Nice work Stuart, very cool what can be done with pipes. The mod & demod have filter memories that need to fill, and the frequency and time acquisition takes a few symbols to acquire. This can probably be improved a little. The modem was designed to sync up quickly.
Cheers, David On Tue, 2012-05-15 at 23:51 +0300, Stuart Marsden wrote: > Your right. I tried: > > > echo "STARTSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTART the > quick brown fox jumped over the lazy dog. the quick brown fox jumped > over the lazy dog. the quick brown fox jumped over the lazy dog. > ENDENDENDENDENDENDENDENDENDENDENDENDENDENDENDENDEND" | ./fdmdv_mod - - > | ./fdmdv_demod - - | cat - > > > and got this back: > > > ����.��TSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTARTSTART the quick brown > fox jumped over the lazy dog. the quick brown fox jumped over the lazy > dog. the quick brown fox jumped over the lazy dog. > ENDENDENDENDENDENDENDENDE > > > So any digital data would have to have a reasonable pre/postamble > before content is actually sent. This is probably not a problem for > digital voice as it will only mean a few tens of milliseconds at > either end. > > > Cheers, > > > Stuart > > On 15 May 2012 23:21, <si...@mungewell.org> wrote: > > > So the first 11 bytes are corrupted and the last 21 are > clipped. I assume > > the modem is built mostly for codec2 but it may be good to > be able to > > interleave any needed digital data. > > > There will always be some sync time at the start, and the end > might be > missing as it doesn't extend the data to ensure the last > (full) block is > sent. > > Try pre-pending and appending some '_' (or something) > characters to your > test string > Simon > > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security > and > threat landscape has changed and how IT managers can respond. > Discussions > will include endpoint security, mobile security and the latest > in malware > threats. > http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
