aboutsummaryrefslogtreecommitdiff
path: root/src/frontend/Util_Audio.cpp
blob: fc80c902ca5a7aab464631ea0e9f4e01cae64608 (plain)
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
/*
    Copyright 2016-2020 Arisotura

    This file is part of melonDS.

    melonDS is free software: you can redistribute it and/or modify it under
    the terms of the GNU General Public License as published by the Free
    Software Foundation, either version 3 of the License, or (at your option)
    any later version.

    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with melonDS. If not, see http://www.gnu.org/licenses/.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "FrontendUtil.h"

#include "NDS.h"

#include "mic_blow.h"


namespace Frontend
{

int AudioOut_Freq;
float AudioOut_SampleFrac;

s16* MicBuffer;
u32 MicBufferLength;
u32 MicBufferReadPos;


void Init_Audio(int outputfreq)
{
    AudioOut_Freq = outputfreq;
    AudioOut_SampleFrac = 0;

    MicBuffer = nullptr;
    MicBufferLength = 0;
    MicBufferReadPos = 0;
}


int AudioOut_GetNumSamples(int outlen)
{
    float f_len_in = (outlen * 32823.6328125) / (float)AudioOut_Freq;
    f_len_in += AudioOut_SampleFrac;
    int len_in = (int)floor(f_len_in);
    AudioOut_SampleFrac = f_len_in - len_in;

    return len_in;
}

void AudioOut_Resample(s16* inbuf, int inlen, s16* outbuf, int outlen, int volume)
{
    float res_incr = inlen / (float)outlen;
    float res_timer = 0;
    int res_pos = 0;

    for (int i = 0; i < outlen; i++)
    {
        outbuf[i*2  ] = (inbuf[res_pos*2  ] * volume) >> 8;
        outbuf[i*2+1] = (inbuf[res_pos*2+1] * volume) >> 8;

        res_timer += res_incr;
        while (res_timer >= 1.0)
        {
            res_timer -= 1.0;
            res_pos++;
        }
    }
}


void Mic_FeedSilence()
{
    MicBufferReadPos = 0;
    NDS::MicInputFrame(NULL, 0);
}

void Mic_FeedNoise()
{
    int sample_len = sizeof(mic_blow) / sizeof(u16);
    static int sample_pos = 0;

    s16 tmp[735];

    for (int i = 0; i < 735; i++)
    {
        tmp[i] = mic_blow[sample_pos];
        sample_pos++;
        if (sample_pos >= sample_len) sample_pos = 0;
    }

    NDS::MicInputFrame(tmp, 735);
}

void Mic_FeedExternalBuffer()
{
    if (!MicBuffer) return Mic_FeedSilence();

    if ((MicBufferReadPos + 735) > MicBufferLength)
    {
        s16 tmp[735];
        u32 len1 = MicBufferLength - MicBufferReadPos;
        memcpy(&tmp[0], &MicBuffer[MicBufferReadPos], len1*sizeof(s16));
        memcpy(&tmp[len1], &MicBuffer[0], (735 - len1)*sizeof(s16));

        NDS::MicInputFrame(tmp, 735);
        MicBufferReadPos = 735 - len1;
    }
    else
    {
        NDS::MicInputFrame(&MicBuffer[MicBufferReadPos], 735);
        MicBufferReadPos += 735;
    }
}

void Mic_SetExternalBuffer(s16* buffer, u32 len)
{
    MicBuffer = buffer;
    MicBufferLength = len;
    MicBufferReadPos = 0;
}

}