dnxhddec.c
Go to the documentation of this file.
1 /*
2  * VC3/DNxHD decoder.
3  * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
4  * Copyright (c) 2011 MirriAd Ltd
5  *
6  * 10 bit support added by MirriAd Ltd, Joseph Artsimovich <joseph@mirriad.com>
7  *
8  * This file is part of Libav.
9  *
10  * Libav is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * Libav is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with Libav; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 //#define TRACE
26 //#define DEBUG
27 
28 #include "libavutil/imgutils.h"
29 #include "avcodec.h"
30 #include "get_bits.h"
31 #include "dnxhddata.h"
32 #include "dsputil.h"
33 
34 typedef struct DNXHDContext {
38  int cid;
39  unsigned int width, height;
40  unsigned int mb_width, mb_height;
41  uint32_t mb_scan_index[68]; /* max for 1080p */
42  int cur_field;
44  int last_dc[3];
49  int bit_depth; // 8, 10 or 0 if not initialized at all.
51  int n, int qscale);
52 } DNXHDContext;
53 
54 #define DNXHD_VLC_BITS 9
55 #define DNXHD_DC_VLC_BITS 7
56 
57 static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, DCTELEM *block, int n, int qscale);
58 static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, DCTELEM *block, int n, int qscale);
59 
61 {
62  DNXHDContext *ctx = avctx->priv_data;
63 
64  ctx->avctx = avctx;
65  avctx->coded_frame = &ctx->picture;
67  ctx->picture.key_frame = 1;
68  return 0;
69 }
70 
71 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
72 {
73  if (cid != ctx->cid) {
74  int index;
75 
76  if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
77  av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
78  return -1;
79  }
81 
82  ff_free_vlc(&ctx->ac_vlc);
83  ff_free_vlc(&ctx->dc_vlc);
84  ff_free_vlc(&ctx->run_vlc);
85 
86  init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
87  ctx->cid_table->ac_bits, 1, 1,
88  ctx->cid_table->ac_codes, 2, 2, 0);
89  init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->bit_depth + 4,
90  ctx->cid_table->dc_bits, 1, 1,
91  ctx->cid_table->dc_codes, 1, 1, 0);
92  init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
93  ctx->cid_table->run_bits, 1, 1,
94  ctx->cid_table->run_codes, 2, 2, 0);
95 
97  ctx->cid = cid;
98  }
99  return 0;
100 }
101 
102 static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
103 {
104  static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
105  int i, cid;
106 
107  if (buf_size < 0x280)
108  return -1;
109 
110  if (memcmp(buf, header_prefix, 5)) {
111  av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
112  return -1;
113  }
114  if (buf[5] & 2) { /* interlaced */
115  ctx->cur_field = buf[5] & 1;
116  ctx->picture.interlaced_frame = 1;
117  ctx->picture.top_field_first = first_field ^ ctx->cur_field;
118  av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
119  }
120 
121  ctx->height = AV_RB16(buf + 0x18);
122  ctx->width = AV_RB16(buf + 0x1a);
123 
124  av_dlog(ctx->avctx, "width %d, height %d\n", ctx->width, ctx->height);
125 
126  if (buf[0x21] & 0x40) {
128  ctx->avctx->bits_per_raw_sample = 10;
129  if (ctx->bit_depth != 10) {
130  dsputil_init(&ctx->dsp, ctx->avctx);
131  ctx->bit_depth = 10;
133  }
134  } else {
135  ctx->avctx->pix_fmt = PIX_FMT_YUV422P;
136  ctx->avctx->bits_per_raw_sample = 8;
137  if (ctx->bit_depth != 8) {
138  dsputil_init(&ctx->dsp, ctx->avctx);
139  ctx->bit_depth = 8;
141  }
142  }
143 
144  cid = AV_RB32(buf + 0x28);
145  av_dlog(ctx->avctx, "compression id %d\n", cid);
146 
147  if (dnxhd_init_vlc(ctx, cid) < 0)
148  return -1;
149 
150  if (buf_size < ctx->cid_table->coding_unit_size) {
151  av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
152  return -1;
153  }
154 
155  ctx->mb_width = ctx->width>>4;
156  ctx->mb_height = buf[0x16d];
157 
158  av_dlog(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
159 
160  if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
161  ctx->height <<= 1;
162 
163  if (ctx->mb_height > 68 ||
164  (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
165  av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);
166  return -1;
167  }
168 
169  for (i = 0; i < ctx->mb_height; i++) {
170  ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
171  av_dlog(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
172  if (buf_size < ctx->mb_scan_index[i] + 0x280) {
173  av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
174  return -1;
175  }
176  }
177 
178  return 0;
179 }
180 
182  DCTELEM *block, int n,
183  int qscale,
184  int index_bits,
185  int level_bias,
186  int level_shift)
187 {
188  int i, j, index1, index2, len;
189  int level, component, sign;
190  const uint8_t *weight_matrix;
191  OPEN_READER(bs, &ctx->gb);
192 
193  if (n&2) {
194  component = 1 + (n&1);
195  weight_matrix = ctx->cid_table->chroma_weight;
196  } else {
197  component = 0;
198  weight_matrix = ctx->cid_table->luma_weight;
199  }
200 
201  UPDATE_CACHE(bs, &ctx->gb);
202  GET_VLC(len, bs, &ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
203  if (len) {
204  level = GET_CACHE(bs, &ctx->gb);
205  LAST_SKIP_BITS(bs, &ctx->gb, len);
206  sign = ~level >> 31;
207  level = (NEG_USR32(sign ^ level, len) ^ sign) - sign;
208  ctx->last_dc[component] += level;
209  }
210  block[0] = ctx->last_dc[component];
211  //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
212 
213  for (i = 1; ; i++) {
214  UPDATE_CACHE(bs, &ctx->gb);
215  GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
216  DNXHD_VLC_BITS, 2);
217  //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index1);
218  level = ctx->cid_table->ac_level[index1];
219  if (!level) { /* EOB */
220  //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
221  break;
222  }
223 
224  sign = SHOW_SBITS(bs, &ctx->gb, 1);
225  SKIP_BITS(bs, &ctx->gb, 1);
226 
227  if (ctx->cid_table->ac_index_flag[index1]) {
228  level += SHOW_UBITS(bs, &ctx->gb, index_bits) << 6;
229  SKIP_BITS(bs, &ctx->gb, index_bits);
230  }
231 
232  if (ctx->cid_table->ac_run_flag[index1]) {
233  UPDATE_CACHE(bs, &ctx->gb);
234  GET_VLC(index2, bs, &ctx->gb, ctx->run_vlc.table,
235  DNXHD_VLC_BITS, 2);
236  i += ctx->cid_table->run[index2];
237  }
238 
239  if (i > 63) {
240  av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
241  break;
242  }
243 
244  j = ctx->scantable.permutated[i];
245  //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
246  //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weight %d\n", level, weight_matrix[i]);
247  level = (2*level+1) * qscale * weight_matrix[i];
248  if (level_bias < 32 || weight_matrix[i] != level_bias)
249  level += level_bias;
250  level >>= level_shift;
251 
252  //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
253  block[j] = (level^sign) - sign;
254  }
255 
256  CLOSE_READER(bs, &ctx->gb);
257 }
258 
260  int n, int qscale)
261 {
262  dnxhd_decode_dct_block(ctx, block, n, qscale, 4, 32, 6);
263 }
264 
266  int n, int qscale)
267 {
268  dnxhd_decode_dct_block(ctx, block, n, qscale, 6, 8, 4);
269 }
270 
271 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
272 {
273  int shift1 = ctx->bit_depth == 10;
274  int dct_linesize_luma = ctx->picture.linesize[0];
275  int dct_linesize_chroma = ctx->picture.linesize[1];
276  uint8_t *dest_y, *dest_u, *dest_v;
277  int dct_y_offset, dct_x_offset;
278  int qscale, i;
279 
280  qscale = get_bits(&ctx->gb, 11);
281  skip_bits1(&ctx->gb);
282  //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
283 
284  for (i = 0; i < 8; i++) {
285  ctx->dsp.clear_block(ctx->blocks[i]);
286  ctx->decode_dct_block(ctx, ctx->blocks[i], i, qscale);
287  }
288 
289  if (ctx->picture.interlaced_frame) {
290  dct_linesize_luma <<= 1;
291  dct_linesize_chroma <<= 1;
292  }
293 
294  dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma) << 4) + (x << (4 + shift1));
295  dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));
296  dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));
297 
298  if (ctx->cur_field) {
299  dest_y += ctx->picture.linesize[0];
300  dest_u += ctx->picture.linesize[1];
301  dest_v += ctx->picture.linesize[2];
302  }
303 
304  dct_y_offset = dct_linesize_luma << 3;
305  dct_x_offset = 8 << shift1;
306  ctx->dsp.idct_put(dest_y, dct_linesize_luma, ctx->blocks[0]);
307  ctx->dsp.idct_put(dest_y + dct_x_offset, dct_linesize_luma, ctx->blocks[1]);
308  ctx->dsp.idct_put(dest_y + dct_y_offset, dct_linesize_luma, ctx->blocks[4]);
309  ctx->dsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, ctx->blocks[5]);
310 
311  if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
312  dct_y_offset = dct_linesize_chroma << 3;
313  ctx->dsp.idct_put(dest_u, dct_linesize_chroma, ctx->blocks[2]);
314  ctx->dsp.idct_put(dest_v, dct_linesize_chroma, ctx->blocks[3]);
315  ctx->dsp.idct_put(dest_u + dct_y_offset, dct_linesize_chroma, ctx->blocks[6]);
316  ctx->dsp.idct_put(dest_v + dct_y_offset, dct_linesize_chroma, ctx->blocks[7]);
317  }
318 
319  return 0;
320 }
321 
322 static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
323 {
324  int x, y;
325  for (y = 0; y < ctx->mb_height; y++) {
326  ctx->last_dc[0] =
327  ctx->last_dc[1] =
328  ctx->last_dc[2] = 1 << (ctx->bit_depth + 2); // for levels +2^(bitdepth-1)
329  init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
330  for (x = 0; x < ctx->mb_width; x++) {
331  //START_TIMER;
332  dnxhd_decode_macroblock(ctx, x, y);
333  //STOP_TIMER("decode macroblock");
334  }
335  }
336  return 0;
337 }
338 
339 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
340  AVPacket *avpkt)
341 {
342  const uint8_t *buf = avpkt->data;
343  int buf_size = avpkt->size;
344  DNXHDContext *ctx = avctx->priv_data;
345  AVFrame *picture = data;
346  int first_field = 1;
347 
348  av_dlog(avctx, "frame size %d\n", buf_size);
349 
350  decode_coding_unit:
351  if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
352  return -1;
353 
354  if ((avctx->width || avctx->height) &&
355  (ctx->width != avctx->width || ctx->height != avctx->height)) {
356  av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
357  avctx->width, avctx->height, ctx->width, ctx->height);
358  first_field = 1;
359  }
360 
361  if (av_image_check_size(ctx->width, ctx->height, 0, avctx))
362  return -1;
363  avcodec_set_dimensions(avctx, ctx->width, ctx->height);
364 
365  if (first_field) {
366  if (ctx->picture.data[0])
367  avctx->release_buffer(avctx, &ctx->picture);
368  if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
369  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
370  return -1;
371  }
372  }
373 
374  dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
375 
376  if (first_field && ctx->picture.interlaced_frame) {
377  buf += ctx->cid_table->coding_unit_size;
378  buf_size -= ctx->cid_table->coding_unit_size;
379  first_field = 0;
380  goto decode_coding_unit;
381  }
382 
383  *picture = ctx->picture;
384  *data_size = sizeof(AVPicture);
385  return buf_size;
386 }
387 
389 {
390  DNXHDContext *ctx = avctx->priv_data;
391 
392  if (ctx->picture.data[0])
393  avctx->release_buffer(avctx, &ctx->picture);
394  ff_free_vlc(&ctx->ac_vlc);
395  ff_free_vlc(&ctx->dc_vlc);
396  ff_free_vlc(&ctx->run_vlc);
397  return 0;
398 }
399 
401  .name = "dnxhd",
402  .type = AVMEDIA_TYPE_VIDEO,
403  .id = CODEC_ID_DNXHD,
404  .priv_data_size = sizeof(DNXHDContext),
408  .capabilities = CODEC_CAP_DR1,
409  .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
410 };