1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libvpx/vp8/encoder/boolhuff.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,128 @@
1.4 +/*
1.5 + * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license
1.8 + * that can be found in the LICENSE file in the root of the source
1.9 + * tree. An additional intellectual property rights grant can be found
1.10 + * in the file PATENTS. All contributing project authors may
1.11 + * be found in the AUTHORS file in the root of the source tree.
1.12 + */
1.13 +
1.14 +
1.15 +/****************************************************************************
1.16 +*
1.17 +* Module Title : boolhuff.h
1.18 +*
1.19 +* Description : Bool Coder header file.
1.20 +*
1.21 +****************************************************************************/
1.22 +#ifndef __INC_BOOLHUFF_H
1.23 +#define __INC_BOOLHUFF_H
1.24 +
1.25 +#include "vpx_ports/mem.h"
1.26 +#include "vpx/internal/vpx_codec_internal.h"
1.27 +
1.28 +typedef struct
1.29 +{
1.30 + unsigned int lowvalue;
1.31 + unsigned int range;
1.32 + int count;
1.33 + unsigned int pos;
1.34 + unsigned char *buffer;
1.35 + unsigned char *buffer_end;
1.36 + struct vpx_internal_error_info *error;
1.37 +
1.38 + /* Variables used to track bit costs without outputing to the bitstream */
1.39 + unsigned int measure_cost;
1.40 + unsigned long bit_counter;
1.41 +} BOOL_CODER;
1.42 +
1.43 +extern void vp8_start_encode(BOOL_CODER *bc, unsigned char *buffer, unsigned char *buffer_end);
1.44 +
1.45 +extern void vp8_encode_value(BOOL_CODER *br, int data, int bits);
1.46 +extern void vp8_stop_encode(BOOL_CODER *bc);
1.47 +extern const unsigned int vp8_prob_cost[256];
1.48 +
1.49 +
1.50 +DECLARE_ALIGNED(16, extern const unsigned char, vp8_norm[256]);
1.51 +
1.52 +static int validate_buffer(const unsigned char *start,
1.53 + size_t len,
1.54 + const unsigned char *end,
1.55 + struct vpx_internal_error_info *error)
1.56 +{
1.57 + if (start + len > start && start + len < end)
1.58 + return 1;
1.59 + else
1.60 + vpx_internal_error(error, VPX_CODEC_CORRUPT_FRAME,
1.61 + "Truncated packet or corrupt partition ");
1.62 +
1.63 + return 0;
1.64 +}
1.65 +static void vp8_encode_bool(BOOL_CODER *br, int bit, int probability)
1.66 +{
1.67 + unsigned int split;
1.68 + int count = br->count;
1.69 + unsigned int range = br->range;
1.70 + unsigned int lowvalue = br->lowvalue;
1.71 + register unsigned int shift;
1.72 +
1.73 +#ifdef VP8_ENTROPY_STATS
1.74 +#if defined(SECTIONBITS_OUTPUT)
1.75 +
1.76 + if (bit)
1.77 + Sectionbits[active_section] += vp8_prob_cost[255-probability];
1.78 + else
1.79 + Sectionbits[active_section] += vp8_prob_cost[probability];
1.80 +
1.81 +#endif
1.82 +#endif
1.83 +
1.84 + split = 1 + (((range - 1) * probability) >> 8);
1.85 +
1.86 + range = split;
1.87 +
1.88 + if (bit)
1.89 + {
1.90 + lowvalue += split;
1.91 + range = br->range - split;
1.92 + }
1.93 +
1.94 + shift = vp8_norm[range];
1.95 +
1.96 + range <<= shift;
1.97 + count += shift;
1.98 +
1.99 + if (count >= 0)
1.100 + {
1.101 + int offset = shift - count;
1.102 +
1.103 + if ((lowvalue << (offset - 1)) & 0x80000000)
1.104 + {
1.105 + int x = br->pos - 1;
1.106 +
1.107 + while (x >= 0 && br->buffer[x] == 0xff)
1.108 + {
1.109 + br->buffer[x] = (unsigned char)0;
1.110 + x--;
1.111 + }
1.112 +
1.113 + br->buffer[x] += 1;
1.114 + }
1.115 +
1.116 + validate_buffer(br->buffer + br->pos, 1, br->buffer_end, br->error);
1.117 + br->buffer[br->pos++] = (lowvalue >> (24 - offset));
1.118 +
1.119 + lowvalue <<= offset;
1.120 + shift = count;
1.121 + lowvalue &= 0xffffff;
1.122 + count -= 8 ;
1.123 + }
1.124 +
1.125 + lowvalue <<= shift;
1.126 + br->count = count;
1.127 + br->lowvalue = lowvalue;
1.128 + br->range = range;
1.129 +}
1.130 +
1.131 +#endif
