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/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "dboolhuff.h"
#include "vpx_ports/mem.h"
#include "vpx_mem/vpx_mem.h"
DECLARE_ALIGNED(16, const unsigned char, vp8dx_bitreader_norm[256]) =
{
0, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
int vp8dx_start_decode_c(BOOL_DECODER *br, const unsigned char *source,
unsigned int source_sz)
{
br->user_buffer_end = source+source_sz;
br->user_buffer = source;
br->value = 0;
br->count = -8;
br->range = 255;
if (source_sz && !source)
return 1;
/* Populate the buffer */
vp8dx_bool_decoder_fill_c(br);
return 0;
}
void vp8dx_bool_decoder_fill_c(BOOL_DECODER *br)
{
const unsigned char *bufptr;
const unsigned char *bufend;
VP8_BD_VALUE value;
int count;
bufend = br->user_buffer_end;
bufptr = br->user_buffer;
value = br->value;
count = br->count;
VP8DX_BOOL_DECODER_FILL(count, value, bufptr, bufend);
br->user_buffer = bufptr;
br->value = value;
br->count = count;
}
#if 0
/*
* Until optimized versions of these functions are available, we
* keep the implementation in the header to allow inlining.
*
* The RTCD-style invocations are still in place so this can
* be switched by just uncommenting these functions here and
* the DBOOLHUFF_INVOKE calls in the header.
*/
int vp8dx_decode_bool_c(BOOL_DECODER *br, int probability)
{
unsigned int bit=0;
VP8_BD_VALUE value;
unsigned int split;
VP8_BD_VALUE bigsplit;
int count;
unsigned int range;
value = br->value;
count = br->count;
range = br->range;
split = 1 + (((range-1) * probability) >> 8);
bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
range = split;
if(value >= bigsplit)
{
range = br->range-split;
value = value-bigsplit;
bit = 1;
}
/*if(range>=0x80)
{
br->value = value;
br->range = range;
return bit;
}*/
{
register unsigned int shift = vp8dx_bitreader_norm[range];
range <<= shift;
value <<= shift;
count -= shift;
}
br->value = value;
br->count = count;
br->range = range;
if (count < 0)
vp8dx_bool_decoder_fill_c(br);
return bit;
}
int vp8dx_decode_value_c(BOOL_DECODER *br, int bits)
{
int z = 0;
int bit;
for ( bit=bits-1; bit>=0; bit-- )
{
z |= (vp8dx_decode_bool(br, 0x80)<<bit);
}
return z;
}
#endif
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