[SOLVED] Skype recording is too fast ("chipmunk" voice)

thurse93 · 2014-03-06 23:23:55

Hi forum!

Two days ago I updated my system, including the 3.13.5-1 kernel and 5.0-1 pulseaudio. When I'm using skype now, my voice gets distorted and played back much faster; "chipmunk"-style. According to https://wiki.archlinux.org/index.php/PulseAudio I tried everything to solve the issue (setting default rates in the config file, disable usb-autosuspend, ...) but still no luck...

https://bbs.archlinux.org/viewtopic.php?id=121607 had a simliar problem but it seemed to appear system-wide, was fixed with kernel 3.1. and mainly Logitech webcams were affected. I used one of them when it occured first, but my old headset produces exactly the same output.

pulseaudio-log during a skype test-call: http://pastebin.com/2U7Wi8g4

What should I try next?

Last edited by thurse93 (2014-03-08 16:04:44)

emeres · 2014-03-07 12:14:59

This usually comes down to different sample rates or other time[r] related issues. I would check if every device on your system has same sample rates, this is not restricted to playback devices. Usually there are no problems if conversions between sample rates and formats are done correctly, but if you force a recording of 22 kHz to play at 48 kHz it will be accelerated, "chipmunk style" (back then magnetic tapes were played back at higher speeds than recordings, that is how chipmunk voices were created). Skype might be recording at 44,1 kHz (or lower) and PA seems to run at 48 kHz.
Downgrading PA as last resort might fix it, however if more users are concerned, upstream should know about it. This probably is not related to kernel, since it does not occur system wide. If you kill PA and try to record directly through alsa and play it back, does the distortion also occur? Have you also tried those steps, what sample rates did you set so far?

thurse93 · 2014-03-07 19:04:35

Thanks for your explanation .
The ALSA hint narrows the problem; recording through it with skype and the issue doesn't show up. I have tried those steps and retried them now.. and it seems that pulseaudio doesn't read it's new uncommened entry (default-sample-rate = 48000) but still tries to record at 44,1 kHz if I'm not missinterpreting this one (I'm not sure about the data because my mic is mono.. don't know nothing about the sound structure in Linux):

arecord -f cd -d 10 test-mic.wav
Recording WAVE 'test-mic.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

There's no overwriting daemon.conf in ~/.config/pulse whatsoever, so I don't know why pulseaudio doesn't take the new framerate and sticks to 44,1k.

What I want to outline again is that the problem is skype-related only. Without any configuration I could perfectly record myself via arecord.

Ouh and what i completely forgot to mention is that im running an x64-system!! But other 32-bit-programs like wine don't have the issue (although I didn't test out running skype in wine yet).

emeres · 2014-03-07 21:45:36

Do you have lib32-libpulse and lib32-speex installed? Your logs indicate speex is used for resampling. You might want run Skype with ldd or strace and look for any missing libraries/dependencies/calls. Skype probably has set/hardcoded the recording sample rate or it is unable to record at other frequencies, because of (internal) driver, missing libraries or some other issues. I do not use Skype any more, because of moral objections, but if I recall correctly there should be more "advanced" settings for recording devices, that may have changed though. Your best bet is to set PA to Skypes frequency, which might be as low as 16 kHz, but that does not seem to be supported by your hardware (PA logs).

So to summarize, I would argue PA is working at 48 kHz but Skype is recording at lower sample rate even though the device itself might work at 48 kHz. If you are positive that this is your scenario and you do not see any possibility to reconfigure Skype, write to them about it.

And if you are feeling lucky and nothing else works, hexedit Skypes binary and look/replace [for] typical sample rate values {16, 22,05, 32, 44,1, 48} kHz.

V1del · 2014-03-08 13:46:50

Edit your /usr/bin/skype script with an editor with root rights and remove the PULSE_LATENCY_MSEC=30 which arguably has been obsoleted with the recent skype update. This fixes the chipmunk, but leaves an obnoxious static on my speakers AFTER the call because skype is too stupid to properly kill its stream, will see if I can experiment some more

EDIT: The obnoxious static seems to have been a temporary woe, after a few retries it works properly. Note there may be still some static with notification and chat sounds etc. You could also crank the PULSE_LATENCY_MSEC to 60 which adds quite a bit of latency but will remove most (all?) static noise (and is also the recommended value since it became necessary http://arunraghavan.net/2013/08/pulseau … and-skype/ )

Last edited by V1del (2014-03-08 14:28:05)

thurse93 · 2014-03-08 16:04:19

Removing PULSE_LATENCY_MSEC=30 was the solution, thanks . The static noise problem didn't occur in my setup, but i will consider your link if it appears.

Thank you two for your reliable help!

adrianx · 2014-03-08 16:27:40

Thanks V1del, you are a saint!

I wish I could convince my "contacts" to stop using Skype, but that will never happen.

mangus · 2014-03-08 18:24:01

OHHH nice , I was struggling with this all day! thank you. I migrated from alsa to pulsaudio just yesterday night to find this , and i was blaming pulsaudio.... lot of
flame involved , lol. It was just this. Bad timing in revamping my audio, thank you.

V1del · 2014-03-09 20:36:10

For anyone interested the static returned but the cause is probably because i run notification sounds on my speakers as opposed to my headset and skype probably tries some internal resample and gehts all confused when the value differs from what it expects and with msec=60 i just give it a big enough window so that it doesn't mess up

Siderant: Bashing pulseaudio was cool 5 years ago if you still have problems like these chances that they really lie with pulse are slim and i'd be especially sceptical if the only program that gives problems is a buggy POS skype

Last edited by V1del (2014-03-09 20:37:11)

cmtonkinson · 2014-03-11 10:48:40

Added a relevant troubleshooting section to the Wiki page for Skype: https://wiki.archlinux.org/index.php/Sk … g_in_Skype

V1del · 2014-03-11 18:34:01

@cmtonkinson thanks for that, I was considering opening a bug or editing the wiki but was a bit busy and went on vacation now so i'm not gonna touch anything arch related for a week

Arch Linux

#1 2014-03-06 23:23:55

[SOLVED] Skype recording is too fast ("chipmunk" voice)

#2 2014-03-07 12:14:59

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#3 2014-03-07 19:04:35

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#4 2014-03-07 21:45:36

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#5 2014-03-08 13:46:50

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#6 2014-03-08 16:04:19

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#7 2014-03-08 16:27:40

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#8 2014-03-08 18:24:01

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#9 2014-03-09 20:36:10

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#10 2014-03-11 10:48:40

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

#11 2014-03-11 18:34:01

Re: [SOLVED] Skype recording is too fast ("chipmunk" voice)

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