dfa.c
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1 /*
2  * Chronomaster DFA Video Decoder
3  * Copyright (c) 2011 Konstantin Shishkov
4  * based on work by Vladimir "VAG" Gneushev
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "avcodec.h"
24 #include "bytestream.h"
25 
26 #include "libavutil/imgutils.h"
27 #include "libavutil/lzo.h" // for av_memcpy_backptr
28 
29 typedef struct DfaContext {
31 
32  uint32_t pal[256];
33  uint8_t *frame_buf;
34 } DfaContext;
35 
37 {
38  DfaContext *s = avctx->priv_data;
39  int ret;
40 
41  avctx->pix_fmt = PIX_FMT_PAL8;
42 
43  if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
44  return ret;
45 
46  s->frame_buf = av_mallocz(avctx->width * avctx->height + AV_LZO_OUTPUT_PADDING);
47  if (!s->frame_buf)
48  return AVERROR(ENOMEM);
49 
50  return 0;
51 }
52 
53 static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
54 {
55  const int size = width * height;
56 
57  if (bytestream2_get_buffer(gb, frame, size) != size)
58  return AVERROR_INVALIDDATA;
59  return 0;
60 }
61 
62 static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
63 {
64  const uint8_t *frame_start = frame;
65  const uint8_t *frame_end = frame + width * height;
66  int mask = 0x10000, bitbuf = 0;
67  int v, count, segments;
68  unsigned offset;
69 
70  segments = bytestream2_get_le32(gb);
71  offset = bytestream2_get_le32(gb);
72  if (frame_end - frame <= offset)
73  return AVERROR_INVALIDDATA;
74  frame += offset;
75  while (segments--) {
76  if (bytestream2_get_bytes_left(gb) < 2)
77  return AVERROR_INVALIDDATA;
78  if (mask == 0x10000) {
79  bitbuf = bytestream2_get_le16u(gb);
80  mask = 1;
81  }
82  if (frame_end - frame < 2)
83  return AVERROR_INVALIDDATA;
84  if (bitbuf & mask) {
85  v = bytestream2_get_le16(gb);
86  offset = (v & 0x1FFF) << 1;
87  count = ((v >> 13) + 2) << 1;
88  if (frame - frame_start < offset || frame_end - frame < count)
89  return AVERROR_INVALIDDATA;
90  av_memcpy_backptr(frame, offset, count);
91  frame += count;
92  } else {
93  *frame++ = bytestream2_get_byte(gb);
94  *frame++ = bytestream2_get_byte(gb);
95  }
96  mask <<= 1;
97  }
98 
99  return 0;
100 }
101 
102 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
103 {
104  const uint8_t *frame_start = frame;
105  const uint8_t *frame_end = frame + width * height;
106  int mask = 0x10000, bitbuf = 0;
107  int v, offset, count, segments;
108 
109  segments = bytestream2_get_le16(gb);
110  while (segments--) {
111  if (bytestream2_get_bytes_left(gb) < 2)
112  return AVERROR_INVALIDDATA;
113  if (mask == 0x10000) {
114  bitbuf = bytestream2_get_le16u(gb);
115  mask = 1;
116  }
117  if (frame_end - frame < 2)
118  return AVERROR_INVALIDDATA;
119  if (bitbuf & mask) {
120  v = bytestream2_get_le16(gb);
121  offset = (v & 0x1FFF) << 1;
122  count = ((v >> 13) + 2) << 1;
123  if (frame - frame_start < offset || frame_end - frame < count)
124  return AVERROR_INVALIDDATA;
125  // can't use av_memcpy_backptr() since it can overwrite following pixels
126  for (v = 0; v < count; v++)
127  frame[v] = frame[v - offset];
128  frame += count;
129  } else if (bitbuf & (mask << 1)) {
130  frame += bytestream2_get_le16(gb);
131  } else {
132  *frame++ = bytestream2_get_byte(gb);
133  *frame++ = bytestream2_get_byte(gb);
134  }
135  mask <<= 2;
136  }
137 
138  return 0;
139 }
140 
141 static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
142 {
143  const uint8_t *frame_start = frame;
144  const uint8_t *frame_end = frame + width * height;
145  int mask = 0x10000, bitbuf = 0;
146  int i, v, offset, count, segments;
147 
148  segments = bytestream2_get_le16(gb);
149  while (segments--) {
150  if (bytestream2_get_bytes_left(gb) < 2)
151  return AVERROR_INVALIDDATA;
152  if (mask == 0x10000) {
153  bitbuf = bytestream2_get_le16u(gb);
154  mask = 1;
155  }
156 
157  if (bitbuf & mask) {
158  v = bytestream2_get_le16(gb);
159  offset = (v & 0x1FFF) << 2;
160  count = ((v >> 13) + 2) << 1;
161  if (frame - frame_start < offset || frame_end - frame < count*2 + width)
162  return AVERROR_INVALIDDATA;
163  for (i = 0; i < count; i++) {
164  frame[0] = frame[1] =
165  frame[width] = frame[width + 1] = frame[-offset];
166 
167  frame += 2;
168  }
169  } else if (bitbuf & (mask << 1)) {
170  v = bytestream2_get_le16(gb)*2;
171  if (frame - frame_end < v)
172  return AVERROR_INVALIDDATA;
173  frame += v;
174  } else {
175  if (frame_end - frame < width + 3)
176  return AVERROR_INVALIDDATA;
177  frame[0] = frame[1] =
178  frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
179  frame += 2;
180  frame[0] = frame[1] =
181  frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
182  frame += 2;
183  }
184  mask <<= 2;
185  }
186 
187  return 0;
188 }
189 
190 static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
191 {
192  uint8_t *line_ptr;
193  int count, lines, segments;
194 
195  count = bytestream2_get_le16(gb);
196  if (count >= height)
197  return AVERROR_INVALIDDATA;
198  frame += width * count;
199  lines = bytestream2_get_le16(gb);
200  if (count + lines > height)
201  return AVERROR_INVALIDDATA;
202 
203  while (lines--) {
204  if (bytestream2_get_bytes_left(gb) < 1)
205  return AVERROR_INVALIDDATA;
206  line_ptr = frame;
207  frame += width;
208  segments = bytestream2_get_byteu(gb);
209  while (segments--) {
210  if (frame - line_ptr <= bytestream2_peek_byte(gb))
211  return AVERROR_INVALIDDATA;
212  line_ptr += bytestream2_get_byte(gb);
213  count = (int8_t)bytestream2_get_byte(gb);
214  if (count >= 0) {
215  if (frame - line_ptr < count)
216  return AVERROR_INVALIDDATA;
217  if (bytestream2_get_buffer(gb, line_ptr, count) != count)
218  return AVERROR_INVALIDDATA;
219  } else {
220  count = -count;
221  if (frame - line_ptr < count)
222  return AVERROR_INVALIDDATA;
223  memset(line_ptr, bytestream2_get_byte(gb), count);
224  }
225  line_ptr += count;
226  }
227  }
228 
229  return 0;
230 }
231 
232 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
233 {
234  const uint8_t *frame_end = frame + width * height;
235  uint8_t *line_ptr;
236  int count, i, v, lines, segments;
237  int y = 0;
238 
239  lines = bytestream2_get_le16(gb);
240  if (lines > height)
241  return AVERROR_INVALIDDATA;
242 
243  while (lines--) {
244  if (bytestream2_get_bytes_left(gb) < 2)
245  return AVERROR_INVALIDDATA;
246  segments = bytestream2_get_le16u(gb);
247  while ((segments & 0xC000) == 0xC000) {
248  unsigned skip_lines = -(int16_t)segments;
249  unsigned delta = -((int16_t)segments * width);
250  if (frame_end - frame <= delta || y + lines + skip_lines > height)
251  return AVERROR_INVALIDDATA;
252  frame += delta;
253  y += skip_lines;
254  segments = bytestream2_get_le16(gb);
255  }
256  if (segments & 0x8000) {
257  frame[width - 1] = segments & 0xFF;
258  segments = bytestream2_get_le16(gb);
259  }
260  line_ptr = frame;
261  if (frame_end - frame < width)
262  return AVERROR_INVALIDDATA;
263  frame += width;
264  y++;
265  while (segments--) {
266  if (frame - line_ptr <= bytestream2_peek_byte(gb))
267  return AVERROR_INVALIDDATA;
268  line_ptr += bytestream2_get_byte(gb);
269  count = (int8_t)bytestream2_get_byte(gb);
270  if (count >= 0) {
271  if (frame - line_ptr < count * 2)
272  return AVERROR_INVALIDDATA;
273  if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
274  return AVERROR_INVALIDDATA;
275  line_ptr += count * 2;
276  } else {
277  count = -count;
278  if (frame - line_ptr < count * 2)
279  return AVERROR_INVALIDDATA;
280  v = bytestream2_get_le16(gb);
281  for (i = 0; i < count; i++)
282  bytestream_put_le16(&line_ptr, v);
283  }
284  }
285  }
286 
287  return 0;
288 }
289 
290 static int decode_unk6(GetByteContext *gb, uint8_t *frame, int width, int height)
291 {
292  return AVERROR_PATCHWELCOME;
293 }
294 
295 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
296 {
297  memset(frame, 0, width * height);
298  return 0;
299 }
300 
301 
302 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
303 
304 static const chunk_decoder decoder[8] = {
307 };
308 
309 static const char* chunk_name[8] = {
310  "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
311 };
312 
314  void *data, int *data_size,
315  AVPacket *avpkt)
316 {
317  DfaContext *s = avctx->priv_data;
318  GetByteContext gb;
319  const uint8_t *buf = avpkt->data;
320  uint32_t chunk_type, chunk_size;
321  uint8_t *dst;
322  int ret;
323  int i, pal_elems;
324 
325  if (s->pic.data[0])
326  avctx->release_buffer(avctx, &s->pic);
327 
328  if ((ret = avctx->get_buffer(avctx, &s->pic))) {
329  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
330  return ret;
331  }
332 
333  bytestream2_init(&gb, avpkt->data, avpkt->size);
334  while (bytestream2_get_bytes_left(&gb) > 0) {
335  bytestream2_skip(&gb, 4);
336  chunk_size = bytestream2_get_le32(&gb);
337  chunk_type = bytestream2_get_le32(&gb);
338  if (!chunk_type)
339  break;
340  if (chunk_type == 1) {
341  pal_elems = FFMIN(chunk_size / 3, 256);
342  for (i = 0; i < pal_elems; i++) {
343  s->pal[i] = bytestream2_get_be24(&gb) << 2;
344  s->pal[i] |= (s->pal[i] >> 6) & 0x333;
345  }
346  s->pic.palette_has_changed = 1;
347  } else if (chunk_type <= 9) {
348  if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
349  av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
350  chunk_name[chunk_type - 2]);
351  return AVERROR_INVALIDDATA;
352  }
353  } else {
354  av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
355  chunk_type);
356  }
357  buf += chunk_size;
358  }
359 
360  buf = s->frame_buf;
361  dst = s->pic.data[0];
362  for (i = 0; i < avctx->height; i++) {
363  memcpy(dst, buf, avctx->width);
364  dst += s->pic.linesize[0];
365  buf += avctx->width;
366  }
367  memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
368 
369  *data_size = sizeof(AVFrame);
370  *(AVFrame*)data = s->pic;
371 
372  return avpkt->size;
373 }
374 
376 {
377  DfaContext *s = avctx->priv_data;
378 
379  if (s->pic.data[0])
380  avctx->release_buffer(avctx, &s->pic);
381 
382  av_freep(&s->frame_buf);
383 
384  return 0;
385 }
386 
388  .name = "dfa",
389  .type = AVMEDIA_TYPE_VIDEO,
390  .id = CODEC_ID_DFA,
391  .priv_data_size = sizeof(DfaContext),
395  .capabilities = CODEC_CAP_DR1,
396  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
397 };