Libav
loco.c
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1 /*
2  * LOCO codec
3  * Copyright (c) 2005 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "golomb.h"
30 #include "internal.h"
31 #include "mathops.h"
32 
33 enum 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 
46 typedef struct LOCOContext {
48  int lossy;
49  int mode;
50 } LOCOContext;
51 
52 typedef struct RICEContext {
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 
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 
72 static 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 
83 static inline int loco_get_rice(RICEContext *r)
84 {
85  int v;
86  if (r->run > 0) { /* we have zero run */
87  r->run--;
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 */
117 static 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 
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  init_get_bits(&rc.gb, buf, buf_size*8);
136  rc.save = 0;
137  rc.run = 0;
138  rc.run2 = 0;
139  rc.lossy = l->lossy;
140 
141  rc.sum = 8;
142  rc.count = 1;
143 
144  /* restore top left pixel */
145  val = loco_get_rice(&rc);
146  data[0] = 128 + val;
147  /* restore top line */
148  for (i = 1; i < width; i++) {
149  val = loco_get_rice(&rc);
150  data[i * step] = data[i * step - step] + val;
151  }
152  data += stride;
153  for (j = 1; j < height; j++) {
154  /* restore left column */
155  val = loco_get_rice(&rc);
156  data[0] = data[-stride] + val;
157  /* restore all other pixels */
158  for (i = 1; i < width; i++) {
159  val = loco_get_rice(&rc);
160  data[i * step] = loco_predict(&data[i * step], stride, step) + val;
161  }
162  data += stride;
163  }
164 
165  return (get_bits_count(&rc.gb) + 7) >> 3;
166 }
167 
168 static int decode_frame(AVCodecContext *avctx,
169  void *data, int *got_frame,
170  AVPacket *avpkt)
171 {
172  LOCOContext * const l = avctx->priv_data;
173  const uint8_t *buf = avpkt->data;
174  int buf_size = avpkt->size;
175  AVFrame * const p = data;
176  int decoded, ret;
177 
178  if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
179  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
180  return ret;
181  }
182  p->key_frame = 1;
183 
184  switch(l->mode) {
185  case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
186  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
187  p->linesize[0], buf, buf_size, 1);
188  if (decoded >= buf_size)
189  goto buf_too_small;
190  buf += decoded; buf_size -= decoded;
191 
192  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
193  p->linesize[1], buf, buf_size, 1);
194  if (decoded >= buf_size)
195  goto buf_too_small;
196  buf += decoded; buf_size -= decoded;
197 
198  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
199  p->linesize[2], buf, buf_size, 1);
200  break;
201  case LOCO_CYV12: case LOCO_YV12:
202  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
203  p->linesize[0], buf, buf_size, 1);
204  if (decoded >= buf_size)
205  goto buf_too_small;
206  buf += decoded; buf_size -= decoded;
207 
208  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
209  p->linesize[2], buf, buf_size, 1);
210  if (decoded >= buf_size)
211  goto buf_too_small;
212  buf += decoded; buf_size -= decoded;
213 
214  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
215  p->linesize[1], buf, buf_size, 1);
216  break;
217  case LOCO_CRGB: case LOCO_RGB:
218  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
219  -p->linesize[0], buf, buf_size, 3);
220  if (decoded >= buf_size)
221  goto buf_too_small;
222  buf += decoded; buf_size -= decoded;
223 
224  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
225  -p->linesize[0], buf, buf_size, 3);
226  if (decoded >= buf_size)
227  goto buf_too_small;
228  buf += decoded; buf_size -= decoded;
229 
230  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
231  -p->linesize[0], buf, buf_size, 3);
232  break;
233  case LOCO_RGBA:
234  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
235  p->linesize[0], buf, buf_size, 4);
236  if (decoded >= buf_size)
237  goto buf_too_small;
238  buf += decoded; buf_size -= decoded;
239 
240  decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
241  p->linesize[0], buf, buf_size, 4);
242  if (decoded >= buf_size)
243  goto buf_too_small;
244  buf += decoded; buf_size -= decoded;
245 
246  decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
247  p->linesize[0], buf, buf_size, 4);
248  if (decoded >= buf_size)
249  goto buf_too_small;
250  buf += decoded; buf_size -= decoded;
251 
252  decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
253  p->linesize[0], buf, buf_size, 4);
254  break;
255  }
256 
257  *got_frame = 1;
258 
259  return buf_size;
260 buf_too_small:
261  av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
262  return AVERROR(EINVAL);
263 }
264 
266 {
267  LOCOContext * const l = avctx->priv_data;
268  int version;
269 
270  l->avctx = avctx;
271  if (avctx->extradata_size < 12) {
272  av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
273  avctx->extradata_size);
274  return AVERROR_INVALIDDATA;
275  }
276  version = AV_RL32(avctx->extradata);
277  switch (version) {
278  case 1:
279  l->lossy = 0;
280  break;
281  case 2:
282  l->lossy = AV_RL32(avctx->extradata + 8);
283  break;
284  default:
285  l->lossy = AV_RL32(avctx->extradata + 8);
286  avpriv_request_sample(avctx, "LOCO codec version %i", version);
287  }
288 
289  l->mode = AV_RL32(avctx->extradata + 4);
290  switch (l->mode) {
291  case LOCO_CYUY2:
292  case LOCO_YUY2:
293  case LOCO_UYVY:
294  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
295  break;
296  case LOCO_CRGB:
297  case LOCO_RGB:
298  avctx->pix_fmt = AV_PIX_FMT_BGR24;
299  break;
300  case LOCO_CYV12:
301  case LOCO_YV12:
302  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
303  break;
304  case LOCO_CRGBA:
305  case LOCO_RGBA:
306  avctx->pix_fmt = AV_PIX_FMT_RGB32;
307  break;
308  default:
309  av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
310  return AVERROR_INVALIDDATA;
311  }
312  if (avctx->debug & FF_DEBUG_PICT_INFO)
313  av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
314 
315  return 0;
316 }
317 
319  .name = "loco",
320  .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
321  .type = AVMEDIA_TYPE_VIDEO,
322  .id = AV_CODEC_ID_LOCO,
323  .priv_data_size = sizeof(LOCOContext),
324  .init = decode_init,
325  .decode = decode_frame,
326  .capabilities = CODEC_CAP_DR1,
327 };