andrew@webrtc.org 8328e7c44d Revert "Revert part of r7561, "Refactor audio conversion functions.""
This restores the conversion changes to AudioProcessing originally
added in r7561, with minor alterations to ensure it passes all tests.

TBR=kwiberg

Review URL: https://webrtc-codereview.appspot.com/28899004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7574 4adac7df-926f-26a2-2b94-8c16560cd09d
2014-10-31 04:58:14 +00:00

103 lines
3.7 KiB
C++

/*
* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_
#define WEBRTC_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_
#include <limits>
#include "webrtc/system_wrappers/interface/scoped_ptr.h"
#include "webrtc/typedefs.h"
namespace webrtc {
typedef std::numeric_limits<int16_t> limits_int16;
// The conversion functions use the following naming convention:
// S16: int16_t [-32768, 32767]
// Float: float [-1.0, 1.0]
// FloatS16: float [-32768.0, 32767.0]
static inline int16_t FloatToS16(float v) {
if (v > 0)
return v >= 1 ? limits_int16::max() :
static_cast<int16_t>(v * limits_int16::max() + 0.5f);
return v <= -1 ? limits_int16::min() :
static_cast<int16_t>(-v * limits_int16::min() - 0.5f);
}
static inline float S16ToFloat(int16_t v) {
static const float kMaxInt16Inverse = 1.f / limits_int16::max();
static const float kMinInt16Inverse = 1.f / limits_int16::min();
return v * (v > 0 ? kMaxInt16Inverse : -kMinInt16Inverse);
}
static inline int16_t FloatS16ToS16(float v) {
static const float kMaxRound = limits_int16::max() - 0.5f;
static const float kMinRound = limits_int16::min() + 0.5f;
if (v > 0)
return v >= kMaxRound ? limits_int16::max() :
static_cast<int16_t>(v + 0.5f);
return v <= kMinRound ? limits_int16::min() :
static_cast<int16_t>(v - 0.5f);
}
static inline float FloatToFloatS16(float v) {
return v * (v > 0 ? limits_int16::max() : -limits_int16::min());
}
static inline float FloatS16ToFloat(float v) {
static const float kMaxInt16Inverse = 1.f / limits_int16::max();
static const float kMinInt16Inverse = 1.f / limits_int16::min();
return v * (v > 0 ? kMaxInt16Inverse : -kMinInt16Inverse);
}
void FloatToS16(const float* src, size_t size, int16_t* dest);
void S16ToFloat(const int16_t* src, size_t size, float* dest);
void FloatS16ToS16(const float* src, size_t size, int16_t* dest);
void FloatToFloatS16(const float* src, size_t size, float* dest);
void FloatS16ToFloat(const float* src, size_t size, float* dest);
// Deinterleave audio from |interleaved| to the channel buffers pointed to
// by |deinterleaved|. There must be sufficient space allocated in the
// |deinterleaved| buffers (|num_channel| buffers with |samples_per_channel|
// per buffer).
template <typename T>
void Deinterleave(const T* interleaved, int samples_per_channel,
int num_channels, T* const* deinterleaved) {
for (int i = 0; i < num_channels; ++i) {
T* channel = deinterleaved[i];
int interleaved_idx = i;
for (int j = 0; j < samples_per_channel; ++j) {
channel[j] = interleaved[interleaved_idx];
interleaved_idx += num_channels;
}
}
}
// Interleave audio from the channel buffers pointed to by |deinterleaved| to
// |interleaved|. There must be sufficient space allocated in |interleaved|
// (|samples_per_channel| * |num_channels|).
template <typename T>
void Interleave(const T* const* deinterleaved, int samples_per_channel,
int num_channels, T* interleaved) {
for (int i = 0; i < num_channels; ++i) {
const T* channel = deinterleaved[i];
int interleaved_idx = i;
for (int j = 0; j < samples_per_channel; ++j) {
interleaved[interleaved_idx] = channel[j];
interleaved_idx += num_channels;
}
}
}
} // namespace webrtc
#endif // WEBRTC_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_