Hi Paul, Sorry for not replying faster but I've been diverted to other things for the last few days.
The noise reduction did have an effect, but not a massive one so we had look at the soundcard in the PC we're using to do the streaming. The onboard sound (it's a micro PC), was replaced with a USB soundcard which cut the amount of noise dramatically. As soon as I get a chance to test in the real world, I'll let you know what happened. Thanks, Jools On Mon, 2022-02-21 at 12:39 +0100, Paul B Mahol wrote: > On Mon, Feb 21, 2022 at 12:34 PM Julian Pilfold-Bagwell < > [email protected]> wrote: > > > Hi Paul, > > > > > > Well, that certainly did the job with the only mod being the db > > level > > going to -20. > > > > That is too low quality or perhaps if you do not use RMS detector but > peak > one than threshold could get lower... > > > > Thanks again for your help, really appreciate it. > > > > All the best, > > > > Jools > > > > > > On Sun, 2022-02-20 at 13:01 +0100, Paul B Mahol wrote: > > > On Sun, Feb 20, 2022 at 12:33 PM Julian Pilfold-Bagwell < > > > [email protected]> wrote: > > > > > > > Thanks for getting back. I was trying to insert a flag for > > > > noise > > > > reduction > > > > into the command above but it always seemed to crash the moment > > > > I > > > > ran it. > > > > Part of my question is what the correct format would be. > > > > > > > > > > What flag? There is numerous examples on web how to use several > > > audio > > > ffmpeg filters. > > > > > > Like agate, afftdn, afwtdn, anlmdn, arnndn, anlms, anlmf. > > > > > > agate audio filter is recommended if you are extreme novice to > > > ffmpeg. > > > > > > For example one possible invocation, of myriad possible > > > combinations > > > is: > > > > > > /usr/bin/ffmpeg -f alsa -i hw:0,0 -af agate=threshold=-40dB > > > -acodec > > > libmp3lame -ab 128k -ac 1 -content_type audio/mpeg -f mp3 > > > icecast://source:<password-removed>@172.20.0.75:8000/tannoy > > > > > > agate audio filter is there because it have very little latency > > > and > > > is very > > > fast, but not much useful than just filtering out only when > > > background > > > noise is present and of certain signal to noise ratio. > > > > > > so threshold argument can be changed to actual dB of your > > > background > > > noise > > > typically captured. > > > > > > > > > > > > > > > > On Sun, 20 Feb 2022 at 11:12, Paul B Mahol <[email protected]> > > > > wrote: > > > > > > > > > On Sun, Feb 20, 2022 at 12:03 PM Julian Pilfold-Bagwell < > > > > > [email protected]> wrote: > > > > > > > > > > > Hi All, > > > > > > > > > > > > > > > > > > I'm trying to set up a tannoy system in our building using > > > > > > FFMPEG and > > > > > > Icecast. The server that is streaming is being fed from > > > > > > the > > > > > > 0db > > > > > recording > > > > > > output from an analogue amplifier that is wired up to an > > > > > > existing 100v > > > > > > system and at the receiving end are PCs with active > > > > > > speakers > > > > > > fitted. > > > > > > > > > > > > The problem that I have is that when there's no audio input > > > > > > to > > > > > > the > > > > > tannoy, > > > > > > there's a background noise that is intrusive enough to play > > > > > > out > > > > > > through > > > > > the > > > > > > speakers. I've been trying to use the noise reduction > > > > > > features > > > > > > in > > > > FFMPEG > > > > > > to reduce the noise but haven't managed to get rid of > > > > > > it. The > > > > > > command > > > > > I'm > > > > > > running to run the system is: > > > > > > > > > > > > > > > > What noise reductions you tried? > > > > > > > > > > > > > > > > /usr/bin/ffmpeg -f alsa -i hw:0,0 -acodec libmp3lame -ab > > > > > > 128k > > > > > > -ac 1 > > > > > > -content_type audio/mpeg -f mp3 icecast://source:<password- > > > > > > removed>@ > > > > > > 172.20.0.75:8000/tannoy > > > > > > > > > > > > > > > > > > Can anyone let me know if this is possible or if there's > > > > > > any > > > > > > way I > > > > could > > > > > > implement something akin to a radio squelch that would just > > > > > > mute the > > > > > output > > > > > > when the input signal drops below a certain level. > > > > > > > > > > > > > > > > > > Thanks in advance, > > > > > > > > > > > > > > > > > > Jools > > > > > > _______________________________________________ > > > > > > ffmpeg-user mailing list > > > > > > [email protected] > > > > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > > > > > > > > > To unsubscribe, visit link above, or email > > > > > > [email protected] with subject "unsubscribe". > > > > > > > > > > > _______________________________________________ > > > > > ffmpeg-user mailing list > > > > > [email protected] > > > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > > > > > > > To unsubscribe, visit link above, or email > > > > > [email protected] with subject "unsubscribe". > > > > > > > > > _______________________________________________ > > > > ffmpeg-user mailing list > > > > [email protected] > > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > > > > > To unsubscribe, visit link above, or email > > > > [email protected] with subject "unsubscribe". > > > > > > > _______________________________________________ > > > ffmpeg-user mailing list > > > [email protected] > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > > > To unsubscribe, visit link above, or email > > > [email protected] with subject "unsubscribe". > > > > _______________________________________________ > > ffmpeg-user mailing list > > [email protected] > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > To unsubscribe, visit link above, or email > > [email protected] with subject "unsubscribe". > > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
