dvdec.c
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1 /*
2  * DV decoder
3  * Copyright (c) 2002 Fabrice Bellard
4  * Copyright (c) 2004 Roman Shaposhnik
5  *
6  * 50 Mbps (DVCPRO50) support
7  * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
8  *
9  * 100 Mbps (DVCPRO HD) support
10  * Initial code by Daniel Maas <dmaas@maasdigital.com> (funded by BBC R&D)
11  * Final code by Roman Shaposhnik
12  *
13  * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
14  * of DV technical info.
15  *
16  * This file is part of Libav.
17  *
18  * Libav is free software; you can redistribute it and/or
19  * modify it under the terms of the GNU Lesser General Public
20  * License as published by the Free Software Foundation; either
21  * version 2.1 of the License, or (at your option) any later version.
22  *
23  * Libav is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26  * Lesser General Public License for more details.
27  *
28  * You should have received a copy of the GNU Lesser General Public
29  * License along with Libav; if not, write to the Free Software
30  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31  */
32 
38 #include "libavutil/pixdesc.h"
39 #include "avcodec.h"
40 #include "dsputil.h"
41 #include "internal.h"
42 #include "get_bits.h"
43 #include "put_bits.h"
44 #include "simple_idct.h"
45 #include "dvdata.h"
46 
47 typedef struct BlockInfo {
48  const uint32_t *factor_table;
50  uint8_t pos; /* position in block */
51  void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);
55 } BlockInfo;
56 
57 static const int dv_iweight_bits = 14;
58 
59 /* decode AC coefficients */
61 {
62  int last_index = gb->size_in_bits;
63  const uint8_t *scan_table = mb->scan_table;
64  const uint32_t *factor_table = mb->factor_table;
65  int pos = mb->pos;
66  int partial_bit_count = mb->partial_bit_count;
67  int level, run, vlc_len, index;
68 
69  OPEN_READER(re, gb);
70  UPDATE_CACHE(re, gb);
71 
72  /* if we must parse a partial VLC, we do it here */
73  if (partial_bit_count > 0) {
74  re_cache = re_cache >> partial_bit_count | mb->partial_bit_buffer;
75  re_index -= partial_bit_count;
76  mb->partial_bit_count = 0;
77  }
78 
79  /* get the AC coefficients until last_index is reached */
80  for (;;) {
81  av_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),
82  re_index);
83  /* our own optimized GET_RL_VLC */
84  index = NEG_USR32(re_cache, TEX_VLC_BITS);
85  vlc_len = ff_dv_rl_vlc[index].len;
86  if (vlc_len < 0) {
87  index = NEG_USR32((unsigned)re_cache << TEX_VLC_BITS, -vlc_len) +
89  vlc_len = TEX_VLC_BITS - vlc_len;
90  }
91  level = ff_dv_rl_vlc[index].level;
92  run = ff_dv_rl_vlc[index].run;
93 
94  /* gotta check if we're still within gb boundaries */
95  if (re_index + vlc_len > last_index) {
96  /* should be < 16 bits otherwise a codeword could have been parsed */
97  mb->partial_bit_count = last_index - re_index;
98  mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
99  re_index = last_index;
100  break;
101  }
102  re_index += vlc_len;
103 
104  av_dlog(NULL, "run=%d level=%d\n", run, level);
105  pos += run;
106  if (pos >= 64)
107  break;
108 
109  level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >> dv_iweight_bits;
110  block[scan_table[pos]] = level;
111 
112  UPDATE_CACHE(re, gb);
113  }
114  CLOSE_READER(re, gb);
115  mb->pos = pos;
116 }
117 
118 static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
119 {
120  int bits_left = get_bits_left(gb);
121  while (bits_left >= MIN_CACHE_BITS) {
123  bits_left -= MIN_CACHE_BITS;
124  }
125  if (bits_left > 0) {
126  put_bits(pb, bits_left, get_bits(gb, bits_left));
127  }
128 }
129 
130 /* mb_x and mb_y are in units of 8 pixels */
131 static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
132 {
133  DVVideoContext *s = avctx->priv_data;
134  DVwork_chunk *work_chunk = arg;
135  int quant, dc, dct_mode, class1, j;
136  int mb_index, mb_x, mb_y, last_index;
137  int y_stride, linesize;
138  DCTELEM *block, *block1;
139  int c_offset;
140  uint8_t *y_ptr;
141  const uint8_t *buf_ptr;
142  PutBitContext pb, vs_pb;
143  GetBitContext gb;
144  BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
145  LOCAL_ALIGNED_16(DCTELEM, sblock, [5*DV_MAX_BPM], [64]);
146  LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [ 80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
147  LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [5*80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
148  const int log2_blocksize = 3;
149  int is_field_mode[5];
150 
151  assert((((int)mb_bit_buffer) & 7) == 0);
152  assert((((int)vs_bit_buffer) & 7) == 0);
153 
154  memset(sblock, 0, 5*DV_MAX_BPM*sizeof(*sblock));
155 
156  /* pass 1: read DC and AC coefficients in blocks */
157  buf_ptr = &s->buf[work_chunk->buf_offset*80];
158  block1 = &sblock[0][0];
159  mb1 = mb_data;
160  init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);
161  for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {
162  /* skip header */
163  quant = buf_ptr[3] & 0x0f;
164  buf_ptr += 4;
165  init_put_bits(&pb, mb_bit_buffer, 80);
166  mb = mb1;
167  block = block1;
168  is_field_mode[mb_index] = 0;
169  for (j = 0; j < s->sys->bpm; j++) {
170  last_index = s->sys->block_sizes[j];
171  init_get_bits(&gb, buf_ptr, last_index);
172 
173  /* get the DC */
174  dc = get_sbits(&gb, 9);
175  dct_mode = get_bits1(&gb);
176  class1 = get_bits(&gb, 2);
177  if (DV_PROFILE_IS_HD(s->sys)) {
178  mb->idct_put = s->idct_put[0];
179  mb->scan_table = s->dv_zigzag[0];
180  mb->factor_table = &s->sys->idct_factor[(j >= 4)*4*16*64 + class1*16*64 + quant*64];
181  is_field_mode[mb_index] |= !j && dct_mode;
182  } else {
183  mb->idct_put = s->idct_put[dct_mode && log2_blocksize == 3];
184  mb->scan_table = s->dv_zigzag[dct_mode];
185  mb->factor_table = &s->sys->idct_factor[(class1 == 3)*2*22*64 + dct_mode*22*64 +
186  (quant + ff_dv_quant_offset[class1])*64];
187  }
188  dc = dc << 2;
189  /* convert to unsigned because 128 is not added in the
190  standard IDCT */
191  dc += 1024;
192  block[0] = dc;
193  buf_ptr += last_index >> 3;
194  mb->pos = 0;
195  mb->partial_bit_count = 0;
196 
197  av_dlog(avctx, "MB block: %d, %d ", mb_index, j);
198  dv_decode_ac(&gb, mb, block);
199 
200  /* write the remaining bits in a new buffer only if the
201  block is finished */
202  if (mb->pos >= 64)
203  bit_copy(&pb, &gb);
204 
205  block += 64;
206  mb++;
207  }
208 
209  /* pass 2: we can do it just after */
210  av_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
211  block = block1;
212  mb = mb1;
213  init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
214  put_bits32(&pb, 0); // padding must be zeroed
215  flush_put_bits(&pb);
216  for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
217  if (mb->pos < 64 && get_bits_left(&gb) > 0) {
218  dv_decode_ac(&gb, mb, block);
219  /* if still not finished, no need to parse other blocks */
220  if (mb->pos < 64)
221  break;
222  }
223  }
224  /* all blocks are finished, so the extra bytes can be used at
225  the video segment level */
226  if (j >= s->sys->bpm)
227  bit_copy(&vs_pb, &gb);
228  }
229 
230  /* we need a pass over the whole video segment */
231  av_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
232  block = &sblock[0][0];
233  mb = mb_data;
234  init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
235  put_bits32(&vs_pb, 0); // padding must be zeroed
236  flush_put_bits(&vs_pb);
237  for (mb_index = 0; mb_index < 5; mb_index++) {
238  for (j = 0; j < s->sys->bpm; j++) {
239  if (mb->pos < 64) {
240  av_dlog(avctx, "start %d:%d\n", mb_index, j);
241  dv_decode_ac(&gb, mb, block);
242  }
243  if (mb->pos >= 64 && mb->pos < 127)
244  av_log(avctx, AV_LOG_ERROR, "AC EOB marker is absent pos=%d\n", mb->pos);
245  block += 64;
246  mb++;
247  }
248  }
249 
250  /* compute idct and place blocks */
251  block = &sblock[0][0];
252  mb = mb_data;
253  for (mb_index = 0; mb_index < 5; mb_index++) {
254  dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);
255 
256  /* idct_put'ting luminance */
257  if ((s->sys->pix_fmt == AV_PIX_FMT_YUV420P) ||
258  (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||
259  (s->sys->height >= 720 && mb_y != 134)) {
260  y_stride = (s->picture.linesize[0] << ((!is_field_mode[mb_index]) * log2_blocksize));
261  } else {
262  y_stride = (2 << log2_blocksize);
263  }
264  y_ptr = s->picture.data[0] + ((mb_y * s->picture.linesize[0] + mb_x) << log2_blocksize);
265  linesize = s->picture.linesize[0] << is_field_mode[mb_index];
266  mb[0] .idct_put(y_ptr , linesize, block + 0*64);
267  if (s->sys->video_stype == 4) { /* SD 422 */
268  mb[2].idct_put(y_ptr + (1 << log2_blocksize) , linesize, block + 2*64);
269  } else {
270  mb[1].idct_put(y_ptr + (1 << log2_blocksize) , linesize, block + 1*64);
271  mb[2].idct_put(y_ptr + y_stride, linesize, block + 2*64);
272  mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3*64);
273  }
274  mb += 4;
275  block += 4*64;
276 
277  /* idct_put'ting chrominance */
278  c_offset = (((mb_y >> (s->sys->pix_fmt == AV_PIX_FMT_YUV420P)) * s->picture.linesize[1] +
279  (mb_x >> ((s->sys->pix_fmt == AV_PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);
280  for (j = 2; j; j--) {
281  uint8_t *c_ptr = s->picture.data[j] + c_offset;
282  if (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) {
283  uint64_t aligned_pixels[64/8];
284  uint8_t *pixels = (uint8_t*)aligned_pixels;
285  uint8_t *c_ptr1, *ptr1;
286  int x, y;
287  mb->idct_put(pixels, 8, block);
288  for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->picture.linesize[j], pixels += 8) {
289  ptr1 = pixels + (1 << (log2_blocksize - 1));
290  c_ptr1 = c_ptr + (s->picture.linesize[j] << log2_blocksize);
291  for (x = 0; x < (1 << (log2_blocksize - 1)); x++) {
292  c_ptr[x] = pixels[x];
293  c_ptr1[x] = ptr1[x];
294  }
295  }
296  block += 64; mb++;
297  } else {
298  y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
299  s->picture.linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);
300  linesize = s->picture.linesize[j] << is_field_mode[mb_index];
301  (mb++)-> idct_put(c_ptr , linesize, block); block += 64;
302  if (s->sys->bpm == 8) {
303  (mb++)->idct_put(c_ptr + y_stride, linesize, block); block += 64;
304  }
305  }
306  }
307  }
308  return 0;
309 }
310 
311 /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
312  144000 bytes for PAL - or twice those for 50Mbps) */
314  void *data, int *got_frame,
315  AVPacket *avpkt)
316 {
317  uint8_t *buf = avpkt->data;
318  int buf_size = avpkt->size;
319  DVVideoContext *s = avctx->priv_data;
320  const uint8_t* vsc_pack;
321  int apt, is16_9;
322 
323  s->sys = avpriv_dv_frame_profile(s->sys, buf, buf_size);
324  if (!s->sys || buf_size < s->sys->frame_size || ff_dv_init_dynamic_tables(s->sys)) {
325  av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");
326  return -1; /* NOTE: we only accept several full frames */
327  }
328 
329  if (s->picture.data[0])
330  avctx->release_buffer(avctx, &s->picture);
331 
332  s->picture.reference = 0;
333  s->picture.key_frame = 1;
335  avctx->pix_fmt = s->sys->pix_fmt;
336  avctx->time_base = s->sys->time_base;
337  avcodec_set_dimensions(avctx, s->sys->width, s->sys->height);
338  if (ff_get_buffer(avctx, &s->picture) < 0) {
339  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
340  return -1;
341  }
342  s->picture.interlaced_frame = 1;
343  s->picture.top_field_first = 0;
344 
345  s->buf = buf;
346  avctx->execute(avctx, dv_decode_video_segment, s->sys->work_chunks, NULL,
347  dv_work_pool_size(s->sys), sizeof(DVwork_chunk));
348 
349  emms_c();
350 
351  /* return image */
352  *got_frame = 1;
353  *(AVFrame*)data = s->picture;
354 
355  /* Determine the codec's sample_aspect ratio from the packet */
356  vsc_pack = buf + 80*5 + 48 + 5;
357  if ( *vsc_pack == dv_video_control ) {
358  apt = buf[4] & 0x07;
359  is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 || (!apt && (vsc_pack[2] & 0x07) == 0x07)));
360  avctx->sample_aspect_ratio = s->sys->sar[is16_9];
361  }
362 
363  return s->sys->frame_size;
364 }
365 
367 {
368  DVVideoContext *s = c->priv_data;
369 
370  if (s->picture.data[0])
371  c->release_buffer(c, &s->picture);
372 
373  return 0;
374 }
375 
377  .name = "dvvideo",
378  .type = AVMEDIA_TYPE_VIDEO,
379  .id = AV_CODEC_ID_DVVIDEO,
380  .priv_data_size = sizeof(DVVideoContext),
382  .close = dvvideo_close,
384  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
385  .long_name = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
386 };