motionpixels.c
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1 /*
2  * Motion Pixels Video Decoder
3  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 
22 #include "avcodec.h"
23 #include "get_bits.h"
24 #include "dsputil.h"
25 
26 #define MAX_HUFF_CODES 16
27 
28 #include "motionpixels_tablegen.h"
29 
30 typedef struct HuffCode {
31  int code;
34 } HuffCode;
35 
36 typedef struct MotionPixelsContext {
51 
53 {
54  MotionPixelsContext *mp = avctx->priv_data;
55  int w4 = (avctx->width + 3) & ~3;
56  int h4 = (avctx->height + 3) & ~3;
57 
59  mp->avctx = avctx;
60  ff_dsputil_init(&mp->dsp, avctx);
61  mp->changes_map = av_mallocz(avctx->width * h4);
62  mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
63  mp->vpt = av_mallocz(avctx->height * sizeof(YuvPixel));
64  mp->hpt = av_mallocz(h4 * w4 / 16 * sizeof(YuvPixel));
65  avctx->pix_fmt = AV_PIX_FMT_RGB555;
66  return 0;
67 }
68 
69 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
70 {
71  uint16_t *pixels;
72  int offset, w, h, color = 0, x, y, i;
73 
74  while (count--) {
75  offset = get_bits_long(gb, mp->offset_bits_len);
76  w = get_bits(gb, bits_len) + 1;
77  h = get_bits(gb, bits_len) + 1;
78  if (read_color)
79  color = get_bits(gb, 15);
80  x = offset % mp->avctx->width;
81  y = offset / mp->avctx->width;
82  if (y >= mp->avctx->height)
83  continue;
84  w = FFMIN(w, mp->avctx->width - x);
85  h = FFMIN(h, mp->avctx->height - y);
86  pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
87  while (h--) {
88  mp->changes_map[offset] = w;
89  if (read_color)
90  for (i = 0; i < w; ++i)
91  pixels[i] = color;
92  offset += mp->avctx->width;
93  pixels += mp->frame.linesize[0] / 2;
94  }
95  }
96 }
97 
98 static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
99 {
100  while (get_bits1(gb)) {
101  ++size;
102  if (size > mp->max_codes_bits) {
103  av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
104  return;
105  }
106  code <<= 1;
107  mp_get_code(mp, gb, size, code + 1);
108  }
109  if (mp->current_codes_count >= MAX_HUFF_CODES) {
110  av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
111  return;
112  }
113  mp->codes[mp->current_codes_count ].code = code;
114  mp->codes[mp->current_codes_count++].size = size;
115 }
116 
118 {
119  if (mp->codes_count == 1) {
120  mp->codes[0].delta = get_bits(gb, 4);
121  } else {
122  int i;
123 
124  mp->max_codes_bits = get_bits(gb, 4);
125  for (i = 0; i < mp->codes_count; ++i)
126  mp->codes[i].delta = get_bits(gb, 4);
127  mp->current_codes_count = 0;
128  mp_get_code(mp, gb, 0, 0);
129  }
130 }
131 
132 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
133 {
134  int delta;
135 
136  delta = (v - 7) * mp->gradient_scale[component];
137  mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
138  return delta;
139 }
140 
142 {
143  int color;
144 
145  color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
146  return mp_rgb_yuv_table[color];
147 }
148 
149 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
150 {
151  int color;
152 
153  color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
154  *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
155 }
156 
158 {
159  int i;
160 
161  i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
162  i = FFMIN(i, FF_ARRAY_ELEMS(mp->codes) - 1);
163  return mp->codes[i].delta;
164 }
165 
167 {
168  YuvPixel p;
169  const int y0 = y * mp->avctx->width;
170  int w, i, x = 0;
171 
172  p = mp->vpt[y];
173  if (mp->changes_map[y0 + x] == 0) {
174  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
175  ++x;
176  }
177  while (x < mp->avctx->width) {
178  w = mp->changes_map[y0 + x];
179  if (w != 0) {
180  if ((y & 3) == 0) {
181  if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
182  mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
183  mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
184  for (i = (x + 3) & ~3; i < x + w; i += 4) {
185  mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
186  }
187  }
188  }
189  x += w;
190  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
191  p = mp_get_yuv_from_rgb(mp, x - 1, y);
192  } else {
193  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
194  p.y = av_clip(p.y, 0, 31);
195  if ((x & 3) == 0) {
196  if ((y & 3) == 0) {
197  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
198  p.v = av_clip(p.v, -32, 31);
199  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
200  p.u = av_clip(p.u, -32, 31);
201  mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
202  } else {
203  p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
204  p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
205  }
206  }
207  mp_set_rgb_from_yuv(mp, x, y, &p);
208  ++x;
209  }
210  }
211 }
212 
214 {
215  YuvPixel p;
216  int y, y0;
217 
218  for (y = 0; y < mp->avctx->height; ++y) {
219  if (mp->changes_map[y * mp->avctx->width] != 0) {
220  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
221  p = mp_get_yuv_from_rgb(mp, 0, y);
222  } else {
223  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
224  p.y = av_clip(p.y, 0, 31);
225  if ((y & 3) == 0) {
226  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
227  p.v = av_clip(p.v, -32, 31);
228  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
229  p.u = av_clip(p.u, -32, 31);
230  }
231  mp->vpt[y] = p;
232  mp_set_rgb_from_yuv(mp, 0, y, &p);
233  }
234  }
235  for (y0 = 0; y0 < 2; ++y0)
236  for (y = y0; y < mp->avctx->height; y += 2)
237  mp_decode_line(mp, gb, y);
238 }
239 
240 static int mp_decode_frame(AVCodecContext *avctx,
241  void *data, int *got_frame,
242  AVPacket *avpkt)
243 {
244  const uint8_t *buf = avpkt->data;
245  int buf_size = avpkt->size;
246  MotionPixelsContext *mp = avctx->priv_data;
247  GetBitContext gb;
248  int i, count1, count2, sz;
249 
250  mp->frame.reference = 1;
252  if (avctx->reget_buffer(avctx, &mp->frame)) {
253  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
254  return -1;
255  }
256 
257  /* le32 bitstream msb first */
259  if (!mp->bswapbuf)
260  return AVERROR(ENOMEM);
261  mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
262  if (buf_size & 3)
263  memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
264  memset(mp->bswapbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
265  init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
266 
267  memset(mp->changes_map, 0, avctx->width * avctx->height);
268  for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
269  count1 = get_bits(&gb, 12);
270  count2 = get_bits(&gb, 12);
271  mp_read_changes_map(mp, &gb, count1, 8, i);
272  mp_read_changes_map(mp, &gb, count2, 4, i);
273  }
274 
275  mp->codes_count = get_bits(&gb, 4);
276  if (mp->codes_count == 0)
277  goto end;
278 
279  if (mp->changes_map[0] == 0) {
280  *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
281  mp->changes_map[0] = 1;
282  }
283  mp_read_codes_table(mp, &gb);
284 
285  sz = get_bits(&gb, 18);
286  if (avctx->extradata[0] != 5)
287  sz += get_bits(&gb, 18);
288  if (sz == 0)
289  goto end;
290 
291  if (mp->max_codes_bits <= 0)
292  goto end;
293  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))
294  goto end;
295  mp_decode_frame_helper(mp, &gb);
296  ff_free_vlc(&mp->vlc);
297 
298 end:
299  *got_frame = 1;
300  *(AVFrame *)data = mp->frame;
301  return buf_size;
302 }
303 
305 {
306  MotionPixelsContext *mp = avctx->priv_data;
307 
308  av_freep(&mp->changes_map);
309  av_freep(&mp->vpt);
310  av_freep(&mp->hpt);
311  av_freep(&mp->bswapbuf);
312  if (mp->frame.data[0])
313  avctx->release_buffer(avctx, &mp->frame);
314 
315  return 0;
316 }
317 
319  .name = "motionpixels",
320  .type = AVMEDIA_TYPE_VIDEO,
322  .priv_data_size = sizeof(MotionPixelsContext),
323  .init = mp_decode_init,
324  .close = mp_decode_end,
326  .capabilities = CODEC_CAP_DR1,
327  .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
328 };