read all audio files in one directory

Hi, I want to remove a frequency from all my mp3 songs, my idea is to use the audioread and audioinfo functions to copy a song in my workspace, see if i can use the filter I created, with a sample rate of 44.1kHz and cut out the frequency (1kHz +/- 300Hz). With audiowrite I can create a .wav file without that frequency. But its a lot of work to do that for every song, is it possible to read the first song in one directory, filter it and generate a wav file in another directory and continue with the second song in the directory and so on? audioread expects the whole filename, I have no idea how to find out how many and which songs are in the directory, can anyone help me?

Answer 1

[Azzi Abdelmalek]

folder='C:\Users\malek\Documents\MATLAB'
audio_files=dir(fullfile(folder,'*.m'))
for k=1:numel(audio_files)
  filename=audio_files(k).name
  %Do what you want with filename
  % create a new file name 'new_file' for example
  folder_destination='C:\Users\malek\Documents'  % for example
  file_dest=fullfile(folder_destination,'new_file'
  % .....
end

[pin kuntha]

Not working

[Walter Roberson]

Your own audio file names probably do not end in .m

Note that the original question was more about handling the files than it was about the audio processing.

[Image Analyst]

And your folder is different too. Use the code in the FAQ (the link I gave in my answer below) and replace the obvious things like file and folder names and extensions, and it should run. If it doesn't, check that the files are actually there and post your non-working code, along with any error messages (ALL the red text, not just part of it).

[Javier]

I happen to need to use the audioread() function, in order to later do a fft().

The code is able to retrieve the first audio, but then it stops.

This is the code and the error.

folder = 'C:\Users\bla bla bla'
audio_files = dir(fullfile(folder,'*.wav'))
for k=1:numel(audio_files)
  filename = audio_files(k).name
  
  [y(k),Fs(k)] = audioread('filename');
end

%The Error
Error using audioread (line 90)
The filename specified was not found in the MATLAB path.

Error in Situacion_problema (line 7)
  [y(k),Fs(k)] = audioread('filename');

[Stephen23]

D = 'C:\Users\bla bla bla';
S = dir(fullfile(D,'*.wav'));
N = numel(S);
y = cell(1,N);
Fs = cell(1,N);
for k = 1:N
    F = fullfile(D,S(k).name);
    [y{k},Fs{k}] = audioread(F);
end

[Javier]

Thank you so much sir! It worked perfectly.

[Cesar Lobo]

javier would you be so kind to show me the work you did for the fft?

I need to write a code for fft of a song as well and i cant do it.

thank you in advance

[Cesar Lobo]

Stephen can you also help me writting a code to plot the fft of a song

[Image Analyst]

Did you try fft()? If so, start your own, new question in a new thread. Post your code and data there.

[Cesar Lobo]

my data is a random song. the code is supposed to import a song from a folder and performe the fft. i want to see the graph

[Image Analyst]

OK, so did you call audioread() followed by fft()? If not, why not?

[Walter Roberson]

see the first example in the fft documentation for information on plotting

Answer 2

[Image Analyst]

See the second code sample in the FAQ; http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

[Josh Burt]

Hola image Analyst

I have attempted to use your code in the link on MatlabFandom - I am struggling to actually save the .wav files I need.

The files are hundreds of audiofiles relating to speach recognition, they all sit in different subfolders, each with its own date (there are 2 files per day). There are hundreds of subfolders with .wav files in them. I would like the .wav files to be read and saved in an array called 'AudioArray'. I run your code below, I receive an output listing all the file names. But there is no raw data available for me to analyse. I also want to do some processing once the file has been read - in this case I have just put max(audioArray) to show this. Gracias for all help!

% Specify the folder where the files live.
myFolder = 'C:\Users\myname\Documents\voicedata\Audio';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '**/*.wav'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    % Now do whatever you want with this file name,
    % such as reading it in as an image array with imread()
    AudioArray = audioread(fullFileName);
    maxaudio=max(AudioArray); %calculates the max value of each audiostored in audioArray
    drawnow; % Force display to update immediately.
end

[Image Analyst]

    AudioArray{k} = audioread(fullFileName);
    maxaudio(k) = max(AudioArray{k});