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