1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
/*
* MixerLoops.cpp
* --------------
* Purpose: Utility inner loops for mixer-related functionality.
* Notes : This file contains performance-critical loops.
* Authors: Olivier Lapicque
* OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#include "stdafx.h"
#include "MixerLoops.h"
#include "Snd_defs.h"
#include "ModChannel.h"
OPENMPT_NAMESPACE_BEGIN
void FloatToStereoMix(const float *pIn1, const float *pIn2, int32 *pOut, uint32 nCount, const float _f2ic)
{
for(uint32 i=0; i<nCount; ++i)
{
*pOut++ = static_cast<int>(*pIn1++ * _f2ic);
*pOut++ = static_cast<int>(*pIn2++ * _f2ic);
}
}
void StereoMixToFloat(const int32 *pSrc, float *pOut1, float *pOut2, uint32 nCount, const float _i2fc)
{
for(uint32 i=0; i<nCount; ++i)
{
*pOut1++ = static_cast<float>(*pSrc++) * _i2fc;
*pOut2++ = static_cast<float>(*pSrc++) * _i2fc;
}
}
void InitMixBuffer(mixsample_t *pBuffer, uint32 nSamples)
{
std::memset(pBuffer, 0, nSamples * sizeof(mixsample_t));
}
void InterleaveFrontRear(mixsample_t *pFrontBuf, mixsample_t *pRearBuf, uint32 nFrames)
{
// copy backwards as we are writing back into FrontBuf
for(int i=nFrames-1; i>=0; i--)
{
pFrontBuf[i*4+3] = pRearBuf[i*2+1];
pFrontBuf[i*4+2] = pRearBuf[i*2+0];
pFrontBuf[i*4+1] = pFrontBuf[i*2+1];
pFrontBuf[i*4+0] = pFrontBuf[i*2+0];
}
}
void MonoFromStereo(mixsample_t *pMixBuf, uint32 nSamples)
{
for(uint32 i=0; i<nSamples; ++i)
{
pMixBuf[i] = (pMixBuf[i*2] + pMixBuf[i*2+1]) / 2;
}
}
#define OFSDECAYSHIFT 8
#define OFSDECAYMASK 0xFF
#define OFSTHRESHOLD static_cast<mixsample_t>(1.0 / (1 << 20)) // Decay threshold for floating point mixer
void StereoFill(mixsample_t *pBuffer, uint32 nSamples, mixsample_t &rofs, mixsample_t &lofs)
{
if((!rofs) && (!lofs))
{
InitMixBuffer(pBuffer, nSamples*2);
return;
}
for(uint32 i=0; i<nSamples; i++)
{
#ifdef MPT_INTMIXER
// Equivalent to int x_r = (rofs + (rofs > 0 ? 255 : -255)) / 256;
const mixsample_t x_r = mpt::rshift_signed(rofs + (mpt::rshift_signed(-rofs, sizeof(mixsample_t) * 8 - 1) & OFSDECAYMASK), OFSDECAYSHIFT);
const mixsample_t x_l = mpt::rshift_signed(lofs + (mpt::rshift_signed(-lofs, sizeof(mixsample_t) * 8 - 1) & OFSDECAYMASK), OFSDECAYSHIFT);
#else
const mixsample_t x_r = rofs * (1.0f / (1 << OFSDECAYSHIFT));
const mixsample_t x_l = lofs * (1.0f / (1 << OFSDECAYSHIFT));
#endif
rofs -= x_r;
lofs -= x_l;
pBuffer[i*2] = rofs;
pBuffer[i*2+1] = lofs;
}
#ifndef MPT_INTMIXER
if(fabs(rofs) < OFSTHRESHOLD) rofs = 0;
if(fabs(lofs) < OFSTHRESHOLD) lofs = 0;
#endif
}
void EndChannelOfs(ModChannel &chn, mixsample_t *pBuffer, uint32 nSamples)
{
mixsample_t rofs = chn.nROfs;
mixsample_t lofs = chn.nLOfs;
if((!rofs) && (!lofs))
{
return;
}
for(uint32 i=0; i<nSamples; i++)
{
#ifdef MPT_INTMIXER
const mixsample_t x_r = mpt::rshift_signed(rofs + (mpt::rshift_signed(-rofs, sizeof(mixsample_t) * 8 - 1) & OFSDECAYMASK), OFSDECAYSHIFT);
const mixsample_t x_l = mpt::rshift_signed(lofs + (mpt::rshift_signed(-lofs, sizeof(mixsample_t) * 8 - 1) & OFSDECAYMASK), OFSDECAYSHIFT);
#else
const mixsample_t x_r = rofs * (1.0f / (1 << OFSDECAYSHIFT));
const mixsample_t x_l = lofs * (1.0f / (1 << OFSDECAYSHIFT));
#endif
rofs -= x_r;
lofs -= x_l;
pBuffer[i*2] += rofs;
pBuffer[i*2+1] += lofs;
}
#ifndef MPT_INTMIXER
if(std::abs(rofs) < OFSTHRESHOLD) rofs = 0;
if(std::abs(lofs) < OFSTHRESHOLD) lofs = 0;
#endif
chn.nROfs = rofs;
chn.nLOfs = lofs;
}
#ifndef MPT_INTMIXER
void InterleaveStereo(const mixsample_t * MPT_RESTRICT inputL, const mixsample_t * MPT_RESTRICT inputR, mixsample_t * MPT_RESTRICT output, size_t numSamples)
{
while(numSamples--)
{
*(output++) = *(inputL++);
*(output++) = *(inputR++);
}
}
void DeinterleaveStereo(const mixsample_t * MPT_RESTRICT input, mixsample_t * MPT_RESTRICT outputL, mixsample_t * MPT_RESTRICT outputR, size_t numSamples)
{
while(numSamples--)
{
*(outputL++) = *(input++);
*(outputR++) = *(input++);
}
}
#endif
OPENMPT_NAMESPACE_END
|
