Input length must be an even power of 2

[HamidLaktarash]

I have real audio signal wave in form of double[]. it's length isn't power of 2. what should I do?

[swharden]

Hi @HamidLaktarash,

There's a helper function that can pad an array with zeros and always return one that is an even power of 2

double[] padded = FftSharp.Pad.ZeroPad(input);

[swharden]

... it's pretty simple, so you could also implement this yourself and not rely on the helper function if you don't want to

FftSharp/src/FftSharp/Pad.cs

Lines 35 to 54 in e2d7058

	/// <summary>
	/// Return the input array (or a new zero-padded new one) ensuring length is a power of 2
	/// </summary>
	/// <param name="input">array of any length</param>
	/// <returns>the input array or a zero-padded copy</returns>
	public static double[] ZeroPad(double[] input)
	{
	if (IsPowerOfTwo(input.Length))
	return input;
	int targetLength = 1;
	while (targetLength < input.Length)
	targetLength *= 2;
	int difference = targetLength - input.Length;
	double[] padded = new double[targetLength];
	Array.Copy(input, 0, padded, difference / 2, input.Length);
	return padded;
	}