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// Copyright 2015 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_FILTERS_VP9_RAW_BITS_READER_H_
#define MEDIA_FILTERS_VP9_RAW_BITS_READER_H_
#include <stddef.h>
#include <stdint.h>
#include <memory>
#include "base/macros.h"
#include "media/base/media_export.h"
namespace media {
class BitReader;
// A class to read raw bits stream. See VP9 spec, "RAW-BITS DECODING" section
// for detail.
class MEDIA_EXPORT Vp9RawBitsReader {
public:
Vp9RawBitsReader();
~Vp9RawBitsReader();
// |data| is the input buffer with |size| bytes.
void Initialize(const uint8_t* data, size_t size);
// Returns true if none of the reads since the last Initialize() call has
// gone beyond the end of available data.
bool IsValid() const { return valid_; }
// Returns how many bytes were read since the last Initialize() call.
// Partial bytes will be counted as one byte. For example, it will return 1
// if 3 bits were read.
size_t GetBytesRead() const;
// Reads one bit.
// If the read goes beyond the end of buffer, the return value is undefined.
bool ReadBool();
// Reads a literal with |bits| bits.
// If the read goes beyond the end of buffer, the return value is undefined.
int ReadLiteral(int bits);
// Reads a signed literal with |bits| bits (not including the sign bit).
// If the read goes beyond the end of buffer, the return value is undefined.
int ReadSignedLiteral(int bits);
private:
std::unique_ptr<BitReader> reader_;
// Indicates if none of the reads since the last Initialize() call has gone
// beyond the end of available data.
bool valid_;
DISALLOW_COPY_AND_ASSIGN(Vp9RawBitsReader);
};
} // namespace media
#endif // MEDIA_FILTERS_VP9_RAW_BITS_READER_H_