CODEWITHSUNDEEP
iphoneiosfftaccelerate-framework
Karthik_S
Karthik_S

Reputation: 119

Accelerate Framework iOS - FFT Input

Hi I have to draw a spectrum graph for the wav file. I am using the AudioFileGetProperty and I am able to retreive the AudioData for the wav file using 

audioData = (SInt16*)malloc( 2 *packetCount);

from this other question.

Gonna use FFT in accelerate framework. Please do let me know how to get the Frequency. I am not sure how the input for FFT should be. I currently have the SInt16 audio data.

Upvotes: 0

Views: 1844

Answers (1)

SSteve
SSteve

Reputation: 10708

This post on NSBlog describes how to perform an FFT using Apple's vDSP. The result of the FFT doesn't give you "a frequency". It gives you the magnitude and phase of all the frequencies below half the sample rate of your audio. If your input signal is a simple sine wave, just look for the maximum in the magnitude values.

Upvotes: 1

Related Questions