FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
motionpixels.c
Go to the documentation of this file.
1 /*
2  * Motion Pixels Video Decoder
3  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 #include "avcodec.h"
23 #include "get_bits.h"
24 #include "bswapdsp.h"
25 #include "internal.h"
26 
27 #define MAX_HUFF_CODES 16
28 
29 #include "motionpixels_tablegen.h"
30 
31 typedef struct HuffCode {
32  int code;
35 } HuffCode;
36 
37 typedef struct MotionPixelsContext {
52 
54 {
55  MotionPixelsContext *mp = avctx->priv_data;
56 
57  av_freep(&mp->changes_map);
58  av_freep(&mp->vpt);
59  av_freep(&mp->hpt);
60  av_freep(&mp->bswapbuf);
61  av_frame_free(&mp->frame);
62 
63  return 0;
64 }
65 
67 {
68  MotionPixelsContext *mp = avctx->priv_data;
69  int w4 = (avctx->width + 3) & ~3;
70  int h4 = (avctx->height + 3) & ~3;
71 
72  if(avctx->extradata_size < 2){
73  av_log(avctx, AV_LOG_ERROR, "extradata too small\n");
74  return AVERROR_INVALIDDATA;
75  }
76 
78  mp->avctx = avctx;
79  ff_bswapdsp_init(&mp->bdsp);
80  mp->changes_map = av_mallocz_array(avctx->width, h4);
81  mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
82  mp->vpt = av_mallocz_array(avctx->height, sizeof(YuvPixel));
83  mp->hpt = av_mallocz_array(h4 / 4, w4 / 4 * sizeof(YuvPixel));
84  if (!mp->changes_map || !mp->vpt || !mp->hpt) {
85  av_freep(&mp->changes_map);
86  av_freep(&mp->vpt);
87  av_freep(&mp->hpt);
88  return AVERROR(ENOMEM);
89  }
90  avctx->pix_fmt = AV_PIX_FMT_RGB555;
91 
92  mp->frame = av_frame_alloc();
93  if (!mp->frame) {
94  mp_decode_end(avctx);
95  return AVERROR(ENOMEM);
96  }
97 
98  return 0;
99 }
100 
101 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
102 {
103  uint16_t *pixels;
104  int offset, w, h, color = 0, x, y, i;
105 
106  while (count--) {
107  offset = get_bits_long(gb, mp->offset_bits_len);
108  w = get_bits(gb, bits_len) + 1;
109  h = get_bits(gb, bits_len) + 1;
110  if (read_color)
111  color = get_bits(gb, 15);
112  x = offset % mp->avctx->width;
113  y = offset / mp->avctx->width;
114  if (y >= mp->avctx->height)
115  continue;
116  w = FFMIN(w, mp->avctx->width - x);
117  h = FFMIN(h, mp->avctx->height - y);
118  pixels = (uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
119  while (h--) {
120  mp->changes_map[offset] = w;
121  if (read_color)
122  for (i = 0; i < w; ++i)
123  pixels[i] = color;
124  offset += mp->avctx->width;
125  pixels += mp->frame->linesize[0] / 2;
126  }
127  }
128 }
129 
130 static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
131 {
132  while (get_bits1(gb)) {
133  ++size;
134  if (size > mp->max_codes_bits) {
135  av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
136  return AVERROR_INVALIDDATA;
137  }
138  code <<= 1;
139  if (mp_get_code(mp, gb, size, code + 1) < 0)
140  return AVERROR_INVALIDDATA;
141  }
142  if (mp->current_codes_count >= MAX_HUFF_CODES) {
143  av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
144  return AVERROR_INVALIDDATA;
145  }
146 
147  mp->codes[mp->current_codes_count ].code = code;
148  mp->codes[mp->current_codes_count++].size = size;
149  return 0;
150 }
151 
153 {
154  if (mp->codes_count == 1) {
155  mp->codes[0].delta = get_bits(gb, 4);
156  } else {
157  int i;
158  int ret;
159 
160  mp->max_codes_bits = get_bits(gb, 4);
161  for (i = 0; i < mp->codes_count; ++i)
162  mp->codes[i].delta = get_bits(gb, 4);
163  mp->current_codes_count = 0;
164  if ((ret = mp_get_code(mp, gb, 0, 0)) < 0)
165  return ret;
166  if (mp->current_codes_count < mp->codes_count) {
167  av_log(mp->avctx, AV_LOG_ERROR, "too few codes\n");
168  return AVERROR_INVALIDDATA;
169  }
170  }
171  return 0;
172 }
173 
174 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
175 {
176  int delta;
177 
178  delta = (v - 7) * mp->gradient_scale[component];
179  mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
180  return delta;
181 }
182 
184 {
185  int color;
186 
187  color = *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
188  return mp_rgb_yuv_table[color];
189 }
190 
191 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
192 {
193  int color;
194 
195  color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
196  *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2] = color;
197 }
198 
200 {
201  int i;
202 
203  i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
204  return mp->codes[i].delta;
205 }
206 
208 {
209  YuvPixel p;
210  const int y0 = y * mp->avctx->width;
211  int w, i, x = 0;
212 
213  p = mp->vpt[y];
214  if (mp->changes_map[y0 + x] == 0) {
215  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
216  ++x;
217  }
218  while (x < mp->avctx->width) {
219  w = mp->changes_map[y0 + x];
220  if (w != 0) {
221  if ((y & 3) == 0) {
222  if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
223  mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
224  mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
225  for (i = (x + 3) & ~3; i < x + w; i += 4) {
226  mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
227  }
228  }
229  }
230  x += w;
231  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
232  p = mp_get_yuv_from_rgb(mp, x - 1, y);
233  } else {
234  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
235  p.y = av_clip(p.y, 0, 31);
236  if ((x & 3) == 0) {
237  if ((y & 3) == 0) {
238  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
239  p.v = av_clip(p.v, -32, 31);
240  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
241  p.u = av_clip(p.u, -32, 31);
242  mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
243  } else {
244  p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
245  p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
246  }
247  }
248  mp_set_rgb_from_yuv(mp, x, y, &p);
249  ++x;
250  }
251  }
252 }
253 
255 {
256  YuvPixel p;
257  int y, y0;
258 
259  av_assert1(mp->changes_map[0]);
260 
261  for (y = 0; y < mp->avctx->height; ++y) {
262  if (mp->changes_map[y * mp->avctx->width] != 0) {
263  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
264  p = mp_get_yuv_from_rgb(mp, 0, y);
265  } else {
266  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
267  p.y = av_clip(p.y, 0, 31);
268  if ((y & 3) == 0) {
269  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
270  p.v = av_clip(p.v, -32, 31);
271  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
272  p.u = av_clip(p.u, -32, 31);
273  }
274  mp->vpt[y] = p;
275  mp_set_rgb_from_yuv(mp, 0, y, &p);
276  }
277  }
278  for (y0 = 0; y0 < 2; ++y0)
279  for (y = y0; y < mp->avctx->height; y += 2)
280  mp_decode_line(mp, gb, y);
281 }
282 
283 static int mp_decode_frame(AVCodecContext *avctx,
284  void *data, int *got_frame,
285  AVPacket *avpkt)
286 {
287  const uint8_t *buf = avpkt->data;
288  int buf_size = avpkt->size;
289  MotionPixelsContext *mp = avctx->priv_data;
290  GetBitContext gb;
291  int i, count1, count2, sz, ret;
292 
293  if ((ret = ff_reget_buffer(avctx, mp->frame)) < 0)
294  return ret;
295 
296  /* le32 bitstream msb first */
297  av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);
298  if (!mp->bswapbuf)
299  return AVERROR(ENOMEM);
300  mp->bdsp.bswap_buf((uint32_t *) mp->bswapbuf, (const uint32_t *) buf,
301  buf_size / 4);
302  if (buf_size & 3)
303  memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
304  init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
305 
306  memset(mp->changes_map, 0, avctx->width * avctx->height);
307  for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
308  count1 = get_bits(&gb, 12);
309  count2 = get_bits(&gb, 12);
310  mp_read_changes_map(mp, &gb, count1, 8, i);
311  mp_read_changes_map(mp, &gb, count2, 4, i);
312  }
313 
314  mp->codes_count = get_bits(&gb, 4);
315  if (mp->codes_count == 0)
316  goto end;
317 
318  if (mp->changes_map[0] == 0) {
319  *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);
320  mp->changes_map[0] = 1;
321  }
322  if (mp_read_codes_table(mp, &gb) < 0)
323  goto end;
324 
325  sz = get_bits(&gb, 18);
326  if (avctx->extradata[0] != 5)
327  sz += get_bits(&gb, 18);
328  if (sz == 0)
329  goto end;
330 
331  if (mp->max_codes_bits <= 0)
332  goto end;
333  if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
334  goto end;
335  mp_decode_frame_helper(mp, &gb);
336  ff_free_vlc(&mp->vlc);
337 
338 end:
339  if ((ret = av_frame_ref(data, mp->frame)) < 0)
340  return ret;
341  *got_frame = 1;
342  return buf_size;
343 }
344 
346  .name = "motionpixels",
347  .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
348  .type = AVMEDIA_TYPE_VIDEO,
350  .priv_data_size = sizeof(MotionPixelsContext),
351  .init = mp_decode_init,
352  .close = mp_decode_end,
354  .capabilities = CODEC_CAP_DR1,
355 };