    /* restore top line */
139    for (i = 1; i < width; i++) {
140        val = loco_get_rice(&rc);
141        data[i * step] = data[i * step - step] + val;
142    }
143    data += stride;
144    for (j = 1; j < height; j++) {
145        /* restore left column */
146        val = loco_get_rice(&rc);
147        data[0] = data[-stride] + val;
148        /* restore all other pixels */
149        for (i = 1; i < width; i++) {
150            val = loco_get_rice(&rc);
151            data[i * step] = loco_predict(&data[i * step], stride, step) + val;
152        }
153        data += stride;
154    }
155
156    return (get_bits_count(&rc.gb) + 7) >> 3;
157}
158
159static int decode_frame(AVCodecContext *avctx,
160                        void *data, int *data_size,
161                        const uint8_t *buf, int buf_size)
162{
163    LOCOContext * const l = avctx->priv_data;
164    AVFrame * const p= (AVFrame*)&l->pic;
165    int decoded;
166
167    if(p->data[0])
168        avctx->release_buffer(avctx, p);
169
170    p->reference = 0;
171    if(avctx->get_buffer(avctx, p) < 0){
172        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
173        return -1;
174    }
175    p->key_frame = 1;
176
177    switch(l->mode) {
178    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
179        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
180                                    p->linesize[0], buf, buf_size, 1);
181        buf += decoded; buf_size -= decoded;
182        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
183                                    p->linesize[1], buf, buf_size, 1);
184        buf += decoded; buf_size -= decoded;
185        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
186                                    p->linesize[2], buf, buf_size, 1);
187        break;
188    case LOCO_CYV12: case LOCO_YV12:
189        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
190                                    p->linesize[0], buf, buf_size, 1);
191        buf += decoded; buf_size -= decoded;
192        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
193                                    p->linesize[2], buf, buf_size, 1);
194        buf += decoded; buf_size -= decoded;
195        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
196                                    p->linesize[1], buf, buf_size, 1);
197        break;
198    case LOCO_CRGB: case LOCO_RGB:
199        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
200                                    -p->linesize[0], buf, buf_size, 3);
201        buf += decoded; buf_size -= decoded;
202        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
203                                    -p->linesize[0], buf, buf_size, 3);
204        buf += decoded; buf_size -= decoded;
205        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
206                                    -p->linesize[0], buf, buf_size, 3);
207        break;
208    case LOCO_RGBA:
209        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
210                                    p->linesize[0], buf, buf_size, 4);
211        buf += decoded; buf_size -= decoded;
212        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
213                                    p->linesize[0], buf, buf_size, 4);
214        buf += decoded; buf_size -= decoded;
215        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
216                                    p->linesize[0], buf, buf_size, 4);
217        buf += decoded; buf_size -= decoded;
218        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
219                                    p->linesize[0], buf, buf_size, 4);
220        break;
221    }
222
223    *data_size = sizeof(AVFrame);
224    *(AVFrame*)data = l->pic;
225
226    return buf_size;
227}
228
229static av_cold int decode_init(AVCodecContext *avctx){
230    LOCOContext * const l = avctx->priv_data;
231    int version;
232
233    l->avctx = avctx;
234    if (avctx->extradata_size < 12) {
235        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
236               avctx->extradata_size);
237        return -1;
238    }
239    version = AV_RL32(avctx->extradata);
240    switch(version) {
241    case 1:
242        l->lossy = 0;
243        break;
244    case 2:
245        l->lossy = AV_RL32(avctx->extradata + 8);
246        break;
247    default:
248        l->lossy = AV_RL32(avctx->extradata + 8);
249        av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
250    }
251
252    l->mode = AV_RL32(avctx->extradata + 4);
253    switch(l->mode) {
254    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
255        avctx->pix_fmt = PIX_FMT_YUV422P;
256        break;
257    case LOCO_CRGB: case LOCO_RGB:
258        avctx->pix_fmt = PIX_FMT_BGR24;
259        break;
260    case LOCO_CYV12: case LOCO_YV12:
261        avctx->pix_fmt = PIX_FMT_YUV420P;
262        break;
263    case LOCO_CRGBA: case LOCO_RGBA:
264        avctx->pix_fmt = PIX_FMT_RGB32;
265        break;
266    default:
267        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
268        return -1;
269    }
270    if(avctx->debug & FF_DEBUG_PICT_INFO)
271        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
272
273    return 0;
274}
275
276AVCodec loco_decoder = {
277    "loco",
278    CODEC_TYPE_VIDEO,
279    CODEC_ID_LOCO,
280    sizeof(LOCOContext),
281    decode_init,
282    NULL,
283    NULL,
284    decode_frame,
285    CODEC_CAP_DR1,
286    .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
287};
288