Need help converting matrix of i2s values to sound

Hi, I have a 32768x1 matrix in matlab, ( 32768 samples of a i2s microphone that i captured from an FPGA, values are currently in decimal but they represent a 18 bit vector of the i2s PCM sample from the microphone). I need to convert this matrix to sound to test the microphone, but i need help to get it done.

Thanks to everybody.

[Sahil Kulkarni]

I am need this help, as i too have captured the i2s microphone data, but dont know who can i playback the same to verify my recording.

Thnaks in advance for any help.

[Walter Roberson]

Is it linear PCM, LPCM ? If so then divide by 2^18, then multiply by 2 and then subtract 1 to get data suitable for playing.

(or just divide by 2^17 and subtract 1)

[Walter Roberson]

By the way, does the fi hint that the data is stored as FixedPoint instead of as int32 or uint32 ?

Answer 1

[Ted Shultz]

You could try to use the audioplayer function. You would need to scale your data, and know the sample frequency.

You code may look something like this:

Fs = 48000; % Hz (use your value here)
Y =2*( fi-min(fi)) / (max(fi)-min(fi))-1; % scale data
player = audioplayer(Y,Fs); %make audio player