FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
dv.c
Go to the documentation of this file.
1 /*
2  * DV decoder
3  * Copyright (c) 2002 Fabrice Bellard
4  * Copyright (c) 2004 Roman Shaposhnik
5  *
6  * DV encoder
7  * Copyright (c) 2003 Roman Shaposhnik
8  *
9  * 50 Mbps (DVCPRO50) support
10  * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
11  *
12  * 100 Mbps (DVCPRO HD) support
13  * Initial code by Daniel Maas <dmaas@maasdigital.com> (funded by BBC R&D)
14  * Final code by Roman Shaposhnik
15  *
16  * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
17  * of DV technical info.
18  *
19  * This file is part of FFmpeg.
20  *
21  * FFmpeg is free software; you can redistribute it and/or
22  * modify it under the terms of the GNU Lesser General Public
23  * License as published by the Free Software Foundation; either
24  * version 2.1 of the License, or (at your option) any later version.
25  *
26  * FFmpeg is distributed in the hope that it will be useful,
27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
29  * Lesser General Public License for more details.
30  *
31  * You should have received a copy of the GNU Lesser General Public
32  * License along with FFmpeg; if not, write to the Free Software
33  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
34  */
35 
36 /**
37  * @file
38  * DV codec.
39  */
40 
41 #include "libavutil/internal.h"
42 #include "libavutil/pixdesc.h"
43 
44 #include "avcodec.h"
45 #include "dv.h"
46 #include "dvdata.h"
47 #include "get_bits.h"
48 #include "internal.h"
49 #include "put_bits.h"
50 #include "simple_idct.h"
51 
52 /* XXX: also include quantization */
54 
55 static inline void dv_calc_mb_coordinates(const AVDVProfile *d, int chan,
56  int seq, int slot, uint16_t *tbl)
57 {
58  static const uint8_t off[] = { 2, 6, 8, 0, 4 };
59  static const uint8_t shuf1[] = { 36, 18, 54, 0, 72 };
60  static const uint8_t shuf2[] = { 24, 12, 36, 0, 48 };
61  static const uint8_t shuf3[] = { 18, 9, 27, 0, 36 };
62 
63  static const uint8_t l_start[] = { 0, 4, 9, 13, 18, 22, 27, 31, 36, 40 };
64  static const uint8_t l_start_shuffled[] = { 9, 4, 13, 0, 18 };
65 
66  static const uint8_t serpent1[] = {
67  0, 1, 2, 2, 1, 0,
68  0, 1, 2, 2, 1, 0,
69  0, 1, 2, 2, 1, 0,
70  0, 1, 2, 2, 1, 0,
71  0, 1, 2
72  };
73  static const uint8_t serpent2[] = {
74  0, 1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 0,
75  0, 1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 0,
76  0, 1, 2, 3, 4, 5
77  };
78 
79  static const uint8_t remap[][2] = {
80  { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 }, /* dummy */
81  { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 }, { 10, 0 },
82  { 10, 1 }, { 10, 2 }, { 10, 3 }, { 20, 0 }, { 20, 1 },
83  { 20, 2 }, { 20, 3 }, { 30, 0 }, { 30, 1 }, { 30, 2 },
84  { 30, 3 }, { 40, 0 }, { 40, 1 }, { 40, 2 }, { 40, 3 },
85  { 50, 0 }, { 50, 1 }, { 50, 2 }, { 50, 3 }, { 60, 0 },
86  { 60, 1 }, { 60, 2 }, { 60, 3 }, { 70, 0 }, { 70, 1 },
87  { 70, 2 }, { 70, 3 }, { 0, 64 }, { 0, 65 }, { 0, 66 },
88  { 10, 64 }, { 10, 65 }, { 10, 66 }, { 20, 64 }, { 20, 65 },
89  { 20, 66 }, { 30, 64 }, { 30, 65 }, { 30, 66 }, { 40, 64 },
90  { 40, 65 }, { 40, 66 }, { 50, 64 }, { 50, 65 }, { 50, 66 },
91  { 60, 64 }, { 60, 65 }, { 60, 66 }, { 70, 64 }, { 70, 65 },
92  { 70, 66 }, { 0, 67 }, { 20, 67 }, { 40, 67 }, { 60, 67 }
93  };
94 
95  int i, k, m;
96  int x, y, blk;
97 
98  for (m = 0; m < 5; m++) {
99  switch (d->width) {
100  case 1440:
101  blk = (chan * 11 + seq) * 27 + slot;
102 
103  if (chan == 0 && seq == 11) {
104  x = m * 27 + slot;
105  if (x < 90) {
106  y = 0;
107  } else {
108  x = (x - 90) * 2;
109  y = 67;
110  }
111  } else {
112  i = (4 * chan + blk + off[m]) % 11;
113  k = (blk / 11) % 27;
114 
115  x = shuf1[m] + (chan & 1) * 9 + k % 9;
116  y = (i * 3 + k / 9) * 2 + (chan >> 1) + 1;
117  }
118  tbl[m] = (x << 1) | (y << 9);
119  break;
120  case 1280:
121  blk = (chan * 10 + seq) * 27 + slot;
122 
123  i = (4 * chan + (seq / 5) + 2 * blk + off[m]) % 10;
124  k = (blk / 5) % 27;
125 
126  x = shuf1[m] + (chan & 1) * 9 + k % 9;
127  y = (i * 3 + k / 9) * 2 + (chan >> 1) + 4;
128 
129  if (x >= 80) {
130  x = remap[y][0] + ((x - 80) << (y > 59));
131  y = remap[y][1];
132  }
133  tbl[m] = (x << 1) | (y << 9);
134  break;
135  case 960:
136  blk = (chan * 10 + seq) * 27 + slot;
137 
138  i = (4 * chan + (seq / 5) + 2 * blk + off[m]) % 10;
139  k = (blk / 5) % 27 + (i & 1) * 3;
140 
141  x = shuf2[m] + k % 6 + 6 * (chan & 1);
142  y = l_start[i] + k / 6 + 45 * (chan >> 1);
143  tbl[m] = (x << 1) | (y << 9);
144  break;
145  case 720:
146  switch (d->pix_fmt) {
147  case AV_PIX_FMT_YUV422P:
148  x = shuf3[m] + slot / 3;
149  y = serpent1[slot] +
150  ((((seq + off[m]) % d->difseg_size) << 1) + chan) * 3;
151  tbl[m] = (x << 1) | (y << 8);
152  break;
153  case AV_PIX_FMT_YUV420P:
154  x = shuf3[m] + slot / 3;
155  y = serpent1[slot] +
156  ((seq + off[m]) % d->difseg_size) * 3;
157  tbl[m] = (x << 1) | (y << 9);
158  break;
159  case AV_PIX_FMT_YUV411P:
160  i = (seq + off[m]) % d->difseg_size;
161  k = slot + ((m == 1 || m == 2) ? 3 : 0);
162 
163  x = l_start_shuffled[m] + k / 6;
164  y = serpent2[k] + i * 6;
165  if (x > 21)
166  y = y * 2 - i * 6;
167  tbl[m] = (x << 2) | (y << 8);
168  break;
169  }
170  default:
171  break;
172  }
173  }
174 }
175 
177 {
178  int j, i, c, s, p;
179 
180  p = i = 0;
181  for (c = 0; c < d->n_difchan; c++) {
182  for (s = 0; s < d->difseg_size; s++) {
183  p += 6;
184  for (j = 0; j < 27; j++) {
185  p += !(j % 3);
186  if (!(DV_PROFILE_IS_1080i50(d) && c != 0 && s == 11) &&
187  !(DV_PROFILE_IS_720p50(d) && s > 9)) {
188  dv_calc_mb_coordinates(d, c, s, j, &ctx->work_chunks[i].mb_coordinates[0]);
189  ctx->work_chunks[i++].buf_offset = p;
190  }
191  p += 5;
192  }
193  }
194  }
195 
196  return 0;
197 }
198 
200 {
201  DVVideoContext *s = avctx->priv_data;
202  static int done = 0;
203  int i, j;
204 
205  if (!done) {
206  VLC dv_vlc;
207  uint16_t new_dv_vlc_bits[NB_DV_VLC * 2];
208  uint8_t new_dv_vlc_len[NB_DV_VLC * 2];
209  uint8_t new_dv_vlc_run[NB_DV_VLC * 2];
210  int16_t new_dv_vlc_level[NB_DV_VLC * 2];
211 
212  done = 1;
213 
214  /* it's faster to include sign bit in a generic VLC parsing scheme */
215  for (i = 0, j = 0; i < NB_DV_VLC; i++, j++) {
216  new_dv_vlc_bits[j] = ff_dv_vlc_bits[i];
217  new_dv_vlc_len[j] = ff_dv_vlc_len[i];
218  new_dv_vlc_run[j] = ff_dv_vlc_run[i];
219  new_dv_vlc_level[j] = ff_dv_vlc_level[i];
220 
221  if (ff_dv_vlc_level[i]) {
222  new_dv_vlc_bits[j] <<= 1;
223  new_dv_vlc_len[j]++;
224 
225  j++;
226  new_dv_vlc_bits[j] = (ff_dv_vlc_bits[i] << 1) | 1;
227  new_dv_vlc_len[j] = ff_dv_vlc_len[i] + 1;
228  new_dv_vlc_run[j] = ff_dv_vlc_run[i];
229  new_dv_vlc_level[j] = -ff_dv_vlc_level[i];
230  }
231  }
232 
233  /* NOTE: as a trick, we use the fact the no codes are unused
234  * to accelerate the parsing of partial codes */
235  init_vlc(&dv_vlc, TEX_VLC_BITS, j, new_dv_vlc_len,
236  1, 1, new_dv_vlc_bits, 2, 2, 0);
237  av_assert1(dv_vlc.table_size == 1664);
238 
239  for (i = 0; i < dv_vlc.table_size; i++) {
240  int code = dv_vlc.table[i][0];
241  int len = dv_vlc.table[i][1];
242  int level, run;
243 
244  if (len < 0) { // more bits needed
245  run = 0;
246  level = code;
247  } else {
248  run = new_dv_vlc_run[code] + 1;
249  level = new_dv_vlc_level[code];
250  }
251  ff_dv_rl_vlc[i].len = len;
252  ff_dv_rl_vlc[i].level = level;
253  ff_dv_rl_vlc[i].run = run;
254  }
255  ff_free_vlc(&dv_vlc);
256  }
257 
258  s->avctx = avctx;
260 
261  return 0;
262 }
263