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ae92244054
The old implementation has undefined behavior in it (unaligned read of uint32_t) Now it's closer to the reference implementation: https://tools.ietf.org/html/rfc6386#section-20.2 Also, added some comments and named some variables to make it more clear, that the parser actually does. Bug: chromium:1057551 Change-Id: I84c1912867e2794502e8a63302c938a0cbab2c4e Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169545 Reviewed-by: Artem Titov <titovartem@webrtc.org> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30661}
40 lines
1.2 KiB
C++
40 lines
1.2 KiB
C++
/*
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* Copyright (c) 2015 The WebRTC 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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#ifndef MODULES_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
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#define MODULES_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
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#include <stdint.h>
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#include <stdio.h>
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namespace webrtc {
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namespace vp8 {
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typedef struct VP8BitReader VP8BitReader;
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struct VP8BitReader {
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// Boolean decoder.
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uint32_t value_; // Current value (2 bytes).
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uint32_t range_; // Current range (always in [128..255] interval).
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int bits_; // Number of bits shifted out of value, at most 7.
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// Read buffer.
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const uint8_t* buf_; // Next byte to be read.
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const uint8_t* buf_end_; // End of read buffer.
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};
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// Gets the QP, QP range: [0, 127].
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// Returns true on success, false otherwise.
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bool GetQp(const uint8_t* buf, size_t length, int* qp);
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} // namespace vp8
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} // namespace webrtc
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#endif // MODULES_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
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