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create a libwebputils under src/utils

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with bit_reader bit_writer and thread for now.

Change-Id: If961933fcfc43e60220913fe4d527230ba8f46bb
This commit is contained in:
Pascal Massimino
2011-09-07 09:26:35 +00:00
committed by James Zern
parent ee697d9fc9
commit b112e83647
16 changed files with 76 additions and 53 deletions
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79
src/utils/bit_reader.c Normal file
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// Copyright 2010 Google Inc.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// Boolean decoder
//
// Author: Skal (pascal.massimino@gmail.com)
#include "./bit_reader.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//------------------------------------------------------------------------------
// VP8BitReader
void VP8InitBitReader(VP8BitReader* const br,
const uint8_t* const start, const uint8_t* const end) {
assert(br);
assert(start);
assert(start <= end);
br->range_ = 255 - 1;
br->buf_ = start;
br->buf_end_ = end;
br->value_ = 0;
br->missing_ = 8;
br->eof_ = 0;
}
const uint8_t kVP8Log2Range[128] = {
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
};
// range = ((range + 1) << kVP8Log2Range[range]) - 1
const uint8_t kVP8NewRange[128] = {
127, 127, 191, 127, 159, 191, 223, 127, 143, 159, 175, 191, 207, 223, 239,
127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239,
247, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179,
183, 187, 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239,
243, 247, 251, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149,
151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179,
181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209,
211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239,
241, 243, 245, 247, 249, 251, 253, 127
};
//------------------------------------------------------------------------------
// Higher-level calls
uint32_t VP8GetValue(VP8BitReader* const br, int bits) {
uint32_t v = 0;
while (bits-- > 0) {
v |= VP8GetBit(br, 0x80) << bits;
}
return v;
}
int32_t VP8GetSignedValue(VP8BitReader* const br, int bits) {
const int value = VP8GetValue(br, bits);
return VP8Get(br) ? -value : value;
}
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif