FFmpeg
mss4.c
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1 /*
2  * Microsoft Screen 4 (aka Microsoft Expression Encoder Screen) decoder
3  * Copyright (c) 2012 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  * Microsoft Screen 4 (aka Microsoft Titanium Screen 2,
25  * aka Microsoft Expression Encoder Screen) decoder
26  */
27 
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "get_bits.h"
31 #include "internal.h"
32 #include "mss34dsp.h"
33 #include "unary.h"
34 
35 #define HEADER_SIZE 8
36 
37 enum FrameType {
41 };
42 
43 enum BlockType {
47 };
48 
49 enum CachePos {
50  LEFT = 0,
52  TOP,
53 };
54 
55 static const uint8_t mss4_dc_vlc_lens[2][16] = {
56  { 0, 1, 5, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0 },
57  { 0, 3, 1, 1, 1, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0 }
58 };
59 
60 static const uint8_t mss4_ac_vlc_lens[2][16] = {
61  { 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125 },
62  { 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 119 }
63 };
64 
65 static const uint8_t mss4_ac_vlc_syms[2][162] = {
66  { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
67  0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
68  0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08,
69  0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0,
70  0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16,
71  0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28,
72  0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
73  0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
74  0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
75  0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
76  0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
77  0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
78  0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
79  0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
80  0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
81  0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5,
82  0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4,
83  0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2,
84  0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
85  0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8,
86  0xF9, 0xFA },
87  { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
88  0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
89  0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
90  0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0,
91  0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16, 0x24, 0x34,
92  0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26,
93  0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38,
94  0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
95  0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
96  0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
97  0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
98  0x79, 0x7A, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
99  0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96,
100  0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5,
101  0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4,
102  0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3,
103  0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2,
104  0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA,
105  0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9,
106  0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8,
107  0xF9, 0xFA }
108 };
109 
110 static const uint8_t vec_len_syms[2][4] = {
111  { 4, 2, 3, 1 },
112  { 4, 1, 2, 3 }
113 };
114 
115 static const uint8_t mss4_vec_entry_vlc_lens[2][16] = {
116  { 0, 2, 2, 3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
117  { 0, 1, 5, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
118 };
119 
120 static const uint8_t mss4_vec_entry_vlc_syms[2][9] = {
121  { 0, 7, 6, 5, 8, 4, 3, 1, 2 },
122  { 0, 2, 3, 4, 5, 6, 7, 1, 8 }
123 };
124 
125 #define MAX_ENTRIES 162
126 
127 typedef struct MSS4Context {
129 
130  VLC dc_vlc[2], ac_vlc[2];
132  int block[64];
133  uint8_t imgbuf[3][16 * 16];
134 
135  int quality;
136  uint16_t quant_mat[2][64];
137 
138  int *prev_dc[3];
139  ptrdiff_t dc_stride[3];
140  int dc_cache[4][4];
141 
142  int prev_vec[3][4];
143 } MSS4Context;
144 
145 static av_cold int mss4_init_vlc(VLC *vlc, const uint8_t *lens,
146  const uint8_t *syms, int num_syms)
147 {
149  uint16_t codes[MAX_ENTRIES];
150  int i, j;
151  int prefix = 0, max_bits = 0, idx = 0;
152 
153  for (i = 0; i < 16; i++) {
154  for (j = 0; j < lens[i]; j++) {
155  bits[idx] = i + 1;
156  codes[idx] = prefix++;
157  max_bits = i + 1;
158  idx++;
159  }
160  prefix <<= 1;
161  }
162 
163  return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), num_syms, bits, 1, 1,
164  codes, 2, 2, syms, 1, 1, 0);
165 }
166 
168 {
169  int ret, i;
170 
171  for (i = 0; i < 2; i++) {
172  ret = mss4_init_vlc(&ctx->dc_vlc[i], mss4_dc_vlc_lens[i], NULL, 12);
173  if (ret)
174  return ret;
175  ret = mss4_init_vlc(&ctx->ac_vlc[i], mss4_ac_vlc_lens[i],
176  mss4_ac_vlc_syms[i], 162);
177  if (ret)
178  return ret;
181  if (ret)
182  return ret;
183  }
184  return 0;
185 }
186 
188 {
189  int i;
190 
191  for (i = 0; i < 2; i++) {
192  ff_free_vlc(&ctx->dc_vlc[i]);
193  ff_free_vlc(&ctx->ac_vlc[i]);
194  ff_free_vlc(&ctx->vec_entry_vlc[i]);
195  }
196 }
197 
198 /* This function returns values in the range
199  * (-range + 1; -range/2] U [range/2; range - 1)
200  * i.e.
201  * nbits = 0 -> 0
202  * nbits = 1 -> -1, 1
203  * nbits = 2 -> -3, -2, 2, 3
204  */
206 {
207  int val;
208 
209  if (!nbits)
210  return 0;
211 
212  val = get_bits(gb, nbits);
213  if (val < (1 << (nbits - 1)))
214  val -= (1 << nbits) - 1;
215 
216  return val;
217 }
218 
219 static inline int get_coeff(GetBitContext *gb, VLC *vlc)
220 {
221  int val = get_vlc2(gb, vlc->table, vlc->bits, 2);
222 
223  return get_coeff_bits(gb, val);
224 }
225 
227  int *block, int *dc_cache,
228  int bx, int by, uint16_t *quant_mat)
229 {
230  int skip, val, pos = 1, zz_pos, dc;
231 
232  memset(block, 0, sizeof(*block) * 64);
233 
234  dc = get_coeff(gb, dc_vlc);
235  // DC prediction is the same as in MSS3
236  if (by) {
237  if (bx) {
238  int l, tl, t;
239 
240  l = dc_cache[LEFT];
241  tl = dc_cache[TOP_LEFT];
242  t = dc_cache[TOP];
243 
244  if (FFABS(t - tl) <= FFABS(l - tl))
245  dc += l;
246  else
247  dc += t;
248  } else {
249  dc += dc_cache[TOP];
250  }
251  } else if (bx) {
252  dc += dc_cache[LEFT];
253  }
254  dc_cache[LEFT] = dc;
255  block[0] = dc * quant_mat[0];
256 
257  while (pos < 64) {
258  val = get_vlc2(gb, ac_vlc->table, 9, 2);
259  if (!val)
260  return 0;
261  if (val == -1)
262  return -1;
263  if (val == 0xF0) {
264  pos += 16;
265  continue;
266  }
267  skip = val >> 4;
268  val = get_coeff_bits(gb, val & 0xF);
269  pos += skip;
270  if (pos >= 64)
271  return -1;
272 
273  zz_pos = ff_zigzag_direct[pos];
274  block[zz_pos] = val * quant_mat[zz_pos];
275  pos++;
276  }
277 
278  return pos == 64 ? 0 : -1;
279 }
280 
282  uint8_t *dst[3], int mb_x, int mb_y)
283 {
284  int i, j, k, ret;
285  uint8_t *out = dst[0];
286 
287  for (j = 0; j < 2; j++) {
288  for (i = 0; i < 2; i++) {
289  int xpos = mb_x * 2 + i;
290  c->dc_cache[j][TOP_LEFT] = c->dc_cache[j][TOP];
291  c->dc_cache[j][TOP] = c->prev_dc[0][mb_x * 2 + i];
292  ret = mss4_decode_dct(gb, c->dc_vlc, c->ac_vlc, c->block,
293  c->dc_cache[j],
294  xpos, mb_y * 2 + j, c->quant_mat[0]);
295  if (ret)
296  return ret;
297  c->prev_dc[0][mb_x * 2 + i] = c->dc_cache[j][LEFT];
298 
299  ff_mss34_dct_put(out + xpos * 8, c->pic->linesize[0],
300  c->block);
301  }
302  out += 8 * c->pic->linesize[0];
303  }
304 
305  for (i = 1; i < 3; i++) {
306  c->dc_cache[i + 1][TOP_LEFT] = c->dc_cache[i + 1][TOP];
307  c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x];
308  ret = mss4_decode_dct(gb, c->dc_vlc + 1, c->ac_vlc + 1,
309  c->block, c->dc_cache[i + 1], mb_x, mb_y,
310  c->quant_mat[1]);
311  if (ret)
312  return ret;
313  c->prev_dc[i][mb_x] = c->dc_cache[i + 1][LEFT];
314 
315  ff_mss34_dct_put(c->imgbuf[i], 8, c->block);
316  out = dst[i] + mb_x * 16;
317  // Since the DCT block is coded as YUV420 and the whole frame as YUV444,
318  // we need to scale chroma.
319  for (j = 0; j < 16; j++) {
320  for (k = 0; k < 8; k++)
321  AV_WN16A(out + k * 2, c->imgbuf[i][k + (j & ~1) * 4] * 0x101);
322  out += c->pic->linesize[i];
323  }
324  }
325 
326  return 0;
327 }
328 
329 static void read_vec_pos(GetBitContext *gb, int *vec_pos, int *sel_flag,
330  int *sel_len, int *prev)
331 {
332  int i, y_flag = 0;
333 
334  for (i = 2; i >= 0; i--) {
335  if (!sel_flag[i]) {
336  vec_pos[i] = 0;
337  continue;
338  }
339  if ((!i && !y_flag) || get_bits1(gb)) {
340  if (sel_len[i] > 0) {
341  int pval = prev[i];
342  vec_pos[i] = get_bits(gb, sel_len[i]);
343  if (vec_pos[i] >= pval)
344  vec_pos[i]++;
345  } else {
346  vec_pos[i] = !prev[i];
347  }
348  y_flag = 1;
349  } else {
350  vec_pos[i] = prev[i];
351  }
352  }
353 }
354 
355 static int get_value_cached(GetBitContext *gb, int vec_pos, uint8_t *vec,
356  int vec_size, int component, int shift, int *prev)
357 {
358  if (vec_pos < vec_size)
359  return vec[vec_pos];
360  if (!get_bits1(gb))
361  return prev[component];
362  prev[component] = get_bits(gb, 8 - shift) << shift;
363  return prev[component];
364 }
365 
366 #define MKVAL(vals) ((vals)[0] | ((vals)[1] << 3) | ((vals)[2] << 6))
367 
368 /* Image mode - the hardest to comprehend MSS4 coding mode.
369  *
370  * In this mode all three 16x16 blocks are coded together with a method
371  * remotely similar to the methods employed in MSS1-MSS3.
372  * The idea is that every component has a vector of 1-4 most common symbols
373  * and an escape mode for reading new value from the bitstream. Decoding
374  * consists of retrieving pixel values from the vector or reading new ones
375  * from the bitstream; depending on flags read from the bitstream, these vector
376  * positions can be updated or reused from the state of the previous line
377  * or previous pixel.
378  */
380  uint8_t *picdst[3], int mb_x, int mb_y)
381 {
382  uint8_t vec[3][4];
383  int vec_len[3];
384  int sel_len[3], sel_flag[3];
385  int i, j, k, mode, split;
386  int prev_vec1 = 0, prev_split = 0;
387  int vals[3] = { 0 };
388  int prev_pix[3] = { 0 };
389  int prev_mode[16] = { 0 };
390  uint8_t *dst[3];
391 
392  const int val_shift = ctx->quality == 100 ? 0 : 2;
393 
394  for (i = 0; i < 3; i++)
395  dst[i] = ctx->imgbuf[i];
396 
397  for (i = 0; i < 3; i++) {
398  vec_len[i] = vec_len_syms[!!i][get_unary(gb, 0, 3)];
399  for (j = 0; j < vec_len[i]; j++) {
400  vec[i][j] = get_coeff(gb, &ctx->vec_entry_vlc[!!i]);
401  vec[i][j] += ctx->prev_vec[i][j];
402  ctx->prev_vec[i][j] = vec[i][j];
403  }
404  sel_flag[i] = vec_len[i] > 1;
405  sel_len[i] = vec_len[i] > 2 ? vec_len[i] - 2 : 0;
406  }
407 
408  for (j = 0; j < 16; j++) {
409  if (get_bits1(gb)) {
410  split = 0;
411  if (get_bits1(gb)) {
412  prev_mode[0] = 0;
413  vals[0] = vals[1] = vals[2] = 0;
414  mode = 2;
415  } else {
416  mode = get_bits1(gb);
417  if (mode)
418  split = get_bits(gb, 4);
419  }
420  for (i = 0; i < 16; i++) {
421  if (mode <= 1) {
422  vals[0] = prev_mode[i] & 7;
423  vals[1] = (prev_mode[i] >> 3) & 7;
424  vals[2] = prev_mode[i] >> 6;
425  if (mode == 1 && i == split) {
426  read_vec_pos(gb, vals, sel_flag, sel_len, vals);
427  }
428  } else if (mode == 2) {
429  if (get_bits1(gb))
430  read_vec_pos(gb, vals, sel_flag, sel_len, vals);
431  }
432  for (k = 0; k < 3; k++)
433  *dst[k]++ = get_value_cached(gb, vals[k], vec[k],
434  vec_len[k], k,
435  val_shift, prev_pix);
436  prev_mode[i] = MKVAL(vals);
437  }
438  } else {
439  if (get_bits1(gb)) {
440  split = get_bits(gb, 4);
441  if (split >= prev_split)
442  split++;
443  prev_split = split;
444  } else {
445  split = prev_split;
446  }
447  if (split) {
448  vals[0] = prev_mode[0] & 7;
449  vals[1] = (prev_mode[0] >> 3) & 7;
450  vals[2] = prev_mode[0] >> 6;
451  for (i = 0; i < 3; i++) {
452  for (k = 0; k < split; k++) {
453  *dst[i]++ = get_value_cached(gb, vals[i], vec[i],
454  vec_len[i], i, val_shift,
455  prev_pix);
456  prev_mode[k] = MKVAL(vals);
457  }
458  }
459  }
460 
461  if (split != 16) {
462  vals[0] = prev_vec1 & 7;
463  vals[1] = (prev_vec1 >> 3) & 7;
464  vals[2] = prev_vec1 >> 6;
465  if (get_bits1(gb)) {
466  read_vec_pos(gb, vals, sel_flag, sel_len, vals);
467  prev_vec1 = MKVAL(vals);
468  }
469  for (i = 0; i < 3; i++) {
470  for (k = 0; k < 16 - split; k++) {
471  *dst[i]++ = get_value_cached(gb, vals[i], vec[i],
472  vec_len[i], i, val_shift,
473  prev_pix);
474  prev_mode[split + k] = MKVAL(vals);
475  }
476  }
477  }
478  }
479  }
480 
481  for (i = 0; i < 3; i++)
482  for (j = 0; j < 16; j++)
483  memcpy(picdst[i] + mb_x * 16 + j * ctx->pic->linesize[i],
484  ctx->imgbuf[i] + j * 16, 16);
485 
486  return 0;
487 }
488 
489 static inline void mss4_update_dc_cache(MSS4Context *c, int mb_x)
490 {
491  int i;
492 
493  c->dc_cache[0][TOP] = c->prev_dc[0][mb_x * 2 + 1];
494  c->dc_cache[0][LEFT] = 0;
495  c->dc_cache[1][TOP] = 0;
496  c->dc_cache[1][LEFT] = 0;
497 
498  for (i = 0; i < 2; i++)
499  c->prev_dc[0][mb_x * 2 + i] = 0;
500 
501  for (i = 1; i < 3; i++) {
502  c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x];
503  c->dc_cache[i + 1][LEFT] = 0;
504  c->prev_dc[i][mb_x] = 0;
505  }
506 }
507 
508 static int mss4_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
509  AVPacket *avpkt)
510 {
511  const uint8_t *buf = avpkt->data;
512  int buf_size = avpkt->size;
513  MSS4Context *c = avctx->priv_data;
514  GetBitContext gb;
515  GetByteContext bc;
516  uint8_t *dst[3];
517  int width, height, quality, frame_type;
518  int x, y, i, mb_width, mb_height, blk_type;
519  int ret;
520 
521  if (buf_size < HEADER_SIZE) {
522  av_log(avctx, AV_LOG_ERROR,
523  "Frame should have at least %d bytes, got %d instead\n",
524  HEADER_SIZE, buf_size);
525  return AVERROR_INVALIDDATA;
526  }
527 
528  bytestream2_init(&bc, buf, buf_size);
529  width = bytestream2_get_be16(&bc);
530  height = bytestream2_get_be16(&bc);
531  bytestream2_skip(&bc, 2);
532  quality = bytestream2_get_byte(&bc);
533  frame_type = bytestream2_get_byte(&bc);
534 
535  if (width > avctx->width ||
536  height != avctx->height) {
537  av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d\n",
538  width, height);
539  return AVERROR_INVALIDDATA;
540  }
541  if (quality < 1 || quality > 100) {
542  av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality);
543  return AVERROR_INVALIDDATA;
544  }
545  if ((frame_type & ~3) || frame_type == 3) {
546  av_log(avctx, AV_LOG_ERROR, "Invalid frame type %d\n", frame_type);
547  return AVERROR_INVALIDDATA;
548  }
549 
550  if (frame_type != SKIP_FRAME && !bytestream2_get_bytes_left(&bc)) {
551  av_log(avctx, AV_LOG_ERROR,
552  "Empty frame found but it is not a skip frame.\n");
553  return AVERROR_INVALIDDATA;
554  }
555  mb_width = FFALIGN(width, 16) >> 4;
556  mb_height = FFALIGN(height, 16) >> 4;
557 
558  if (frame_type != SKIP_FRAME && 8*buf_size < 8*HEADER_SIZE + mb_width*mb_height)
559  return AVERROR_INVALIDDATA;
560 
561  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
562  return ret;
563  c->pic->key_frame = (frame_type == INTRA_FRAME);
564  c->pic->pict_type = (frame_type == INTRA_FRAME) ? AV_PICTURE_TYPE_I
566  if (frame_type == SKIP_FRAME) {
567  *got_frame = 1;
568  if ((ret = av_frame_ref(data, c->pic)) < 0)
569  return ret;
570 
571  return buf_size;
572  }
573 
574  if (c->quality != quality) {
575  c->quality = quality;
576  for (i = 0; i < 2; i++)
577  ff_mss34_gen_quant_mat(c->quant_mat[i], quality, !i);
578  }
579 
580  if ((ret = init_get_bits8(&gb, buf + HEADER_SIZE, buf_size - HEADER_SIZE)) < 0)
581  return ret;
582  dst[0] = c->pic->data[0];
583  dst[1] = c->pic->data[1];
584  dst[2] = c->pic->data[2];
585 
586  memset(c->prev_vec, 0, sizeof(c->prev_vec));
587  for (y = 0; y < mb_height; y++) {
588  memset(c->dc_cache, 0, sizeof(c->dc_cache));
589  for (x = 0; x < mb_width; x++) {
590  blk_type = decode012(&gb);
591  switch (blk_type) {
592  case DCT_BLOCK:
593  if (mss4_decode_dct_block(c, &gb, dst, x, y) < 0) {
594  av_log(avctx, AV_LOG_ERROR,
595  "Error decoding DCT block %d,%d\n",
596  x, y);
597  return AVERROR_INVALIDDATA;
598  }
599  break;
600  case IMAGE_BLOCK:
601  if (mss4_decode_image_block(c, &gb, dst, x, y) < 0) {
602  av_log(avctx, AV_LOG_ERROR,
603  "Error decoding VQ block %d,%d\n",
604  x, y);
605  return AVERROR_INVALIDDATA;
606  }
607  break;
608  case SKIP_BLOCK:
609  if (frame_type == INTRA_FRAME) {
610  av_log(avctx, AV_LOG_ERROR, "Skip block in intra frame\n");
611  return AVERROR_INVALIDDATA;
612  }
613  break;
614  }
615  if (blk_type != DCT_BLOCK)
616  mss4_update_dc_cache(c, x);
617  }
618  dst[0] += c->pic->linesize[0] * 16;
619  dst[1] += c->pic->linesize[1] * 16;
620  dst[2] += c->pic->linesize[2] * 16;
621  }
622 
623  if ((ret = av_frame_ref(data, c->pic)) < 0)
624  return ret;
625 
626  *got_frame = 1;
627 
628  return buf_size;
629 }
630 
632 {
633  MSS4Context * const c = avctx->priv_data;
634  int i;
635 
636  av_frame_free(&c->pic);
637  for (i = 0; i < 3; i++)
638  av_freep(&c->prev_dc[i]);
639  mss4_free_vlcs(c);
640 
641  return 0;
642 }
643 
645 {
646  MSS4Context * const c = avctx->priv_data;
647  int i;
648 
649  if (mss4_init_vlcs(c)) {
650  av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
651  mss4_free_vlcs(c);
652  return AVERROR(ENOMEM);
653  }
654  for (i = 0; i < 3; i++) {
655  c->dc_stride[i] = FFALIGN(avctx->width, 16) >> (2 + !!i);
656  c->prev_dc[i] = av_malloc_array(c->dc_stride[i], sizeof(**c->prev_dc));
657  if (!c->prev_dc[i]) {
658  av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n");
659  mss4_free_vlcs(c);
660  return AVERROR(ENOMEM);
661  }
662  }
663 
664  c->pic = av_frame_alloc();
665  if (!c->pic) {
666  mss4_decode_end(avctx);
667  return AVERROR(ENOMEM);
668  }
669 
670  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
671 
672  return 0;
673 }
674 
676  .name = "mts2",
677  .long_name = NULL_IF_CONFIG_SMALL("MS Expression Encoder Screen"),
678  .type = AVMEDIA_TYPE_VIDEO,
679  .id = AV_CODEC_ID_MTS2,
680  .priv_data_size = sizeof(MSS4Context),
682  .close = mss4_decode_end,
684  .capabilities = AV_CODEC_CAP_DR1,
685 };
static av_cold int mss4_decode_end(AVCodecContext *avctx)
Definition: mss4.c:631
#define NULL
Definition: coverity.c:32
const char const char void * val
Definition: avisynth_c.h:863
void ff_mss34_gen_quant_mat(uint16_t *qmat, int quality, int luma)
Generate quantisation matrix for given quality.
Definition: mss34dsp.c:48
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static int shift(int a, int b)
Definition: sonic.c:82
uint16_t quant_mat[2][64]
Definition: mss4.c:136
static int mss4_decode_dct_block(MSS4Context *c, GetBitContext *gb, uint8_t *dst[3], int mb_x, int mb_y)
Definition: mss4.c:281
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
VLC vec_entry_vlc[2]
Definition: mss4.c:131
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
Definition: mss4.c:51
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static void read_vec_pos(GetBitContext *gb, int *vec_pos, int *sel_flag, int *sel_len, int *prev)
Definition: mss4.c:329
int ff_init_vlc_sparse(VLC *vlc_arg, int nb_bits, int nb_codes, const void *bits, int bits_wrap, int bits_size, const void *codes, int codes_wrap, int codes_size, const void *symbols, int symbols_wrap, int symbols_size, int flags)
Definition: bitstream.c:273
int size
Definition: avcodec.h:1481
int * prev_dc[3]
Definition: mss4.c:138
Definition: mss4.c:50
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
Definition: mss4.c:52
int block[64]
Definition: mss4.c:132
AVCodec.
Definition: avcodec.h:3484
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVFrame * pic
Definition: mss4.c:128
int prev_vec[3][4]
Definition: mss4.c:142
uint8_t
#define av_cold
Definition: attributes.h:82
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
#define MKVAL(vals)
Definition: mss4.c:366
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:443
VLC dc_vlc[2]
Definition: mss4.c:130
#define height
uint8_t * data
Definition: avcodec.h:1480
static int mss4_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: mss4.c:508
bitstream reader API header.
static av_always_inline int get_coeff_bits(GetBitContext *gb, int nbits)
Definition: mss4.c:205
#define FFALIGN(x, a)
Definition: macros.h:48
ptrdiff_t dc_stride[3]
Definition: mss4.c:139
#define av_log(a,...)
FrameType
G723.1 frame types.
Definition: g723_1.h:63
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
CachePos
Definition: mss4.c:49
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
static const uint8_t vec_len_syms[2][4]
Definition: mss4.c:110
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available...
Definition: decode.c:2010
int dc_cache[4][4]
Definition: mss4.c:140
static int get_value_cached(GetBitContext *gb, int vec_pos, uint8_t *vec, int vec_size, int component, int shift, int *prev)
Definition: mss4.c:355
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
const char * name
Name of the codec implementation.
Definition: avcodec.h:3491
static const uint8_t mss4_ac_vlc_syms[2][162]
Definition: mss4.c:65
uint8_t bits
Definition: vp3data.h:202
Definition: mss4.c:45
static int get_coeff(GetBitContext *gb, VLC *vlc)
Definition: mss4.c:219
Definition: vlc.h:26
static char * split(char *message, char delim)
Definition: af_channelmap.c:81
void ff_mss34_dct_put(uint8_t *dst, ptrdiff_t stride, int *block)
Transform and output DCT block.
Definition: mss34dsp.c:90
static av_cold void mss4_free_vlcs(MSS4Context *ctx)
Definition: mss4.c:187
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:378
#define FFMIN(a, b)
Definition: common.h:96
#define width
static av_cold int mss4_init_vlc(VLC *vlc, const uint8_t *lens, const uint8_t *syms, int num_syms)
Definition: mss4.c:145
int width
picture width / height.
Definition: avcodec.h:1741
static const uint8_t mss4_dc_vlc_lens[2][16]
Definition: mss4.c:55
AVFormatContext * ctx
Definition: movenc.c:48
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:797
#define AV_WN16A(p, v)
Definition: intreadwrite.h:534
int bits
Definition: vlc.h:27
static av_cold int mss4_init_vlcs(MSS4Context *ctx)
Definition: mss4.c:167
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
main external API structure.
Definition: avcodec.h:1568
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2]...the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so...,+,-,+,-,+,+,-,+,-,+,...hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32-hcoeff[1]-hcoeff[2]-...a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2}an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||.........intra?||||:Block01:yes no||||:Block02:.................||||:Block03::y DC::ref index:||||:Block04::cb DC::motion x:||||.........:cr DC::motion y:||||.................|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------------------------------|||Y subbands||Cb subbands||Cr subbands||||------||------||------|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||------||------||------||||------||------||------|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||------||------||------||||------||------||------|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||------||------||------||||------||------||------|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------------------------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction------------|\Dequantization-------------------\||Reference frames|\IDWT|--------------|Motion\|||Frame 0||Frame 1||Compensation.OBMC v-------|--------------|--------------.\------> Frame n output Frame Frame<----------------------------------/|...|-------------------Range Coder:============Binary Range Coder:-------------------The implemented range coder is an adapted version based upon"Range encoding: an algorithm for removing redundancy from a digitised message."by G.N.N.Martin.The symbols encoded by the Snow range coder are bits(0|1).The associated probabilities are not fix but change depending on the symbol mix seen so far.bit seen|new state---------+-----------------------------------------------0|256-state_transition_table[256-old_state];1|state_transition_table[old_state];state_transition_table={0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:-------------------------FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1.the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled top and top right vectors is used as motion vector prediction the used motion vector is the sum of the predictor and(mvx_diff, mvy_diff)*mv_scale Intra DC Prediction block[y][x] dc[1]
Definition: snow.txt:400
VLC ac_vlc[2]
Definition: mss4.c:130
void * buf
Definition: avisynth_c.h:766
static void mss4_update_dc_cache(MSS4Context *c, int mb_x)
Definition: mss4.c:489
static av_cold int mss4_decode_init(AVCodecContext *avctx)
Definition: mss4.c:644
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
int quality
Definition: mss4.c:135
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
static const uint8_t mss4_ac_vlc_lens[2][16]
Definition: mss4.c:60
BlockType
Definition: mss3.c:68
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
static const uint8_t mss4_vec_entry_vlc_lens[2][16]
Definition: mss4.c:115
static int mss4_decode_image_block(MSS4Context *ctx, GetBitContext *gb, uint8_t *picdst[3], int mb_x, int mb_y)
Definition: mss4.c:379
common internal api header.
static int get_unary(GetBitContext *gb, int stop, int len)
Get unary code of limited length.
Definition: unary.h:46
void * priv_data
Definition: avcodec.h:1595
static int decode012(GetBitContext *gb)
Definition: get_bits.h:831
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:373
#define HEADER_SIZE
Definition: mss4.c:35
FILE * out
Definition: movenc.c:54
#define av_freep(p)
#define av_always_inline
Definition: attributes.h:39
static int mss4_decode_dct(GetBitContext *gb, VLC *dc_vlc, VLC *ac_vlc, int *block, int *dc_cache, int bx, int by, uint16_t *quant_mat)
Definition: mss4.c:226
#define av_malloc_array(a, b)
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
uint8_t imgbuf[3][16 *16]
Definition: mss4.c:133
AVCodec ff_mts2_decoder
Definition: mss4.c:675
This structure stores compressed data.
Definition: avcodec.h:1457
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:359
mode
Use these values in ebur128_init (or&#39;ed).
Definition: ebur128.h:83
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984
for(j=16;j >0;--j)
Predicted.
Definition: avutil.h:275
static const uint8_t mss4_vec_entry_vlc_syms[2][9]
Definition: mss4.c:120
#define MAX_ENTRIES
Definition: mss4.c:125