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eamad.c
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1 /*
2  * Electronic Arts Madcow Video Decoder
3  * Copyright (c) 2007-2009 Peter Ross
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 St, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Electronic Arts Madcow Video Decoder
25  * @author Peter Ross <pross@xvid.org>
26  *
27  * @see technical details at
28  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
29  */
30 
31 #include "avcodec.h"
32 #include "bytestream.h"
33 #include "bswapdsp.h"
34 #include "get_bits.h"
35 #include "aandcttab.h"
36 #include "eaidct.h"
37 #include "idctdsp.h"
38 #include "internal.h"
39 #include "mpeg12.h"
40 #include "mpeg12data.h"
41 #include "libavutil/imgutils.h"
42 
43 #define EA_PREAMBLE_SIZE 8
44 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
45 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
46 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
47 
48 typedef struct MadContext {
56  unsigned int bitstream_buf_size;
57  DECLARE_ALIGNED(16, int16_t, block)[64];
59  uint16_t quant_matrix[64];
60  int mb_x;
61  int mb_y;
62 } MadContext;
63 
65 {
66  MadContext *s = avctx->priv_data;
67  s->avctx = avctx;
68  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
69  ff_blockdsp_init(&s->bdsp, avctx);
71  ff_idctdsp_init(&s->idsp, avctx);
75 
77  if (!s->last_frame)
78  return AVERROR(ENOMEM);
79 
80  return 0;
81 }
82 
83 static inline void comp(unsigned char *dst, int dst_stride,
84  unsigned char *src, int src_stride, int add)
85 {
86  int j, i;
87  for (j=0; j<8; j++)
88  for (i=0; i<8; i++)
89  dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
90 }
91 
92 static inline void comp_block(MadContext *t, AVFrame *frame,
93  int mb_x, int mb_y,
94  int j, int mv_x, int mv_y, int add)
95 {
96  if (j < 4) {
97  unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
98  if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
99  return;
100  comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
101  frame->linesize[0],
102  t->last_frame->data[0] + offset,
103  t->last_frame->linesize[0], add);
104  } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
105  int index = j - 3;
106  unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
107  if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
108  return;
109  comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
110  frame->linesize[index],
111  t->last_frame->data[index] + offset,
112  t->last_frame->linesize[index], add);
113  }
114 }
115 
116 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
117  int mb_x, int mb_y, int j)
118 {
119  if (j < 4) {
121  frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
122  frame->linesize[0], block);
123  } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
124  int index = j - 3;
126  frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
127  frame->linesize[index], block);
128  }
129 }
130 
131 static inline int decode_block_intra(MadContext *s, int16_t * block)
132 {
133  int level, i, j, run;
134  RLTable *rl = &ff_rl_mpeg1;
135  const uint8_t *scantable = s->scantable.permutated;
136  int16_t *quant_matrix = s->quant_matrix;
137 
138  block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
139 
140  /* The RL decoder is derived from mpeg1_decode_block_intra;
141  Escaped level and run values a decoded differently */
142  i = 0;
143  {
144  OPEN_READER(re, &s->gb);
145  /* now quantify & encode AC coefficients */
146  for (;;) {
147  UPDATE_CACHE(re, &s->gb);
148  GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
149 
150  if (level == 127) {
151  break;
152  } else if (level != 0) {
153  i += run;
154  j = scantable[i];
155  level = (level*quant_matrix[j]) >> 4;
156  level = (level-1)|1;
157  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
158  LAST_SKIP_BITS(re, &s->gb, 1);
159  } else {
160  /* escape */
161  UPDATE_CACHE(re, &s->gb);
162  level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
163 
164  UPDATE_CACHE(re, &s->gb);
165  run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
166 
167  i += run;
168  j = scantable[i];
169  if (level < 0) {
170  level = -level;
171  level = (level*quant_matrix[j]) >> 4;
172  level = (level-1)|1;
173  level = -level;
174  } else {
175  level = (level*quant_matrix[j]) >> 4;
176  level = (level-1)|1;
177  }
178  }
179  if (i > 63) {
180  av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
181  return -1;
182  }
183 
184  block[j] = level;
185  }
186  CLOSE_READER(re, &s->gb);
187  }
188  return 0;
189 }
190 
192 {
193  int value = 0;
194  if (get_bits1(gb)) {
195  if (get_bits1(gb))
196  value = -17;
197  value += get_bits(gb, 4) + 1;
198  }
199  return value;
200 }
201 
202 static int decode_mb(MadContext *s, AVFrame *frame, int inter)
203 {
204  int mv_map = 0;
205  int av_uninit(mv_x), av_uninit(mv_y);
206  int j;
207 
208  if (inter) {
209  int v = decode210(&s->gb);
210  if (v < 2) {
211  mv_map = v ? get_bits(&s->gb, 6) : 63;
212  mv_x = decode_motion(&s->gb);
213  mv_y = decode_motion(&s->gb);
214  }
215  }
216 
217  for (j=0; j<6; j++) {
218  if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
219  int add = 2*decode_motion(&s->gb);
220  if (s->last_frame->data[0])
221  comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
222  } else {
223  s->bdsp.clear_block(s->block);
224  if(decode_block_intra(s, s->block) < 0)
225  return -1;
226  idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
227  }
228  }
229  return 0;
230 }
231 
232 static void calc_quant_matrix(MadContext *s, int qscale)
233 {
234  int i;
235 
237  for (i=1; i<64; i++)
238  s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
239 }
240 
241 static int decode_frame(AVCodecContext *avctx,
242  void *data, int *got_frame,
243  AVPacket *avpkt)
244 {
245  const uint8_t *buf = avpkt->data;
246  int buf_size = avpkt->size;
247  MadContext *s = avctx->priv_data;
248  AVFrame *frame = data;
249  GetByteContext gb;
250  int width, height;
251  int chunk_type;
252  int inter, ret;
253 
254  bytestream2_init(&gb, buf, buf_size);
255 
256  chunk_type = bytestream2_get_le32(&gb);
257  inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
258  bytestream2_skip(&gb, 10);
259 
260  av_reduce(&avctx->time_base.num, &avctx->time_base.den,
261  bytestream2_get_le16(&gb), 1000, 1<<30);
262 
263  width = bytestream2_get_le16(&gb);
264  height = bytestream2_get_le16(&gb);
265  bytestream2_skip(&gb, 1);
266  calc_quant_matrix(s, bytestream2_get_byte(&gb));
267  bytestream2_skip(&gb, 2);
268 
269  if (bytestream2_get_bytes_left(&gb) < 2) {
270  av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
271  return AVERROR_INVALIDDATA;
272  }
273 
274  if (width < 16 || height < 16) {
275  av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
276  return AVERROR_INVALIDDATA;
277  }
278 
279  if (avctx->width != width || avctx->height != height) {
281  if((width * height)/2048*7 > bytestream2_get_bytes_left(&gb))
282  return AVERROR_INVALIDDATA;
283  if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
284  return ret;
285  }
286 
287  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
288  return ret;
289 
290  if (inter && !s->last_frame->data[0]) {
291  av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
293  if (ret < 0)
294  return ret;
295  memset(s->last_frame->data[0], 0, s->last_frame->height *
296  s->last_frame->linesize[0]);
297  memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
298  s->last_frame->linesize[1]);
299  memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
300  s->last_frame->linesize[2]);
301  }
302 
305  if (!s->bitstream_buf)
306  return AVERROR(ENOMEM);
307  s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
308  bytestream2_get_bytes_left(&gb) / 2);
311 
312  for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
313  for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
314  if(decode_mb(s, frame, inter) < 0)
315  return AVERROR_INVALIDDATA;
316 
317  *got_frame = 1;
318 
319  if (chunk_type != MADe_TAG) {
321  if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
322  return ret;
323  }
324 
325  return buf_size;
326 }
327 
329 {
330  MadContext *t = avctx->priv_data;
333  return 0;
334 }
335 
337  .name = "eamad",
338  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
339  .type = AVMEDIA_TYPE_VIDEO,
340  .id = AV_CODEC_ID_MAD,
341  .priv_data_size = sizeof(MadContext),
342  .init = decode_init,
343  .close = decode_end,
344  .decode = decode_frame,
345  .capabilities = CODEC_CAP_DR1,
346 };