29 lines
928 B
Mathematica
29 lines
928 B
Mathematica
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function output = fade_in(input, time)
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% Creates a fade-in sound effect that lasts a given
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% time parameter of the input sound signal
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% By Yalu Ouyang
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% input: a 1D array that represents the sound signal in the time domain
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% time: how long the fade in effect should last
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% Shouldn't be longer than the input signal (in which case the function
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% treats it as the duration of the signal)
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% Returns modified signal in the time domain (output).
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len = length(input);
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% if time parameter longer than signal, treat time as
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% the duration of original signal
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if time > len
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time = len
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end
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% set multiplier as 1D array
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% fade in effect: from no volume to full volume of signal
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multiplier = (1 : time) / time;
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% the resulting fade-in output
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output = input .* multiplier;
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end
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% This is useful for making videos, specifically the intro part
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