On Tue, 2011-08-16 at 08:52 +0200, Holger Hans Peter Freyther wrote:
any numbers for that?
I don't have any hard numbers for that, but consider that before float_to_bits was using 100% cpu on a atom core and was decoding 2-3 times slower than real-time. Now, it doesn't even pop up in top (less than 1%) :-D
yes, I think that is still the plan. I once started trying to do this in python but the GNU Radio bindings only allow to control modules, not really do processing in python.
Sorry, i didn't explain myself properly... I was planning to write it as a C module. Have a look at the gr_float_to_uchar module, but instead of returning a single uchar, it should return uchar[2], where each item of the array contains 00 or 01. Alternatively, we can pack the two bits into a single uchar and change how tetra-rx reads it. The second approach looks cleaner, but it's a bit more invasive.. (it breaks compatibility with all the previously made dumps). I have one last question for Harald: which parts of the TETRA protocol hasn't been implemented yet? I would really to contribute the remaining bits, and maybe finish the rx part. Low-cost open-source TETRA handset anyone? :-) Cheers!
Ciaby