[Solved] Skype trashes my voice

n2liquid · n00b Joined: 24 Mar 2011 Posts: 6

Hey,

I'm needing do use Skype here on my Gentoo installation, but when I test it through the Echo Service I just get noise back. It sort of resembles what I said, but is simply trashed gutural-like noise. What should I do?

I'm using a Realtek AC97 sound card. I've adjusted alsamixer so that audio capture is enabled. Changing input sources make no difference. I have to select HDA Intel, ALC888 Analog (hw:0,2) since none other work (they record nothing instead of noises). If I unmute microphone playback on the mixer my sound card echoes everything I say perfectly through the speakers, so it's probably a Skype problem.

I'm at a complete loss. What should I do?

-- edit

Further info:

BradN · Posted: Thu Mar 31, 2011 11:38 pm Post subject:

Try testing with arecord (alsa command line record utility) and see if it's garbled there too. If it is, it's probably an ALSA (either kernel driver or userspace library) bug. If it does work there, it may be a format conversion problem for whatever format skype wants to use, but this seems unlikely because skype is pretty widely used and a problem like that would probably be noticed quickly.

If you try older kernel versions and find a version that it does work properly with, then it's considered a regression (ie, worked before but some change broke it). There's a way to trace where a problem like this got introduced, but not worth explaining unless you find an older kernel it worked with.

Of course, you can always try a newer kernel and alsa library if available - it might be a recently fixed bug.

virtguru · Posted: Fri Apr 01, 2011 5:02 pm Post subject:

Are you running pulseaudio ? Also off the top of my head do you have auto adjust mixer levels in skype ?

what type of mic are you using ? Webcam mic ? Also you have all the needed intel HD Audio modules and correct webcam set in your kernel .config ?

*edit* what also helped here was adding and recompiling stuff with "v4l2" in my make.conf (depending on webcam might be you need v4l)

n2liquid · n00b Joined: 24 Mar 2011 Posts: 6

Yeah, cool. So I discovered what was the problem. ALSA is not detecting the sound format of my microphone. If I use arecord with the -f dat option (Signed 16 bit Little Endian, Rate 48000 Hz, Stereo) it saves my file perfectly. But the default option is "Signed 8 bit, Rate 8000 Hz, Mono", which saves gibberish.

How should I configure ALSA so that it defaults to the correct format?

@BradN
Many thanks for the arecord tip. I was looking for something like that but didn't find it.

@tr0ll
Nope, I'm not running PulseAudio, just ALSA (I read somewhere I should avoid PulseAudio, I dunno why). My microphone is a generic microphone, separate from the webcam (in fact, I don't have a webcam). I just have to get ALSA to properly recognize my soundcards' input format, but thanks for the tips, too!

-- edit

Oh, boy, I just noticed my kernel wasn't compiled with Realtek's *ANALOG* HD-audio codec support, only HD-audio codec support (supposedly SP/DIF). I just wonder why sound output was working without this..?

I'll recompile it and see if it works. I'll post back with news.

ferreirafm · Posted: Fri Apr 01, 2011 6:57 pm Post subject:

Hi n2liquid,
If you can record something with arecord, you shoud be all done with skype. The skype defaults settings work fine for me.
Play with the alsamix or kmix channels in order to adjust the "mic" and "digital" channels level.
I hope it helps.
ferreirafm

n2liquid · n00b Joined: 24 Mar 2011 Posts: 6

Hah, managed to work it out. The problem was this: [menuconfig screenshot] (ps.: doesn't this forum support images? That's.. a pity.)

When I compiled my kernel I quickly found the first option and marked it. I didn't notice the second one since the first one seemed like what I needed. I think the first one is for the digital interfaces, but I don't understand why analog sound output was working even though I didn't mark the second one. I find this quite misleading.. maybe that could be patched on Gentoo?

@ferreirafm
I couldn't record with arecord's default settings too. I had to select the correct format myself. Skype used "the defaults" too, which caused my problem. But as you can see above, all that was missing was my analog codec. Now everything works.

Thanks, everybody!