Files
melonDS/src/frontend/Util_Audio.cpp
2022-01-09 02:15:50 +01:00

136 lines
2.9 KiB
C++

/*
Copyright 2016-2022 melonDS team
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;
}
}