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 
43  VP56mv *vect);
44 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
45  int offset1, int offset2, int stride,
46  VP56mv mv, int mask, int select, int luma);
50 typedef int (*VP56ParseCoeffModels)(VP56Context *s);
51 typedef int (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
52  int buf_size, int *golden_frame);
53 
54 typedef struct {
55  int high;
56  int bits; /* stored negated (i.e. negative "bits" is a positive number of
57  bits left) in order to eliminate a negate in cache refilling */
58  const uint8_t *buffer;
59  const uint8_t *end;
60  unsigned int code_word;
62 
63 typedef struct {
64  uint8_t not_null_dc;
67 } VP56RefDc;
68 
69 typedef struct {
70  uint8_t type;
73 
74 typedef struct {
75  uint8_t coeff_reorder[64]; /* used in vp6 only */
76  uint8_t coeff_index_to_pos[64]; /* used in vp6 only */
77  uint8_t vector_sig[2]; /* delta sign */
78  uint8_t vector_dct[2]; /* delta coding types */
79  uint8_t vector_pdi[2][2]; /* predefined delta init */
80  uint8_t vector_pdv[2][7]; /* predefined delta values */
81  uint8_t vector_fdv[2][8]; /* 8 bit delta value definition */
82  uint8_t coeff_dccv[2][11]; /* DC coeff value */
83  uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
84  uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
85  uint8_t coeff_dcct[2][36][5]; /* DC coeff coding type */
86  uint8_t coeff_runv[2][14]; /* run value (vp6 only) */
87  uint8_t mb_type[3][10][10]; /* model for decoding MB type */
88  uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
89 } VP56Model;
90 
91 struct vp56_context {
99  uint8_t *edge_emu_buffer;
104 
105  /* frame info */
106  int plane_width[4];
107  int plane_height[4];
108  int mb_width; /* number of horizontal MB */
109  int mb_height; /* number of vertical MB */
110  int block_offset[6];
111 
113  uint16_t dequant_dc;
114  uint16_t dequant_ac;
115  int8_t *qscale_table;
116 
117  /* DC predictors management */
121  DCTELEM prev_dc[3][3]; /* [plan][ref_frame] */
122 
123  /* blocks / macroblock */
127 
128  /* motion vectors */
129  VP56mv mv[6]; /* vectors for each block in MB */
132 
133  /* filtering hints */
134  int filter_header; /* used in vp6 only */
140 
141  uint8_t coeff_ctx[4][64]; /* used in vp5 only */
142  uint8_t coeff_ctx_last[4]; /* used in vp5 only */
143 
145 
146  /* upside-down flipping hints */
147  int flip; /* are we flipping ? */
148  int frbi; /* first row block index in MB */
149  int srbi; /* second row block index in MB */
150  int stride[4]; /* stride for each plan */
151 
152  const uint8_t *vp56_coord_div;
160 
163 
164  /* huffman decoding */
169  VLC ract_vlc[2][3][6];
170  unsigned int nb_null[2][2]; /* number of consecutive NULL DC/AC */
171 };
172 
173 
174 void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
175 int ff_vp56_free(AVCodecContext *avctx);
176 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
177 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
178  AVPacket *avpkt);
179 
180 
185 extern const uint8_t ff_vp56_norm_shift[256];
186 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
187 
189 {
190  int shift = ff_vp56_norm_shift[c->high];
191  int bits = c->bits;
192  unsigned int code_word = c->code_word;
193 
194  c->high <<= shift;
195  code_word <<= shift;
196  bits += shift;
197  if(bits >= 0 && c->buffer < c->end) {
198  code_word |= bytestream_get_be16(&c->buffer) << bits;
199  bits -= 16;
200  }
201  c->bits = bits;
202  return code_word;
203 }
204 
205 #if ARCH_ARM
206 #include "arm/vp56_arith.h"
207 #elif ARCH_X86
208 #include "x86/vp56_arith.h"
209 #endif
210 
211 #ifndef vp56_rac_get_prob
212 #define vp56_rac_get_prob vp56_rac_get_prob
214 {
215  unsigned int code_word = vp56_rac_renorm(c);
216  unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
217  unsigned int low_shift = low << 16;
218  int bit = code_word >= low_shift;
219 
220  c->high = bit ? c->high - low : low;
221  c->code_word = bit ? code_word - low_shift : code_word;
222 
223  return bit;
224 }
225 #endif
226 
227 #ifndef vp56_rac_get_prob_branchy
228 // branchy variant, to be used where there's a branch based on the bit decoded
230 {
231  unsigned long code_word = vp56_rac_renorm(c);
232  unsigned low = 1 + (((c->high - 1) * prob) >> 8);
233  unsigned low_shift = low << 16;
234 
235  if (code_word >= low_shift) {
236  c->high -= low;
237  c->code_word = code_word - low_shift;
238  return 1;
239  }
240 
241  c->high = low;
242  c->code_word = code_word;
243  return 0;
244 }
245 #endif
246 
248 {
249  unsigned int code_word = vp56_rac_renorm(c);
250  /* equiprobable */
251  int low = (c->high + 1) >> 1;
252  unsigned int low_shift = low << 16;
253  int bit = code_word >= low_shift;
254  if (bit) {
255  c->high -= low;
256  code_word -= low_shift;
257  } else {
258  c->high = low;
259  }
260 
261  c->code_word = code_word;
262  return bit;
263 }
264 
265 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
267 {
268  return vp56_rac_get_prob(c, 128);
269 }
270 
272 {
273  int value = 0;
274 
275  while (bits--) {
276  value = (value << 1) | vp56_rac_get(c);
277  }
278 
279  return value;
280 }
281 
283 {
284  int value = 0;
285 
286  while (bits--) {
287  value = (value << 1) | vp8_rac_get(c);
288  }
289 
290  return value;
291 }
292 
293 // fixme: add 1 bit to all the calls to this?
295 {
296  int v;
297 
298  if (!vp8_rac_get(c))
299  return 0;
300 
301  v = vp8_rac_get_uint(c, bits);
302 
303  if (vp8_rac_get(c))
304  v = -v;
305 
306  return v;
307 }
308 
309 // P(7)
311 {
312  int v = vp56_rac_gets(c, 7) << 1;
313  return v + !v;
314 }
315 
317 {
318  int v = vp8_rac_get_uint(c, 7) << 1;
319  return v + !v;
320 }
321 
322 static av_always_inline
324  const VP56Tree *tree,
325  const uint8_t *probs)
326 {
327  while (tree->val > 0) {
328  if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
329  tree += tree->val;
330  else
331  tree++;
332  }
333  return -tree->val;
334 }
335 
341 static av_always_inline
342 int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
343  const uint8_t *probs, int i)
344 {
345  do {
346  i = tree[i][vp56_rac_get_prob(c, probs[i])];
347  } while (i > 0);
348 
349  return -i;
350 }
351 
352 // how probabilities are associated with decisions is different I think
353 // well, the new scheme fits in the old but this way has one fewer branches per decision
354 static av_always_inline
355 int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
356  const uint8_t *probs)
357 {
358  return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
359 }
360 
361 // DCTextra
362 static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
363 {
364  int v = 0;
365 
366  do {
367  v = (v<<1) + vp56_rac_get_prob(c, *prob++);
368  } while (*prob);
369 
370  return v;
371 }
372 
373 #endif /* AVCODEC_VP56_H */