**** BEGIN LOGGING AT Tue Oct 31 03:00:02 2017
Oct 31 19:30:29 <Pali> Hello, do you know if n900 supports line-in audio? And if it can be configured in Maemo?
Oct 31 19:41:37 <Pali> DocScrutinizer05: any idea?
Oct 31 19:56:02 <sicelo> Pali: out of the box, no.
Oct 31 19:58:43 <sicelo> if any of you somehow manage to implement it, i'm more than willing to be a tester. using old Nokia N-Gage for line-in needs on the go
Oct 31 20:06:28 <pkill9> is that line-in through the headphone port?
Oct 31 20:16:46 <sicelo> n-gage? yes. (actually n-gage and 5510(?) have two ports. one for headphone, and another for headset. the headphone port is also line-in, and records in AAC)
Oct 31 20:20:07 <pkill9> hi Pali, i use your kernel for now
Oct 31 20:20:54 <Maxdamantus> Presumably you could just wire something the right way to a TRRS plug to work as a "line in" adapter/cable/something
Oct 31 20:21:35 <Maxdamantus> Though I'm guessing the question is about using a tip and single ring as the left/right.
Oct 31 20:21:47 <sicelo> don't you need some internal circuitry though? with an ADC or something
Oct 31 20:23:06 <Maxdamantus> I wouldn't imagine so .. I would imagine headsets would just have a normal analogue microphone, though I don't really know much about headsets.
Oct 31 20:26:41 <Maxdamantus> I guess one main pitfall to just wiring it differently would be that you still wouldn't get two channels, since if it is just analogue as I'd've guessed, you'd only have one channel on the extra ring.
Oct 31 20:27:15 <Maxdamantus> (or sleeve,depending on which it uses)
Oct 31 20:27:46 <sicelo> i seem to doubt that's what he meant
Oct 31 20:29:16 <sicelo> i could be wrong, but i think he meant the same "line-in" you get on a sound card, as opposed to "mic-in"
Oct 31 20:32:41 <Pali> yes
Oct 31 20:36:25 <sicelo> i guess first stop is schematics - is there a chip supporting audio in? (i doubt)
Oct 31 21:20:46 <Maxdamantus> Hm, apparently line-in usually has higher impedence than a microphone input.
Oct 31 21:21:15 <Maxdamantus> other than that, and potentially some difference between mono/stereo .. would they really be any different in hardware?
Oct 31 21:21:34 <KotCzarny> yes
Oct 31 21:21:46 <KotCzarny> different voltage levels and other characteristics
Oct 31 21:29:39 <DocScrutinizer05> Pali: N900 has no line-in
Oct 31 21:30:31 <DocScrutinizer05> hw-limitation
Oct 31 21:31:17 <DocScrutinizer05> Pali: only microphone mono audio-in
Oct 31 21:31:27 <Pali> ok
Oct 31 21:32:01 <DocScrutinizer05> Neo900 has stereo line-in
Oct 31 21:46:12 <ff_> alsamixer -c0 shows DAC_L1 R1, DAC_L2 R2 and DAC_L3 R3. What's a difference between them?
Oct 31 21:46:58 <ff_> I can hear some diff with harmonic / equalizer / pan between L1 and L3. L3 is a little bit pleasant.
Oct 31 21:49:17 <ff_> Can N900 records audio from built in mic to left ch and from headset mic to right ch?
Oct 31 21:54:05 <DocScrutinizer05> good question. Should work
Oct 31 21:55:31 <ff_> only DAC L1 and L3 works, is it two different Digital Analog Converter or it's some kind of separate interial lines with the same DAC?
Oct 31 21:56:42 <DocScrutinizer05> ask the ALSA coders, they are notorious to not provide correct schematics-matching names for their controls
Oct 31 21:57:06 <ff_> I was trying this semi stereo record with gstreamer (two stream to one file) but dunno how to operate with left / right ch
Oct 31 21:57:51 <DocScrutinizer05> and digging through all sourcecode to find out which alsa control is linked to which hardware audio lines is tedious at best
Oct 31 21:58:28 <KotCzarny> if it was pure alsa, you could create virtual audio device with hybrid configs
Oct 31 21:58:41 <KotCzarny> but this is n900 owned by evilaudio, so who knows
Oct 31 21:59:04 <ff_> ok, it just curious, probably not worth of work
Oct 31 22:06:51 <ff_> Can alsa virtual audio device mix two stream (from build mic and headset mic) accordingly into left / right ch potentially?
Oct 31 22:06:59 <KotCzarny> yes
Oct 31 22:07:03 <KotCzarny> that's what i wrote
Oct 31 22:07:32 <KotCzarny> but i also wrote that it would require messing with evilaudio, which is not a good idea on n900
Oct 31 22:11:00 <ff_> it's new to me, thx for hint
Oct 31 22:15:58 <DocScrutinizer05> ff_: check ALSA data
Oct 31 22:20:05 <DocScrutinizer05> http://www.alsa-project.org/main/index.php/Main_Page  http://www.alsa-project.org/~jfulmer/alsa-faq.html  https://alsa.opensrc.org/Dsnoop  
Oct 31 22:21:52 <DocScrutinizer05> https://alsa.opensrc.org/PCM_device
Oct 31 22:22:28 <DocScrutinizer05> https://alsa.opensrc.org/Alsa-lib
Oct 31 22:49:28 <ff_> powered OTG works, it's unstable here, works around 5min and 'disconnect' but dmesg doesn't show disconnect keyboard
Oct 31 22:52:46 <ff_> maybe keyboard is a crap
Oct 31 22:54:43 <ff_> alsa virt dev need some time, go to sleep
**** ENDING LOGGING AT Wed Nov 01 03:00:01 2017