First test of Codec 2

I’ve previously mentioned David Rowe’s excellent work on a patent free codec for amateur radio, Codec2, but today is the first time I actually downloaded the code and gave it a shot. You can find the code and the quickstart here:

Codec 2 « Rowetel

My own voice has some fairly low frequencies in it, so I was intrigued to find out how my own voice would do. David’s page mentions that Kristoff, ON1ARF, has a voice where the existing AMBE voice encoder does a much better job, largely because the low frequency encoding of AMBE is much more effective, so I took a short message that I used for some companding experiments I did a while ago, and gave it a try.

The original, as recorded via my iPhone, and downsampled to 8khz using sox.
The same clip after encoding/decoding with codec2.

As you can probably tell, the fidelity isn’t all that stellar with my own voice either. I have nothing to add other than that base observation, but perhaps this will serve as incentive for me to look into this stuff more.