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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 FFmpeg.
7  *
8  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavutil/avassert.h"
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "internal.h"
27 
28 #include "libavutil/imgutils.h"
29 #include "libavutil/mem.h"
30 
31 typedef struct DfaContext {
32  uint32_t pal[256];
33  uint8_t *frame_buf;
34 } DfaContext;
35 
36 static av_cold int dfa_decode_init(AVCodecContext *avctx)
37 {
38  DfaContext *s = avctx->priv_data;
39 
40  avctx->pix_fmt = AV_PIX_FMT_PAL8;
41 
42  if (!avctx->width || !avctx->height)
43  return AVERROR_INVALIDDATA;
44 
45  av_assert0(av_image_check_size(avctx->width, avctx->height, 0, avctx) >= 0);
46 
47  s->frame_buf = av_mallocz(avctx->width * avctx->height);
48  if (!s->frame_buf)
49  return AVERROR(ENOMEM);
50 
51  return 0;
52 }
53 
54 static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
55 {
56  const int size = width * height;
57 
58  if (bytestream2_get_buffer(gb, frame, size) != size)
59  return AVERROR_INVALIDDATA;
60  return 0;
61 }
62 
63 static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
64 {
65  const uint8_t *frame_start = frame;
66  const uint8_t *frame_end = frame + width * height;
67  int mask = 0x10000, bitbuf = 0;
68  int v, count, segments;
69  unsigned offset;
70 
71  segments = bytestream2_get_le32(gb);
72  offset = bytestream2_get_le32(gb);
73  if (segments == 0 && offset == frame_end - frame)
74  return 0; // skip frame
75  if (frame_end - frame <= offset)
76  return AVERROR_INVALIDDATA;
77  frame += offset;
78  while (segments--) {
79  if (bytestream2_get_bytes_left(gb) < 2)
80  return AVERROR_INVALIDDATA;
81  if (mask == 0x10000) {
82  bitbuf = bytestream2_get_le16u(gb);
83  mask = 1;
84  }
85  if (frame_end - frame < 2)
86  return AVERROR_INVALIDDATA;
87  if (bitbuf & mask) {
88  v = bytestream2_get_le16(gb);
89  offset = (v & 0x1FFF) << 1;
90  count = ((v >> 13) + 2) << 1;
91  if (frame - frame_start < offset || frame_end - frame < count)
92  return AVERROR_INVALIDDATA;
93  av_memcpy_backptr(frame, offset, count);
94  frame += count;
95  } else {
96  *frame++ = bytestream2_get_byte(gb);
97  *frame++ = bytestream2_get_byte(gb);
98  }
99  mask <<= 1;
100  }
101 
102  return 0;
103 }
104 
105 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
106 {
107  const uint8_t *frame_start = frame;
108  const uint8_t *frame_end = frame + width * height;
109  int mask = 0x10000, bitbuf = 0;
110  int v, offset, count, segments;
111 
112  segments = bytestream2_get_le16(gb);
113  while (segments--) {
114  if (bytestream2_get_bytes_left(gb) < 2)
115  return AVERROR_INVALIDDATA;
116  if (mask == 0x10000) {
117  bitbuf = bytestream2_get_le16u(gb);
118  mask = 1;
119  }
120  if (frame_end - frame < 2)
121  return AVERROR_INVALIDDATA;
122  if (bitbuf & mask) {
123  v = bytestream2_get_le16(gb);
124  offset = (v & 0x1FFF) << 1;
125  count = ((v >> 13) + 2) << 1;
126  if (frame - frame_start < offset || frame_end - frame < count)
127  return AVERROR_INVALIDDATA;
128  av_memcpy_backptr(frame, offset, count);
129  frame += count;
130  } else if (bitbuf & (mask << 1)) {
131  frame += bytestream2_get_le16(gb);
132  } else {
133  *frame++ = bytestream2_get_byte(gb);
134  *frame++ = bytestream2_get_byte(gb);
135  }
136  mask <<= 2;
137  }
138 
139  return 0;
140 }
141 
142 static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
143 {
144  const uint8_t *frame_start = frame;
145  const uint8_t *frame_end = frame + width * height;
146  int mask = 0x10000, bitbuf = 0;
147  int i, v, offset, count, segments;
148 
149  segments = bytestream2_get_le16(gb);
150  while (segments--) {
151  if (bytestream2_get_bytes_left(gb) < 2)
152  return AVERROR_INVALIDDATA;
153  if (mask == 0x10000) {
154  bitbuf = bytestream2_get_le16u(gb);
155  mask = 1;
156  }
157 
158  if (bitbuf & mask) {
159  v = bytestream2_get_le16(gb);
160  offset = (v & 0x1FFF) << 2;
161  count = ((v >> 13) + 2) << 1;
162  if (frame - frame_start < offset || frame_end - frame < count*2 + width)
163  return AVERROR_INVALIDDATA;
164  for (i = 0; i < count; i++) {
165  frame[0] = frame[1] =
166  frame[width] = frame[width + 1] = frame[-offset];
167 
168  frame += 2;
169  }
170  } else if (bitbuf & (mask << 1)) {
171  v = bytestream2_get_le16(gb)*2;
172  if (frame - frame_end < v)
173  return AVERROR_INVALIDDATA;
174  frame += v;
175  } else {
176  if (frame_end - frame < width + 3)
177  return AVERROR_INVALIDDATA;
178  frame[0] = frame[1] =
179  frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
180  frame += 2;
181  frame[0] = frame[1] =
182  frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
183  frame += 2;
184  }
185  mask <<= 2;
186  }
187 
188  return 0;
189 }
190 
191 static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
192 {
193  uint8_t *line_ptr;
194  int count, lines, segments;
195 
196  count = bytestream2_get_le16(gb);
197  if (count >= height)
198  return AVERROR_INVALIDDATA;
199  frame += width * count;
200  lines = bytestream2_get_le16(gb);
201  if (count + lines > height)
202  return AVERROR_INVALIDDATA;
203 
204  while (lines--) {
205  if (bytestream2_get_bytes_left(gb) < 1)
206  return AVERROR_INVALIDDATA;
207  line_ptr = frame;
208  frame += width;
209  segments = bytestream2_get_byteu(gb);
210  while (segments--) {
211  if (frame - line_ptr <= bytestream2_peek_byte(gb))
212  return AVERROR_INVALIDDATA;
213  line_ptr += bytestream2_get_byte(gb);
214  count = (int8_t)bytestream2_get_byte(gb);
215  if (count >= 0) {
216  if (frame - line_ptr < count)
217  return AVERROR_INVALIDDATA;
218  if (bytestream2_get_buffer(gb, line_ptr, count) != count)
219  return AVERROR_INVALIDDATA;
220  } else {
221  count = -count;
222  if (frame - line_ptr < count)
223  return AVERROR_INVALIDDATA;
224  memset(line_ptr, bytestream2_get_byte(gb), count);
225  }
226  line_ptr += count;
227  }
228  }
229 
230  return 0;
231 }
232 
233 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
234 {
235  const uint8_t *frame_end = frame + width * height;
236  uint8_t *line_ptr;
237  int count, i, v, lines, segments;
238  int y = 0;
239 
240  lines = bytestream2_get_le16(gb);
241  if (lines > height)
242  return AVERROR_INVALIDDATA;
243 
244  while (lines--) {
245  if (bytestream2_get_bytes_left(gb) < 2)
246  return AVERROR_INVALIDDATA;
247  segments = bytestream2_get_le16u(gb);
248  while ((segments & 0xC000) == 0xC000) {
249  unsigned skip_lines = -(int16_t)segments;
250  unsigned delta = -((int16_t)segments * width);
251  if (frame_end - frame <= delta || y + lines + skip_lines > height)
252  return AVERROR_INVALIDDATA;
253  frame += delta;
254  y += skip_lines;
255  segments = bytestream2_get_le16(gb);
256  }
257 
258  if (frame_end <= frame)
259  return AVERROR_INVALIDDATA;
260  if (segments & 0x8000) {
261  frame[width - 1] = segments & 0xFF;
262  segments = bytestream2_get_le16(gb);
263  }
264  line_ptr = frame;
265  if (frame_end - frame < width)
266  return AVERROR_INVALIDDATA;
267  frame += width;
268  y++;
269  while (segments--) {
270  if (frame - line_ptr <= bytestream2_peek_byte(gb))
271  return AVERROR_INVALIDDATA;
272  line_ptr += bytestream2_get_byte(gb);
273  count = (int8_t)bytestream2_get_byte(gb);
274  if (count >= 0) {
275  if (frame - line_ptr < count * 2)
276  return AVERROR_INVALIDDATA;
277  if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
278  return AVERROR_INVALIDDATA;
279  line_ptr += count * 2;
280  } else {
281  count = -count;
282  if (frame - line_ptr < count * 2)
283  return AVERROR_INVALIDDATA;
284  v = bytestream2_get_le16(gb);
285  for (i = 0; i < count; i++)
286  bytestream_put_le16(&line_ptr, v);
287  }
288  }
289  }
290 
291  return 0;
292 }
293 
294 static int decode_tdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
295 {
296  const uint8_t *frame_end = frame + width * height;
297  uint32_t segments = bytestream2_get_le32(gb);
298  int skip, copy;
299 
300  while (segments--) {
301  if (bytestream2_get_bytes_left(gb) < 2)
302  return AVERROR_INVALIDDATA;
303  copy = bytestream2_get_byteu(gb) * 2;
304  skip = bytestream2_get_byteu(gb) * 2;
305  if (frame_end - frame < copy + skip ||
306  bytestream2_get_bytes_left(gb) < copy)
307  return AVERROR_INVALIDDATA;
308  frame += skip;
309  bytestream2_get_buffer(gb, frame, copy);
310  frame += copy;
311  }
312 
313  return 0;
314 }
315 
316 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
317 {
318  memset(frame, 0, width * height);
319  return 0;
320 }
321 
322 
323 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
324 
325 static const chunk_decoder decoder[8] = {
326  decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
327  decode_tdlt, decode_dsw1, decode_blck, decode_dds1,
328 };
329 
330 static const char* chunk_name[8] = {
331  "COPY", "TSW1", "BDLT", "WDLT", "TDLT", "DSW1", "BLCK", "DDS1"
332 };
333 
334 static int dfa_decode_frame(AVCodecContext *avctx,
335  void *data, int *got_frame,
336  AVPacket *avpkt)
337 {
338  AVFrame *frame = data;
339  DfaContext *s = avctx->priv_data;
340  GetByteContext gb;
341  const uint8_t *buf = avpkt->data;
342  uint32_t chunk_type, chunk_size;
343  uint8_t *dst;
344  int ret;
345  int i, pal_elems;
346  int version = avctx->extradata_size==2 ? AV_RL16(avctx->extradata) : 0;
347 
348  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
349  return ret;
350 
351  bytestream2_init(&gb, avpkt->data, avpkt->size);
352  while (bytestream2_get_bytes_left(&gb) > 0) {
353  bytestream2_skip(&gb, 4);
354  chunk_size = bytestream2_get_le32(&gb);
355  chunk_type = bytestream2_get_le32(&gb);
356  if (!chunk_type)
357  break;
358  if (chunk_type == 1) {
359  pal_elems = FFMIN(chunk_size / 3, 256);
360  for (i = 0; i < pal_elems; i++) {
361  s->pal[i] = bytestream2_get_be24(&gb) << 2;
362  s->pal[i] |= 0xFFU << 24 | (s->pal[i] >> 6) & 0x30303;
363  }
364  frame->palette_has_changed = 1;
365  } else if (chunk_type <= 9) {
366  if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
367  av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
368  chunk_name[chunk_type - 2]);
369  return AVERROR_INVALIDDATA;
370  }
371  } else {
372  av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
373  chunk_type);
374  }
375  buf += chunk_size;
376  }
377 
378  buf = s->frame_buf;
379  dst = frame->data[0];
380  for (i = 0; i < avctx->height; i++) {
381  if(version == 0x100) {
382  int j;
383  for(j = 0; j < avctx->width; j++) {
384  dst[j] = buf[ (i&3)*(avctx->width /4) + (j/4) +
385  ((j&3)*(avctx->height/4) + (i/4))*avctx->width];
386  }
387  } else {
388  memcpy(dst, buf, avctx->width);
389  buf += avctx->width;
390  }
391  dst += frame->linesize[0];
392  }
393  memcpy(frame->data[1], s->pal, sizeof(s->pal));
394 
395  *got_frame = 1;
396 
397  return avpkt->size;
398 }
399 
400 static av_cold int dfa_decode_end(AVCodecContext *avctx)
401 {
402  DfaContext *s = avctx->priv_data;
403 
404  av_freep(&s->frame_buf);
405 
406  return 0;
407 }
408 
409 AVCodec ff_dfa_decoder = {
410  .name = "dfa",
411  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
412  .type = AVMEDIA_TYPE_VIDEO,
413  .id = AV_CODEC_ID_DFA,
414  .priv_data_size = sizeof(DfaContext),
415  .init = dfa_decode_init,
416  .close = dfa_decode_end,
417  .decode = dfa_decode_frame,
418  .capabilities = CODEC_CAP_DR1,
419 };
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