FFmpeg  1.2.12
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 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 
27 #include <stdio.h>
28 #include <stdlib.h>
29 
30 #include "libavutil/common.h"
31 #include "libavutil/intreadwrite.h"
32 #include "bytestream.h"
33 #include "avcodec.h"
34 #include "internal.h"
35 
36 #include <zlib.h>
37 
38 /*
39  * Decoder context
40  */
41 typedef struct DxaDecContext {
43 
44  int dsize;
46  uint32_t pal[256];
48 
49 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
50 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
51 
52 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
53 {
54  uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
55  int i, j, k;
56  int type, x, y, d, d2;
57  int stride = c->pic.linesize[0];
58  uint32_t mask;
59 
60  code = src + 12;
61  data = code + ((avctx->width * avctx->height) >> 4);
62  mv = data + AV_RB32(src + 0);
63  msk = mv + AV_RB32(src + 4);
64 
65  for(j = 0; j < avctx->height; j += 4){
66  for(i = 0; i < avctx->width; i += 4){
67  tmp = dst + i;
68  tmp2 = ref + i;
69  type = *code++;
70  switch(type){
71  case 4: // motion compensation
72  x = (*mv) >> 4; if(x & 8) x = 8 - x;
73  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
74  if (i < -x || avctx->width - i - 4 < x ||
75  j < -y || avctx->height - j - 4 < y) {
76  av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
77  return AVERROR_INVALIDDATA;
78  }
79  tmp2 += x + y*stride;
80  case 0: // skip
81  case 5: // skip in method 12
82  for(y = 0; y < 4; y++){
83  memcpy(tmp, tmp2, 4);
84  tmp += stride;
85  tmp2 += stride;
86  }
87  break;
88  case 1: // masked change
89  case 10: // masked change with only half of pixels changed
90  case 11: // cases 10-15 are for method 12 only
91  case 12:
92  case 13:
93  case 14:
94  case 15:
95  if(type == 1){
96  mask = AV_RB16(msk);
97  msk += 2;
98  }else{
99  type -= 10;
100  mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
101  msk++;
102  }
103  for(y = 0; y < 4; y++){
104  for(x = 0; x < 4; x++){
105  tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
106  mask <<= 1;
107  }
108  tmp += stride;
109  tmp2 += stride;
110  }
111  break;
112  case 2: // fill block
113  for(y = 0; y < 4; y++){
114  memset(tmp, data[0], 4);
115  tmp += stride;
116  }
117  data++;
118  break;
119  case 3: // raw block
120  for(y = 0; y < 4; y++){
121  memcpy(tmp, data, 4);
122  data += 4;
123  tmp += stride;
124  }
125  break;
126  case 8: // subblocks - method 13 only
127  mask = *msk++;
128  for(k = 0; k < 4; k++){
129  d = ((k & 1) << 1) + ((k & 2) * stride);
130  d2 = ((k & 1) << 1) + ((k & 2) * stride);
131  tmp2 = ref + i + d2;
132  switch(mask & 0xC0){
133  case 0x80: // motion compensation
134  x = (*mv) >> 4; if(x & 8) x = 8 - x;
135  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
136  if (i + 2*(k & 1) < -x || avctx->width - i - 2*(k & 1) - 2 < x ||
137  j + (k & 2) < -y || avctx->height - j - (k & 2) - 2 < y) {
138  av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
139  return AVERROR_INVALIDDATA;
140  }
141  tmp2 += x + y*stride;
142  case 0x00: // skip
143  tmp[d + 0 ] = tmp2[0];
144  tmp[d + 1 ] = tmp2[1];
145  tmp[d + 0 + stride] = tmp2[0 + stride];
146  tmp[d + 1 + stride] = tmp2[1 + stride];
147  break;
148  case 0x40: // fill
149  tmp[d + 0 ] = data[0];
150  tmp[d + 1 ] = data[0];
151  tmp[d + 0 + stride] = data[0];
152  tmp[d + 1 + stride] = data[0];
153  data++;
154  break;
155  case 0xC0: // raw
156  tmp[d + 0 ] = *data++;
157  tmp[d + 1 ] = *data++;
158  tmp[d + 0 + stride] = *data++;
159  tmp[d + 1 + stride] = *data++;
160  break;
161  }
162  mask <<= 2;
163  }
164  break;
165  case 32: // vector quantization - 2 colors
166  mask = AV_RB16(msk);
167  msk += 2;
168  for(y = 0; y < 4; y++){
169  for(x = 0; x < 4; x++){
170  tmp[x] = data[mask & 1];
171  mask >>= 1;
172  }
173  tmp += stride;
174  tmp2 += stride;
175  }
176  data += 2;
177  break;
178  case 33: // vector quantization - 3 or 4 colors
179  case 34:
180  mask = AV_RB32(msk);
181  msk += 4;
182  for(y = 0; y < 4; y++){
183  for(x = 0; x < 4; x++){
184  tmp[x] = data[mask & 3];
185  mask >>= 2;
186  }
187  tmp += stride;
188  tmp2 += stride;
189  }
190  data += type - 30;
191  break;
192  default:
193  av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
194  return AVERROR_INVALIDDATA;
195  }
196  }
197  dst += stride * 4;
198  ref += stride * 4;
199  }
200  return 0;
201 }
202 
203 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
204 {
205  DxaDecContext * const c = avctx->priv_data;
206  uint8_t *outptr, *srcptr, *tmpptr;
207  unsigned long dsize;
208  int i, j, compr, ret;
209  int stride;
210  int pc = 0;
211  GetByteContext gb;
212 
213  bytestream2_init(&gb, avpkt->data, avpkt->size);
214 
215  /* make the palette available on the way out */
216  if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {
217  bytestream2_skip(&gb, 4);
218  for(i = 0; i < 256; i++){
219  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
220  }
221  pc = 1;
222  }
223 
224  if ((ret = ff_get_buffer(avctx, &c->pic)) < 0) {
225  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
226  return ret;
227  }
228  memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
229  c->pic.palette_has_changed = pc;
230 
231  outptr = c->pic.data[0];
232  srcptr = c->decomp_buf;
233  tmpptr = c->prev.data[0];
234  stride = c->pic.linesize[0];
235 
236  if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
237  compr = -1;
238  else
239  compr = bytestream2_get_byte(&gb);
240 
241  dsize = c->dsize;
242  if (compr != 4 && compr != -1) {
243  bytestream2_skip(&gb, 4);
244  if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),
245  bytestream2_get_bytes_left(&gb)) != Z_OK) {
246  av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
247  return AVERROR_UNKNOWN;
248  }
249  }
250  switch(compr){
251  case -1:
252  c->pic.key_frame = 0;
254  if(c->prev.data[0])
255  memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
256  else{ // Should happen only when first frame is 'NULL'
257  memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
258  c->pic.key_frame = 1;
260  }
261  break;
262  case 2:
263  case 3:
264  case 4:
265  case 5:
266  c->pic.key_frame = !(compr & 1);
267  c->pic.pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
268  for(j = 0; j < avctx->height; j++){
269  if((compr & 1) && tmpptr){
270  for(i = 0; i < avctx->width; i++)
271  outptr[i] = srcptr[i] ^ tmpptr[i];
272  tmpptr += stride;
273  }else
274  memcpy(outptr, srcptr, avctx->width);
275  outptr += stride;
276  srcptr += avctx->width;
277  }
278  break;
279  case 12: // ScummVM coding
280  case 13:
281  c->pic.key_frame = 0;
283  if (!c->prev.data[0]) {
284  av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
285  return AVERROR_INVALIDDATA;
286  }
287  decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
288  break;
289  default:
290  av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
291  return AVERROR_INVALIDDATA;
292  }
293 
294  FFSWAP(AVFrame, c->pic, c->prev);
295  if(c->pic.data[0])
296  avctx->release_buffer(avctx, &c->pic);
297 
298  *got_frame = 1;
299  *(AVFrame*)data = c->prev;
300 
301  /* always report that the buffer was completely consumed */
302  return avpkt->size;
303 }
304 
306 {
307  DxaDecContext * const c = avctx->priv_data;
308 
309  avctx->pix_fmt = AV_PIX_FMT_PAL8;
310 
311  if (avctx->width%4 || avctx->height%4) {
312  av_log(avctx, AV_LOG_ERROR, "dimensions are not a multiple of 4");
313  return AVERROR_INVALIDDATA;
314  }
315 
318 
319  c->dsize = avctx->width * avctx->height * 2;
320  c->decomp_buf = av_malloc(c->dsize);
321  if (!c->decomp_buf) {
322  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
323  return AVERROR(ENOMEM);
324  }
325 
326  return 0;
327 }
328 
330 {
331  DxaDecContext * const c = avctx->priv_data;
332 
333  av_freep(&c->decomp_buf);
334  if(c->prev.data[0])
335  avctx->release_buffer(avctx, &c->prev);
336  if(c->pic.data[0])
337  avctx->release_buffer(avctx, &c->pic);
338 
339  return 0;
340 }
341 
343  .name = "dxa",
344  .type = AVMEDIA_TYPE_VIDEO,
345  .id = AV_CODEC_ID_DXA,
346  .priv_data_size = sizeof(DxaDecContext),
347  .init = decode_init,
348  .close = decode_end,
349  .decode = decode_frame,
350  .capabilities = CODEC_CAP_DR1,
351  .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
352 };