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/*
* Copyright (c) 2015 The WebRTC 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.
*/
#ifndef WEBRTC_MODULES_VIDEO_CODING_UTILITY_VP8_PARSE_HEADER_H_
#define WEBRTC_MODULES_VIDEO_CODING_UTILITY_VP8_PARSE_HEADER_H_
namespace webrtc {
namespace vp8 {
enum {
MB_FEATURE_TREE_PROBS = 3,
NUM_MB_SEGMENTS = 4,
NUM_REF_LF_DELTAS = 4,
NUM_MODE_LF_DELTAS = 4,
};
typedef struct VP8BitReader VP8BitReader;
struct VP8BitReader {
// Boolean decoder.
uint32_t value_; // Current value.
uint32_t range_; // Current range minus 1. In [127, 254] interval.
int bits_; // Number of valid bits left.
// Read buffer.
const uint8_t* buf_; // Next byte to be read.
const uint8_t* buf_end_; // End of read buffer.
int eof_; // True if input is exhausted.
};
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
};
// Gets the QP, QP range: [0, 127].
// Returns true on success, false otherwise.
bool GetQp(const uint8_t* buf, size_t length, int* qp);
} // namespace vp8
} // namespace webrtc
#endif // WEBRTC_MODULES_VIDEO_CODING_UTILITY_VP8_PARSE_HEADER_H_
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