How to audiowrite a soundfile from m4a to wav?

Hello!

I want to write an audiofile from m4a to wav? I thought it was easy, but I miss something I guess..

This is what I'm doing:

load hoi.m4a

filename='hoi.wav'

audiowrite(filename, y, Fs)

This is what the help function says, but what am I supposed to fill in on y and Fs?

Thanks!

Answer 1

[Geoff Hayes]

Laura - I think that you want to use audioread first as

 m4AFilename = 'hoi.m4a';
 [y,Fs] = audioread(m4AFilename);

and then write it as a wav file using audiowrite as

 wavFilename = 'hoi.wav';
 audio write(wavFilename,y,Fs);

Try the above and see what happens!

[Laura Sels]

Thank you! I forgot the audioread! And I had a not working soundfile but now it works!

[Laura Sels]

Now I want to audiowrite and save not from a m4a or wav file but from a recorded file in matlab. How can I do that, because this does not work..

% record some speech (chien):

r= audiorecorder;

disp('Start speaking.')

recordblocking(r, 5);

disp('End of Recording.');

% Play back the recording.

play(r);

% Store data in double-precision array.

myRecording = getaudiodata(r);

% write the recording in a wav file

filename='chien.wav';

audiowrite(filename, y, Fs);

[y, Fs] = audioread(filename);

[Geoff Hayes]

Laura - presumably it isn't working because you haven't defined the y and Fs and so the line

 audiowrite(filename, y, Fs);

fails. Is that correct? If so, then you need to define them

 y  = getaudiodata(r);
 Fs = get(r,'SampleRate');

Answer 2

[Thorsten]

Use audioread to read the m4a. audioread returns y and Fs, and you can pass these to audio write:

[y, Fs] = audioread('hoi.m4a');
audiowrite('hoi.wav', y, Fs)

[Laura Sels]

Thank you! I forgot the audioread! And I had a not working soundfile but now it works!