Smooth sound speed adjustment

[Petr]

Hi. This is another of many experiments with _MEMSOUND. It's a piece of code from another program of mine that I'm writing now. I thought someone might be interested. If someone could change the speed logarithmically, the effect could be achieved as if the DJ on the turntable changes the speed and direction of rotation of the turntable by hand. Now it is set linearly, to demonstrate the functionality of the smooth speed change. Note that it is allowed to play from the end to the beginning, just like when a DJ spins a playback to the other side for a while. Unfortunately, it is still very far from perfect.

It uses _MOUSEMOVEMENTY, so drag the mouse in the Y axis to change the playback speed (and direction).

On row 1 rewrite your audio file name.

Code: QB64: [Select]

1. SndFile$ = "01 Mydlovar.mp3"
2. DIM AS _MEM SndL, SndR
3. DIM AS _OFFSET CurPos, R
4. DIM AS DOUBLE STP, S
5.  
6. Snd = _SNDOPEN(SndFile$)
7. SndL = _MEMSOUND(Snd, 1)
8. SndR = _MEMSOUND(Snd, 2)
9.  
10. TYPE sam
11.     Left AS INTEGER
12.     Right AS INTEGER
13. END TYPE
14.  
15. size& = OFFSET_to_I64(SndL.SIZE) \ 2
16. DIM Sam(size&) AS sam
17. STP = 1
18.  
19.  
20. DO UNTIL i = UBOUND(sam)
21.     Sam(i).Left = _MEMGET(SndL, SndL.OFFSET + ap&, INTEGER)
22.     Sam(i).Right = _MEMGET(SndR, SndR.OFFSET + ap&, INTEGER)
23.     i = i + 1
24.     ap& = ap& + 2
25. LOOP
26.  
27. _MEMFREE SndL
28. _MEMFREE SndR
29.  
30. PRINT "Drag the mouse in the y-axis to correct the speed of sound, ESC for quit!"
31.  
32. DO WHILE K& <> 27
33.     K& = _KEYHIT
34.  
35.     WHILE _MOUSEINPUT
36.         MMY = _MOUSEMOVEMENTY
37.         IF MMY THEN
38.             STP = STP + (MMY / 100)
39.         END IF
40.     WEND
41.  
42.     S = S + STP
43.     IF S > UBOUND(sam) THEN S = UBOUND(sam)
44.     IF S < LBOUND(sam) THEN S = LBOUND(sam)
45.  
46.     LeftValue = Sam(S).Left
47.     RightValue = Sam(S).Right
48.  
49.     _MOUSEMOVE _WIDTH / 2, _HEIGHT / 2
50.  
51.     _SNDRAW LeftValue / 32767, RightValue / 32767
52.  
53.     DO WHILE _SNDRAWLEN > 0
54.     LOOP
55. LOOP
56.  
57. FUNCTION OFFSET_to_I64 (value AS _OFFSET)
58.     DIM m AS _MEM
59.     $IF 32BIT THEN
60.         DIM num AS LONG
61.         m = _MEM(num)
62.         _MEMPUT m,m.offset, value
63.         Offset_to_i64 = num
64.         _MEMFREE m
65.     $ELSE
66.         DIM num AS _INTEGER64
67.         m = _MEM(num)
68.         _MEMPUT m, m.OFFSET, value
69.         OFFSET_to_I64 = num
70.         _MEMFREE m
71.     $END IF
72. END FUNCTION
73.  

[Petr]

Small modification of the previous program - now press the left mouse button to change the speed while moving the mouse in the y-axis. When you release the mouse button, the music smoothly returns to normal speed and direction of playback (simulation of the turntable motor, which gives the board the correct speed and direction at the moment when the DJ stops influencing the speed by hand)

Code: QB64: [Select]

1. SndFile$ = "01 Mydlovar.mp3"
2. DIM AS _MEM SndL, SndR
3. DIM AS _OFFSET CurPos, R
4. DIM AS DOUBLE STP, S
5.  
6. Snd = _SNDOPEN(SndFile$)
7. SndL = _MEMSOUND(Snd, 1)
8. SndR = _MEMSOUND(Snd, 2)
9.  
10. TYPE sam
11.     Left AS INTEGER
12.     Right AS INTEGER
13. END TYPE
14.  
15. size& = OFFSET_to_I64(SndL.SIZE) \ 2
16. DIM Sam(size&) AS sam
17. STP = 1
18.  
19.  
20. DO UNTIL i = UBOUND(sam)
21.     Sam(i).Left = _MEMGET(SndL, SndL.OFFSET + ap&, INTEGER)
22.     Sam(i).Right = _MEMGET(SndR, SndR.OFFSET + ap&, INTEGER)
23.     i = i + 1
24.     ap& = ap& + 2
25. LOOP
26.  
27. _MEMFREE SndL
28. _MEMFREE SndR
29.  
30. PRINT "Drag the mouse in the y-axis to correct the speed of sound, ESC for quit!"
31.  
32. 'S = i / 2 'play track from middle
33.  
34. DO WHILE K& <> 27
35.     K& = _KEYHIT
36.  
37.     WHILE _MOUSEINPUT
38.         MMY = _MOUSEMOVEMENTY
39.         IF MMY THEN
40.             IF _MOUSEBUTTON(1) THEN
41.                 STP = STP + (MMY / 100)
42.             END IF
43.         END IF
44.     WEND
45.  
46.     IF _MOUSEBUTTON(1) = 0 THEN
47.         IF STP < 1 THEN STP = STP + .0001
48.         IF STP > 1 THEN STP = STP - .0001
49.     END IF
50.  
51.  
52.  
53.     S = S + STP
54.     IF S > UBOUND(sam) THEN S = UBOUND(sam)
55.     IF S < LBOUND(sam) THEN S = LBOUND(sam)
56.  
57.     LeftValue = Sam(S).Left
58.     RightValue = Sam(S).Right
59.  
60.     _MOUSEMOVE _WIDTH / 2, _HEIGHT / 2
61.  
62.     _SNDRAW LeftValue / 32767, RightValue / 32767
63.  
64.     DO WHILE _SNDRAWLEN > 0
65.     LOOP
66. LOOP
67.  
68. FUNCTION OFFSET_to_I64 (value AS _OFFSET)
69.     DIM m AS _MEM
70.     $IF 32BIT THEN
71.         DIM num AS LONG
72.         m = _MEM(num)
73.         _MEMPUT m,m.offset, value
74.         Offset_to_i64 = num
75.         _MEMFREE m
76.     $ELSE
77.         DIM num AS _INTEGER64
78.         m = _MEM(num)
79.         _MEMPUT m, m.OFFSET, value
80.         OFFSET_to_I64 = num
81.         _MEMFREE m
82.     $END IF
83. END FUNCTION
84.