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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 
22 /**
23  * @file
24  * DXA Video decoder
25  */
26 
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  tmp2 += x + y*stride;
75  case 0: // skip
76  case 5: // skip in method 12
77  for(y = 0; y < 4; y++){
78  memcpy(tmp, tmp2, 4);
79  tmp += stride;
80  tmp2 += stride;
81  }
82  break;
83  case 1: // masked change
84  case 10: // masked change with only half of pixels changed
85  case 11: // cases 10-15 are for method 12 only
86  case 12:
87  case 13:
88  case 14:
89  case 15:
90  if(type == 1){
91  mask = AV_RB16(msk);
92  msk += 2;
93  }else{
94  type -= 10;
95  mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
96  msk++;
97  }
98  for(y = 0; y < 4; y++){
99  for(x = 0; x < 4; x++){
100  tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
101  mask <<= 1;
102  }
103  tmp += stride;
104  tmp2 += stride;
105  }
106  break;
107  case 2: // fill block
108  for(y = 0; y < 4; y++){
109  memset(tmp, data[0], 4);
110  tmp += stride;
111  }
112  data++;
113  break;
114  case 3: // raw block
115  for(y = 0; y < 4; y++){
116  memcpy(tmp, data, 4);
117  data += 4;
118  tmp += stride;
119  }
120  break;
121  case 8: // subblocks - method 13 only
122  mask = *msk++;
123  for(k = 0; k < 4; k++){
124  d = ((k & 1) << 1) + ((k & 2) * stride);
125  d2 = ((k & 1) << 1) + ((k & 2) * stride);
126  tmp2 = ref + i + d2;
127  switch(mask & 0xC0){
128  case 0x80: // motion compensation
129  x = (*mv) >> 4; if(x & 8) x = 8 - x;
130  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
131  tmp2 += x + y*stride;
132  case 0x00: // skip
133  tmp[d + 0 ] = tmp2[0];
134  tmp[d + 1 ] = tmp2[1];
135  tmp[d + 0 + stride] = tmp2[0 + stride];
136  tmp[d + 1 + stride] = tmp2[1 + stride];
137  break;
138  case 0x40: // fill
139  tmp[d + 0 ] = data[0];
140  tmp[d + 1 ] = data[0];
141  tmp[d + 0 + stride] = data[0];
142  tmp[d + 1 + stride] = data[0];
143  data++;
144  break;
145  case 0xC0: // raw
146  tmp[d + 0 ] = *data++;
147  tmp[d + 1 ] = *data++;
148  tmp[d + 0 + stride] = *data++;
149  tmp[d + 1 + stride] = *data++;
150  break;
151  }
152  mask <<= 2;
153  }
154  break;
155  case 32: // vector quantization - 2 colors
156  mask = AV_RB16(msk);
157  msk += 2;
158  for(y = 0; y < 4; y++){
159  for(x = 0; x < 4; x++){
160  tmp[x] = data[mask & 1];
161  mask >>= 1;
162  }
163  tmp += stride;
164  tmp2 += stride;
165  }
166  data += 2;
167  break;
168  case 33: // vector quantization - 3 or 4 colors
169  case 34:
170  mask = AV_RB32(msk);
171  msk += 4;
172  for(y = 0; y < 4; y++){
173  for(x = 0; x < 4; x++){
174  tmp[x] = data[mask & 3];
175  mask >>= 2;
176  }
177  tmp += stride;
178  tmp2 += stride;
179  }
180  data += type - 30;
181  break;
182  default:
183  av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
184  return AVERROR_INVALIDDATA;
185  }
186  }
187  dst += stride * 4;
188  ref += stride * 4;
189  }
190  return 0;
191 }
192 
193 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
194 {
195  DxaDecContext * const c = avctx->priv_data;
196  uint8_t *outptr, *srcptr, *tmpptr;
197  unsigned long dsize;
198  int i, j, compr, ret;
199  int stride;
200  int pc = 0;
201  GetByteContext gb;
202 
203  bytestream2_init(&gb, avpkt->data, avpkt->size);
204 
205  /* make the palette available on the way out */
206  if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {
207  bytestream2_skip(&gb, 4);
208  for(i = 0; i < 256; i++){
209  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
210  }
211  pc = 1;
212  }
213 
214  if ((ret = ff_get_buffer(avctx, &c->pic)) < 0) {
215  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
216  return ret;
217  }
218  memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
219  c->pic.palette_has_changed = pc;
220 
221  outptr = c->pic.data[0];
222  srcptr = c->decomp_buf;
223  tmpptr = c->prev.data[0];
224  stride = c->pic.linesize[0];
225 
226  if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
227  compr = -1;
228  else
229  compr = bytestream2_get_byte(&gb);
230 
231  dsize = c->dsize;
232  if (compr != 4 && compr != -1) {
233  bytestream2_skip(&gb, 4);
234  if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),
235  bytestream2_get_bytes_left(&gb)) != Z_OK) {
236  av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
237  return AVERROR_UNKNOWN;
238  }
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  for(j = 0; j < avctx->height; j++){
259  if((compr & 1) && tmpptr){
260  for(i = 0; i < avctx->width; i++)
261  outptr[i] = srcptr[i] ^ tmpptr[i];
262  tmpptr += stride;
263  }else
264  memcpy(outptr, srcptr, avctx->width);
265  outptr += stride;
266  srcptr += avctx->width;
267  }
268  break;
269  case 12: // ScummVM coding
270  case 13:
271  c->pic.key_frame = 0;
273  if (!c->prev.data[0]) {
274  av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
275  return AVERROR_INVALIDDATA;
276  }
277  decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
278  break;
279  default:
280  av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
281  return AVERROR_INVALIDDATA;
282  }
283 
284  FFSWAP(AVFrame, c->pic, c->prev);
285  if(c->pic.data[0])
286  avctx->release_buffer(avctx, &c->pic);
287 
288  *got_frame = 1;
289  *(AVFrame*)data = c->prev;
290 
291  /* always report that the buffer was completely consumed */
292  return avpkt->size;
293 }
294 
296 {
297  DxaDecContext * const c = avctx->priv_data;
298 
299  avctx->pix_fmt = AV_PIX_FMT_PAL8;
300 
303 
304  c->dsize = avctx->width * avctx->height * 2;
305  c->decomp_buf = av_malloc(c->dsize);
306  if (!c->decomp_buf) {
307  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
308  return AVERROR(ENOMEM);
309  }
310 
311  return 0;
312 }
313 
315 {
316  DxaDecContext * const c = avctx->priv_data;
317 
318  av_freep(&c->decomp_buf);
319  if(c->prev.data[0])
320  avctx->release_buffer(avctx, &c->prev);
321  if(c->pic.data[0])
322  avctx->release_buffer(avctx, &c->pic);
323 
324  return 0;
325 }
326 
328  .name = "dxa",
329  .type = AVMEDIA_TYPE_VIDEO,
330  .id = AV_CODEC_ID_DXA,
331  .priv_data_size = sizeof(DxaDecContext),
332  .init = decode_init,
333  .close = decode_end,
334  .decode = decode_frame,
335  .capabilities = CODEC_CAP_DR1,
336  .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
337 };