Tuesday, February 12, 2008

lab 82, again

NAME

lab 82, again - txt2iaf

NOTES

After thinking the matter a little, I finally wrote the txt2iaf app. This allows to use any text file, with one or two columns of data, to be converted to an iaf file that can be played using auplay(1). Now, my sound analysis goes something like this:

1. Record something using a microphone. For now, I only record stuff using some app in Windows (Sound Recorder) or Linux (arecord(1)). This is because Inferno has some issues when trying to record something from /dev/audio: an annoying tick every so often that wrecks my sound analysis intentions. Maybe, I can help to fix this problem, probably related with buffering.

2. Convert the wav file obtained to an iaf file, using wav2iaf(1).

3. Get the data from the iaf file to a text format, using iaf2txt(?).

4. Read data from the text file using any data analysis package.

5. Do whatever you want to with the data.

6. If you wish or need to, output the data in a text file.

7. Using txt2iaf(?), create an iaf file using the data in the text file. Enjoy your new song using auplay(1) ;-)

8. If you want to, convert your iaf file to a wav file using iaf2wav(?).

I also fixed some ugly code in iaf2txt(?) and iaf2wav(?) (really ugly, indeed). Please, update.

Cheers

FILES

lab 82 code

Wednesday, February 06, 2008

A couple of IAF utilities

NAME

lab 82 - iaf2txt and iaf2wav

NOTES

Currently, a couple of my friends and I are playing a little with human voices. For this purpose I wrote two applications to convert iaf files to plain text and to the wav audio format. Both apps support the standard iaf files as described in audio(6), except for the encoding: only PCM is supported for now.

Why in the world would one need a text file converted from an iaf? Well... text files are easier to handle with data analysis software like the R programming language. I know MATLAB supports working with wav files directly, but there are mainly two reasons I needed an iaf to txt converter:

1. I do no use MATLAB.

2. When I wrote the iaf2txt app there was not an iaf to wav converter.

Maybe R can handle wav files directly, but I do not know.

I am not really sure if I need a text to iaf converter, but I am thinking about this issue. So far I do not need one.

FILES

lab 82 code