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vb.c
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1 /*
2  * Beam Software VB decoder
3  * Copyright (c) 2007 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  * VB Video decoder
25  */
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33 
34 enum VBFlags{
35  VB_HAS_GMC = 0x01,
36  VB_HAS_AUDIO = 0x04,
37  VB_HAS_VIDEO = 0x08,
40 };
41 
42 typedef struct VBDecContext {
45 
47  uint32_t pal[AVPALETTE_COUNT];
49 } VBDecContext;
50 
51 static const uint16_t vb_patterns[64] = {
52  0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
53  0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
54  0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
55  0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
56  0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
57  0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
58  0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
59  0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
60 };
61 
62 static void vb_decode_palette(VBDecContext *c, int data_size)
63 {
64  int start, size, i;
65 
66  start = bytestream2_get_byte(&c->stream);
67  size = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
68  if(start + size > 255){
69  av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
70  return;
71  }
72  if(size*3+2 > data_size){
73  av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
74  return;
75  }
76  for(i = start; i <= start + size; i++)
77  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
78 }
79 
80 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
81 {
82  return buf >= start && buf < end;
83 }
84 
85 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
86 {
87  return buf >= start && (buf + 4) <= end;
88 }
89 
91 {
93  uint8_t *prev, *cur;
94  int blk, blocks, t, blk2;
95  int blocktypes = 0;
96  int x, y, a, b;
97  int pattype, pattern;
98  const int width = c->avctx->width;
99  uint8_t *pstart = c->prev_frame;
100  uint8_t *pend = c->prev_frame + width*c->avctx->height;
101 
102  g = c->stream;
103 
104  prev = c->prev_frame + offset;
105  cur = c->frame;
106 
107  blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
108  blk2 = 0;
109  for(blk = 0; blk < blocks; blk++){
110  if(!(blk & 3)) {
111  blocktypes = bytestream2_get_byte(&g);
112  }
113  switch(blocktypes & 0xC0){
114  case 0x00: //skip
115  for(y = 0; y < 4; y++)
116  if(check_line(prev + y*width, pstart, pend))
117  memcpy(cur + y*width, prev + y*width, 4);
118  else
119  memset(cur + y*width, 0, 4);
120  break;
121  case 0x40:
122  t = bytestream2_get_byte(&g);
123  if(!t){ //raw block
124  if (bytestream2_get_bytes_left(&g) < 16) {
125  av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
126  return -1;
127  }
128  for(y = 0; y < 4; y++)
129  bytestream2_get_buffer(&g, cur + y * width, 4);
130  }else{ // motion compensation
131  x = ((t & 0xF)^8) - 8;
132  y = ((t >> 4) ^8) - 8;
133  t = x + y*width;
134  for(y = 0; y < 4; y++)
135  if(check_line(prev + t + y*width, pstart, pend))
136  memcpy(cur + y*width, prev + t + y*width, 4);
137  else
138  memset(cur + y*width, 0, 4);
139  }
140  break;
141  case 0x80: // fill
142  t = bytestream2_get_byte(&g);
143  for(y = 0; y < 4; y++)
144  memset(cur + y*width, t, 4);
145  break;
146  case 0xC0: // pattern fill
147  t = bytestream2_get_byte(&g);
148  pattype = t >> 6;
149  pattern = vb_patterns[t & 0x3F];
150  switch(pattype){
151  case 0:
152  a = bytestream2_get_byte(&g);
153  b = bytestream2_get_byte(&g);
154  for(y = 0; y < 4; y++)
155  for(x = 0; x < 4; x++, pattern >>= 1)
156  cur[x + y*width] = (pattern & 1) ? b : a;
157  break;
158  case 1:
159  pattern = ~pattern;
160  case 2:
161  a = bytestream2_get_byte(&g);
162  for(y = 0; y < 4; y++)
163  for(x = 0; x < 4; x++, pattern >>= 1)
164  if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
165  cur[x + y*width] = prev[x + y*width];
166  else
167  cur[x + y*width] = a;
168  break;
169  case 3:
170  av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
171  return -1;
172  }
173  break;
174  }
175  blocktypes <<= 2;
176  cur += 4;
177  prev += 4;
178  blk2++;
179  if(blk2 == (width >> 2)){
180  blk2 = 0;
181  cur += width * 3;
182  prev += width * 3;
183  }
184  }
185  return 0;
186 }
187 
188 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
189  AVPacket *avpkt)
190 {
191  VBDecContext * const c = avctx->priv_data;
192  uint8_t *outptr, *srcptr;
193  int i, j;
194  int flags;
195  uint32_t size;
196  int offset = 0;
197 
198  bytestream2_init(&c->stream, avpkt->data, avpkt->size);
199 
200  if(c->pic.data[0])
201  avctx->release_buffer(avctx, &c->pic);
202  c->pic.reference = 3;
203  if(ff_get_buffer(avctx, &c->pic) < 0){
204  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
205  return -1;
206  }
207 
208  flags = bytestream2_get_le16(&c->stream);
209 
210  if(flags & VB_HAS_GMC){
211  i = (int16_t)bytestream2_get_le16(&c->stream);
212  j = (int16_t)bytestream2_get_le16(&c->stream);
213  offset = i + j * avctx->width;
214  }
215  if(flags & VB_HAS_VIDEO){
216  size = bytestream2_get_le32(&c->stream);
217  if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
218  av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
219  return -1;
220  }
221  vb_decode_framedata(c, offset);
222  bytestream2_skip(&c->stream, size - 4);
223  }
224  if(flags & VB_HAS_PALETTE){
225  size = bytestream2_get_le32(&c->stream);
226  vb_decode_palette(c, size);
227  }
228 
229  memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
231 
232  outptr = c->pic.data[0];
233  srcptr = c->frame;
234 
235  for(i = 0; i < avctx->height; i++){
236  memcpy(outptr, srcptr, avctx->width);
237  srcptr += avctx->width;
238  outptr += c->pic.linesize[0];
239  }
240 
241  FFSWAP(uint8_t*, c->frame, c->prev_frame);
242 
243  *got_frame = 1;
244  *(AVFrame*)data = c->pic;
245 
246  /* always report that the buffer was completely consumed */
247  return avpkt->size;
248 }
249 
251 {
252  VBDecContext * const c = avctx->priv_data;
253 
254  c->avctx = avctx;
255  avctx->pix_fmt = AV_PIX_FMT_PAL8;
257 
258  c->frame = av_mallocz(avctx->width * avctx->height);
259  c->prev_frame = av_mallocz(avctx->width * avctx->height);
260 
261  return 0;
262 }
263 
265 {
266  VBDecContext *c = avctx->priv_data;
267 
268  av_freep(&c->frame);
269  av_freep(&c->prev_frame);
270  if(c->pic.data[0])
271  avctx->release_buffer(avctx, &c->pic);
272 
273  return 0;
274 }
275 
277  .name = "vb",
278  .type = AVMEDIA_TYPE_VIDEO,
279  .id = AV_CODEC_ID_VB,
280  .priv_data_size = sizeof(VBDecContext),
281  .init = decode_init,
282  .close = decode_end,
283  .decode = decode_frame,
284  .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
285  .capabilities = CODEC_CAP_DR1,
286 };