media/libvpx/vp8/common/entropymv.h

   1 /*
   2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11
  12 #ifndef __INC_ENTROPYMV_H
  13 #define __INC_ENTROPYMV_H
  14
  15 #include "treecoder.h"
  16
  17 enum
  18 {
  19     mv_max  = 1023,              /* max absolute value of a MV component */
  20     MVvals = (2 * mv_max) + 1,   /* # possible values "" */
  21
  22     mvlong_width = 10,       /* Large MVs have 9 bit magnitudes */
  23     mvnum_short = 8,         /* magnitudes 0 through 7 */
  24
  25     /* probability offsets for coding each MV component */
  26
  27     mvpis_short = 0,         /* short (<= 7) vs long (>= 8) */
  28     MVPsign,                /* sign for non-zero */
  29     MVPshort,               /* 8 short values = 7-position tree */
  30
  31     MVPbits = MVPshort + mvnum_short - 1, /* mvlong_width long value bits */
  32     MVPcount = MVPbits + mvlong_width    /* (with independent probabilities) */
  33 };
  34
  35 typedef struct mv_context
  36 {
  37     vp8_prob prob[MVPcount];  /* often come in row, col pairs */
  38 } MV_CONTEXT;
  39
  40 extern const MV_CONTEXT vp8_mv_update_probs[2], vp8_default_mv_context[2];
  41
  42 #endif