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- // Copyright 2021 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_BITRATE_H_
- #define MEDIA_BASE_BITRATE_H_
- #include <stdint.h>
- #include <string>
- #include "media/base/media_export.h"
- namespace media {
- class MEDIA_EXPORT Bitrate {
- public:
- // Indicates whether constant bitrate (CBR) or variable bitrate (VBR) should
- // be used for encoding.
- enum class Mode { kConstant, kVariable };
- // Required by Mojo for serialization and de-serialization. Creates an
- // invalid constant bitrate with |target_| and |peak_| set to 0u. Prefer
- // to use the Bitrate::ConstantBitrate() method.
- constexpr Bitrate() = default;
- constexpr Bitrate(const Bitrate& other) = default;
- constexpr Bitrate& operator=(const Bitrate& other) = default;
- // Do not use int or uint64_t variations of these. If you have a signed
- // or 64-bit value you want to use as input, you must explicitly convert to
- // uint32_t before calling. This is intended to prevent implicit and unsafe
- // type conversion.
- static constexpr Bitrate ConstantBitrate(uint32_t target_bps) {
- return Bitrate(Mode::kConstant, target_bps, 0);
- }
- static Bitrate VariableBitrate(uint32_t target_bps, uint32_t peak_bps);
- // Deleted variants: you must SAFELY convert to uint32_t before calling.
- // See base/numerics/safe_conversions.h for functions to safely convert
- // between types.
- static Bitrate ConstantBitrate(int target_bps) = delete;
- static Bitrate VariableBitrate(int target_bps, int peak_bps) = delete;
- static Bitrate VariableBitrate(int target_bps, uint32_t peak_bps) = delete;
- static Bitrate VariableBitrate(uint32_t target_bps, int peak_bps) = delete;
- static Bitrate ConstantBitrate(uint64_t target_bps) = delete;
- static Bitrate VariableBitrate(uint64_t target_bps,
- uint64_t peak_bps) = delete;
- static Bitrate VariableBitrate(uint64_t target_bps,
- uint32_t peak_bps) = delete;
- static Bitrate VariableBitrate(uint32_t target_bps,
- uint64_t peak_bps) = delete;
- bool operator==(const Bitrate& right) const;
- bool operator!=(const Bitrate& right) const;
- // Accessor for |mode_|.
- constexpr Mode mode() const { return mode_; }
- // Accessor for |target_|.
- constexpr uint32_t target_bps() const { return target_bps_; }
- // Accessor for |peak_|. Returns 0 if |mode_| is
- // Mode::kConstantBitrate.
- uint32_t peak_bps() const;
- std::string ToString() const;
- private:
- constexpr Bitrate(Mode mode, uint32_t target_bps, uint32_t peak_bps)
- : mode_(mode), target_bps_(target_bps), peak_bps_(peak_bps) {}
- // These member variables cannot be const (despite the intent that we do not
- // change them after creation) because we must have an assignment operator for
- // Mojo, and const member variables are incompatible with an assignment
- // operator.
- // The bitrate mode.
- Mode mode_ = Mode::kConstant;
- // Target bitrate for the stream in bits per second.
- uint32_t target_bps_ = 0u;
- // For use with Mode::kVariable. Peak bitrate in bits per second.
- uint32_t peak_bps_ = 0u;
- };
- } // namespace media
- #endif // MEDIA_BASE_BITRATE_H_
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