Choppy sound (recording and playback)

Hello everyone,

I’m having a very strange problem here. I get choppy sound on record or playback, and this is new on my system !
Before we start, let me give you the specifics of my system :

  • Using Jack audio server
  • Using PlanetCCRMA RT kernel
  • Never experience Jack XRuns !

The symptoms look like it’s a Jack backend problem. I tried to change the latency, the sampling format of the files, nothing is good. I’m still having this choppy sound.

The last recording I made on this machine was in the exact same conditions, 10 days ago, and the sound is perfect !
The only thing that changed is a system update.

I’m running Fedora 19, so here is the YUM log. Maybe that could tell something :

Dec 20 11:53:40 Updated: libgcc-4.8.2-7.fc19.x86_64
Dec 20 11:53:40 Updated: libstdc++-4.8.2-7.fc19.x86_64
Dec 20 11:53:41 Updated: satyr-0.12-1.fc19.x86_64
Dec 20 11:53:42 Updated: 1:libreoffice-ure-4.1.3.2-12.fc19.x86_64
Dec 20 11:53:42 Updated: colord-libs-1.0.5-2.fc19.x86_64
Dec 20 11:53:42 Updated: libquadmath-4.8.2-7.fc19.x86_64
Dec 20 11:53:43 Updated: gnutls-3.1.17-2.fc19.x86_64
Dec 20 11:53:43 Updated: gnutls-dane-3.1.17-2.fc19.x86_64
Dec 20 11:53:43 Updated: libgfortran-4.8.2-7.fc19.x86_64
Dec 20 11:53:44 Updated: colord-1.0.5-2.fc19.x86_64
Dec 20 11:53:46 Updated: libstdc++-devel-4.8.2-7.fc19.x86_64
Dec 20 11:53:49 Updated: 1:qt-4.8.5-11.fc19.x86_64
Dec 20 11:53:49 Updated: libreport-filesystem-2.1.10-1.fc19.x86_64
Dec 20 11:53:49 Updated: libreport-python-2.1.10-1.fc19.x86_64
Dec 20 11:53:49 Updated: libreport-2.1.10-1.fc19.x86_64
Dec 20 11:53:49 Updated: abrt-libs-2.1.10-1.fc19.x86_64
Dec 20 11:53:49 Updated: libreport-web-2.1.10-1.fc19.x86_64
Dec 20 11:53:49 Updated: libreport-plugin-ureport-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-python-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-addon-python-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-addon-xorg-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-plugin-bodhi-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-dbus-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: libreport-plugin-bugzilla-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: libreport-plugin-kerneloops-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-addon-kerneloops-2.1.10-1.fc19.x86_64
Dec 20 11:53:50 Updated: abrt-addon-vmcore-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: abrt-addon-pstoreoops-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: libreport-plugin-reportuploader-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: libreport-gtk-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: abrt-gui-libs-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: abrt-gui-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: libreport-plugin-logger-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: libreport-fedora-2.1.10-1.fc19.x86_64
Dec 20 11:53:51 Updated: 1:autocorr-fr-4.1.3.2-12.fc19.noarch
Dec 20 11:53:52 Updated: 2:tar-1.26-28.fc19.x86_64
Dec 20 11:53:52 Updated: abrt-retrace-client-2.1.10-1.fc19.x86_64
Dec 20 11:53:52 Updated: abrt-addon-ccpp-2.1.10-1.fc19.x86_64
Dec 20 11:53:53 Updated: argyllcms-1.6.2-1.fc19.x86_64
Dec 20 11:53:53 Updated: pciutils-libs-3.2.1-1.fc19.x86_64
Dec 20 11:53:54 Updated: 1:autocorr-en-4.1.3.2-12.fc19.noarch
Dec 20 11:53:54 Updated: libgomp-4.8.2-7.fc19.x86_64
Dec 20 11:53:57 Updated: cpp-4.8.2-7.fc19.x86_64
Dec 20 11:54:03 Updated: gcc-4.8.2-7.fc19.x86_64
Dec 20 11:54:03 Updated: 1:libreoffice-opensymbol-fonts-4.1.3.2-12.fc19.noarch
Dec 20 11:54:47 Updated: 1:libreoffice-core-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:50 Updated: 1:libreoffice-writer-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:51 Updated: 1:libreoffice-pyuno-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:51 Updated: 1:libreoffice-graphicfilter-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:52 Updated: 1:libreoffice-draw-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:52 Updated: 1:libreoffice-pdfimport-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:52 Updated: 1:libreoffice-emailmerge-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:56 Updated: 1:libreoffice-calc-4.1.3.2-12.fc19.x86_64
Dec 20 11:54:57 Updated: 1:libreoffice-impress-4.1.3.2-12.fc19.x86_64
Dec 20 11:55:02 Updated: 1:libreoffice-langpack-fr-4.1.3.2-12.fc19.x86_64
Dec 20 11:55:03 Updated: 1:libreoffice-math-4.1.3.2-12.fc19.x86_64
Dec 20 11:55:06 Updated: gcc-c++-4.8.2-7.fc19.x86_64
Dec 20 11:55:06 Updated: pciutils-3.2.1-1.fc19.x86_64
Dec 20 11:55:09 Updated: gnome-color-manager-3.8.3-2.fc19.x86_64
Dec 20 11:55:09 Updated: abrt-desktop-2.1.10-1.fc19.x86_64
Dec 20 11:55:15 Updated: 1:qt-x11-4.8.5-11.fc19.x86_64
Dec 20 11:55:18 Updated: 1:numpy-1.7.1-7.fc19.x86_64
Dec 20 11:55:18 Updated: gnutls-utils-3.1.17-2.fc19.x86_64
Dec 20 11:55:22 Updated: llvm-libs-3.3-3.fc19.x86_64
Dec 20 11:55:23 Updated: highlight-3.16.1-1.fc19.x86_64
Dec 20 11:55:24 Updated: yum-3.4.3-122.fc19.noarch
Dec 20 11:55:24 Updated: libbluray-0.4.0-2.fc19.x86_64
Dec 20 11:55:24 Updated: SDL-1.2.15-12.fc19.x86_64
Dec 20 11:55:25 Updated: 1:wpa_supplicant-2.0-8.fc19.x86_64
Dec 20 11:55:25 Updated: libgcc-4.8.2-7.fc19.i686
Dec 20 11:55:25 Updated: libstdc++-4.8.2-7.fc19.i686
Dec 22 20:45:38 Updated: glibc-2.17-20.fc19.x86_64
Dec 22 20:45:57 Updated: glibc-common-2.17-20.fc19.x86_64
Dec 22 20:45:59 Updated: 1:libreoffice-ure-4.1.4.2-1.fc19.x86_64
Dec 22 20:45:59 Updated: cryptsetup-libs-1.6.3-1.fc19.x86_64
Dec 22 20:46:01 Updated: kernel-headers-3.12.5-200.fc19.x86_64
Dec 22 20:46:02 Updated: glibc-headers-2.17-20.fc19.x86_64
Dec 22 20:46:02 Updated: 1:autocorr-en-4.1.4.2-1.fc19.noarch
Dec 22 20:46:02 Updated: 1:libreoffice-opensymbol-fonts-4.1.4.2-1.fc19.noarch
Dec 22 20:46:47 Updated: 1:libreoffice-core-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:51 Updated: 1:libreoffice-writer-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:52 Updated: 1:libreoffice-pyuno-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:52 Updated: 1:libreoffice-graphicfilter-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:53 Updated: 1:libreoffice-draw-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:53 Updated: 1:libreoffice-pdfimport-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:53 Updated: 1:autocorr-fr-4.1.4.2-1.fc19.noarch
Dec 22 20:46:58 Updated: 1:libreoffice-langpack-fr-4.1.4.2-1.fc19.x86_64
Dec 22 20:46:58 Updated: 1:libreoffice-emailmerge-4.1.4.2-1.fc19.x86_64
Dec 22 20:47:02 Updated: 1:libreoffice-calc-4.1.4.2-1.fc19.x86_64
Dec 22 20:47:03 Updated: 1:libreoffice-impress-4.1.4.2-1.fc19.x86_64
Dec 22 20:47:04 Updated: 1:libreoffice-math-4.1.4.2-1.fc19.x86_64
Dec 22 20:47:05 Updated: glibc-devel-2.17-20.fc19.x86_64
Dec 22 20:47:05 Updated: cryptsetup-1.6.3-1.fc19.x86_64
Dec 22 20:47:06 Updated: sudo-1.8.6p7-2.fc19.x86_64
Dec 22 20:47:06 Updated: icedtea-web-1.4.1-1.fc19.x86_64
Dec 22 20:47:06 Updated: netpbm-10.61.02-7.fc19.x86_64
Dec 22 20:47:06 Updated: xorg-x11-drv-qxl-0.1.1-3.fc19.x86_64
Dec 22 20:47:10 Updated: ca-certificates-2013.1.95-1.fc19.noarch
Dec 22 20:47:29 Installed: kernel-3.12.5-200.fc19.x86_64
Dec 22 20:47:31 Installed: kernel-modules-extra-3.12.5-200.fc19.x86_64
Dec 22 20:47:34 Updated: glibc-2.17-20.fc19.i686
Dec 23 12:12:26 Updated: 1:openssl-libs-1.0.1e-36.fc19.x86_64
Dec 23 12:12:26 Updated: 1:openssl-1.0.1e-36.fc19.x86_64
Dec 23 12:12:28 Updated: 1:openssl-devel-1.0.1e-36.fc19.x86_64
Dec 23 12:12:28 Updated: iftop-1.0-0.6.pre2.fc19.x86_64
Dec 23 12:12:28 Updated: libisofs-1.3.4-1.fc19.x86_64
Dec 23 12:12:29 Updated: libburn-1.3.4-1.fc19.x86_64
Dec 23 12:12:30 Updated: libreswan-3.7-1.fc19.x86_64
Dec 23 21:03:06 Installed: opus-devel-1.1-1.fc19.x86_64

I really don’t know where to look. If anyone has an idea, it would be really welcome.

Thanks in advance.

Hoggins!

I just installed the lastest version from source, and the problem still occurs.
I wiped out the previous ardour configuration, just to see if anything I had previously changed could have affected its normal behaviour. No effect.

But I noticed something quite strange : even when idle (no playback, no recording), the transport timestamp jumps to another value for a few milliseconds, and returns back to its current value.

Could these curious time jumps be causing my troubles ? Am I near a black hole occasionnaly warping time around me ?

Interesting : when I enable monitoring, I also get these glitches in audio, in real time. That’s annoying, and that proves the responsibility of Ardour here, but I cannot find how it ended like that.

What a shame. I switched to Audacity, using PortAudio to connect to Jack (PortAudio is not known to be the most stable connector to Jack), and it works like a charm. No audible audio dropouts.
I feel sad because there is no comparison between Ardour and Audacity, in terms of performance and ease of use. If I could, I would stick to Ardour.
But hey. If it refuses to perform ok, I’ll let it down.

Did you try to boot with the old kernel?

Yes, of course. I tried with different versions of different kernel types. RT and “normal”. No luck.