Transcode from and to a wide variety of formats.
FFmpeg is a powerful open source tool for multimedia handling like conversion/transcoding.
Installing is easy with a sufficient recent Linux distribution, install the “ffmpeg” package.
Note that you may need to install “libavcodec-unstripped-52”, to make mp3 encoding possible.
FFmpeg is typically used for video, but audio transcoding works too and is pretty simple:
Minimal example: transcode from MP3 to WMA.
ffmpeg -i input.mp3 output.wma
Get the list of supported formats with:
ffmpeg -formats
Convert WAV to MP3, mix down to mono (use 1 audio channel), set bit rate to 64 kbps and sample rate to 22050 Hz.
ffmpeg -i input.wav -ac 1 -ab 64000 -ar 22050 output.mp3
Note: you can also use '-ab 64k', but unsure how well this is supported in different version of FFmpeg.
Picking the 30 seconds fragment at an offset of 1 minute: In seconds
ffmpeg -i input.mp3 -ss 60 -t 30 output.wav
In HH:MM:SS format
ffmpeg -i input.mp3 -ss 0:01:00 -t 0:00:30 output.wav