1 /* 2 * Copyright 2015, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_AUDIO_BIT_FIELD_PARSER_H 18 #define ANDROID_AUDIO_BIT_FIELD_PARSER_H 19 20 #include <stdint.h> 21 22 namespace android { 23 24 /** 25 * Extract bit fields from a byte array. 26 */ 27 class BitFieldParser { 28 public: 29 30 explicit BitFieldParser(uint8_t *data); 31 virtual ~BitFieldParser(); 32 33 /** 34 * Read numBits bits from the data array. 35 * Fields may span byte boundaries but may not exceed 32-bits. 36 * Note that the caller must ensure that there is suffcient data. 37 * Assume data is organized as BigEndian format. 38 */ 39 uint32_t readBits(uint32_t numBits); 40 41 /* 42 * When the cursor is zero it points to a position right before 43 * the most significant bit. 44 * When the cursor is seven it points to a position right before 45 * the least significant bit. 46 */ 47 uint32_t getBitCursor() const { return mBitCursor; } 48 49 private: 50 uint8_t *mData; 51 uint32_t mBitCursor; 52 }; 53 54 55 } // namespace android 56 57 #endif // ANDROID_AUDIO_BIT_FIELD_PARSER_H 58
