FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
dsicinvideo.c
Go to the documentation of this file.
1 /*
2  * Delphine Software International CIN video decoder
3  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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  * Delphine Software International CIN video decoder
25  */
26 
27 #include "avcodec.h"
28 #include "bytestream.h"
29 #include "internal.h"
30 
31 typedef enum CinVideoBitmapIndex {
32  CIN_CUR_BMP = 0, /* current */
33  CIN_PRE_BMP = 1, /* previous */
34  CIN_INT_BMP = 2 /* intermediate */
35 } CinVideoBitmapIndex;
36 
37 typedef struct CinVideoContext {
38  AVCodecContext *avctx;
39  AVFrame *frame;
40  unsigned int bitmap_size;
41  uint32_t palette[256];
42  uint8_t *bitmap_table[3];
43 } CinVideoContext;
44 
45 static av_cold void destroy_buffers(CinVideoContext *cin)
46 {
47  int i;
48 
49  for (i = 0; i < 3; ++i)
50  av_freep(&cin->bitmap_table[i]);
51 }
52 
53 static av_cold int allocate_buffers(CinVideoContext *cin)
54 {
55  int i;
56 
57  for (i = 0; i < 3; ++i) {
58  cin->bitmap_table[i] = av_mallocz(cin->bitmap_size);
59  if (!cin->bitmap_table[i]) {
60  av_log(cin->avctx, AV_LOG_ERROR, "Can't allocate bitmap buffers.\n");
61  destroy_buffers(cin);
62  return AVERROR(ENOMEM);
63  }
64  }
65 
66  return 0;
67 }
68 
69 static av_cold int cinvideo_decode_init(AVCodecContext *avctx)
70 {
71  CinVideoContext *cin = avctx->priv_data;
72 
73  cin->avctx = avctx;
74  avctx->pix_fmt = AV_PIX_FMT_PAL8;
75 
76  cin->frame = av_frame_alloc();
77  if (!cin->frame)
78  return AVERROR(ENOMEM);
79 
80  cin->bitmap_size = avctx->width * avctx->height;
81  if (allocate_buffers(cin))
82  return AVERROR(ENOMEM);
83 
84  return 0;
85 }
86 
87 static void cin_apply_delta_data(const unsigned char *src, unsigned char *dst,
88  int size)
89 {
90  while (size--)
91  *dst++ += *src++;
92 }
93 
94 static int cin_decode_huffman(const unsigned char *src, int src_size,
95  unsigned char *dst, int dst_size)
96 {
97  int b, huff_code = 0;
98  unsigned char huff_code_table[15];
99  unsigned char *dst_cur = dst;
100  unsigned char *dst_end = dst + dst_size;
101  const unsigned char *src_end = src + src_size;
102 
103  memcpy(huff_code_table, src, 15);
104  src += 15;
105 
106  while (src < src_end) {
107  huff_code = *src++;
108  if ((huff_code >> 4) == 15) {
109  b = huff_code << 4;
110  huff_code = *src++;
111  *dst_cur++ = b | (huff_code >> 4);
112  } else
113  *dst_cur++ = huff_code_table[huff_code >> 4];
114  if (dst_cur >= dst_end)
115  break;
116 
117  huff_code &= 15;
118  if (huff_code == 15) {
119  *dst_cur++ = *src++;
120  } else
121  *dst_cur++ = huff_code_table[huff_code];
122  if (dst_cur >= dst_end)
123  break;
124  }
125 
126  return dst_cur - dst;
127 }
128 
129 static int cin_decode_lzss(const unsigned char *src, int src_size,
130  unsigned char *dst, int dst_size)
131 {
132  uint16_t cmd;
133  int i, sz, offset, code;
134  unsigned char *dst_end = dst + dst_size, *dst_start = dst;
135  const unsigned char *src_end = src + src_size;
136 
137  while (src < src_end && dst < dst_end) {
138  code = *src++;
139  for (i = 0; i < 8 && src < src_end && dst < dst_end; ++i) {
140  if (code & (1 << i)) {
141  *dst++ = *src++;
142  } else {
143  cmd = AV_RL16(src);
144  src += 2;
145  offset = cmd >> 4;
146  if ((int)(dst - dst_start) < offset + 1)
147  return AVERROR_INVALIDDATA;
148  sz = (cmd & 0xF) + 2;
149  /* don't use memcpy/memmove here as the decoding routine
150  * (ab)uses buffer overlappings to repeat bytes in the
151  * destination */
152  sz = FFMIN(sz, dst_end - dst);
153  while (sz--) {
154  *dst = *(dst - offset - 1);
155  ++dst;
156  }
157  }
158  }
159  }
160 
161  return 0;
162 }
163 
164 static int cin_decode_rle(const unsigned char *src, int src_size,
165  unsigned char *dst, int dst_size)
166 {
167  int len, code;
168  unsigned char *dst_end = dst + dst_size;
169  const unsigned char *src_end = src + src_size;
170 
171  while (src + 1 < src_end && dst < dst_end) {
172  code = *src++;
173  if (code & 0x80) {
174  len = code - 0x7F;
175  memset(dst, *src++, FFMIN(len, dst_end - dst));
176  } else {
177  len = code + 1;
178  if (len > src_end-src) {
179  av_log(NULL, AV_LOG_ERROR, "RLE overread\n");
180  return AVERROR_INVALIDDATA;
181  }
182  memcpy(dst, src, FFMIN3(len, dst_end - dst, src_end - src));
183  src += len;
184  }
185  dst += len;
186  }
187  return 0;
188 }
189 
190 static int cinvideo_decode_frame(AVCodecContext *avctx,
191  void *data, int *got_frame,
192  AVPacket *avpkt)
193 {
194  const uint8_t *buf = avpkt->data;
195  int buf_size = avpkt->size;
196  CinVideoContext *cin = avctx->priv_data;
197  int i, y, palette_type, palette_colors_count,
198  bitmap_frame_type, bitmap_frame_size, res = 0;
199 
200  palette_type = buf[0];
201  palette_colors_count = AV_RL16(buf + 1);
202  bitmap_frame_type = buf[3];
203  buf += 4;
204 
205  bitmap_frame_size = buf_size - 4;
206 
207  /* handle palette */
208  if (bitmap_frame_size < palette_colors_count * (3 + (palette_type != 0)))
209  return AVERROR_INVALIDDATA;
210  if (palette_type == 0) {
211  if (palette_colors_count > 256)
212  return AVERROR_INVALIDDATA;
213  for (i = 0; i < palette_colors_count; ++i) {
214  cin->palette[i] = 0xFFU << 24 | bytestream_get_le24(&buf);
215  bitmap_frame_size -= 3;
216  }
217  } else {
218  for (i = 0; i < palette_colors_count; ++i) {
219  cin->palette[buf[0]] = 0xFFU << 24 | AV_RL24(buf + 1);
220  buf += 4;
221  bitmap_frame_size -= 4;
222  }
223  }
224 
225  /* note: the decoding routines below assumes that
226  * surface.width = surface.pitch */
227  switch (bitmap_frame_type) {
228  case 9:
229  cin_decode_rle(buf, bitmap_frame_size,
230  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
231  break;
232  case 34:
233  cin_decode_rle(buf, bitmap_frame_size,
234  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
235  cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],
236  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
237  break;
238  case 35:
239  bitmap_frame_size = cin_decode_huffman(buf, bitmap_frame_size,
240  cin->bitmap_table[CIN_INT_BMP], cin->bitmap_size);
241  cin_decode_rle(cin->bitmap_table[CIN_INT_BMP], bitmap_frame_size,
242  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
243  break;
244  case 36:
245  bitmap_frame_size = cin_decode_huffman(buf, bitmap_frame_size,
246  cin->bitmap_table[CIN_INT_BMP],
247  cin->bitmap_size);
248  cin_decode_rle(cin->bitmap_table[CIN_INT_BMP], bitmap_frame_size,
249  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
250  cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],
251  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
252  break;
253  case 37:
254  cin_decode_huffman(buf, bitmap_frame_size,
255  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
256  break;
257  case 38:
258  res = cin_decode_lzss(buf, bitmap_frame_size,
259  cin->bitmap_table[CIN_CUR_BMP],
260  cin->bitmap_size);
261  if (res < 0)
262  return res;
263  break;
264  case 39:
265  res = cin_decode_lzss(buf, bitmap_frame_size,
266  cin->bitmap_table[CIN_CUR_BMP],
267  cin->bitmap_size);
268  if (res < 0)
269  return res;
270  cin_apply_delta_data(cin->bitmap_table[CIN_PRE_BMP],
271  cin->bitmap_table[CIN_CUR_BMP], cin->bitmap_size);
272  break;
273  }
274 
275  if ((res = ff_reget_buffer(avctx, cin->frame)) < 0)
276  return res;
277 
278  memcpy(cin->frame->data[1], cin->palette, sizeof(cin->palette));
279  cin->frame->palette_has_changed = 1;
280  for (y = 0; y < cin->avctx->height; ++y)
281  memcpy(cin->frame->data[0] + (cin->avctx->height - 1 - y) * cin->frame->linesize[0],
282  cin->bitmap_table[CIN_CUR_BMP] + y * cin->avctx->width,
283  cin->avctx->width);
284 
285  FFSWAP(uint8_t *, cin->bitmap_table[CIN_CUR_BMP],
286  cin->bitmap_table[CIN_PRE_BMP]);
287 
288  if ((res = av_frame_ref(data, cin->frame)) < 0)
289  return res;
290 
291  *got_frame = 1;
292 
293  return buf_size;
294 }
295 
296 static av_cold int cinvideo_decode_end(AVCodecContext *avctx)
297 {
298  CinVideoContext *cin = avctx->priv_data;
299 
300  av_frame_free(&cin->frame);
301 
302  destroy_buffers(cin);
303 
304  return 0;
305 }
306 
307 AVCodec ff_dsicinvideo_decoder = {
308  .name = "dsicinvideo",
309  .long_name = NULL_IF_CONFIG_SMALL("Delphine Software International CIN video"),
310  .type = AVMEDIA_TYPE_VIDEO,
311  .id = AV_CODEC_ID_DSICINVIDEO,
312  .priv_data_size = sizeof(CinVideoContext),
313  .init = cinvideo_decode_init,
314  .close = cinvideo_decode_end,
315  .decode = cinvideo_decode_frame,
316  .capabilities = CODEC_CAP_DR1,
317 };
Generated on Sun Mar 8 2015 02:34:50 for FFmpeg by   doxygen 1.8.2