dxa.c
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1 /*
2  * Feeble Files/ScummVM DXA decoder
3  * Copyright (c) 2007 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include <stdio.h>
28 #include <stdlib.h>
29 
30 #include "libavutil/intreadwrite.h"
31 #include "avcodec.h"
32 
33 #include <zlib.h>
34 
35 /*
36  * Decoder context
37  */
38 typedef struct DxaDecContext {
41 
42  int dsize;
43  uint8_t *decomp_buf;
44  uint32_t pal[256];
46 
47 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
48 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
49 
50 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
51 {
52  uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
53  int i, j, k;
54  int type, x, y, d, d2;
55  int stride = c->pic.linesize[0];
56  uint32_t mask;
57 
58  code = src + 12;
59  data = code + ((avctx->width * avctx->height) >> 4);
60  mv = data + AV_RB32(src + 0);
61  msk = mv + AV_RB32(src + 4);
62 
63  for(j = 0; j < avctx->height; j += 4){
64  for(i = 0; i < avctx->width; i += 4){
65  tmp = dst + i;
66  tmp2 = ref + i;
67  type = *code++;
68  switch(type){
69  case 4: // motion compensation
70  x = (*mv) >> 4; if(x & 8) x = 8 - x;
71  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
72  tmp2 += x + y*stride;
73  case 0: // skip
74  case 5: // skip in method 12
75  for(y = 0; y < 4; y++){
76  memcpy(tmp, tmp2, 4);
77  tmp += stride;
78  tmp2 += stride;
79  }
80  break;
81  case 1: // masked change
82  case 10: // masked change with only half of pixels changed
83  case 11: // cases 10-15 are for method 12 only
84  case 12:
85  case 13:
86  case 14:
87  case 15:
88  if(type == 1){
89  mask = AV_RB16(msk);
90  msk += 2;
91  }else{
92  type -= 10;
93  mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
94  msk++;
95  }
96  for(y = 0; y < 4; y++){
97  for(x = 0; x < 4; x++){
98  tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
99  mask <<= 1;
100  }
101  tmp += stride;
102  tmp2 += stride;
103  }
104  break;
105  case 2: // fill block
106  for(y = 0; y < 4; y++){
107  memset(tmp, data[0], 4);
108  tmp += stride;
109  }
110  data++;
111  break;
112  case 3: // raw block
113  for(y = 0; y < 4; y++){
114  memcpy(tmp, data, 4);
115  data += 4;
116  tmp += stride;
117  }
118  break;
119  case 8: // subblocks - method 13 only
120  mask = *msk++;
121  for(k = 0; k < 4; k++){
122  d = ((k & 1) << 1) + ((k & 2) * stride);
123  d2 = ((k & 1) << 1) + ((k & 2) * stride);
124  tmp2 = ref + i + d2;
125  switch(mask & 0xC0){
126  case 0x80: // motion compensation
127  x = (*mv) >> 4; if(x & 8) x = 8 - x;
128  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
129  tmp2 += x + y*stride;
130  case 0x00: // skip
131  tmp[d + 0 ] = tmp2[0];
132  tmp[d + 1 ] = tmp2[1];
133  tmp[d + 0 + stride] = tmp2[0 + stride];
134  tmp[d + 1 + stride] = tmp2[1 + stride];
135  break;
136  case 0x40: // fill
137  tmp[d + 0 ] = data[0];
138  tmp[d + 1 ] = data[0];
139  tmp[d + 0 + stride] = data[0];
140  tmp[d + 1 + stride] = data[0];
141  data++;
142  break;
143  case 0xC0: // raw
144  tmp[d + 0 ] = *data++;
145  tmp[d + 1 ] = *data++;
146  tmp[d + 0 + stride] = *data++;
147  tmp[d + 1 + stride] = *data++;
148  break;
149  }
150  mask <<= 2;
151  }
152  break;
153  case 32: // vector quantization - 2 colors
154  mask = AV_RB16(msk);
155  msk += 2;
156  for(y = 0; y < 4; y++){
157  for(x = 0; x < 4; x++){
158  tmp[x] = data[mask & 1];
159  mask >>= 1;
160  }
161  tmp += stride;
162  tmp2 += stride;
163  }
164  data += 2;
165  break;
166  case 33: // vector quantization - 3 or 4 colors
167  case 34:
168  mask = AV_RB32(msk);
169  msk += 4;
170  for(y = 0; y < 4; y++){
171  for(x = 0; x < 4; x++){
172  tmp[x] = data[mask & 3];
173  mask >>= 2;
174  }
175  tmp += stride;
176  tmp2 += stride;
177  }
178  data += type - 30;
179  break;
180  default:
181  av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
182  return -1;
183  }
184  }
185  dst += stride * 4;
186  ref += stride * 4;
187  }
188  return 0;
189 }
190 
191 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
192 {
193  const uint8_t *buf = avpkt->data;
194  int buf_size = avpkt->size;
195  DxaDecContext * const c = avctx->priv_data;
196  uint8_t *outptr, *srcptr, *tmpptr;
197  unsigned long dsize;
198  int i, j, compr;
199  int stride;
200  int orig_buf_size = buf_size;
201  int pc = 0;
202 
203  /* make the palette available on the way out */
204  if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
205  int r, g, b;
206 
207  buf += 4;
208  for(i = 0; i < 256; i++){
209  r = *buf++;
210  g = *buf++;
211  b = *buf++;
212  c->pal[i] = (r << 16) | (g << 8) | b;
213  }
214  pc = 1;
215  buf_size -= 768+4;
216  }
217 
218  if(avctx->get_buffer(avctx, &c->pic) < 0){
219  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
220  return -1;
221  }
222  memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
223  c->pic.palette_has_changed = pc;
224 
225  outptr = c->pic.data[0];
226  srcptr = c->decomp_buf;
227  tmpptr = c->prev.data[0];
228  stride = c->pic.linesize[0];
229 
230  if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
231  compr = -1;
232  else
233  compr = buf[4];
234 
235  dsize = c->dsize;
236  if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
237  av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
238  return -1;
239  }
240  switch(compr){
241  case -1:
242  c->pic.key_frame = 0;
244  if(c->prev.data[0])
245  memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
246  else{ // Should happen only when first frame is 'NULL'
247  memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
248  c->pic.key_frame = 1;
250  }
251  break;
252  case 2:
253  case 3:
254  case 4:
255  case 5:
256  c->pic.key_frame = !(compr & 1);
257  c->pic.pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
258 
259  if (!tmpptr && !c->pic.key_frame) {
260  av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
261  return AVERROR_INVALIDDATA;
262  }
263 
264  for(j = 0; j < avctx->height; j++){
265  if(compr & 1){
266  for(i = 0; i < avctx->width; i++)
267  outptr[i] = srcptr[i] ^ tmpptr[i];
268  tmpptr += stride;
269  }else
270  memcpy(outptr, srcptr, avctx->width);
271  outptr += stride;
272  srcptr += avctx->width;
273  }
274  break;
275  case 12: // ScummVM coding
276  case 13:
277  c->pic.key_frame = 0;
279  decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
280  break;
281  default:
282  av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
283  return -1;
284  }
285 
286  FFSWAP(AVFrame, c->pic, c->prev);
287  if(c->pic.data[0])
288  avctx->release_buffer(avctx, &c->pic);
289 
290  *data_size = sizeof(AVFrame);
291  *(AVFrame*)data = c->prev;
292 
293  /* always report that the buffer was completely consumed */
294  return orig_buf_size;
295 }
296 
298 {
299  DxaDecContext * const c = avctx->priv_data;
300 
301  c->avctx = avctx;
302  avctx->pix_fmt = PIX_FMT_PAL8;
303 
304  c->dsize = avctx->width * avctx->height * 2;
305  if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
306  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
307  return -1;
308  }
309 
310  return 0;
311 }
312 
314 {
315  DxaDecContext * const c = avctx->priv_data;
316 
317  av_freep(&c->decomp_buf);
318  if(c->prev.data[0])
319  avctx->release_buffer(avctx, &c->prev);
320  if(c->pic.data[0])
321  avctx->release_buffer(avctx, &c->pic);
322 
323  return 0;
324 }
325 
327  .name = "dxa",
328  .type = AVMEDIA_TYPE_VIDEO,
329  .id = CODEC_ID_DXA,
330  .priv_data_size = sizeof(DxaDecContext),
331  .init = decode_init,
332  .close = decode_end,
333  .decode = decode_frame,
334  .capabilities = CODEC_CAP_DR1,
335  .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
336 };
337