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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 FFmpeg.
17  *
18  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
30  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31  */
32 
33 /**
34  * @file
35  * DV decoder
36  */
37 
38 #include "libavutil/avassert.h"
39 #include "libavutil/imgutils.h"
40 #include "libavutil/internal.h"
41 #include "libavutil/pixdesc.h"
42 
43 #include "avcodec.h"
44 #include "dv.h"
45 #include "dvdata.h"
46 #include "get_bits.h"
47 #include "idctdsp.h"
48 #include "internal.h"
49 #include "put_bits.h"
50 #include "simple_idct.h"
51 
52 typedef struct BlockInfo {
53  const uint32_t *factor_table;
55  uint8_t pos; /* position in block */
56  void (*idct_put)(uint8_t *dest, int line_size, int16_t *block);
60 } BlockInfo;
61 
62 static const int dv_iweight_bits = 14;
63 
65 {
66  DVVideoContext *s = avctx->priv_data;
67  IDCTDSPContext idsp;
68  int i;
69 
70  memset(&idsp,0, sizeof(idsp));
71  ff_idctdsp_init(&idsp, avctx);
72 
73  for (i = 0; i < 64; i++)
74  s->dv_zigzag[0][i] = idsp.idct_permutation[ff_zigzag_direct[i]];
75 
76  if (avctx->lowres){
77  for (i = 0; i < 64; i++){
78  int j = ff_dv_zigzag248_direct[i];
79  s->dv_zigzag[1][i] = idsp.idct_permutation[(j & 7) + (j & 8) * 4 + (j & 48) / 2];
80  }
81  }else
82  memcpy(s->dv_zigzag[1], ff_dv_zigzag248_direct, sizeof(s->dv_zigzag[1]));
83 
84  s->idct_put[0] = idsp.idct_put;
86 
87  return ff_dvvideo_init(avctx);
88 }
89 
90 /* decode AC coefficients */
91 static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, int16_t *block)
92 {
93  int last_index = gb->size_in_bits;
94  const uint8_t *scan_table = mb->scan_table;
95  const uint32_t *factor_table = mb->factor_table;
96  int pos = mb->pos;
97  int partial_bit_count = mb->partial_bit_count;
98  int level, run, vlc_len, index;
99 
100  OPEN_READER_NOSIZE(re, gb);
101  UPDATE_CACHE(re, gb);
102 
103  /* if we must parse a partial VLC, we do it here */
104  if (partial_bit_count > 0) {
105  re_cache = re_cache >> partial_bit_count |
106  mb->partial_bit_buffer;
107  re_index -= partial_bit_count;
108  mb->partial_bit_count = 0;
109  }
110 
111  /* get the AC coefficients until last_index is reached */
112  for (;;) {
113  av_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),
114  re_index);
115  /* our own optimized GET_RL_VLC */
116  index = NEG_USR32(re_cache, TEX_VLC_BITS);
117  vlc_len = ff_dv_rl_vlc[index].len;
118  if (vlc_len < 0) {
119  index = NEG_USR32((unsigned) re_cache << TEX_VLC_BITS, -vlc_len) +
121  vlc_len = TEX_VLC_BITS - vlc_len;
122  }
123  level = ff_dv_rl_vlc[index].level;
124  run = ff_dv_rl_vlc[index].run;
125 
126  /* gotta check if we're still within gb boundaries */
127  if (re_index + vlc_len > last_index) {
128  /* should be < 16 bits otherwise a codeword could have been parsed */
129  mb->partial_bit_count = last_index - re_index;
130  mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
131  re_index = last_index;
132  break;
133  }
134  re_index += vlc_len;
135 
136  av_dlog(NULL, "run=%d level=%d\n", run, level);
137  pos += run;
138  if (pos >= 64)
139  break;
140 
141  level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >>
143  block[scan_table[pos]] = level;
144 
145  UPDATE_CACHE(re, gb);
146  }
147  CLOSE_READER(re, gb);
148  mb->pos = pos;
149 }
150 
151 static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
152 {
153  int bits_left = get_bits_left(gb);
154  while (bits_left >= MIN_CACHE_BITS) {
156  bits_left -= MIN_CACHE_BITS;
157  }
158  if (bits_left > 0)
159  put_bits(pb, bits_left, get_bits(gb, bits_left));
160 }
161 
162 /* mb_x and mb_y are in units of 8 pixels */
163 static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
164 {
165  DVVideoContext *s = avctx->priv_data;
166  DVwork_chunk *work_chunk = arg;
167  int quant, dc, dct_mode, class1, j;
168  int mb_index, mb_x, mb_y, last_index;
169  int y_stride, linesize;
170  int16_t *block, *block1;
171  int c_offset;
172  uint8_t *y_ptr;
173  const uint8_t *buf_ptr;
174  PutBitContext pb, vs_pb;
175  GetBitContext gb;
176  BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
177  LOCAL_ALIGNED_16(int16_t, sblock, [5 * DV_MAX_BPM], [64]);
178  LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
179  LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [80 * 5 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
180  const int log2_blocksize = 3-s->avctx->lowres;
181  int is_field_mode[5];
182 
183  av_assert1((((int) mb_bit_buffer) & 7) == 0);
184  av_assert1((((int) vs_bit_buffer) & 7) == 0);
185 
186  memset(sblock, 0, 5 * DV_MAX_BPM * sizeof(*sblock));
187 
188  /* pass 1: read DC and AC coefficients in blocks */
189  buf_ptr = &s->buf[work_chunk->buf_offset * 80];
190  block1 = &sblock[0][0];
191  mb1 = mb_data;
192  init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);
193  for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {
194  /* skip header */
195  quant = buf_ptr[3] & 0x0f;
196  buf_ptr += 4;
197  init_put_bits(&pb, mb_bit_buffer, 80);
198  mb = mb1;
199  block = block1;
200  is_field_mode[mb_index] = 0;
201  for (j = 0; j < s->sys->bpm; j++) {
202  last_index = s->sys->block_sizes[j];
203  init_get_bits(&gb, buf_ptr, last_index);
204 
205  /* get the DC */
206  dc = get_sbits(&gb, 9);
207  dct_mode = get_bits1(&gb);
208  class1 = get_bits(&gb, 2);
209  if (DV_PROFILE_IS_HD(s->sys)) {
210  mb->idct_put = s->idct_put[0];
211  mb->scan_table = s->dv_zigzag[0];
212  mb->factor_table = &s->idct_factor[(j >= 4) * 4 * 16 * 64 +
213  class1 * 16 * 64 +
214  quant * 64];
215  is_field_mode[mb_index] |= !j && dct_mode;
216  } else {
217  mb->idct_put = s->idct_put[dct_mode && log2_blocksize == 3];
218  mb->scan_table = s->dv_zigzag[dct_mode];
219  mb->factor_table =
220  &s->idct_factor[(class1 == 3) * 2 * 22 * 64 +
221  dct_mode * 22 * 64 +
222  (quant + ff_dv_quant_offset[class1]) * 64];
223  }
224  dc = dc << 2;
225  /* convert to unsigned because 128 is not added in the
226  * standard IDCT */
227  dc += 1024;
228  block[0] = dc;
229  buf_ptr += last_index >> 3;
230  mb->pos = 0;
231  mb->partial_bit_count = 0;
232 
233  av_dlog(avctx, "MB block: %d, %d ", mb_index, j);
234  dv_decode_ac(&gb, mb, block);
235 
236  /* write the remaining bits in a new buffer only if the
237  * block is finished */
238  if (mb->pos >= 64)
239  bit_copy(&pb, &gb);
240 
241  block += 64;
242  mb++;
243  }
244 
245  /* pass 2: we can do it just after */
246  av_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
247  block = block1;
248  mb = mb1;
249  init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
250  put_bits32(&pb, 0); // padding must be zeroed
251  flush_put_bits(&pb);
252  for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
253  if (mb->pos < 64 && get_bits_left(&gb) > 0) {
254  dv_decode_ac(&gb, mb, block);
255  /* if still not finished, no need to parse other blocks */
256  if (mb->pos < 64)
257  break;
258  }
259  }
260  /* all blocks are finished, so the extra bytes can be used at
261  * the video segment level */
262  if (j >= s->sys->bpm)
263  bit_copy(&vs_pb, &gb);
264  }
265 
266  /* we need a pass over the whole video segment */
267  av_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
268  block = &sblock[0][0];
269  mb = mb_data;
270  init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
271  put_bits32(&vs_pb, 0); // padding must be zeroed
272  flush_put_bits(&vs_pb);
273  for (mb_index = 0; mb_index < 5; mb_index++) {
274  for (j = 0; j < s->sys->bpm; j++) {
275  if (mb->pos < 64 && get_bits_left(&gb) > 0) {
276  av_dlog(avctx, "start %d:%d\n", mb_index, j);
277  dv_decode_ac(&gb, mb, block);
278  }
279  if (mb->pos >= 64 && mb->pos < 127)
280  av_log(avctx, AV_LOG_ERROR,
281  "AC EOB marker is absent pos=%d\n", mb->pos);
282  block += 64;
283  mb++;
284  }
285  }
286 
287  /* compute idct and place blocks */
288  block = &sblock[0][0];
289  mb = mb_data;
290  for (mb_index = 0; mb_index < 5; mb_index++) {
291  dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);
292 
293  /* idct_put'ting luminance */
294  if ((s->sys->pix_fmt == AV_PIX_FMT_YUV420P) ||
295  (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||
296  (s->sys->height >= 720 && mb_y != 134)) {
297  y_stride = (s->frame->linesize[0] <<
298  ((!is_field_mode[mb_index]) * log2_blocksize));
299  } else {
300  y_stride = (2 << log2_blocksize);
301  }
302  y_ptr = s->frame->data[0] +
303  ((mb_y * s->frame->linesize[0] + mb_x) << log2_blocksize);
304  linesize = s->frame->linesize[0] << is_field_mode[mb_index];
305  mb[0].idct_put(y_ptr, linesize, block + 0 * 64);
306  if (s->sys->video_stype == 4) { /* SD 422 */
307  mb[2].idct_put(y_ptr + (1 << log2_blocksize), linesize, block + 2 * 64);
308  } else {
309  mb[1].idct_put(y_ptr + (1 << log2_blocksize), linesize, block + 1 * 64);
310  mb[2].idct_put(y_ptr + y_stride, linesize, block + 2 * 64);
311  mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3 * 64);
312  }
313  mb += 4;
314  block += 4 * 64;
315 
316  /* idct_put'ting chrominance */
317  c_offset = (((mb_y >> (s->sys->pix_fmt == AV_PIX_FMT_YUV420P)) * s->frame->linesize[1] +
318  (mb_x >> ((s->sys->pix_fmt == AV_PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);
319  for (j = 2; j; j--) {
320  uint8_t *c_ptr = s->frame->data[j] + c_offset;
321  if (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) {
322  uint64_t aligned_pixels[64 / 8];
323  uint8_t *pixels = (uint8_t *) aligned_pixels;
324  uint8_t *c_ptr1, *ptr1;
325  int x, y;
326  mb->idct_put(pixels, 8, block);
327  for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->frame->linesize[j], pixels += 8) {
328  ptr1 = pixels + ((1 << (log2_blocksize))>>1);
329  c_ptr1 = c_ptr + (s->frame->linesize[j] << log2_blocksize);
330  for (x = 0; x < (1 << FFMAX(log2_blocksize - 1, 0)); x++) {
331  c_ptr[x] = pixels[x];
332  c_ptr1[x] = ptr1[x];
333  }
334  }
335  block += 64;
336  mb++;
337  } else {
338  y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
339  s->frame->linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);
340  linesize = s->frame->linesize[j] << is_field_mode[mb_index];
341  (mb++)->idct_put(c_ptr, linesize, block);
342  block += 64;
343  if (s->sys->bpm == 8) {
344  (mb++)->idct_put(c_ptr + y_stride, linesize, block);
345  block += 64;
346  }
347  }
348  }
349  }
350  return 0;
351 }
352 
353 /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
354  * 144000 bytes for PAL - or twice those for 50Mbps) */
355 static int dvvideo_decode_frame(AVCodecContext *avctx, void *data,
356  int *got_frame, AVPacket *avpkt)
357 {
358  uint8_t *buf = avpkt->data;
359  int buf_size = avpkt->size;
360  DVVideoContext *s = avctx->priv_data;
361  const uint8_t *vsc_pack;
362  int apt, is16_9, ret;
363  const AVDVProfile *sys;
364 
365  sys = avpriv_dv_frame_profile2(avctx, s->sys, buf, buf_size);
366  if (!sys || buf_size < sys->frame_size) {
367  av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");
368  return -1; /* NOTE: we only accept several full frames */
369  }
370 
371  if (sys != s->sys) {
372  ret = ff_dv_init_dynamic_tables(s, sys);
373  if (ret < 0) {
374  av_log(avctx, AV_LOG_ERROR, "Error initializing the work tables.\n");
375  return ret;
376  }
377  s->sys = sys;
378  }
379 
380  s->frame = data;
381  s->frame->key_frame = 1;
383  avctx->pix_fmt = s->sys->pix_fmt;
384  avctx->time_base = s->sys->time_base;
385 
386  ret = ff_set_dimensions(avctx, s->sys->width, s->sys->height);
387  if (ret < 0)
388  return ret;
389 
390  /* Determine the codec's sample_aspect ratio from the packet */
391  vsc_pack = buf + 80 * 5 + 48 + 5;
392  if (*vsc_pack == dv_video_control) {
393  apt = buf[4] & 0x07;
394  is16_9 = (vsc_pack[2] & 0x07) == 0x02 ||
395  (!apt && (vsc_pack[2] & 0x07) == 0x07);
396  ff_set_sar(avctx, s->sys->sar[is16_9]);
397  }
398 
399  if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
400  return ret;
401  s->frame->interlaced_frame = 1;
402  s->frame->top_field_first = 0;
403 
404  /* Determine the codec's field order from the packet */
405  if ( *vsc_pack == dv_video_control ) {
406  s->frame->top_field_first = !(vsc_pack[3] & 0x40);
407  }
408 
409  s->buf = buf;
410  avctx->execute(avctx, dv_decode_video_segment, s->work_chunks, NULL,
411  dv_work_pool_size(s->sys), sizeof(DVwork_chunk));
412 
413  emms_c();
414 
415  /* return image */
416  *got_frame = 1;
417 
418  return s->sys->frame_size;
419 }
420 
422  .name = "dvvideo",
423  .long_name = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
424  .type = AVMEDIA_TYPE_VIDEO,
425  .id = AV_CODEC_ID_DVVIDEO,
426  .priv_data_size = sizeof(DVVideoContext),
429  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
430  .max_lowres = 3,
431 };