c2140b8af1
Changes 'The VP8 project' to 'The WebM project', for consistency with other webmproject.org repositories. Fixes issue #97. Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
131 lines
3.6 KiB
C
131 lines
3.6 KiB
C
/*
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* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "dboolhuff.h"
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#include "vpx_ports/mem.h"
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#include "vpx_mem/vpx_mem.h"
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DECLARE_ALIGNED(16, const unsigned char, vp8dx_bitreader_norm[256]) =
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{
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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,
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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,
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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,
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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,
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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,
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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,
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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,
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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
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};
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int vp8dx_start_decode_c(BOOL_DECODER *br, const unsigned char *source,
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unsigned int source_sz)
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{
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br->user_buffer_end = source+source_sz;
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br->user_buffer = source;
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br->value = 0;
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br->count = -8;
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br->range = 255;
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if (source_sz && !source)
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return 1;
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/* Populate the buffer */
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vp8dx_bool_decoder_fill_c(br);
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return 0;
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}
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void vp8dx_bool_decoder_fill_c(BOOL_DECODER *br)
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{
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const unsigned char *bufptr;
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const unsigned char *bufend;
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VP8_BD_VALUE value;
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int count;
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bufend = br->user_buffer_end;
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bufptr = br->user_buffer;
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value = br->value;
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count = br->count;
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VP8DX_BOOL_DECODER_FILL(count, value, bufptr, bufend);
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br->user_buffer = bufptr;
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br->value = value;
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br->count = count;
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}
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#if 0
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/*
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* Until optimized versions of these functions are available, we
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* keep the implementation in the header to allow inlining.
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*
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* The RTCD-style invocations are still in place so this can
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* be switched by just uncommenting these functions here and
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* the DBOOLHUFF_INVOKE calls in the header.
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*/
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int vp8dx_decode_bool_c(BOOL_DECODER *br, int probability)
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{
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unsigned int bit=0;
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VP8_BD_VALUE value;
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unsigned int split;
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VP8_BD_VALUE bigsplit;
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int count;
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unsigned int range;
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value = br->value;
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count = br->count;
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range = br->range;
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split = 1 + (((range-1) * probability) >> 8);
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bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
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range = split;
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if(value >= bigsplit)
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{
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range = br->range-split;
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value = value-bigsplit;
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bit = 1;
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}
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/*if(range>=0x80)
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{
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br->value = value;
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br->range = range;
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return bit;
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}*/
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{
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register unsigned int shift = vp8dx_bitreader_norm[range];
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range <<= shift;
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value <<= shift;
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count -= shift;
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}
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br->value = value;
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br->count = count;
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br->range = range;
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if (count < 0)
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vp8dx_bool_decoder_fill_c(br);
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return bit;
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}
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int vp8dx_decode_value_c(BOOL_DECODER *br, int bits)
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{
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int z = 0;
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int bit;
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for ( bit=bits-1; bit>=0; bit-- )
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{
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z |= (vp8dx_decode_bool(br, 0x80)<<bit);
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}
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return z;
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}
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#endif
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