Resample and convert into PCM

Hello,

First of all I'm using rMATLAB2018.

I'm trying to resample an audio file with sampling rate 44100 Hz to 22050 Hz and then convert the last one into a PCM with 16 bits.

The resample was an easy step but I'm struggling to convert to PCM 16 bits...

This is my attempt:

[x, fs] = audioread(a_filename);
% resample:
fsin    = fs;
fsout   = 22050;
m       = lcm(fsin,fsout);
up      = m/fsin;
down    = m/fsout;
x_22    = resample(x, up, down);
audiowrite([a_filename,'_22050','.wav'], x_22, fsout);
% convert to PCM 16 bit
fid     = fopen([a_filename,'_22050','.wav'], 'r'); % Open wav file
wF      = fread (fid, inf, 'int16');% 16-bit signed integer
fwrite(wF,'short');
fclose(fid);

I'm getting this error message:

Error using fwrite

Invalid file identifier. Use fopen to generate a valid file identifier.

What am I doing wrong here? Thank you.

Answer 1

[João]

I get it:

% convert to PCM 16 bit
precision = 'int16';
fidr      = fopen([a_filename(1:11), '_22050','.wav'], 'r');  % open .wav file to read 
fidw      = fopen([a_filename(1:11), '_22050','.pcm'], 'wb'); % open .pcm file to write
w         = int16(fread(fidr, inf, precision));% read .wav file
fwrite(fidw, w, precision); % write .pcm file
fclose(fidr); 
fclose(fidw);