Ken Linder (KC7RAD)
2008-Aug-22 23:22 UTC
[Speex-dev] Digital speech within 100 Hz bandwidth
HA! Just when I was getting ready to drop myself from this list, along comes a ham radio question! Shoving digital voice down a 100 Hz pipe would be mighty darned tough/impossible. N0YMV has a good suggestion. Try those WSJT modes. They use narrow bandwidth and are fun to play with. There are documented instances where moon-bounce QSOs have been completed with these modes. No, it's not voice, but it does work. Oh, JT65 mode in WSJT is designed specifically for EME communication. I used the HSCW (high speed CW) for meteor scatter & had a lot of fun with it. Best of luck in your EME endeavor. Oh, what is your call??? 73s Ken - KC7RAD I have used . ----- Original Message ----- From: "David Willmore" <davidwillmore at gmail.com> To: <mike-lebo at ieee.org> Cc: <speex-dev at xiph.org> Sent: Friday, August 22, 2008 8:45 AM Subject: Re: [Speex-dev] Digital speech within 100 Hz bandwidth>> Could you please forward this e-mail to your engineering department. I >> am a >> ham radio person who wants to transmit from the Earth to the moon and >> back >> to the Earth by phone not by Morris code. This will be a very weak >> signal. I >> need an extra 13.8 dB of gain. Could you please help me distribute the >> attached paper to someone who could take this project into the next >> level? > > Mike, > > If you don't like Morse, how about K1JT's WSJT suite of modes? They were > designed by Joe Taylor--who is an EME'er and very competent ham. They > are all keyboard-to-keyboard modes, so you can cut out the whole voice > side of things. No point in involving analog modes when you can keep it > all digital. > > Best of luck. > > Cheers, > David n0ymv > _______________________________________________ > Speex-dev mailing list > Speex-dev at xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev >
off topic ... this is vu2ese.... - farhan On 8/23/08, Ken Linder (KC7RAD) <kc7rad at radstream.com> wrote:> HA! Just when I was getting ready to drop myself from this list, along > comes a ham radio question! > > Shoving digital voice down a 100 Hz pipe would be mighty darned > tough/impossible. N0YMV has a good suggestion. Try those WSJT modes. They > use narrow bandwidth and are fun to play with. There are documented > instances where moon-bounce QSOs have been completed with these modes. No, > it's not voice, but it does work. Oh, JT65 mode in WSJT is designed > specifically for EME communication. > > I used the HSCW (high speed CW) for meteor scatter & had a lot of fun with > it. > > Best of luck in your EME endeavor. Oh, what is your call??? > > 73s > Ken - KC7RAD > > I have used . > ----- Original Message ----- > From: "David Willmore" <davidwillmore at gmail.com> > To: <mike-lebo at ieee.org> > Cc: <speex-dev at xiph.org> > Sent: Friday, August 22, 2008 8:45 AM > Subject: Re: [Speex-dev] Digital speech within 100 Hz bandwidth > > >>> Could you please forward this e-mail to your engineering department. I >>> am a >>> ham radio person who wants to transmit from the Earth to the moon and >>> back >>> to the Earth by phone not by Morris code. This will be a very weak >>> signal. I >>> need an extra 13.8 dB of gain. Could you please help me distribute the >>> attached paper to someone who could take this project into the next >>> level? >> >> Mike, >> >> If you don't like Morse, how about K1JT's WSJT suite of modes? They were >> designed by Joe Taylor--who is an EME'er and very competent ham. They >> are all keyboard-to-keyboard modes, so you can cut out the whole voice >> side of things. No point in involving analog modes when you can keep it >> all digital. >> >> Best of luck. >> >> Cheers, >> David n0ymv >> _______________________________________________ >> Speex-dev mailing list >> Speex-dev at xiph.org >> http://lists.xiph.org/mailman/listinfo/speex-dev >> > > > _______________________________________________ > Speex-dev mailing list > Speex-dev at xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev >
I am using 'portaudio' and 'speex' to implement a speech audio capture/playback. Preprocess works fine but not the echo canceller (associated with preprocessor). I have read 'testecho.c' but it didn't help me. What I am doing bad? This is my implementation: One thread to capture and playback, both are different functions called in different times directly from 'portaudio'. On capture I do: speex_echo_cancellation(es,input,buffer,output); Input is the audio just captured Buffer is the last frame audio playbacked Output is obvious On playback I do: speex_preprocess_run(ps,(spx_int16_t*)output); memcopy(buffer,output,settings.bufferSize()); output is the frame audio to sound (different that the 'output' in capture) buffer store the last frame audio to be used later on capture (look on capture) Echo and preprocess states are conveniently initiated using speex_echo_state_init(fpb,fpb*25) and speex_echo_ctl(es,SPEEX_ECHO_SET_SAMPLING_RATE,&sr) (and, of course speex_preprocess_state_init) Echo state is associated with preprocess state using SPEEX_PREPROCESS_SET_ECHO_STATE What is wrong?