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 "codec_internal.h"
29 #include "get_bits.h"
30 #include "golomb.h"
31 #include "internal.h"
32 #include "mathops.h"
33 
34 enum LOCO_MODE {
35     LOCO_UNKN  =  0,
36     LOCO_CYUY2 = -1,
37     LOCO_CRGB  = -2,
38     LOCO_CRGBA = -3,
39     LOCO_CYV12 = -4,
40     LOCO_YUY2  =  1,
41     LOCO_UYVY  =  2,
42     LOCO_RGB   =  3,
43     LOCO_RGBA  =  4,
44     LOCO_YV12  =  5,
45 };
46 
47 typedef struct LOCOContext {
48     AVCodecContext *avctx;
49     int lossy;
50     enum LOCO_MODE mode;
51 } LOCOContext;
52 
53 typedef struct RICEContext {
54     GetBitContext gb;
55     int save, run, run2; /* internal rice decoder state */
56     int sum, count; /* sum and count for getting rice parameter */
57     int lossy;
58 } RICEContext;
59 
loco_get_rice_param(RICEContext *r)60 static int loco_get_rice_param(RICEContext *r)
61 {
62     int cnt = 0;
63     int val = r->count;
64 
65     while (r->sum > val && cnt < 9) {
66         val <<= 1;
67         cnt++;
68     }
69 
70     return cnt;
71 }
72 
loco_update_rice_param(RICEContext *r, int val)73 static inline void loco_update_rice_param(RICEContext *r, int val)
74 {
75     r->sum += val;
76     r->count++;
77 
78     if (r->count == 16) {
79         r->sum   >>= 1;
80         r->count >>= 1;
81     }
82 }
83 
loco_get_rice(RICEContext *r)84 static inline int loco_get_rice(RICEContext *r)
85 {
86     unsigned v;
87     if (r->run > 0) { /* we have zero run */
88         r->run--;
89         loco_update_rice_param(r, 0);
90         return 0;
91     }
92     if (get_bits_left(&r->gb) < 1)
93         return INT_MIN;
94     v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
95     loco_update_rice_param(r, (v + 1) >> 1);
96     if (!v) {
97         if (r->save >= 0) {
98             r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
99             if (r->run > 1)
100                 r->save += r->run + 1;
101             else
102                 r->save -= 3;
103         } else
104             r->run2++;
105     } else {
106         v = ((v >> 1) + r->lossy) ^ -(v & 1);
107         if (r->run2 > 0) {
108             if (r->run2 > 2)
109                 r->save += r->run2;
110             else
111                 r->save -= 3;
112             r->run2 = 0;
113         }
114     }
115 
116     return v;
117 }
118 
119 /* LOCO main predictor - LOCO-I/JPEG-LS predictor */
loco_predict(uint8_t* data, int stride)120 static inline int loco_predict(uint8_t* data, int stride)
121 {
122     int a, b, c;
123 
124     a = data[-stride];
125     b = data[-1];
126     c = data[-stride - 1];
127 
128     return mid_pred(a, a + b - c, b);
129 }
130 
loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height, int stride, const uint8_t *buf, int buf_size)131 static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
132                              int stride, const uint8_t *buf, int buf_size)
133 {
134     RICEContext rc;
135     unsigned val;
136     int ret;
137     int i, j;
138 
139     if(buf_size<=0)
140         return -1;
141 
142     if ((ret = init_get_bits8(&rc.gb, buf, buf_size)) < 0)
143         return ret;
144 
145     rc.save  = 0;
146     rc.run   = 0;
147     rc.run2  = 0;
148     rc.lossy = l->lossy;
149 
150     rc.sum   = 8;
151     rc.count = 1;
152 
153     /* restore top left pixel */
154     val     = loco_get_rice(&rc);
155     data[0] = 128 + val;
156     /* restore top line */
157     for (i = 1; i < width; i++) {
158         val = loco_get_rice(&rc);
159         if (val == INT_MIN)
160            return AVERROR_INVALIDDATA;
161         data[i] = data[i - 1] + val;
162     }
163     data += stride;
164     for (j = 1; j < height; j++) {
165         /* restore left column */
166         val = loco_get_rice(&rc);
167         if (val == INT_MIN)
168            return AVERROR_INVALIDDATA;
169         data[0] = data[-stride] + val;
170         /* restore all other pixels */
171         for (i = 1; i < width; i++) {
172             val = loco_get_rice(&rc);
173             if (val == INT_MIN)
174                 return -1;
175             data[i] = loco_predict(&data[i], stride) + val;
176         }
177         data += stride;
178     }
179 
180     return (get_bits_count(&rc.gb) + 7) >> 3;
181 }
182 
rotate_faulty_loco(uint8_t *data, int width, int height, int stride)183 static void rotate_faulty_loco(uint8_t *data, int width, int height, int stride)
184 {
185     int y;
186 
187     for (y=1; y<height; y++) {
188         if (width>=y) {
189             memmove(data + y*stride,
190                     data + y*(stride + 1),
191                     (width-y));
192             if (y+1 < height)
193                 memmove(data + y*stride + (width-y),
194                         data + (y+1)*stride, y);
195         }
196     }
197 }
198 
decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)199 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
200                         int *got_frame, AVPacket *avpkt)
201 {
202     LOCOContext * const l = avctx->priv_data;
203     const uint8_t *buf    = avpkt->data;
204     int buf_size          = avpkt->size;
205     int decoded, ret;
206 
207     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
208         return ret;
209     p->key_frame = 1;
210 
211 #define ADVANCE_BY_DECODED do { \
212     if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \
213     buf += decoded; buf_size -= decoded; \
214 } while(0)
215     switch(l->mode) {
216     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
217         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
218                                     p->linesize[0], buf, buf_size);
219         ADVANCE_BY_DECODED;
220         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
221                                     p->linesize[1], buf, buf_size);
222         ADVANCE_BY_DECODED;
223         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
224                                     p->linesize[2], buf, buf_size);
225         break;
226     case LOCO_CYV12: case LOCO_YV12:
227         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
228                                     p->linesize[0], buf, buf_size);
229         ADVANCE_BY_DECODED;
230         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
231                                     p->linesize[2], buf, buf_size);
232         ADVANCE_BY_DECODED;
233         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
234                                     p->linesize[1], buf, buf_size);
235         break;
236     case LOCO_CRGB: case LOCO_RGB:
237         decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
238                                     -p->linesize[1], buf, buf_size);
239         ADVANCE_BY_DECODED;
240         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
241                                     -p->linesize[0], buf, buf_size);
242         ADVANCE_BY_DECODED;
243         decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
244                                     -p->linesize[2], buf, buf_size);
245         if (avctx->width & 1) {
246             rotate_faulty_loco(p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[0]);
247             rotate_faulty_loco(p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[1]);
248             rotate_faulty_loco(p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[2]);
249         }
250         break;
251     case LOCO_CRGBA:
252     case LOCO_RGBA:
253         decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
254                                     -p->linesize[1], buf, buf_size);
255         ADVANCE_BY_DECODED;
256         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
257                                     -p->linesize[0], buf, buf_size);
258         ADVANCE_BY_DECODED;
259         decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
260                                     -p->linesize[2], buf, buf_size);
261         ADVANCE_BY_DECODED;
262         decoded = loco_decode_plane(l, p->data[3] + p->linesize[3]*(avctx->height-1), avctx->width, avctx->height,
263                                     -p->linesize[3], buf, buf_size);
264         break;
265     default:
266         av_assert0(0);
267     }
268 
269     if (decoded < 0 || decoded > buf_size)
270         goto buf_too_small;
271     buf_size -= decoded;
272 
273     *got_frame      = 1;
274 
275     return avpkt->size - buf_size;
276 buf_too_small:
277     av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
278     return AVERROR(EINVAL);
279 }
280 
decode_init(AVCodecContext *avctx)281 static av_cold int decode_init(AVCodecContext *avctx)
282 {
283     LOCOContext * const l = avctx->priv_data;
284     int version;
285 
286     l->avctx = avctx;
287     if (avctx->extradata_size < 12) {
288         av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
289                avctx->extradata_size);
290         return AVERROR_INVALIDDATA;
291     }
292     version = AV_RL32(avctx->extradata);
293     switch (version) {
294     case 1:
295         l->lossy = 0;
296         break;
297     case 2:
298         l->lossy = AV_RL32(avctx->extradata + 8);
299         break;
300     default:
301         l->lossy = AV_RL32(avctx->extradata + 8);
302         avpriv_request_sample(avctx, "LOCO codec version %i", version);
303     }
304 
305     if (l->lossy > 65536U) {
306         av_log(avctx, AV_LOG_ERROR, "lossy %i is too large\n", l->lossy);
307         return AVERROR_INVALIDDATA;
308     }
309 
310     l->mode = AV_RL32(avctx->extradata + 4);
311     switch (l->mode) {
312     case LOCO_CYUY2:
313     case LOCO_YUY2:
314     case LOCO_UYVY:
315         avctx->pix_fmt = AV_PIX_FMT_YUV422P;
316         break;
317     case LOCO_CRGB:
318     case LOCO_RGB:
319         avctx->pix_fmt = AV_PIX_FMT_GBRP;
320         break;
321     case LOCO_CYV12:
322     case LOCO_YV12:
323         avctx->pix_fmt = AV_PIX_FMT_YUV420P;
324         break;
325     case LOCO_CRGBA:
326     case LOCO_RGBA:
327         avctx->pix_fmt = AV_PIX_FMT_GBRAP;
328         break;
329     default:
330         av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
331         return AVERROR_INVALIDDATA;
332     }
333     if (avctx->debug & FF_DEBUG_PICT_INFO)
334         av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
335 
336     return 0;
337 }
338 
339 const FFCodec ff_loco_decoder = {
340     .p.name         = "loco",
341     .p.long_name    = NULL_IF_CONFIG_SMALL("LOCO"),
342     .p.type         = AVMEDIA_TYPE_VIDEO,
343     .p.id           = AV_CODEC_ID_LOCO,
344     .priv_data_size = sizeof(LOCOContext),
345     .init           = decode_init,
346     FF_CODEC_DECODE_CB(decode_frame),
347     .p.capabilities = AV_CODEC_CAP_DR1,
348     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
349 };
350