mirror of https://github.com/axmolengine/axmol.git
66 lines
2.3 KiB
C++
66 lines
2.3 KiB
C++
/*
|
|
* Copyright (C) 2007 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <stdint.h>
|
|
#include <sys/types.h>
|
|
|
|
#include "audio/android/AudioResampler.h"
|
|
#include "audio/android/AudioBufferProvider.h"
|
|
|
|
namespace cocos2d { namespace experimental {
|
|
// ----------------------------------------------------------------------------
|
|
|
|
class AudioResamplerCubic : public AudioResampler {
|
|
public:
|
|
AudioResamplerCubic(int inChannelCount, int32_t sampleRate) :
|
|
AudioResampler(inChannelCount, sampleRate, MED_QUALITY) {
|
|
}
|
|
virtual size_t resample(int32_t* out, size_t outFrameCount,
|
|
AudioBufferProvider* provider);
|
|
private:
|
|
// number of bits used in interpolation multiply - 14 bits avoids overflow
|
|
static const int kNumInterpBits = 14;
|
|
|
|
// bits to shift the phase fraction down to avoid overflow
|
|
static const int kPreInterpShift = kNumPhaseBits - kNumInterpBits;
|
|
typedef struct {
|
|
int32_t a, b, c, y0, y1, y2, y3;
|
|
} state;
|
|
void init();
|
|
size_t resampleMono16(int32_t* out, size_t outFrameCount,
|
|
AudioBufferProvider* provider);
|
|
size_t resampleStereo16(int32_t* out, size_t outFrameCount,
|
|
AudioBufferProvider* provider);
|
|
static inline int32_t interp(state* p, int32_t x) {
|
|
return (((((p->a * x >> 14) + p->b) * x >> 14) + p->c) * x >> 14) + p->y1;
|
|
}
|
|
static inline void advance(state* p, int16_t in) {
|
|
p->y0 = p->y1;
|
|
p->y1 = p->y2;
|
|
p->y2 = p->y3;
|
|
p->y3 = in;
|
|
p->a = (3 * (p->y1 - p->y2) - p->y0 + p->y3) >> 1;
|
|
p->b = (p->y2 << 1) + p->y0 - (((5 * p->y1 + p->y3)) >> 1);
|
|
p->c = (p->y2 - p->y0) >> 1;
|
|
}
|
|
state left, right;
|
|
};
|
|
|
|
// ----------------------------------------------------------------------------
|
|
}} // namespace cocos2d { namespace experimental {
|