Background amplification and voice blur on phone call
jerjoz.forums at gmail.com
Wed Jul 8 22:02:27 CEST 2009
thats a might big log youve got there...
On Wed, Jul 8, 2009 at 12:57 PM, Risto H. Kurppa<risto at kurppa.fi> wrote:
> om2009t5 and the same issue here.
> I had a discussion about it at #openmoko(-cdevel), here's the log
> Jun 17 23:51:10 <rhkfin> DocScrutinizer: The echo doesn't to seem to
> be stable: during one call it sometimes echoes sometimes doesn't (when
> I'm quiet and the other end talks). To me it sounds like the noise
> gate doesn't work fully but the background noise (be it the voice of
> the other person or background noise like bus, computer fan, whatever)
> is amplified a lot..
> Jun 17 23:52:23 <DocScrutinizer> hmmm, so maybe reducing control.5 a
> few units may help a lot then
> Jun 17 23:52:56 <DocScrutinizer> also I'm not quite sure OM2009
> handles AT%N correctly
> Jun 17 23:53:49 <rhkfin> the echo reduction? Hmm.. I really hope it
> doesn't and when it's fixed things get easier.. I'll ask nytowl
> Jun 17 23:53:51 <DocScrutinizer> and if OM2009 has borked statefiles,
> everything may happen, even feedback inside mixer
> Jun 17 23:54:15 <rhkfin> DocScrutinizer: I'm using the -new (-based
> I've tried to fix further a bit myself)
> Jun 17 23:55:51 <DocScrutinizer> aah, ok. Then just reduce control.5
> until you get decent sensitivity for far end hearing you loud but
> without ambient noise penetrating noisegate
> Jun 17 23:55:53 <rhkfin> DocScrutinizer: Do you think the -new
> statefile should work for all FR's or are there small differencies in
> the component values that cause the need for a little tuning for each
> unit? (well, depends on the operator etc... Hmm.. )
> Jun 17 23:56:42 <DocScrutinizer> rhkfin: for sure you need to adjust
> according to your particular buzzfix situation
> Jun 17 23:56:59 <rhkfin> 'mono playback volume' is the volume of
> signal from my microphone sent to calypso?
> Jun 17 23:57:14 <DocScrutinizer> *sigh* mompl
> Jun 17 23:57:27 <DocScrutinizer> numid=5,iface=MIXER,name='Mono Playback Volume'
> Jun 17 23:57:32 <rhkfin> yes
> Jun 17 23:59:32 <DocScrutinizer> during call open amixer, adjust "mono
> pl.b. vol", then do a `alsactl store .../gsmhandset.state`
> Jun 17 23:59:45 <DocScrutinizer> *then* finish call
> Jun 18 00:00:23 <DocScrutinizer> probably you prefer to do this from a
> decent PC via ssh
> Jun 18 00:00:33 <rhkfin> yes, understand and can do that, just want to
> understand the behaviour..
> Jun 18 00:01:14 <rhkfin> mono playb. vol is the signal that I hear
> from my speaker, isn't it?
> Jun 18 00:01:39 <DocScrutinizer> alternatively write a script you call
> in FR terminal that does the amixer invocation and after amixwer
> returns does the alsactl store thingie automatically
> Jun 18 00:01:54 <rhkfin> reducing it reduces the changes of the mic
> picking up the signal - but also at the same time makes it harder for
> me to hear the other end?
> Jun 18 00:02:10 <DocScrutinizer> rhkfin: nope, control.5 is mixer-to-gsmMicInput
> Jun 18 00:02:19 <rhkfin> oh, ok..
> Jun 18 00:02:46 <DocScrutinizer> it's the sensitivity of your handsets
> Jun 18 00:03:02 <rhkfin> ok, understand. Now it makes sense.
> Jun 18 00:03:17 <rhkfin> How can I play with the gate level?
> Jun 18 00:03:46 <DocScrutinizer> see wiki for description of AT%N
> valid numeric arguments
> Jun 18 00:04:02 <rhkfin> so the gate is in calypso, not alsa. ok
> Jun 18 00:04:03 <DocScrutinizer> sorry no pointer ATM, you have to search for it
> Jun 18 00:04:15 <rhkfin> np
> Jun 18 00:04:20 <DocScrutinizer> yup, gate and echo cancellation in modem
> Jun 18 00:04:36 <rhkfin> ok, got it..
> Jun 18 00:04:54 <rhkfin> Thanks for this, let's see if i'd be able to
> improve it a bit again..
> Jun 18 00:05:13 <DocScrutinizer> mixer is a simple preamp for mic from
> modems POV
> Jun 18 00:06:13 <rhkfin> This is the one, I guess:
> Jun 18 00:06:44 <DocScrutinizer> yup, exactly
> Jun 18 00:06:57 <rhkfin> what's short & long AEC?
> Jun 18 00:07:08 <DocScrutinizer> I think it's n some of FSOs config-files
> Jun 18 00:08:04 <DocScrutinizer> I guess it'S about signal delay from
> output to input, I.E. how long the sound needs thru the air from
> speaker to mic
> Jun 18 00:08:31 <DocScrutinizer> not sure about that though, mere guess
> Jun 18 00:08:37 <rhkfin> ok..
> Jun 18 00:09:23 <DocScrutinizer> might as well be sth about how long
> it takes the AEC to recalibrate from silence to voice and back
> Jun 18 00:11:04 <rhkfin> and noise cancellation is the gate?
> Jun 18 00:11:07 <DocScrutinizer> rhkfin: check mailing lists, there
> has to be a better more comprehensive explanation of AT%N
> Jun 18 00:11:14 <DocScrutinizer> yup,
> Jun 18 00:11:31 <rhkfin> ok, thanks for the pointerst!
> Jun 18 00:11:41 <DocScrutinizer> the dB value is probably the level
> where it kicks in
> Jun 18 00:11:51 <rhkfin> right
> Jun 18 00:12:41 <DocScrutinizer> be aware there's lots of confusion
> about exact semantics of AT%N
> Jun 18 00:13:28 <rhkfin> ok.. I'll try to find my way through the
> nasty poisonous AT-spikes shot at me from the Fortress of Calypso..
> Jun 18 00:13:50 <DocScrutinizer> I even seen statements these commands
> are accumulative, like "AT%N293; AT%N105"
> Jun 18 00:15:22 <rhkfin> long AEC -12dB and nose reducion is active..
> Jun 18 00:19:27 <DocScrutinizer> mompl, started search across *all* my OM-mail
> Jun 18 00:19:45 <DocScrutinizer> may take a few minutes (no quadcore here ;-)
> Jun 18 00:24:13 <wpwrak> i'd have to call the CIA to do that ...
> Jun 18 00:25:41 <DocScrutinizer> sheeesh, 80.000 msgs searched, no
> success to find the code sniplet I know I've seen long ago :-/
> Jun 18 00:25:57 <DocScrutinizer> start agin with more fuzzy searchstring
> Jun 18 00:26:19 <DocScrutinizer> start agin' - yeah, true ;-)
> Jun 18 00:29:54 <DocScrutinizer> kmail search eats swap like hell
> Jun 18 00:32:39 <DocScrutinizer> ooooh my....
> Jun 18 00:33:16 * DocScrutinizer considers to install a beowulf with
> all the FR around here ;-)
> Jun 18 00:34:18 <DocScrutinizer> though kmail using threads for search
> would help a lot to exploit full power of dual cores
> Jun 18 00:34:53 * DocScrutinizer considers using grep instead
> Jun 18 00:36:11 <wpwrak> mutt can also search mail bodies
> Jun 18 00:50:17 <DocScrutinizer> rhkfin:
> Jun 18 00:51:36 <fredrin> wpwrak: thanks again for the buzzfix :DD
> Jun 18 00:52:58 <DocScrutinizer> rhkfin: be aware though nobody knows
> exactly what's the meaning of ""reset trigger for AEC / SPENH ""
> Jun 18 00:54:06 <DocScrutinizer> rhkfin: I strongly suggest to OR the
> bitmasks for the desired settings, and send these to calypso as a
> single AT%N command
> Jun 18 00:55:22 <fredrin> DocScrutinizer: Do i need to use the AT
> command to fix the echo? how?
> Jun 18 00:55:49 <DocScrutinizer> the meaning of bit0 ""ACK bit : set
> to 1 in order to warn DSP..."" is completely up to anybody's guess
> Jun 18 00:57:40 <DocScrutinizer> depends on your distro, and on your
> config. please read backscroll of this #chan, starting with
> ""[2009-06-18 01:44:45] <wpwrak> DocMobilizer: 1k seems good, yes. he
> had some big problems with echo, but that may be the alsa state""
> Jun 18 00:58:01 <DocScrutinizer> fredrin: you got backscroll?
> I also have these links open as tabs to try out at some stage to play
> around with the settings - haven't had the time so far..
> | risto h. kurppa
> | risto at kurppa dot fi
> | http://risto.kurppa.fi
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