I’ve written about using podcasts in my courses in the past, but have some recent insight. When I record the audio, how do I convert it from the Windows-favorite of .WMA to the more widespread .MP3? After I pull the files via USB, I have access to work with them via command line and that is my intent. Let me share what it is that I do.
Mathematics Class Podcasts
I use an Olympus VN-6200PC to record audio in my classrooms. It records to .WMA (unprotected, of course), but MP3 is the format of choice. Using a handful of websites, I now use the script:
# wma to mp3 script by mtron
mplayer -vo null -vc dummy -af resample=22050 -ao pcm:waveheader $1
lame audiodump.wav $2 --lowpass 15 -V 9 --vbr-new -mm -h -q 0 -B 32
I use mplayer to convert the .WMA files to 22.05 kHz .wav files. Then I use “lame” to convert to variable bitrate .mp3 with a max bitrate of 32 kB/s.
It works pretty well. Now, this is heavily in part to contributors at these two links:
The use of the script now semi-automates the process of converting my audio from the unfriendly Windows media audio file to the MP3. Although it creates a .WAV file, the script deletes that additional file. The whole process is relatively quick.
If you have any questions, please leave them below in the comments section. I look forward to reading them!