70 lines
1.7 KiB
C++
70 lines
1.7 KiB
C++
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BIT_READER_H_
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#define BIT_READER_H_
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#include <stdint.h>
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#include <string>
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#include "base/compiler_specific.h"
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#include "base/macros.h"
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#include "bit_reader_core.h"
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namespace media {
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class BitReader
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: NON_EXPORTED_BASE(private BitReaderCore::ByteStreamProvider) {
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public:
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// Initialize the reader to start reading at |data|, |size| being size
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// of |data| in bytes.
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BitReader(const uint8_t* data, int size);
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~BitReader() override;
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template<typename T> bool ReadBits(int num_bits, T* out) {
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return bit_reader_core_.ReadBits(num_bits, out);
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}
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bool ReadFlag(bool* flag) {
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return bit_reader_core_.ReadFlag(flag);
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}
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// Read |num_bits| of binary data into |str|. |num_bits| must be a positive
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// multiple of 8. This is not efficient for extracting large strings.
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// If false is returned, |str| may not be valid.
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bool ReadString(int num_bits, std::string* str);
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bool SkipBits(int num_bits) {
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return bit_reader_core_.SkipBits(num_bits);
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}
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int bits_available() const {
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return initial_size_ * 8 - bits_read();
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}
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int bits_read() const {
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return bit_reader_core_.bits_read();
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}
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private:
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// BitReaderCore::ByteStreamProvider implementation.
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int GetBytes(int max_n, const uint8_t** out) override;
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// Total number of bytes that was initially passed to BitReader.
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const int initial_size_;
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// Pointer to the next unread byte in the stream.
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const uint8_t* data_;
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// Bytes left in the stream.
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int bytes_left_;
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BitReaderCore bit_reader_core_;
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DISALLOW_COPY_AND_ASSIGN(BitReader);
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};
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} // namespace media
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#endif // BIT_READER_H_
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