Bug#600256: ardour-i686: Loud, painful clicking noises immediately after export

Fri Oct 15 05:27:23 UTC 2010

Package: ardour-i686
Version: 1:2.8.11-3
Severity: important

Whenever I go to export an Ardour session with a significant number of LADSPA
plugins to an audio file, I hear a loud, repetitive clicking noise that
persists until I close Ardour. Playback does start when this noise is present,
but proceeds too slowly to produce any sound, and the clicking continues
during and after playback.

It doesn't happen if I have no LADSPA plugins in the session, but it does not
appear to be traceable to a particular plugin or a particular session; it
happens consistently wherever more than a few plugins are involved.

The noise is definitely coming from the master bus, as disconnecting this from
my system playback ports in qjackctl causes the noise to stop. However, the
level meter for the master bus does not show any sound output, and the source
of the noise is definitely _after_ the LADSPA chain, as adding a simple
amplifier plugin to the end of it does not affect the volume of the noise.

Muting the master bus causes the noise to go away, but it comes back after
unmuting it. Soloing the master bus causes the frequency of the clicks to
increase. Moving the pan controls has no effect unless they are both hard to
one side, in which case the noise comes only from that channel. Bypassing a
LADSPA plugin on the master bus causes a slight increase in click frequency,
but not as much as soloing the master bus does.

Some background system info:
JACK version: jackd1 1:0.118+svn3796-7
Sound driver: oss4-dkms 4.2-build2003-1

JACK command line (called via qjackctl):
/usr/bin/nice -n -19 /usr/bin/jackd -Z -t5000 -doss -r96000 -p1024 -n2 -w16 -P/dev/dsp -i0

Here is the full output of the ardour2 command for a typical session when
this happens:

--- BEGIN ARDOUR OUTPUT ---

Ardour 2.8.11
   (built using 7387 and GCC version 4.4.5)
Copyright (C) 1999-2008 Paul Davis
Some portions Copyright (C) Steve Harris, Ari Johnson, Brett Viren, Joel Baker

Ardour comes with ABSOLUTELY NO WARRANTY
not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
This is free software, and you are welcome to redistribute it 
under certain conditions; see the source for copying conditions.
loading default ui configuration file /etc/ardour2/ardour2_ui_default.conf
loading user ui configuration file /home/parsifal/.ardour2/ardour2_ui.conf
Loading ui configuration file /etc/ardour2/ardour2_ui_dark.rc
theme_init() called from internal clearlooks engine
ardour: [INFO]: Ardour will be limited to 1024 open files
loading system configuration file /etc/ardour2/ardour_system.rc
loading user configuration file /home/parsifal/.ardour2/ardour.rc
ALSA lib seq_hw.c:457:(snd_seq_hw_open) open /dev/snd/seq failed: No such file or directory
ardour: [WARNING]: The ALSA MIDI system is not available. No ports based on it will be created
ardour: [WARNING]: No MMC control (MIDI port "default" not available)
ardour: [INFO]: No H/W specific optimizations in use
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
librdf warning - Model does not support contexts
ardour: [INFO]: looking for control protocols in /home/parsifal/.ardour2/surfaces/:/usr/lib/ardour2/surfaces/
ardour: [INFO]: Control protocol Tranzport not usable
ardour: [INFO]: Control surface protocol discovered: "Generic MIDI"
powermate: Opening of powermate failed - No such file or directory
ardour: [INFO]: Control protocol powermate not usable
ardour: [INFO]: Mackie: No MIDI port called mcu
ardour: [INFO]: Control protocol Mackie not usable
loading bindings from /etc/ardour2/mnemonic-us.bindings

(ardour-2.8.11:22387): Gtk-WARNING **: EnableTranslation: missing action EnableTranslation
Session writable based on /media/disk/ardour/20091102-messing_around/
Start export at pos = 2842782
Everybdy is at 2842782
	Export ... not running or at end, no_roll() for 1024

--- END ARDOUR OUTPUT ---

The very last line corresponds to the start of the clicking sounds. As you can
see, there is no more output after this.

-- System Information:
Debian Release: squeeze/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)

Kernel: Linux 2.6.32.21-libre1-20100918 (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages ardour-i686 depends on:
ii  jackd                  5                 JACK Audio Connection Kit (default
ii  libart-2.0-2           2.3.21-1          Library of functions for 2D graphi
ii  libasound2             1.0.23-2          shared library for ALSA applicatio
ii  libatk1.0-0            1.30.0-1          The ATK accessibility toolkit
ii  libaubio2              0.3.2-4+b2        a library for audio segmentation
ii  libc6                  2.11.2-6          Embedded GNU C Library: Shared lib
ii  libcairo2              1.8.10-6          The Cairo 2D vector graphics libra
ii  libcairomm-1.0-1       1.8.4-3           C++ wrappers for Cairo (shared lib
ii  libcurl3-gnutls        7.21.0-1          Multi-protocol file transfer libra
ii  libfftw3-3             3.2.2-1           library for computing Fast Fourier
ii  libfontconfig1         2.8.0-2.1         generic font configuration library
ii  libfreetype6           2.4.2-1           FreeType 2 font engine, shared lib
ii  libgcc1                1:4.4.5-2         GCC support library
ii  libglib2.0-0           2.24.2-1          The GLib library of C routines
ii  libglibmm-2.4-1c2a     2.24.2-1          C++ wrapper for the GLib toolkit (
ii  libgnomecanvas2-0      2.30.1-1          A powerful object-oriented display
ii  libgnomecanvasmm-2.6-1 2.26.0-1          C++ wrappers for libgnomecanvas2 (
ii  libgtk2.0-0            2.20.1-1+b1       The GTK+ graphical user interface 
ii  libgtkmm-2.4-1c2a      1:2.20.3-1        C++ wrappers for GTK+ (shared libr
ii  libjack0 [libjack-0.11 1:0.118+svn3796-7 JACK Audio Connection Kit (librari
ii  liblo7                 0.26~repack-5     Lightweight OSC library
ii  liblrdf0               0.4.0-3           a library to manipulate RDF files 
ii  libpango1.0-0          1.28.1-1          Layout and rendering of internatio
ii  libpangomm-1.4-1       2.26.2-1          C++ Wrapper for pango (shared libr
ii  libraptor1             1.4.21-2          Raptor RDF parser and serializer l
ii  librasqal2             0.9.20-1          Rasqal RDF query library
ii  librdf0                1.0.10-3          Redland Resource Description Frame
ii  libsamplerate0         0.1.7-3           Audio sample rate conversion libra
ii  libsigc++-2.0-0c2a     2.2.4.2-1         type-safe Signal Framework for C++
ii  libslv2-9              0.6.6-5           A library for simple use of LV2 pl
ii  libsndfile1            1.0.21-3          Library for reading/writing audio 
ii  libstdc++6             4.4.5-2           The GNU Standard C++ Library v3
ii  libusb-0.1-4           2:0.1.12-16       userspace USB programming library
ii  libvamp-hostsdk3       2.1-1             helper library for Vamp hosts writ
ii  libvamp-sdk2           2.1-1             helper library for Vamp plugins wr
ii  libxml2                2.7.7.dfsg-4      GNOME XML library
ii  libxslt1.1             1.1.26-6          XSLT 1.0 processing library - runt
ii  python                 2.6.6-3           interactive high-level object-orie
ii  python-gtk2            2.17.0-4          Python bindings for the GTK+ widge
ii  python-twisted         10.1.0-3          Event-based framework for internet

Versions of packages ardour-i686 recommends:
ii  iceweasel [www-browser]       3.5.13-1   Web browser based on Firefox
ii  w3m [www-browser]             0.5.2-9    WWW browsable pager with excellent

ardour-i686 suggests no packages.

-- debconf-show failed