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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 {
44 
46  uint32_t pal[AVPALETTE_COUNT];
48 } VBDecContext;
49 
50 static const uint16_t vb_patterns[64] = {
51  0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
52  0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
53  0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
54  0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
55  0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
56  0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
57  0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
58  0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
59 };
60 
61 static void vb_decode_palette(VBDecContext *c, int data_size)
62 {
63  int start, size, i;
64 
65  start = bytestream2_get_byte(&c->stream);
66  size = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
67  if (start + size > 255) {
68  av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
69  return;
70  }
71  if (size*3+2 > data_size) {
72  av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
73  return;
74  }
75  for (i = start; i <= start + size; i++)
76  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
77 }
78 
79 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
80 {
81  return buf >= start && buf < end;
82 }
83 
84 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
85 {
86  return buf >= start && (buf + 4) <= end;
87 }
88 
90 {
92  uint8_t *prev, *cur;
93  int blk, blocks, t, blk2;
94  int blocktypes = 0;
95  int x, y, a, b;
96  int pattype, pattern;
97  const int width = c->avctx->width;
98  uint8_t *pstart = c->prev_frame;
99  uint8_t *pend = c->prev_frame + width*c->avctx->height;
100 
101  g = c->stream;
102 
103  prev = c->prev_frame + offset;
104  cur = c->frame;
105 
106  blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
107  blk2 = 0;
108  for (blk = 0; blk < blocks; blk++) {
109  if (!(blk & 3)) {
110  blocktypes = bytestream2_get_byte(&g);
111  }
112  switch (blocktypes & 0xC0) {
113  case 0x00: //skip
114  for (y = 0; y < 4; y++)
115  if (check_line(prev + y*width, pstart, pend))
116  memcpy(cur + y*width, prev + y*width, 4);
117  else
118  memset(cur + y*width, 0, 4);
119  break;
120  case 0x40:
121  t = bytestream2_get_byte(&g);
122  if (!t) { //raw block
123  if (bytestream2_get_bytes_left(&g) < 16) {
124  av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
125  return AVERROR_INVALIDDATA;
126  }
127  for (y = 0; y < 4; y++)
128  bytestream2_get_buffer(&g, cur + y * width, 4);
129  } else { // motion compensation
130  x = ((t & 0xF)^8) - 8;
131  y = ((t >> 4) ^8) - 8;
132  t = x + y*width;
133  for (y = 0; y < 4; y++)
134  if (check_line(prev + t + y*width, pstart, pend))
135  memcpy(cur + y*width, prev + t + y*width, 4);
136  else
137  memset(cur + y*width, 0, 4);
138  }
139  break;
140  case 0x80: // fill
141  t = bytestream2_get_byte(&g);
142  for (y = 0; y < 4; y++)
143  memset(cur + y*width, t, 4);
144  break;
145  case 0xC0: // pattern fill
146  t = bytestream2_get_byte(&g);
147  pattype = t >> 6;
148  pattern = vb_patterns[t & 0x3F];
149  switch (pattype) {
150  case 0:
151  a = bytestream2_get_byte(&g);
152  b = bytestream2_get_byte(&g);
153  for (y = 0; y < 4; y++)
154  for (x = 0; x < 4; x++, pattern >>= 1)
155  cur[x + y*width] = (pattern & 1) ? b : a;
156  break;
157  case 1:
158  pattern = ~pattern;
159  case 2:
160  a = bytestream2_get_byte(&g);
161  for (y = 0; y < 4; y++)
162  for (x = 0; x < 4; x++, pattern >>= 1)
163  if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
164  cur[x + y*width] = prev[x + y*width];
165  else
166  cur[x + y*width] = a;
167  break;
168  case 3:
169  av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
170  return AVERROR_INVALIDDATA;
171  }
172  break;
173  }
174  blocktypes <<= 2;
175  cur += 4;
176  prev += 4;
177  blk2++;
178  if (blk2 == (width >> 2)) {
179  blk2 = 0;
180  cur += width * 3;
181  prev += width * 3;
182  }
183  }
184  return 0;
185 }
186 
187 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
188  AVPacket *avpkt)
189 {
190  VBDecContext * const c = avctx->priv_data;
191  AVFrame *frame = data;
192  uint8_t *outptr, *srcptr;
193  int i, j, ret;
194  int flags;
195  uint32_t size;
196  int offset = 0;
197 
198  bytestream2_init(&c->stream, avpkt->data, avpkt->size);
199 
200  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
201  return ret;
202 
203  flags = bytestream2_get_le16(&c->stream);
204 
205  if (flags & VB_HAS_GMC) {
206  i = (int16_t)bytestream2_get_le16(&c->stream);
207  j = (int16_t)bytestream2_get_le16(&c->stream);
208  offset = i + j * avctx->width;
209  }
210  if (flags & VB_HAS_VIDEO) {
211  size = bytestream2_get_le32(&c->stream);
212  if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
213  av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
214  return -1;
215  }
216  vb_decode_framedata(c, offset);
217  bytestream2_skip(&c->stream, size - 4);
218  }
219  if (flags & VB_HAS_PALETTE) {
220  size = bytestream2_get_le32(&c->stream);
221  vb_decode_palette(c, size);
222  }
223 
224  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
225  frame->palette_has_changed = flags & VB_HAS_PALETTE;
226 
227  outptr = frame->data[0];
228  srcptr = c->frame;
229 
230  for (i = 0; i < avctx->height; i++) {
231  memcpy(outptr, srcptr, avctx->width);
232  srcptr += avctx->width;
233  outptr += frame->linesize[0];
234  }
235 
236  FFSWAP(uint8_t*, c->frame, c->prev_frame);
237 
238  *got_frame = 1;
239 
240  /* always report that the buffer was completely consumed */
241  return avpkt->size;
242 }
243 
245 {
246  VBDecContext * const c = avctx->priv_data;
247 
248  c->avctx = avctx;
249  avctx->pix_fmt = AV_PIX_FMT_PAL8;
250 
251  c->frame = av_mallocz(avctx->width * avctx->height);
252  c->prev_frame = av_mallocz(avctx->width * avctx->height);
253 
254  return 0;
255 }
256 
258 {
259  VBDecContext *c = avctx->priv_data;
260 
261  av_freep(&c->frame);
262  av_freep(&c->prev_frame);
263 
264  return 0;
265 }
266 
268  .name = "vb",
269  .type = AVMEDIA_TYPE_VIDEO,
270  .id = AV_CODEC_ID_VB,
271  .priv_data_size = sizeof(VBDecContext),
272  .init = decode_init,
273  .close = decode_end,
274  .decode = decode_frame,
275  .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
276  .capabilities = CODEC_CAP_DR1,
277 };