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loco.c
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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 
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 {
47  AVCodecContext *avctx;
48  int lossy;
49  enum LOCO_MODE mode;
50 } LOCOContext;
51 
52 typedef 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 
59 static 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 
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--;
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 */
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 
128 static 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 ret;
134  int i, j;
135 
136  if(buf_size<=0)
137  return -1;
138 
139  if ((ret = init_get_bits8(&rc.gb, buf, buf_size)) < 0)
140  return ret;
141 
142  rc.save = 0;
143  rc.run = 0;
144  rc.run2 = 0;
145  rc.lossy = l->lossy;
146 
147  rc.sum = 8;
148  rc.count = 1;
149 
150  /* restore top left pixel */
151  val = loco_get_rice(&rc);
152  data[0] = 128 + val;
153  /* restore top line */
154  for (i = 1; i < width; i++) {
155  val = loco_get_rice(&rc);
156  data[i * step] = data[i * step - step] + val;
157  }
158  data += stride;
159  for (j = 1; j < height; j++) {
160  /* restore left column */
161  val = loco_get_rice(&rc);
162  data[0] = data[-stride] + val;
163  /* restore all other pixels */
164  for (i = 1; i < width; i++) {
165  val = loco_get_rice(&rc);
166  data[i * step] = loco_predict(&data[i * step], stride, step) + val;
167  }
168  data += stride;
169  }
170 
171  return (get_bits_count(&rc.gb) + 7) >> 3;
172 }
173 
174 static void rotate_faulty_loco(uint8_t *data, int width, int height, int stride, int step)
175 {
176  int y;
177 
178  for (y=1; y<height; y++) {
179  if (width>=y) {
180  memmove(data + y*stride,
181  data + y*(stride + step),
182  step*(width-y));
183  if (y+1 < height)
184  memmove(data + y*stride + step*(width-y),
185  data + (y+1)*stride,
186  step*y);
187  }
188  }
189 }
190 
191 static int decode_frame(AVCodecContext *avctx,
192  void *data, int *got_frame,
193  AVPacket *avpkt)
194 {
195  LOCOContext * const l = avctx->priv_data;
196  const uint8_t *buf = avpkt->data;
197  int buf_size = avpkt->size;
198  AVFrame * const p = data;
199  int decoded, ret;
200 
201  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
202  return ret;
203  p->key_frame = 1;
204 
205 #define ADVANCE_BY_DECODED do { \
206  if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \
207  buf += decoded; buf_size -= decoded; \
208 } while(0)
209  switch(l->mode) {
210  case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
211  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
212  p->linesize[0], buf, buf_size, 1);
213  ADVANCE_BY_DECODED;
214  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
215  p->linesize[1], buf, buf_size, 1);
216  ADVANCE_BY_DECODED;
217  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
218  p->linesize[2], buf, buf_size, 1);
219  break;
220  case LOCO_CYV12: case LOCO_YV12:
221  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
222  p->linesize[0], buf, buf_size, 1);
223  ADVANCE_BY_DECODED;
224  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
225  p->linesize[2], buf, buf_size, 1);
226  ADVANCE_BY_DECODED;
227  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
228  p->linesize[1], buf, buf_size, 1);
229  break;
230  case LOCO_CRGB: case LOCO_RGB:
231  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
232  -p->linesize[0], buf, buf_size, 3);
233  ADVANCE_BY_DECODED;
234  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
235  -p->linesize[0], buf, buf_size, 3);
236  ADVANCE_BY_DECODED;
237  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
238  -p->linesize[0], buf, buf_size, 3);
239  if (avctx->width & 1)
240  rotate_faulty_loco(p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[0], 3);
241  break;
242  case LOCO_CRGBA:
243  case LOCO_RGBA:
244  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
245  -p->linesize[0], buf, buf_size, 4);
246  ADVANCE_BY_DECODED;
247  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
248  -p->linesize[0], buf, buf_size, 4);
249  ADVANCE_BY_DECODED;
250  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
251  -p->linesize[0], buf, buf_size, 4);
252  ADVANCE_BY_DECODED;
253  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 3, avctx->width, avctx->height,
254  -p->linesize[0], buf, buf_size, 4);
255  break;
256  default:
257  av_assert0(0);
258  }
259 
260  if (decoded < 0 || decoded > buf_size)
261  goto buf_too_small;
262  buf_size -= decoded;
263 
264  *got_frame = 1;
265 
266  return avpkt->size - buf_size;
267 buf_too_small:
268  av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
269  return AVERROR(EINVAL);
270 }
271 
272 static av_cold int decode_init(AVCodecContext *avctx)
273 {
274  LOCOContext * const l = avctx->priv_data;
275  int version;
276 
277  l->avctx = avctx;
278  if (avctx->extradata_size < 12) {
279  av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
280  avctx->extradata_size);
281  return AVERROR_INVALIDDATA;
282  }
283  version = AV_RL32(avctx->extradata);
284  switch (version) {
285  case 1:
286  l->lossy = 0;
287  break;
288  case 2:
289  l->lossy = AV_RL32(avctx->extradata + 8);
290  break;
291  default:
292  l->lossy = AV_RL32(avctx->extradata + 8);
293  avpriv_request_sample(avctx, "LOCO codec version %i", version);
294  }
295 
296  l->mode = AV_RL32(avctx->extradata + 4);
297  switch (l->mode) {
298  case LOCO_CYUY2:
299  case LOCO_YUY2:
300  case LOCO_UYVY:
301  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
302  break;
303  case LOCO_CRGB:
304  case LOCO_RGB:
305  avctx->pix_fmt = AV_PIX_FMT_BGR24;
306  break;
307  case LOCO_CYV12:
308  case LOCO_YV12:
309  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
310  break;
311  case LOCO_CRGBA:
312  case LOCO_RGBA:
313  avctx->pix_fmt = AV_PIX_FMT_BGRA;
314  break;
315  default:
316  av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
317  return AVERROR_INVALIDDATA;
318  }
319  if (avctx->debug & FF_DEBUG_PICT_INFO)
320  av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
321 
322  return 0;
323 }
324 
325 AVCodec ff_loco_decoder = {
326  .name = "loco",
327  .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
328  .type = AVMEDIA_TYPE_VIDEO,
329  .id = AV_CODEC_ID_LOCO,
330  .priv_data_size = sizeof(LOCOContext),
331  .init = decode_init,
332  .decode = decode_frame,
333  .capabilities = CODEC_CAP_DR1,
334 };
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