Posts: 246
Threads: 44
Joined: May 2022
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The following program performs a sound effect by rapidly changing the frequency of the sound being played. It's a small thing that occurred to me today while traveling by car. It does not have filtered harmonic frequencies, so even lower frequencies creep into the sound above 1000Hz (well, that's how I explain it). I'm writing something completely different now, this was just an escape attempt for distraction.
Try value 10, 300, use MP3 (need single array type created with MemSound)
Code: (Select All)
$NoPrefix
Screen _NewImage(600, 600, 32)
S = SndOpen("belfast.mp3")
Dim m As MEM
Dim As Single L, R, L2, R2
Dim As Long X, f
m = MemSound(S, 0)
If m.ELEMENTSIZE <> 8 Then
Print "Try another music file, program required SINGLE array. Try MP3."
Sleep
SndClose S
MemFree m
System
End If
Input "Insert start and end freq (start, end); 2 to 10600:"; U, D
If D > U Then Swap D, U
If D > 10600 Then D = 10600
If U < 2 Then U = 2
'try U = 10, D = 300
X = D
Stp = 4 'frequency step
Y = Stp
Do Until n& >= m.SIZE - SndRate
If n& Mod SndRate \ 6 = 0 Then 'set speed for setting freq
X = X + Y
If X > U Then Y = -Stp
If X < D Then Y = Stp
End If
f = _SndRate / X 'get freqency in samples
Do Until f Mod 4 = 0 'set f dividible by 4 for use with mem
f = f + 1
Loop
MemGet m, m.OFFSET + n&, L
MemGet m, m.OFFSET + n& + 4, R
MemGet m, m.OFFSET + n& + f, L2
MemGet m, m.OFFSET + n& + f + 4, R2
SndRaw (L2 - L), (R2 - R)
Do Until SndRawLen <= .2
Locate 2
Print X
Limit 20
Loop
n& = n& + 8
Loop
SndClose S
MemFree m
System
Posts: 246
Threads: 44
Joined: May 2022
Reputation:
28
I played with it a bit more, so here are two similar outputs.
Rapid anti-phase change - weak "quack" form - best heard on stringed instruments
Code: (Select All)
$NoPrefix
Screen _NewImage(600, 600, 32)
S = SndOpen("08.mp3")
Dim m As MEM
Dim As Single L, R, L2, R2
Dim As Long X, f
m = MemSound(S, 0)
If m.ELEMENTSIZE <> 8 Then
Print "Try another music file, program required SINGLE array. Try MP3."
Sleep
SndClose S
MemFree m
System
End If
Stp = 1 'frequency step
Y = 1
Do Until n& >= m.SIZE - SndRate
OldX = X
If n& Mod SndRate \ 30 = 0 Then X = X + Y
If X > 18 Then Y = -1
If X < 6 Then Y = 1
'get freqency in samples
f = _SndRate \ 2 \ X
So& = n& + 16 * X
MemGet m, m.OFFSET + n&, L
MemGet m, m.OFFSET + n& + 4, R
MemGet m, m.OFFSET + So&, L2
MemGet m, m.OFFSET + So& + 4, R2
SndRaw (L2 - L), (R2 - R)
Do Until SndRawLen <= .1
Locate 2
Print "Antiphase Freqency:"; f; "Hz "
Loop
n& = n& + 8
Loop
SndClose S
MemFree m
System
And here is the predecessor:
Code: (Select All)
$NoPrefix
Screen _NewImage(600, 600, 32)
S = SndOpen("103.mp3")
Dim m As MEM
Dim As Single L, R, L2, R2
Dim As Long X, f
m = MemSound(S, 0)
If m.ELEMENTSIZE <> 8 Then
Print "Try another music file, program required SINGLE array. Try MP3."
Sleep
SndClose S
MemFree m
System
End If
Stp = 1 'frequency step
Y = 1
Do Until n& >= m.SIZE - SndRate
OldX = X
If n& Mod SndRate \ 20 = 0 Then X = X + Y
If X > 99 Then Y = -1
If X < 3 Then Y = 1
'get freqency in samples
f = _SndRate \ 2 \ X
So& = n& + 16 * X
MemGet m, m.OFFSET + n&, L
MemGet m, m.OFFSET + n& + 4, R
MemGet m, m.OFFSET + So&, L2
MemGet m, m.OFFSET + So& + 4, R2
SndRaw (L2 - L), (R2 - R)
Do Until SndRawLen <= .1
Locate 2
Print "Antiphase Freqency:"; f; "Hz "
Loop
n& = n& + 8
Loop
SndClose S
MemFree m
System
The difference between them is only in the width of the changed antiphase frequency and also in the speed with which the change is made.
Posts: 246
Threads: 44
Joined: May 2022
Reputation:
28
Next version - Here you can hold the automatically changing audio frequency by tapping the space bar. The program reads the harmonic frequencies to the selected frequency (if I understood the theory correctly) to make the sound more detailed.
So, now for equalization. When this program is taken and the individual bands are read, one should (probably) just set their volume and then via SNDOPENRAW, so that there is no mixing of the signals, the equalizer should be assembled. However, it is still necessary to solve the removal of higher frequencies from the signal with depths.
Code: (Select All)
$NoPrefix
Screen _NewImage(600, 600, 32)
S = SndOpen("10.mp3")
Dim m As MEM
Dim As Single L(5), R(5), L2(5), R2(5), L, R
Dim As Long f, Y(5)
Dim As Single X(5)
m = MemSound(S, 0)
If m.ELEMENTSIZE <> 8 Then
Print "Try another music file, program required SINGLE array. Try MP3."
Sleep
SndClose S
MemFree m
System
End If
For a = 1 To 5
Y(a) = 1 ' increase / decrease frequency (1 / -1)
X(a) = a * 2 'frequency indicator. So, if the number is 2, the signal value is read from the MEMSOUND field
' by 32 bytes further than the start of the signal
Next
'The program (if written correctly) should read two harmonic frequencies above and two below the selected frequency
'to make the sound denser
FreqChange = -1
Do Until n& >= m.SIZE - SndRate
If KeyHit = 32 Then FreqChange = Not FreqChange
If FreqChange Then
If n& Mod SndRate / 2 = 0 Then
a = 1
Do Until a = 5
X(a) = X(a) + Y(a)
If X(a) > 300 Then Y(a) = -1 'higher number here = lower minimal frequency
If X(a) < 2 Then Y(a) = 1 '2 is maximal value for high frequency (1/2 SndRate)
a = a + 1
Loop
End If
End If
a = 1
Do Until a = 5
'get freqency in samples
f& = _SndRate \ 2 \ X(a)
So& = n& + 8 * X(a)
MemGet m, m.OFFSET + n&, L(a)
MemGet m, m.OFFSET + n& + 4, R(a)
MemGet m, m.OFFSET + So&, L2(a)
MemGet m, m.OFFSET + So& + 4, R2(a)
L = L - (L(a) - L2(a))
R = R - (R(a) - R2(a))
a = a + 1
Loop
SndRaw L, R
L = 0
R = 0
Do Until SndRawLen <= .01
Locate 2
Print "Antiphase Freqency:"; f&; "Hz "
Print "Press space for hold / autochange frequency"
Loop
n& = n& + 8
Loop
SndClose S
MemFree m
System
Posts: 246
Threads: 44
Joined: May 2022
Reputation:
28
04-07-2024, 06:35 PM
(This post was last modified: 04-07-2024, 06:40 PM by Petr.)
So here's something as the equalizer style. I was lazy to do with the graphics and adjust the sliders here.... so I did it using the keyboard, or repeatedly press V to start or end the quick adjustment of the equalization.
Code: (Select All)
$NoPrefix
Screen _NewImage(600, 600, 32)
Title "Equalizer"
S = SndOpen("10.mp3")
Dim m As MEM
Dim Shared As Single L(5), R(5), L2(5), R2(5), Le(10), Ri(10), LVol(10), RVol(10), X(10)
Dim As Long f
Dim As Long Raw(10)
m = MemSound(S, 0)
If m.ELEMENTSIZE <> 8 Then
Print "Try another music file, program required SINGLE array. Try MP3."
Sleep
SndClose S
MemFree m
System
End If
eff = 0
X(1) = SetFreq(80)
X(2) = SetFreq(125)
X(3) = SetFreq(180)
X(4) = SetFreq(250)
X(5) = SetFreq(500)
X(6) = SetFreq(1000)
X(7) = SetFreq(2000)
X(8) = SetFreq(4000)
X(8) = SetFreq(8000)
X(9) = SetFreq(12000)
X(10) = SetFreq(16000)
For SetVol = 1 To 10
LVol(SetVol) = 0.1
RVol(SetVol) = 0.1
Next
For R = 1 To 10
Raw(R) = SndOpenRaw
Next
'The program (if written correctly) should read two harmonic frequencies above and two below the selected frequency
'to make the sound denser
FreqChange = -1
Do Until n& >= m.SIZE - SndRate
eq = 1
Do Until eq = 10
a = 1
Le(eq) = 0
Ri(eq) = 0
Do Until a = 5
'get freqency in samples
So& = n& + 8 * X(eq)
MemGet m, m.OFFSET + n&, L(a)
MemGet m, m.OFFSET + n& + 4, R(a)
MemGet m, m.OFFSET + So&, L2(a)
MemGet m, m.OFFSET + So& + 4, R2(a)
Le(eq) = Le(eq) - (L(a) - L2(a))
Ri(eq) = Ri(eq) - (R(a) - R2(a))
a = a + 1
Loop
Le(eq) = Le(eq) * LVol(eq)
Ri(eq) = Ri(eq) * RVol(eq)
eq = eq + 1
Loop
For eq = 1 To 10
SndRaw Le(eq), Ri(eq), Raw(eq) ', Raw(eq)
Next
If eff Then
If n& Mod SndRate / 20 = 0 Then
omega = omega + .1
For eq = 1 To 10
LVol(eq) = Abs(Sin(omega + eq * Pi / 20))
RVol(eq) = Abs(Sin(omega + eq * Pi / 20))
Next
End If
End If
Do Until SndRawLen(Raw(10)) <= .1
i$ = InKey$
Select Case LCase$(i$)
Case "q": SetEqVolP 1
Case "a": SetEqVolM 1
Case "w": SetEqVolP 2
Case "s": SetEqVolM 2
Case "e": SetEqVolP 3
Case "d": SetEqVolM 3
Case "r": SetEqVolP 4
Case "f": SetEqVolM 4
Case "t": SetEqVolP 5
Case "g": SetEqVolM 5
Case "y": SetEqVolP 6
Case "h": SetEqVolM 6
Case "u": SetEqVolP 7
Case "j": SetEqVolM 7
Case "i": SetEqVolP 8
Case "k": SetEqVolM 8
Case "o": SetEqVolP 9
Case "l": SetEqVolM 9
Case "p": SetEqVolP 10
Case "ů": SetEqVolM 10
Case "v": eff = Not eff
End Select
Locate 2
Print "First equalizer."
Print "Press: q,w,e,r,t,y,u,i,o,p for eq volume up"
Print " a,s,d,f,g,h,j,k,l,ů for eq volume down"
For eqva = 1 To 10
Print "Freq: "; SndRate \ X(eqva); " vol:"; LVol(eqva); " "
Next
Loop
n& = n& + 8
Loop
SndClose S
MemFree m
System
Sub SetEqVolM (i)
LVol(i) = LVol(i) - .1
If LVol(i) < 0 Then LVol(i) = 0
RVol(i) = LVol(i)
End Sub
Sub SetEqVolP (i)
LVol(i) = LVol(i) + .1
If LVol(i) > 1.4 Then LVol(i) = 1.4
RVol(i) = LVol(i)
End Sub
Function SetFreq (f)
SetFreq = SndRate \ 2 \ f
End Function
Finally is used SndOpenRaw too.
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