chromium/media/base/audio_sample_types.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_AUDIO_SAMPLE_TYPES_H_
#define MEDIA_BASE_AUDIO_SAMPLE_TYPES_H_

#include <algorithm>
#include <cmath>
#include <cstdint>
#include <limits>
#include <type_traits>

// To specify different sample formats, we provide a class for each sample
// format that knows certain things about it, such as the C++ data type used
// to store sample values, min and max values, as well as how to convert to
// and from floating point formats. Each class must satisfy a concept we call
// "SampleTypeTraits", which requires that the following publics are provided:
//   * A type |ValueType| specifying the C++ type for storing sample values
//   * A static constant kMinValue which specifies the minimum sample value
//   * A static constant kMaxValue which specifies the maximum sample value
//   * A static constant kZeroPointValue which specifies the sample value
//     representing an amplitude of zero
//   * A static method ConvertFromFloat() that takes a float sample value and
//     converts it to the corresponding ValueType
//   * A static method ConvertFromDouble() that takes a double sample value and
//     converts it to the corresponding ValueType
//   * A static method ConvertToFloat() that takes a ValueType sample value and
//     converts it to the corresponding float value
//   * A static method ConvertToDouble() that takes a ValueType sample value and
//     converts it to the corresponding double value

namespace media {

// For float or double.
// See also the aliases for commonly used types at the bottom of this file.
template <typename SampleType>
class FloatSampleTypeTraits { … };

// Similar to above, but does not apply clipping.
template <typename SampleType>
class FloatSampleTypeTraitsNoClip { … };

// For uint8_t, int16_t, int32_t...
// See also the aliases for commonly used types at the bottom of this file.
template <typename SampleType>
class FixedSampleTypeTraits { … };

// Aliases for commonly used sample formats.
Float32SampleTypeTraits;
Float32SampleTypeTraitsNoClip;
Float64SampleTypeTraits;
UnsignedInt8SampleTypeTraits;
SignedInt16SampleTypeTraits;
SignedInt32SampleTypeTraits;

}  // namespace media

#endif  // MEDIA_BASE_AUDIO_SAMPLE_TYPES_H_