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 "vp56dsp.h"
34 
35 typedef struct vp56_context VP56Context;
36 
37 typedef struct {
38  int16_t x;
39  int16_t y;
40 } DECLARE_ALIGNED(4, , VP56mv);
41 
42 #define VP56_SIZE_CHANGE 1
43 
45  VP56mv *vect);
46 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
47  int offset1, int offset2, int stride,
48  VP56mv mv, int mask, int select, int luma);
52 typedef int (*VP56ParseCoeffModels)(VP56Context *s);
53 typedef int (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
54  int buf_size, int *golden_frame);
55 
56 typedef struct {
57  int high;
58  int bits; /* stored negated (i.e. negative "bits" is a positive number of
59  bits left) in order to eliminate a negate in cache refilling */
60  const uint8_t *buffer;
61  const uint8_t *end;
62  unsigned int code_word;
64 
65 typedef struct {
66  uint8_t not_null_dc;
69 } VP56RefDc;
70 
71 typedef struct {
72  uint8_t type;
75 
76 typedef struct {
77  uint8_t coeff_reorder[64]; /* used in vp6 only */
78  uint8_t coeff_index_to_pos[64]; /* used in vp6 only */
79  uint8_t vector_sig[2]; /* delta sign */
80  uint8_t vector_dct[2]; /* delta coding types */
81  uint8_t vector_pdi[2][2]; /* predefined delta init */
82  uint8_t vector_pdv[2][7]; /* predefined delta values */
83  uint8_t vector_fdv[2][8]; /* 8 bit delta value definition */
84  uint8_t coeff_dccv[2][11]; /* DC coeff value */
85  uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
86  uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
87  uint8_t coeff_dcct[2][36][5]; /* DC coeff coding type */
88  uint8_t coeff_runv[2][14]; /* run value (vp6 only) */
89  uint8_t mb_type[3][10][10]; /* model for decoding MB type */
90  uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
91 } VP56Model;
92 
93 struct vp56_context {
101  uint8_t *edge_emu_buffer;
106 
107  /* frame info */
108  int plane_width[4];
109  int plane_height[4];
110  int mb_width; /* number of horizontal MB */
111  int mb_height; /* number of vertical MB */
112  int block_offset[6];
113 
115  uint16_t dequant_dc;
116  uint16_t dequant_ac;
117  int8_t *qscale_table;
118 
119  /* DC predictors management */
123  DCTELEM prev_dc[3][3]; /* [plan][ref_frame] */
124 
125  /* blocks / macroblock */
129 
130  /* motion vectors */
131  VP56mv mv[6]; /* vectors for each block in MB */
134 
135  /* filtering hints */
136  int filter_header; /* used in vp6 only */
142 
143  uint8_t coeff_ctx[4][64]; /* used in vp5 only */
144  uint8_t coeff_ctx_last[4]; /* used in vp5 only */
145 
147 
148  /* upside-down flipping hints */
149  int flip; /* are we flipping ? */
150  int frbi; /* first row block index in MB */
151  int srbi; /* second row block index in MB */
152  int stride[4]; /* stride for each plan */
153 
154  const uint8_t *vp56_coord_div;
162 
165 
166  /* huffman decoding */
171  VLC ract_vlc[2][3][6];
172  unsigned int nb_null[2][2]; /* number of consecutive NULL DC/AC */
173 };
174 
175 
176 void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
177 int ff_vp56_free(AVCodecContext *avctx);
178 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
179 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
180  AVPacket *avpkt);
181 
182 
187 extern const uint8_t ff_vp56_norm_shift[256];
188 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
189 
191 {
192  int shift = ff_vp56_norm_shift[c->high];
193  int bits = c->bits;
194  unsigned int code_word = c->code_word;
195 
196  c->high <<= shift;
197  code_word <<= shift;
198  bits += shift;
199  if(bits >= 0 && c->buffer < c->end) {
200  code_word |= bytestream_get_be16(&c->buffer) << bits;
201  bits -= 16;
202  }
203  c->bits = bits;
204  return code_word;
205 }
206 
207 #if ARCH_ARM
208 #include "arm/vp56_arith.h"
209 #elif ARCH_X86
210 #include "x86/vp56_arith.h"
211 #endif
212 
213 #ifndef vp56_rac_get_prob
214 #define vp56_rac_get_prob vp56_rac_get_prob
216 {
217  unsigned int code_word = vp56_rac_renorm(c);
218  unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
219  unsigned int low_shift = low << 16;
220  int bit = code_word >= low_shift;
221 
222  c->high = bit ? c->high - low : low;
223  c->code_word = bit ? code_word - low_shift : code_word;
224 
225  return bit;
226 }
227 #endif
228 
229 #ifndef vp56_rac_get_prob_branchy
230 // branchy variant, to be used where there's a branch based on the bit decoded
232 {
233  unsigned long code_word = vp56_rac_renorm(c);
234  unsigned low = 1 + (((c->high - 1) * prob) >> 8);
235  unsigned low_shift = low << 16;
236 
237  if (code_word >= low_shift) {
238  c->high -= low;
239  c->code_word = code_word - low_shift;
240  return 1;
241  }
242 
243  c->high = low;
244  c->code_word = code_word;
245  return 0;
246 }
247 #endif
248 
250 {
251  unsigned int code_word = vp56_rac_renorm(c);
252  /* equiprobable */
253  int low = (c->high + 1) >> 1;
254  unsigned int low_shift = low << 16;
255  int bit = code_word >= low_shift;
256  if (bit) {
257  c->high -= low;
258  code_word -= low_shift;
259  } else {
260  c->high = low;
261  }
262 
263  c->code_word = code_word;
264  return bit;
265 }
266 
267 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
269 {
270  return vp56_rac_get_prob(c, 128);
271 }
272 
274 {
275  int value = 0;
276 
277  while (bits--) {
278  value = (value << 1) | vp56_rac_get(c);
279  }
280 
281  return value;
282 }
283 
285 {
286  int value = 0;
287 
288  while (bits--) {
289  value = (value << 1) | vp8_rac_get(c);
290  }
291 
292  return value;
293 }
294 
295 // fixme: add 1 bit to all the calls to this?
297 {
298  int v;
299 
300  if (!vp8_rac_get(c))
301  return 0;
302 
303  v = vp8_rac_get_uint(c, bits);
304 
305  if (vp8_rac_get(c))
306  v = -v;
307 
308  return v;
309 }
310 
311 // P(7)
313 {
314  int v = vp56_rac_gets(c, 7) << 1;
315  return v + !v;
316 }
317 
319 {
320  int v = vp8_rac_get_uint(c, 7) << 1;
321  return v + !v;
322 }
323 
324 static av_always_inline
326  const VP56Tree *tree,
327  const uint8_t *probs)
328 {
329  while (tree->val > 0) {
330  if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
331  tree += tree->val;
332  else
333  tree++;
334  }
335  return -tree->val;
336 }
337 
343 static av_always_inline
344 int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
345  const uint8_t *probs, int i)
346 {
347  do {
348  i = tree[i][vp56_rac_get_prob(c, probs[i])];
349  } while (i > 0);
350 
351  return -i;
352 }
353 
354 // how probabilities are associated with decisions is different I think
355 // well, the new scheme fits in the old but this way has one fewer branches per decision
356 static av_always_inline
357 int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
358  const uint8_t *probs)
359 {
360  return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
361 }
362 
363 // DCTextra
364 static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
365 {
366  int v = 0;
367 
368  do {
369  v = (v<<1) + vp56_rac_get_prob(c, *prob++);
370  } while (*prob);
371 
372  return v;
373 }
374 
375 #endif /* AVCODEC_VP56_H */