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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 {
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  if(buf_size<=0)
136  return -1;
137 
138  init_get_bits(&rc.gb, buf, buf_size*8);
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 
171 static 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);
194  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
195  p->linesize[1], buf, buf_size, 1);
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);
204  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
205  p->linesize[2], buf, buf_size, 1);
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);
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);
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);
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);
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);
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;
245 buf_too_small:
246  av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
247  return AVERROR(EINVAL);
248 }
249 
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 
304  .name = "loco",
305  .type = AVMEDIA_TYPE_VIDEO,
306  .id = AV_CODEC_ID_LOCO,
307  .priv_data_size = sizeof(LOCOContext),
308  .init = decode_init,
309  .decode = decode_frame,
310  .capabilities = CODEC_CAP_DR1,
311  .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
312 };