This will generate sound (a waveform) at a given frequency for a given length of time in seconds.
Tone( [ float length, float frequency, int samplerate, int channels, string type, float level ] )
- float length = 10.0
- Length of time in seconds.
- float frequency = 440
- Tone frequency.
- int samplerate = 48000
- Audio sample rate.
- int channels = 2
- Number of audio channels.
- string type = "Sine"
- "Silence", "Sine", "Noise", "Square", "Triangle" or "Sawtooth".
- float level = 1.0
The audio sample type is 32-bit float. Use ConvertAudio if this is not what you want.
- In the figure above, a sinus is generated (on a gray clip with framerate 24 fps). The period of the waveform (in frames) is the framerate divided by frequency (or fps/freq, which is 24/2=12 frames in our example). The part of the graph which is light-green represents all samples of the frame under consideration (which is frame 1 here). The number of samples in a particular frame is given by the samplerate divided by the framerate (which is 48000/24 = 2000 samples in our example).
- More generally, the waveform above is described by
- g(n,s) = level · sin(2 · pi · (frequency · n / framerate + s · frequency / samplerate))
- with n the frame and s the sample under consideration (note that s runs from 0 to samplerate/framerate - 1).
- In the example above, this reduces to
- g(n,s) = 0.4 · sin(2 · pi · (2 · n / 24 + s · 2 / 48000))
- with n the frame and s the sample under consideration (note that s runs from 0 to 1999).
- We Wish You a Merry Christmas, in harmony (author hanzfrunz)