Hi David So, in my TRX, I will use floating point, but when I implement my own floating point entry in freeDV, it is not standard. I suggest, that one should add a floating point demodulation entry, but as standard, not just in my private code... What do you think?
Cheers Alfred, hb9epu On 17.10.2014 23:54, David Rowe wrote: > Hi Steve, > > Codec 2 has a 5 bit energy quantiser which is scaled to expect numbers > in the +/- 32767 range. > > The fdmdv demodulator however is truly "floating point", it doesn't have > any internal references to fixed levels. So it should work at really > low levels and not need an AGC. > > This is an interesting example of digital versus analog. The human ear > "likes" speech in a certain range for comfort, but the modem doesn't > really care. > > Actually I switch off AGC on the HF receiver when I use FreeDV, as it > makes the signal bob around too much on the displays. > > Cheers, > > David > > On 18/10/14 02:22, Steve wrote: >> It's too bad C can't de-reference a void pointer to a data type, as you >> could just swap all the short[] references to void[] and then >> de-reference as to what was being used (too Java I know... ha). >> >> Maybe the best thing would be to just make the codec2 a floating point >> vocoder. Maybe change it internally to +/- 1.0 maximum. >> >> Then the interface person would make whatever wrapper they need to get >> to that. >> >> Interestingly, the codec doesn't work at +/- 1.0 limits, and needs +/- >> 32767.0. I never looked farther as to why. Just went with the flow... >> >> Steve >> >> >> >> ------------------------------------------------------------------------------ >> Comprehensive Server Monitoring with Site24x7. >> Monitor 10 servers for $9/Month. >> Get alerted through email, SMS, voice calls or mobile push notifications. >> Take corrective actions from your mobile device. >> http://p.sf.net/sfu/Zoho >> >> >> >> _______________________________________________ >> Freetel-codec2 mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > ------------------------------------------------------------------------------ > Comprehensive Server Monitoring with Site24x7. > Monitor 10 servers for $9/Month. > Get alerted through email, SMS, voice calls or mobile push notifications. > Take corrective actions from your mobile device. > http://p.sf.net/sfu/Zoho > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Comprehensive Server Monitoring with Site24x7. Monitor 10 servers for $9/Month. Get alerted through email, SMS, voice calls or mobile push notifications. Take corrective actions from your mobile device. http://p.sf.net/sfu/Zoho _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
