Hi,
I've read here (http://www.spiritdsp.com/app.html) that their application can reconstruct high-frequencies from a decoded signal that were cut off by the audio codec in low bit-rate mode. Is it really possible ?? If yes, how they can do such things ??
Thanks
You can't recover the original high frequencies exactly as they were, the best you can do is estimate what the high frequencies were by looking at what's left and adding harmonics in the high frequency range.
If you're interested in harmonic generators, take a look at the DFX plugin for Winamp. It has a function called 'Fidelity' which adds harmonics. Last time I checked this was a free download.