WAV-file format.
We use this information to make 16bit stereo WAV-files.
The following program should be once saved in a file before it is executed.
The file BeatWave.MAV shall be made in the same folder in which the program is saved.
The lines 140 and 150 decide the waves of the left and right channels. The unit of t is the second. The values must fall into the range of -1 to 1. These can be replaced by external functions.
The line 160 designates the duration in seconds.
PLAYSOUND, which plays a sound file, in the line 400 is a original statement of Decimal BASIC for Windows.
DWORD$(n) is an original supplied function that returns the 4 byte image of an integer n.
WORD$(n) is an original supplied function that returns the 2 byte image of an integer n.
DWORD$ and WORD$ are supplied in Ver. 7.4.8 or later.
110 OPTION ARITHMETIC NATIVE 130 LET file$="BeatWave.WAV" 140 DEF wl(t)=SIN(2*PI*440*t) 150 DEF wr(t)=SIN(2*PI*441*t) 160 LET duration=5 ! duration in seconds 170 LET fs=44100 ! sampling frequency in Herz 180 LET SIZE=duration*fs 190 OPEN #1: NAME file$ 200 ERASE #1 210 PRINT #1: "RIFF"; 220 PRINT #1: DWORD$(SIZE*2*2 + 36); 230 PRINT #1: "WAVE"; 240 PRINT #1: "fmt "; 250 PRINT #1: DWORD$(16); 260 PRINT #1: WORD$(1); ! linear PCM 270 PRINT #1: WORD$(2); ! number of channles 280 PRINT #1: DWORD$(fs); 290 PRINT #1: DWORD$(fs*2*2); ! data speed (byte/sec) 300 PRINT #1: WORD$(2*2); ! block size 310 PRINT #1: WORD$(16); ! bit size 320 PRINT #1: "data"; 330 PRINT #1: DWORD$(SIZE*2*2); ! wave data size in bytes 340 FOR i=0 TO SIZE-1 350 LET t=i/fs 360 PRINT #1: WORD$(ROUND(32767*wl(t))); 370 PRINT #1: WORD$(ROUND(32767*wr(t))); 380 NEXT i 390 CLOSE #1 400 PLAYSOUND file$ 410 END
The module WAV, defined in the line 900 or below, reads a WAV-file. It supports linear PCM 16 bit monaural or stereophonic WAV-files.
For the first, we assign the WAV-file with WAV.OPEN.
WAV.READ(L,R) reads a pair of numerical data of the wave. They are gotten not below -1 and below 1. If the wave is monaural, L and R shall be identical.
100 OPTION ARITHMETIC NATIVE 110 DECLARE EXTERNAL SUB wav.open, wav.read, wav.close 120 DECLARE EXTERNAL NUMERIC wav.size, wav.rate, wav.NChannels 130 DECLARE NUMERIC i,L,R,t,d 140 DECLARE STRING FName$ 150 FILE GETNAME FName$, "WAV" 160 CALL wav.open (FName$) 170 PRINT FName$ 180 PRINT "Sampling rate in Herz", wav.rate 190 IF wav.NChannels=1 THEN PRINT "Mono" ELSE PRINT "Stereo" 200 PRINT "Duration in sec.", wav.size / wav.rate 210 LET d=1/32 220 SET WINDOW 0, d , -2, 2 230 FOR i=0 TO wav.size-1 240 LET t = i/wav.rate 250 LET t = MOD(t,d) 260 IF t < 1/wav.rate THEN 270 WAIT DELAY d 280 CLEAR 290 PLOT LINES 300 END if 310 CALL wav.read(L,R) 320 PLOT LINES :t,L+R; 330 NEXT i 340 CALL wav.close 350 END 360 9000 MODULE WAV 9010 MODULE OPTION ARITHMETIC NATIVE 9020 PUBLIC SUB OPEN, READ, CLOSE 9030 PUBLIC NUMERIC SIZE ! Number of Samples. size/rate becomes duration 9040 PUBLIC NUMERIC RATE ! Sampling rate 9050 PUBLIC NUMERIC nchannels ! The number of channels, 1 or 2. 9060 SHARE STRING FNAME$ 9070 SHARE NUMERIC count 9080 SHARE FUNCTION DWORD, INT16 9090 SHARE FUNCTION Chars4$ 9100 SHARE CHANNEL #1 9110 LET count=0 9120 9130 EXTERNAL SUB OPEN(f$) 9140 DECLARE NUMERIC n,id,blocksize 9150 DECLARE STRING s$ 9160 OPEN #1: NAME f$, ACCESS INPUT 9170 LET s$=Chars4$ 9180 IF s$<>"RIFF" THEN CAUSE EXCEPTION 999 9190 LET n=DWORD ! The size of the file below 9200 LET s$=Chars4$ 9210 IF s$<>"WAVE" THEN CAUSE EXCEPTION 999 9220 LET s$=Chars4$ 9230 IF s$<>"fmt " THEN CAUSE EXCEPTION 999 9240 LET n=DWord 9250 IF n<>16 THEN CAUSE EXCEPTION 999 9260 LET id=int16 9270 IF id<>1 THEN CAUSE EXCEPTION 999 9280 LET nchannels =int16 ! The number of channels 9290 LET Rate = dword ! Sampling rate 9300 LET n=DWORD ! Data speed 9310 LET BlockSize=int16 ! Block size 9320 LET n=int16 ! 8 or 16 9330 IF n<>16 THEN CAUSE EXCEPTION 998 9340 LET s$=Chars4$ 9350 IF s$<>"data" THEN CAUSE EXCEPTION 999 9360 LET SIZE=DWORD/BlockSize 9370 END SUB 9380 9390 EXTERNAL SUB READ (L, R) 9400 IF count < SIZE THEN 9410 LET L=int16/2^16 9420 IF nchannels=2 THEN 9430 LET R=int16/2^16 9440 ELSE 9450 LET R=L 9460 END IF 9470 LET count=count+1 9480 ELSE 9490 CAUSE EXCEPTION 997 9500 END if 9510 END SUB 9520 9530 EXTERNAL FUNCTION Chars4$ 9540 OPTION CHARACTER byte 9550 DECLARE STRING s$ 9560 CHARACTER INPUT #1: s$ 9570 CHARACTER INPUT #1: s$(2:2) 9580 CHARACTER INPUT #1: s$(3:3) 9590 CHARACTER INPUT #1: s$(4:4) 9600 LET Chars4$=s$ 9610 END FUNCTION 9620 9630 EXTERNAL FUNCTION DWord 9640 OPTION CHARACTER byte 9650 DECLARE NUMERIC n 9660 DECLARE STRING s$ 9670 CHARACTER INPUT #1: s$ 9680 LET n=ORD(s$) 9690 CHARACTER INPUT #1: s$ 9700 LET n=n + ORD(s$)*2^8 9710 CHARACTER INPUT #1: s$ 9720 LET n=n + ORD(s$)*2^16 9730 CHARACTER INPUT #1: s$ 9740 LET n=n + ORD(s$)*2^24 9750 LET DWord=n 9760 END FUNCTION 9770 9780 EXTERNAL FUNCTION Int16 9790 OPTION CHARACTER byte 9800 DECLARE NUMERIC n 9810 DECLARE STRING s$ 9820 CHARACTER INPUT #1: s$ 9830 LET n=ORD(s$) 9840 CHARACTER INPUT #1: s$ 9850 LET n=n+ORD(s$)*2^8 9860 IF n>=2^15 THEN LET n=n-2^16 9870 LET int16=n 9880 END FUNCTION 9890 9900 EXTERNAL SUB CLOSE 9910 CLOSE #1 9920 END SUB 9930 END MODULE
On Windows 95～XP, we use the SoundRecorder of Windows Accessories to make a sound file from the sound source such as a microphone.
We may be able to use on Windows Vista or 7 the following free software.
Re:Sound - 帰ってきた サウンド レコーダー