vp56.h
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1 /*
2  * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #ifndef AVCODEC_VP56_H
27 #define AVCODEC_VP56_H
28 
29 #include "vp56data.h"
30 #include "dsputil.h"
31 #include "get_bits.h"
32 #include "bytestream.h"
33 #include "videodsp.h"
34 #include "vp3dsp.h"
35 #include "vp56dsp.h"
36 
37 typedef struct vp56_context VP56Context;
38 
39 typedef struct VP56mv {
40  DECLARE_ALIGNED(4, int16_t, x);
41  int16_t y;
42 } VP56mv;
43 
44 #define VP56_SIZE_CHANGE 1
45 
47  VP56mv *vect);
48 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
49  int offset1, int offset2, int stride,
50  VP56mv mv, int mask, int select, int luma);
54 typedef int (*VP56ParseCoeffModels)(VP56Context *s);
55 typedef int (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
56  int buf_size, int *golden_frame);
57 
58 typedef struct VP56RangeCoder {
59  int high;
60  int bits; /* stored negated (i.e. negative "bits" is a positive number of
61  bits left) in order to eliminate a negate in cache refilling */
62  const uint8_t *buffer;
63  const uint8_t *end;
64  unsigned int code_word;
66 
67 typedef struct VP56RefDc {
71 } VP56RefDc;
72 
73 typedef struct VP56Macroblock {
77 
78 typedef struct VP56Model {
79  uint8_t coeff_reorder[64]; /* used in vp6 only */
80  uint8_t coeff_index_to_pos[64]; /* used in vp6 only */
81  uint8_t vector_sig[2]; /* delta sign */
82  uint8_t vector_dct[2]; /* delta coding types */
83  uint8_t vector_pdi[2][2]; /* predefined delta init */
84  uint8_t vector_pdv[2][7]; /* predefined delta values */
85  uint8_t vector_fdv[2][8]; /* 8 bit delta value definition */
86  uint8_t coeff_dccv[2][11]; /* DC coeff value */
87  uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
88  uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
89  uint8_t coeff_dcct[2][36][5]; /* DC coeff coding type */
90  uint8_t coeff_runv[2][14]; /* run value (vp6 only) */
91  uint8_t mb_type[3][10][10]; /* model for decoding MB type */
92  uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
93 } VP56Model;
94 
95 struct vp56_context {
110 
111  /* frame info */
112  int plane_width[4];
113  int plane_height[4];
114  int mb_width; /* number of horizontal MB */
115  int mb_height; /* number of vertical MB */
116  int block_offset[6];
117 
119  uint16_t dequant_dc;
120  uint16_t dequant_ac;
121  int8_t *qscale_table;
122 
123  /* DC predictors management */
127  DCTELEM prev_dc[3][3]; /* [plan][ref_frame] */
128 
129  /* blocks / macroblock */
133 
134  /* motion vectors */
135  VP56mv mv[6]; /* vectors for each block in MB */
138 
139  /* filtering hints */
140  int filter_header; /* used in vp6 only */
146 
147  uint8_t coeff_ctx[4][64]; /* used in vp5 only */
148  uint8_t coeff_ctx_last[4]; /* used in vp5 only */
149 
151 
152  /* upside-down flipping hints */
153  int flip; /* are we flipping ? */
154  int frbi; /* first row block index in MB */
155  int srbi; /* second row block index in MB */
156  int stride[4]; /* stride for each plan */
157 
166 
169 
170  /* huffman decoding */
175  VLC ract_vlc[2][3][6];
176  unsigned int nb_null[2][2]; /* number of consecutive NULL DC/AC */
177 };
178 
179 
180 void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
181 int ff_vp56_free(AVCodecContext *avctx);
182 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
183 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
184  AVPacket *avpkt);
185 
186 
191 extern const uint8_t ff_vp56_norm_shift[256];
192 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
193 
195 {
196  int shift = ff_vp56_norm_shift[c->high];
197  int bits = c->bits;
198  unsigned int code_word = c->code_word;
199 
200  c->high <<= shift;
201  code_word <<= shift;
202  bits += shift;
203  if(bits >= 0 && c->buffer < c->end) {
204  code_word |= bytestream_get_be16(&c->buffer) << bits;
205  bits -= 16;
206  }
207  c->bits = bits;
208  return code_word;
209 }
210 
211 #if ARCH_ARM
212 #include "arm/vp56_arith.h"
213 #elif ARCH_X86
214 #include "x86/vp56_arith.h"
215 #endif
216 
217 #ifndef vp56_rac_get_prob
218 #define vp56_rac_get_prob vp56_rac_get_prob
220 {
221  unsigned int code_word = vp56_rac_renorm(c);
222  unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
223  unsigned int low_shift = low << 16;
224  int bit = code_word >= low_shift;
225 
226  c->high = bit ? c->high - low : low;
227  c->code_word = bit ? code_word - low_shift : code_word;
228 
229  return bit;
230 }
231 #endif
232 
233 #ifndef vp56_rac_get_prob_branchy
234 // branchy variant, to be used where there's a branch based on the bit decoded
236 {
237  unsigned long code_word = vp56_rac_renorm(c);
238  unsigned low = 1 + (((c->high - 1) * prob) >> 8);
239  unsigned low_shift = low << 16;
240 
241  if (code_word >= low_shift) {
242  c->high -= low;
243  c->code_word = code_word - low_shift;
244  return 1;
245  }
246 
247  c->high = low;
248  c->code_word = code_word;
249  return 0;
250 }
251 #endif
252 
254 {
255  unsigned int code_word = vp56_rac_renorm(c);
256  /* equiprobable */
257  int low = (c->high + 1) >> 1;
258  unsigned int low_shift = low << 16;
259  int bit = code_word >= low_shift;
260  if (bit) {
261  c->high -= low;
262  code_word -= low_shift;
263  } else {
264  c->high = low;
265  }
266 
267  c->code_word = code_word;
268  return bit;
269 }
270 
271 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
273 {
274  return vp56_rac_get_prob(c, 128);
275 }
276 
278 {
279  int value = 0;
280 
281  while (bits--) {
282  value = (value << 1) | vp56_rac_get(c);
283  }
284 
285  return value;
286 }
287 
289 {
290  int value = 0;
291 
292  while (bits--) {
293  value = (value << 1) | vp8_rac_get(c);
294  }
295 
296  return value;
297 }
298 
299 // fixme: add 1 bit to all the calls to this?
301 {
302  int v;
303 
304  if (!vp8_rac_get(c))
305  return 0;
306 
307  v = vp8_rac_get_uint(c, bits);
308 
309  if (vp8_rac_get(c))
310  v = -v;
311 
312  return v;
313 }
314 
315 // P(7)
317 {
318  int v = vp56_rac_gets(c, 7) << 1;
319  return v + !v;
320 }
321 
323 {
324  int v = vp8_rac_get_uint(c, 7) << 1;
325  return v + !v;
326 }
327 
328 static av_always_inline
330  const VP56Tree *tree,
331  const uint8_t *probs)
332 {
333  while (tree->val > 0) {
334  if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
335  tree += tree->val;
336  else
337  tree++;
338  }
339  return -tree->val;
340 }
341 
347 static av_always_inline
348 int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
349  const uint8_t *probs, int i)
350 {
351  do {
352  i = tree[i][vp56_rac_get_prob(c, probs[i])];
353  } while (i > 0);
354 
355  return -i;
356 }
357 
358 // how probabilities are associated with decisions is different I think
359 // well, the new scheme fits in the old but this way has one fewer branches per decision
360 static av_always_inline
361 int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
362  const uint8_t *probs)
363 {
364  return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
365 }
366 
367 // DCTextra
369 {
370  int v = 0;
371 
372  do {
373  v = (v<<1) + vp56_rac_get_prob(c, *prob++);
374  } while (*prob);
375 
376  return v;
377 }
378 
379 #endif /* AVCODEC_VP56_H */