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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,
53  int stride, uint8_t *src, uint8_t *ref)
54 {
55  uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
56  int i, j, k;
57  int type, x, y, d, d2;
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  AVFrame *frame = data;
206  DxaDecContext * const c = avctx->priv_data;
207  uint8_t *outptr, *srcptr, *tmpptr;
208  unsigned long dsize;
209  int i, j, compr, ret;
210  int stride;
211  int pc = 0;
212  GetByteContext gb;
213 
214  bytestream2_init(&gb, avpkt->data, avpkt->size);
215 
216  /* make the palette available on the way out */
217  if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {
218  bytestream2_skip(&gb, 4);
219  for(i = 0; i < 256; i++){
220  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
221  }
222  pc = 1;
223  }
224 
225  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
226  return ret;
227  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
228  frame->palette_has_changed = pc;
229 
230  outptr = frame->data[0];
231  srcptr = c->decomp_buf;
232  tmpptr = c->prev->data[0];
233  stride = frame->linesize[0];
234 
235  if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
236  compr = -1;
237  else
238  compr = bytestream2_get_byte(&gb);
239 
240  dsize = c->dsize;
241  if (compr != 4 && compr != -1) {
242  bytestream2_skip(&gb, 4);
243  if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),
244  bytestream2_get_bytes_left(&gb)) != Z_OK) {
245  av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
246  return AVERROR_UNKNOWN;
247  }
248  }
249  switch(compr){
250  case -1:
251  frame->key_frame = 0;
252  frame->pict_type = AV_PICTURE_TYPE_P;
253  if (c->prev->data[0])
254  memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);
255  else{ // Should happen only when first frame is 'NULL'
256  memset(frame->data[0], 0, frame->linesize[0] * avctx->height);
257  frame->key_frame = 1;
258  frame->pict_type = AV_PICTURE_TYPE_I;
259  }
260  break;
261  case 2:
262  case 3:
263  case 4:
264  case 5:
265  frame->key_frame = !(compr & 1);
266  frame->pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
267  for(j = 0; j < avctx->height; j++){
268  if((compr & 1) && tmpptr){
269  for(i = 0; i < avctx->width; i++)
270  outptr[i] = srcptr[i] ^ tmpptr[i];
271  tmpptr += stride;
272  }else
273  memcpy(outptr, srcptr, avctx->width);
274  outptr += stride;
275  srcptr += avctx->width;
276  }
277  break;
278  case 12: // ScummVM coding
279  case 13:
280  frame->key_frame = 0;
281  frame->pict_type = AV_PICTURE_TYPE_P;
282  if (!c->prev->data[0]) {
283  av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
284  return AVERROR_INVALIDDATA;
285  }
286  decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, c->prev->data[0]);
287  break;
288  default:
289  av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
290  return AVERROR_INVALIDDATA;
291  }
292 
293  av_frame_unref(c->prev);
294  if ((ret = av_frame_ref(c->prev, frame)) < 0)
295  return ret;
296 
297  *got_frame = 1;
298 
299  /* always report that the buffer was completely consumed */
300  return avpkt->size;
301 }
302 
304 {
305  DxaDecContext * const c = avctx->priv_data;
306 
307  avctx->pix_fmt = AV_PIX_FMT_PAL8;
308 
309  c->prev = av_frame_alloc();
310  if (!c->prev)
311  return AVERROR(ENOMEM);
312 
313  c->dsize = avctx->width * avctx->height * 2;
314  c->decomp_buf = av_malloc(c->dsize);
315  if (!c->decomp_buf) {
316  av_frame_free(&c->prev);
317  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
318  return AVERROR(ENOMEM);
319  }
320 
321  return 0;
322 }
323 
325 {
326  DxaDecContext * const c = avctx->priv_data;
327 
328  av_freep(&c->decomp_buf);
329  av_frame_free(&c->prev);
330 
331  return 0;
332 }
333 
335  .name = "dxa",
336  .type = AVMEDIA_TYPE_VIDEO,
337  .id = AV_CODEC_ID_DXA,
338  .priv_data_size = sizeof(DxaDecContext),
339  .init = decode_init,
340  .close = decode_end,
341  .decode = decode_frame,
342  .capabilities = CODEC_CAP_DR1,
343  .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
344 };