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 "internal.h"
31#include "mathops.h"
32
33enum LOCO_MODE {
34    LOCO_UNKN  =  0,
35    LOCO_CYUY2 = -1,
36    LOCO_CRGB  = -2,
37    LOCO_CRGBA = -3,
38    LOCO_CYV12 = -4,
39    LOCO_YUY2  =  1,
40    LOCO_UYVY  =  2,
41    LOCO_RGB   =  3,
42    LOCO_RGBA  =  4,
43    LOCO_YV12  =  5,
44};
45
46typedef struct LOCOContext {
47    AVCodecContext *avctx;
48    int lossy;
49    int mode;
50} LOCOContext;
51
52typedef struct RICEContext {
53    GetBitContext gb;
54    int save, run, run2; /* internal rice decoder state */
55    int sum, count; /* sum and count for getting rice parameter */
56    int lossy;
57} RICEContext;
58
59static int loco_get_rice_param(RICEContext *r)
60{
61    int cnt = 0;
62    int val = r->count;
63
64    while (r->sum > val && cnt < 9) {
65        val <<= 1;
66        cnt++;
67    }
68
69    return cnt;
70}
71
72static inline void loco_update_rice_param(RICEContext *r, int val)
73{
74    r->sum += val;
75    r->count++;
76
77    if (r->count == 16) {
78        r->sum   >>= 1;
79        r->count >>= 1;
80    }
81}
82
83static inline int loco_get_rice(RICEContext *r)
84{
85    int v;
86    if (r->run > 0) { /* we have zero run */
87        r->run--;
88        loco_update_rice_param(r, 0);
89        return 0;
90    }
91    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
92    loco_update_rice_param(r, (v + 1) >> 1);
93    if (!v) {
94        if (r->save >= 0) {
95            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
96            if (r->run > 1)
97                r->save += r->run + 1;
98            else
99                r->save -= 3;
100        } else
101            r->run2++;
102    } else {
103        v = ((v >> 1) + r->lossy) ^ -(v & 1);
104        if (r->run2 > 0) {
105            if (r->run2 > 2)
106                r->save += r->run2;
107            else
108                r->save -= 3;
109            r->run2 = 0;
110        }
111    }
112
113    return v;
114}
115
116/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
117static inline int loco_predict(uint8_t* data, int stride, int step)
118{
119    int a, b, c;
120
121    a = data[-stride];
122    b = data[-step];
123    c = data[-stride - step];
124
125    return mid_pred(a, a + b - c, b);
126}
127
128static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
129                             int stride, const uint8_t *buf, int buf_size, int step)
130{
131    RICEContext rc;
132    int val;
133    int i, j;
134
135    if(buf_size<=0)
136        return -1;
137
138    init_get_bits8(&rc.gb, buf, buf_size);
139    rc.save  = 0;
140    rc.run   = 0;
141    rc.run2  = 0;
142    rc.lossy = l->lossy;
143
144    rc.sum   = 8;
145    rc.count = 1;
146
147    /* restore top left pixel */
148    val     = loco_get_rice(&rc);
149    data[0] = 128 + val;
150    /* restore top line */
151    for (i = 1; i < width; i++) {
152        val = loco_get_rice(&rc);
153        data[i * step] = data[i * step - step] + val;
154    }
155    data += stride;
156    for (j = 1; j < height; j++) {
157        /* restore left column */
158        val = loco_get_rice(&rc);
159        data[0] = data[-stride] + val;
160        /* restore all other pixels */
161        for (i = 1; i < width; i++) {
162            val = loco_get_rice(&rc);
163            data[i * step] = loco_predict(&data[i * step], stride, step) + val;
164        }
165        data += stride;
166    }
167
168    return (get_bits_count(&rc.gb) + 7) >> 3;
169}
170
171static int decode_frame(AVCodecContext *avctx,
172                        void *data, int *got_frame,
173                        AVPacket *avpkt)
174{
175    LOCOContext * const l = avctx->priv_data;
176    const uint8_t *buf    = avpkt->data;
177    int buf_size          = avpkt->size;
178    AVFrame * const p     = data;
179    int decoded, ret;
180
181    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
182        return ret;
183    p->key_frame = 1;
184
185#define ADVANCE_BY_DECODED do { \
186    if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \
187    buf += decoded; buf_size -= decoded; \
188} while(0)
189    switch(l->mode) {
190    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
191        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
192                                    p->linesize[0], buf, buf_size, 1);
193        ADVANCE_BY_DECODED;
194        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
195                                    p->linesize[1], buf, buf_size, 1);
196        ADVANCE_BY_DECODED;
197        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
198                                    p->linesize[2], buf, buf_size, 1);
199        break;
200    case LOCO_CYV12: case LOCO_YV12:
201        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
202                                    p->linesize[0], buf, buf_size, 1);
203        ADVANCE_BY_DECODED;
204        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
205                                    p->linesize[2], buf, buf_size, 1);
206        ADVANCE_BY_DECODED;
207        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
208                                    p->linesize[1], buf, buf_size, 1);
209        break;
210    case LOCO_CRGB: case LOCO_RGB:
211        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
212                                    -p->linesize[0], buf, buf_size, 3);
213        ADVANCE_BY_DECODED;
214        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
215                                    -p->linesize[0], buf, buf_size, 3);
216        ADVANCE_BY_DECODED;
217        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
218                                    -p->linesize[0], buf, buf_size, 3);
219        break;
220    case LOCO_CRGBA:
221    case LOCO_RGBA:
222        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
223                                    -p->linesize[0], buf, buf_size, 4);
224        ADVANCE_BY_DECODED;
225        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
226                                    -p->linesize[0], buf, buf_size, 4);
227        ADVANCE_BY_DECODED;
228        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
229                                    -p->linesize[0], buf, buf_size, 4);
230        ADVANCE_BY_DECODED;
231        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 3, avctx->width, avctx->height,
232                                    -p->linesize[0], buf, buf_size, 4);
233        break;
234    default:
235        av_assert0(0);
236    }
237
238    if (decoded < 0 || decoded > buf_size)
239        goto buf_too_small;
240    buf_size -= decoded;
241
242    *got_frame      = 1;
243
244    return avpkt->size - buf_size;
245buf_too_small:
246    av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
247    return AVERROR(EINVAL);
248}
249
250static av_cold int decode_init(AVCodecContext *avctx)
251{
252    LOCOContext * const l = avctx->priv_data;
253    int version;
254
255    l->avctx = avctx;
256    if (avctx->extradata_size < 12) {
257        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
258               avctx->extradata_size);
259        return AVERROR_INVALIDDATA;
260    }
261    version = AV_RL32(avctx->extradata);
262    switch (version) {
263    case 1:
264        l->lossy = 0;
265        break;
266    case 2:
267        l->lossy = AV_RL32(avctx->extradata + 8);
268        break;
269    default:
270        l->lossy = AV_RL32(avctx->extradata + 8);
271        avpriv_request_sample(avctx, "LOCO codec version %i", version);
272    }
273
274    l->mode = AV_RL32(avctx->extradata + 4);
275    switch (l->mode) {
276    case LOCO_CYUY2:
277    case LOCO_YUY2:
278    case LOCO_UYVY:
279        avctx->pix_fmt = AV_PIX_FMT_YUV422P;
280        break;
281    case LOCO_CRGB:
282    case LOCO_RGB:
283        avctx->pix_fmt = AV_PIX_FMT_BGR24;
284        break;
285    case LOCO_CYV12:
286    case LOCO_YV12:
287        avctx->pix_fmt = AV_PIX_FMT_YUV420P;
288        break;
289    case LOCO_CRGBA:
290    case LOCO_RGBA:
291        avctx->pix_fmt = AV_PIX_FMT_BGRA;
292        break;
293    default:
294        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
295        return AVERROR_INVALIDDATA;
296    }
297    if (avctx->debug & FF_DEBUG_PICT_INFO)
298        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
299
300    return 0;
301}
302
303AVCodec ff_loco_decoder = {
304    .name           = "loco",
305    .long_name      = NULL_IF_CONFIG_SMALL("LOCO"),
306    .type           = AVMEDIA_TYPE_VIDEO,
307    .id             = AV_CODEC_ID_LOCO,
308    .priv_data_size = sizeof(LOCOContext),
309    .init           = decode_init,
310    .decode         = decode_frame,
311    .capabilities   = CODEC_CAP_DR1,
312};
313