long mail! re: GSM audio level and mic sensitivity, echo issue, alsa statefiles
Joerg Reisenweber
joerg at openmoko.org
Wed May 6 01:30:32 CEST 2009
Am Di 5. Mai 2009 schrieb Joerg Reisenweber:
> Dear distro maintainers and developers
> please recheck
> http://docs.openmoko.org/trac/ticket/2121#comment:3
>
> cheers
> jOERG
>
for your convenience (beware, long IRC log, only partially cleaned to topic)
[2009-05-05 23:35:48] <lindi-> DocScrutinizer: now the volume level is ok but
people complain about odd distortion :)
[2009-05-06 00:01:19] <DocScrutinizer> lindi-: if distortion happens I
recommend reducing #48 by one step, increasing #5 accordingly to get same
level at far end, and see if distortion is away
[2009-05-06 00:02:50] <DocScrutinizer> lindi-: think of #48 like the record
level dial for a tape recorder, and #5 the playback volume dial
[2009-05-06 00:04:36] <DocScrutinizer> lindi-: if you set #48 very odd, you
either get distortion one way, or noise the other way. You need to find
correct setting for #49 close to clipping (distortion), then adjust actual
level to your preferences with #5
[2009-05-06 00:05:06] <DocScrutinizer> s/#49/#48/
[2009-05-06 00:05:08] <bzzbot> DocScrutinizer meant: lindi-: if you set #48
very odd, you either get distortion one way, or noise the other way. You need
to find correct setting for #48 close to clipping (distortion), then adjust
actual level to your preferences with #5
[2009-05-06 00:06:39] <lindi-> DocScrutinizer: it seems to be
non-deterministic
[2009-05-06 00:07:05] <lindi-> DocScrutinizer: it can be heard only on some
calls, and during those calls it persists during the whole call
[2009-05-06 00:07:55] <DocScrutinizer> ny recommendation is: call to a quite
place far end, set #5 to a rather low level (~10..15 below usual), then
adjust #48 to get low but clear sound (no distortion) when *shouting* at the
device. Then level up #5 to get good volume level when speaking gently to
device
[2009-05-06 00:09:15] <DocScrutinizer> try to level up #48 bat much as
possible in procedure mentioned above
[2009-05-06 00:11:08] <lindi-> DocScrutinizer: still i don't understand where
the non-determinism comes from
[2009-05-06 00:11:14] <ptitjes> mickey|tv: but it seems the same missing
throws clause also
[2009-05-06 00:11:37] <DocScrutinizer> lindi-: btw - is distortion a worse
problem than people not hearing you?
[2009-05-06 00:12:12] <lindi-> DocScrutinizer: two out of two people say yes
[2009-05-06 00:12:20] <mickey|tv> k
[2009-05-06 00:12:24] <DocScrutinizer> lindi-: there's plenty of sources for
non-determinism in GSM
[2009-05-06 00:13:34] <DocScrutinizer> lindi-: (2 of 2) That would bother me,
honestly ;-) If people prefer to not hear you at all, rather than get some
distortion
[2009-05-06 00:13:51] <lindi-> DocScrutinizer: remember voice distortion
caused by AT%CBHZ=1 ?
[2009-05-06 00:13:52] <DocScrutinizer> XD
[2009-05-06 00:14:04] <DocScrutinizer> yup, cloudy
[2009-05-06 00:14:23] <lindi-> I've got recorded calls now :)
[2009-05-06 00:14:45] <lindi-> DocScrutinizer: so I'm somewhat suspecting
something similar
[2009-05-06 00:14:48] <DocScrutinizer> lindi-: I closed your ticket for that
behalf
[2009-05-06 00:15:04] <lindi-> DocScrutinizer: the one about -a7.state?
[2009-05-06 00:18:32] <DocScrutinizer> lindi-:
http://docs.openmoko.org/trac/ticket/2282#comment:1
[2009-05-06 00:19:26] <lindi-> DocScrutinizer: yep that is all fine
[2009-05-06 00:20:29] <DocScrutinizer> lindi-: so publish your new results and
we'll see how to tackle this
[2009-05-06 00:21:00] <DocScrutinizer> lindi-: either change topic of #2282 or
open a new one
[2009-05-06 00:21:48] <DocScrutinizer> muahaha, *bad* for python
[2009-05-06 00:21:53] <lindi-> DocScrutinizer: yep i'll open a new one
[2009-05-06 00:22:00] <lindi-> DocScrutinizer: the non-determinism scares
[2009-05-06 00:22:02] <lindi-> DocScrutinizer: the non-determinism scares me
[2009-05-06 00:22:05] <mickey|tv> s/python/patch/
[2009-05-06 00:22:19] <DocScrutinizer> lindi-: me too, sometimes
[2009-05-06 00:22:21] <lindi-> DocScrutinizer: i'm thinking about setting up
automated daily 60-second test calls that get recorded :)
[2009-05-06 00:22:22] <DocScrutinizer> :-o
[2009-05-06 00:22:38] <lindi-> since my voip provider gives me 3000 minutes
free per month
[2009-05-06 00:22:48] <DocScrutinizer> duh
[2009-05-06 00:22:56] <DocScrutinizer> which one???
[2009-05-06 00:22:59] <lindi-> (if I call their GSM numbers of course)
[2009-05-06 00:23:05] <DocScrutinizer> aaaah
[2009-05-06 00:23:11] <DocScrutinizer> so nebermind
[2009-05-06 00:23:22] <DocScrutinizer> never even
[2009-05-06 00:24:19] <DocScrutinizer> hehe
[2009-05-06 00:25:49] <lindi-> DocScrutinizer: is there any docs on what
happens inside calypso vrt. audio and how to control it?
[2009-05-06 00:26:52] <DocScrutinizer> honestly not even linebreak should make
any diff
[2009-05-06 00:27:22] <DocScrutinizer> lindi-: sparse and poor
[2009-05-06 00:27:24] <DocScrutinizer> :-/
[2009-05-06 00:28:36] <DocScrutinizer> mickey|tv: no intetion to argue. U
know: real hackers can code FORTRAN in *any* language ;)
[2009-05-06 00:29:32] <mickey|tv> yo
[2009-05-06 00:29:49] <DocScrutinizer>
http://www.phttp://www.pbm.com/~lindahl/real.programmers.htmlbm.com/~lindahl/real.programmers.html
[2009-05-06 00:31:46] <DocScrutinizer> lindi-: nevertheless you should contact
alphaone|gone for the "nondeterministic" topic, it seems there's something
going on that needs investigation
[2009-05-06 00:32:56] <DocScrutinizer> lindi-: alphaone|gone thought it's
related to moko-FW version, but this theory seems to not pan out as well
[2009-05-06 00:33:41] <lindi-> DocScrutinizer: hmm
[2009-05-06 00:33:50] <DocScrutinizer> neverheless *something* obviously is
odd there
[2009-05-06 00:35:04] <DocScrutinizer> maybe calypso ALC is locking up on
extreme conditions or sth. No bright idea what might be the root cause, but
its too much complaints same general direction to simply ignore them
[2009-05-06 00:35:12] <lindi-> DocScrutinizer: check
http://iki.fi/lindi/openmoko/call-quality/recordings/
[2009-05-06 00:35:25] <lindi-> DocScrutinizer: openmoko-correct-state2.wav
shows the problem, openmoko-correct-state3.wav and
openmoko-correct-state4.wav don't
[2009-05-06 00:35:51] <DocScrutinizer> lindi-: check your permissions ;-)
[2009-05-06 00:36:31] <DocScrutinizer> bbiab
[2009-05-06 00:37:00] <lindi-> DocScrutinizer: should work now
[2009-05-06 00:38:08] <lindi-> DocScrutinizer: how about restarting wolfson in
the middle of the call just to make sure it is not causing this?
[2009-05-06 00:38:48] <DocScrutinizer> WTF?! sounds like backwards
[2009-05-06 00:39:01] <lindi-> DocScrutinizer: do we know that wolfson is
innocent? ;)
[2009-05-06 00:39:20] <DocScrutinizer> wolfson isn't mangeling audio either
way whatsoever
[2009-05-06 00:39:31] <DocScrutinizer> yup
[2009-05-06 00:39:35] <DocScrutinizer> we know
[2009-05-06 00:39:47] <DocScrutinizer> if you set #63 to mic2
[2009-05-06 00:39:49] <lindi-> DocScrutinizer: but i thought those gain
controls in alsa were part of wolfson?
[2009-05-06 00:40:01] <DocScrutinizer> they are
[2009-05-06 00:40:20] <DocScrutinizer> but that can't cause the mess I heard
10sec ago ;-)
[2009-05-06 00:41:20] <DocScrutinizer> I'm not trained to listen to finish(?)
but THAT sounds RATHER STRAAAANGE
[2009-05-06 00:42:13] <DocScrutinizer> never heard such a mess of echo back
and forth and background noise even with my worst RTP-SIP-commections
[2009-05-06 00:42:36] <lindi-> DocScrutinizer: hmm, was there really echo?
[2009-05-06 00:42:48] <lindi-> DocScrutinizer: mostly just everything I say
gets clipped
[2009-05-06 00:43:04] <DocScrutinizer> half of the sound feels like playback
backwards echo to me
[2009-05-06 00:43:32] <lindi-> DocScrutinizer: are those other recordings ok
by your standards?
[2009-05-06 00:44:08] <DocScrutinizer> yeah I noticed some clipping. but thats
not really bad and just indicates we got reserve in amplification and you
should probably go down on #48 from 3 to 2
[2009-05-06 00:44:37] <DocScrutinizer> (other) was so buffled I hadn't even a
test on them
[2009-05-06 00:45:17] <lindi-> DocScrutinizer: hmm, what do you mean?
[2009-05-06 00:45:40] <lindi-> DocScrutinizer: (re the other recordings)
[2009-05-06 00:45:42] <DocScrutinizer> lindi-: (3 to 2) though you should
check first if it gets better on adjusting #5
[2009-05-06 00:46:02] <DocScrutinizer> a minute please
[2009-05-06 00:46:21] <lindi-> i'll be away for 45 minutes or so now
[2009-05-06 00:49:01] <DocScrutinizer> lindi-: ok, it's pretty clear now those
recordings have a strong slow dynamic compression+noisegate which makes the
start of a word ramp up in volume - this leads to other non-finish feeling
like it's backwards
[2009-05-06 00:49:19] <DocScrutinizer> the second recording also has a little
clipping
[2009-05-06 00:49:45] <DocScrutinizer> you should do as adviced: go down #48 1
step, readjust #5
[2009-05-06 00:50:14] <DocScrutinizer> and you should try other AT%Nxxxx
values, urgently!
[2009-05-06 00:52:57] <DocScrutinizer> I never was aware ther could be such a
bad compression/noisegate (such a slow attack time) anywhere in our device. I
wonder if it might be introduced by some other ghost cooking the audio in
amoniak
[2009-05-06 00:54:23] <DocScrutinizer> to realy rely on these recordings we
had to verify all the involved components to ensure what is Freerunner and
what is recording equipment
[2009-05-06 00:55:40] <DocScrutinizer> anyway, I'm rather scared now, as I
never before heard such effects on OM devices
[2009-05-06 00:57:54] <DocScrutinizer> a standard "one two, one two, popp!
eeeek, pop, one two three" probably would help a lot to take out oddity of
finish language which nobody except lindi- knows how it should sound in
original.
[2009-05-06 00:58:30] <DocScrutinizer> an plain recording done by laptop
microphone and e.g. krecord would also help a lot, to compare
[2009-05-06 01:02:05] <DocScrutinizer> basics of noisegate: low volumes get
even lower, high volumes are boosted. the ramp up and ramp down is a
timeconstant that's much too long in the samples I heard, also the noisegate
effect is too strong (too much boost for loud words, low words a too much
attenuated)
[2009-05-06 01:04:05] <DocScrutinizer> now I suggest to c&p all this mumbling
of mine of he last 30min to some appropriate place in wiki or where-ever, and
I'll go to watch TV for a while
[2009-05-06 01:05:40] <tmzt> how much of this is caused by using an anolg link
from baseband to wm codec?
[2009-05-06 01:05:50] <tmzt> analog
[2009-05-06 01:06:06] <DocScrutinizer> there's no codec in wm
[2009-05-06 01:06:32] <DocScrutinizer> wm8753 is a mere audio mixer for
calypso
[2009-05-06 01:06:49] <tmzt> it doesn't have one or your not using it in this
design?
[2009-05-06 01:07:13] <DocScrutinizer> we are not using it, and it doesn't
have a GSM codec
[2009-05-06 01:07:24] <DocScrutinizer> it has a PCM codec
[2009-05-06 01:07:28] <tmzt> pcm codec
[2009-05-06 01:07:29] <DocScrutinizer> aka ADC
[2009-05-06 01:07:32] <tmzt> right
[2009-05-06 01:07:50] <tmzt> many phones use ssp or other pcm link
[2009-05-06 01:07:54] <DocScrutinizer> it's not used for gsmhandset.state
[2009-05-06 01:08:03] <tmzt> between baseband and codec
[2009-05-06 01:08:06] <DocScrutinizer> we use analog audio
[2009-05-06 01:08:24] <DocScrutinizer> our baseband does PCM as well
[2009-05-06 01:08:37] <DocScrutinizer> see schematics
[2009-05-06 01:08:40] <tmzt> which is what I'm asking, is this a major reason
for these problems?
[2009-05-06 01:08:48] <DocScrutinizer> nope
[2009-05-06 01:08:57] <tmzt> ok
[2009-05-06 01:09:57] <DocScrutinizer> calypso is the major problem (heard
this before? ;D )
[2009-05-06 01:10:41] <DocScrutinizer> ahh sorry. calypso == baseband
[2009-05-06 01:12:00] <DocScrutinizer> (for the 119 who might wonder what I'm
talking about)
[2009-05-06 01:12:08] <tmzt> how can volume in bp affect pcm though?
[2009-05-06 01:12:23] <DocScrutinizer> err, please rephrase
[2009-05-06 01:12:32] <DocScrutinizer> elaborate
[2009-05-06 01:12:43] <tmzt> the AT commands for setting volume
[2009-05-06 01:12:48] <DocScrutinizer> yup
[2009-05-06 01:13:10] <DocScrutinizer> these are for playback (earpiece)
mainly
[2009-05-06 01:13:10] <tmzt> since part of the solution seems to set that to
yhe highest setting
[2009-05-06 01:13:43] <DocScrutinizer> yup, as we got too low volume on
earpiece sometimes aka on some devices
[2009-05-06 01:14:19] <tmzt> earpiece isn't connected directly to bp though?
[2009-05-06 01:14:30] <DocScrutinizer> so we need decent level on WM8753
*input* so we can juggle with mixer settings
[2009-05-06 01:14:47] <DocScrutinizer> nope, is thru WM8753 as well as mic
[2009-05-06 01:15:59] <DocScrutinizer>
http://wiki.openmoko.org/wiki/Neo_1973_audio_subsystem#using_phone-internal_microphone_and_speaker
[2009-05-06 01:16:07] <DocScrutinizer> tho this is incorrect
[2009-05-06 01:16:51] <tmzt> I'm asking because the gta03 list said mc71 would
work the same way, with analog rather than pcm routing
[2009-05-06 01:17:04] <DocScrutinizer> this is correct one
[2009-05-06 01:17:07] <DocScrutinizer>
http://people.openmoko.org/joerg/ALSA/doc/WM8753_control_diag_gsmhandset_mic_std.png
[2009-05-06 01:17:28] <DocScrutinizer> mc75i, yup correct
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