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
24 * LOCO codec.
25 */
26
27#include "avcodec.h"
28#include "get_bits.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                        AVPacket *avpkt)
162{
163    const uint8_t *buf = avpkt->data;
164    int buf_size = avpkt->size;
165    LOCOContext * const l = avctx->priv_data;
166    AVFrame * const p= (AVFrame*)&l->pic;
167    int decoded;
168
169    if(p->data[0])
170        avctx->release_buffer(avctx, p);
171
172    p->reference = 0;
173    if(avctx->get_buffer(avctx, p) < 0){
174        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
175        return -1;
176    }
177    p->key_frame = 1;
178
179    switch(l->mode) {
180    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
181        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
182                                    p->linesize[0], buf, buf_size, 1);
183        buf += decoded; buf_size -= decoded;
184        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
185                                    p->linesize[1], buf, buf_size, 1);
186        buf += decoded; buf_size -= decoded;
187        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
188                                    p->linesize[2], buf, buf_size, 1);
189        break;
190    case LOCO_CYV12: case LOCO_YV12:
191        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
192                                    p->linesize[0], buf, buf_size, 1);
193        buf += decoded; buf_size -= decoded;
194        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
195                                    p->linesize[2], buf, buf_size, 1);
196        buf += decoded; buf_size -= decoded;
197        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
198                                    p->linesize[1], buf, buf_size, 1);
199        break;
200    case LOCO_CRGB: case LOCO_RGB:
201        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
202                                    -p->linesize[0], buf, buf_size, 3);
203        buf += decoded; buf_size -= decoded;
204        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
205                                    -p->linesize[0], buf, buf_size, 3);
206        buf += decoded; buf_size -= decoded;
207        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
208                                    -p->linesize[0], buf, buf_size, 3);
209        break;
210    case LOCO_RGBA:
211        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
212                                    p->linesize[0], buf, buf_size, 4);
213        buf += decoded; buf_size -= decoded;
214        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
215                                    p->linesize[0], buf, buf_size, 4);
216        buf += decoded; buf_size -= decoded;
217        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
218                                    p->linesize[0], buf, buf_size, 4);
219        buf += decoded; buf_size -= decoded;
220        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
221                                    p->linesize[0], buf, buf_size, 4);
222        break;
223    }
224
225    *data_size = sizeof(AVFrame);
226    *(AVFrame*)data = l->pic;
227
228    return buf_size;
229}
230
231static av_cold int decode_init(AVCodecContext *avctx){
232    LOCOContext * const l = avctx->priv_data;
233    int version;
234
235    l->avctx = avctx;
236    if (avctx->extradata_size < 12) {
237        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
238               avctx->extradata_size);
239        return -1;
240    }
241    version = AV_RL32(avctx->extradata);
242    switch(version) {
243    case 1:
244        l->lossy = 0;
245        break;
246    case 2:
247        l->lossy = AV_RL32(avctx->extradata + 8);
248        break;
249    default:
250        l->lossy = AV_RL32(avctx->extradata + 8);
251        av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
252    }
253
254    l->mode = AV_RL32(avctx->extradata + 4);
255    switch(l->mode) {
256    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
257        avctx->pix_fmt = PIX_FMT_YUV422P;
258        break;
259    case LOCO_CRGB: case LOCO_RGB:
260        avctx->pix_fmt = PIX_FMT_BGR24;
261        break;
262    case LOCO_CYV12: case LOCO_YV12:
263        avctx->pix_fmt = PIX_FMT_YUV420P;
264        break;
265    case LOCO_CRGBA: case LOCO_RGBA:
266        avctx->pix_fmt = PIX_FMT_RGB32;
267        break;
268    default:
269        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
270        return -1;
271    }
272    if(avctx->debug & FF_DEBUG_PICT_INFO)
273        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
274
275    return 0;
276}
277
278static av_cold int decode_end(AVCodecContext *avctx){
279    LOCOContext * const l = avctx->priv_data;
280    AVFrame *pic = &l->pic;
281
282    if (pic->data[0])
283        avctx->release_buffer(avctx, pic);
284
285    return 0;
286}
287
288AVCodec loco_decoder = {
289    "loco",
290    AVMEDIA_TYPE_VIDEO,
291    CODEC_ID_LOCO,
292    sizeof(LOCOContext),
293    decode_init,
294    NULL,
295    decode_end,
296    decode_frame,
297    CODEC_CAP_DR1,
298    .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
299};
300