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If this doesn't sort it im rolling way back

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arcadez2003 2024-08-17 20:09:02 +01:00 committed by GitHub
parent dd43fddb29
commit 9f52be61b4
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1 changed files with 30 additions and 26 deletions
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56
src/sound/streams.c
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@ -25,10 +25,7 @@ static void (*stream_callback[MIXER_MAX_CHANNELS])(int param,INT16 *buffer,int l
static void (*stream_callback_multi[MIXER_MAX_CHANNELS])(int param,INT16 **buffer,int length);
static int memory[MIXER_MAX_CHANNELS];
static int r1[MIXER_MAX_CHANNELS];
static int r2[MIXER_MAX_CHANNELS];
static int r3[MIXER_MAX_CHANNELS];
static int c[MIXER_MAX_CHANNELS];
static int k[MIXER_MAX_CHANNELS];
/*
signal >--R1--+--R2--+
@ -42,37 +39,44 @@ signal >--R1--+--R2--+
/* set C = 0 to disable the filter */
void set_RC_filter(int channel,int R1,int R2,int R3,int C)
{
r1[channel] = R1;
r2[channel] = R2;
r3[channel] = R3;
c[channel] = C;
}
stream_update(channel, 0);
void apply_RC_filter(int channel,INT16 *buf,int len,int sample_rate)
{
float R1,R2,R3,C;
float f_R1,f_R2,f_R3,f_C;
float Req;
int K;
int i;
if (C == 0)
{
/* filter disabled */
k[channel] = 0;
return;
}
if (c[channel] == 0) return; /* filter disabled */
R1 = r1[channel];
R2 = r2[channel];
R3 = r3[channel];
C = (float)c[channel] * 1E-12; /* convert pF to F */
f_R1 = R1;
f_R2 = R2;
f_R3 = R3;
f_C = (float)C * 1E-12; /* convert pF to F */
/* Cut Frequency = 1/(2*Pi*Req*C) */
Req = (R1*(R2+R3))/(R1+R2+R3);
Req = (f_R1 * (f_R2 + f_R3)) / (f_R1 + f_R2 + f_R3);
K = 0x10000 * (1 - (exp(-1 / (Req * C) / sample_rate)));
/* k = (1-(EXP(-TIMEDELTA/RC))) */
k[channel] = 0x10000 * (1 - (exp(-1 / (Req * f_C) / stream_sample_rate[channel])));
}
buf[0] = buf[0] + (memory[channel] - buf[0]) * K / 0x10000;
void apply_RC_filter(int channel,int len)
{
int i;
INT16 *buf = stream_buffer[channel];
if (len == 0 || k[channel] == 0) return;
/* Next Value = PREV + (INPUT_VALUE - PREV) * k */
buf[0] = memory[channel] + ((int)(buf[0] - memory[channel]) * k[channel] / 0x10000);
for (i = 1;i < len;i++)
buf[i] = buf[i] + (buf[i-1] - buf[i]) * K / 0x10000;
buf[i] = buf[i-1] + ((int)(buf[i] - buf[i-1]) * k[channel] / 0x10000);
memory[channel] = buf[len-1];
}
@ -144,7 +148,7 @@ void streams_sh_update(void)
stream_buffer_pos[channel+i] = 0;
for (i = 0;i < stream_joined_channels[channel];i++)
apply_RC_filter(channel+i,stream_buffer[channel+i],buflen,stream_sample_rate[channel+i]);
apply_RC_filter(channel+i,buflen);
}
else
{
@ -160,7 +164,7 @@ void streams_sh_update(void)
stream_buffer_pos[channel] = 0;
apply_RC_filter(channel,stream_buffer[channel],buflen,stream_sample_rate[channel]);
apply_RC_filter(channel,buflen);
}
}
}