зеркало из https://github.com/mozilla/gecko-dev.git
55 строки
1.6 KiB
C++
55 строки
1.6 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef BIT_READER_H_
|
|
#define BIT_READER_H_
|
|
|
|
#include "MediaData.h"
|
|
|
|
namespace mozilla {
|
|
|
|
class BitReader {
|
|
public:
|
|
explicit BitReader(const MediaByteBuffer* aBuffer);
|
|
BitReader(const MediaByteBuffer* aBuffer, size_t aBits);
|
|
BitReader(const uint8_t* aBuffer, size_t aBits);
|
|
~BitReader();
|
|
uint32_t ReadBits(size_t aNum);
|
|
bool ReadBit() { return ReadBits(1) != 0; }
|
|
uint32_t ReadU32() { return ReadBits(32); }
|
|
uint64_t ReadU64();
|
|
|
|
// Read the UTF-8 sequence and convert it to its 64-bit UCS-4 encoded form.
|
|
// Return 0xfffffffffffffff if sequence was invalid.
|
|
uint64_t ReadUTF8();
|
|
// Read unsigned integer Exp-Golomb-coded.
|
|
uint32_t ReadUE();
|
|
// Read signed integer Exp-Golomb-coded.
|
|
int32_t ReadSE();
|
|
// Read unsigned integer Little Endian Base 128 coded.
|
|
// Limited to unsigned 64 bits.
|
|
CheckedUint64 ReadULEB128();
|
|
|
|
// Return the number of bits parsed so far;
|
|
size_t BitCount() const;
|
|
// Return the number of bits left.
|
|
size_t BitsLeft() const;
|
|
|
|
// Return RBSP bit length.
|
|
static uint32_t GetBitLength(const MediaByteBuffer* aNAL);
|
|
|
|
private:
|
|
void FillReservoir();
|
|
const uint8_t* mData;
|
|
const size_t mOriginalBitSize;
|
|
size_t mTotalBitsLeft;
|
|
size_t mSize; // Size left in bytes
|
|
uint32_t mReservoir; // Left-aligned bits
|
|
size_t mNumBitsLeft; // Number of bits left in reservoir.
|
|
};
|
|
|
|
} // namespace mozilla
|
|
|
|
#endif // BIT_READER_H_
|