| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // 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 "base/macros.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() 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_; |
| |
| DISALLOW_COPY_AND_ASSIGN(BitReader); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_BIT_READER_H_ |