Using media-libs/alsa-lib-1.0.11 with dmix and low bitrate, I'm getting issues (distorted and out of sync sound). This can be seen using a simple gstreamer pipeline: gst-launch-0.10 audiotestsrc ! audio/x-raw-int,rate=8000 ! alsasink There is a fix which solves those issues available here : http://hg.alsa-project.org/alsa-lib?cs=8c310c3277b7 A similar issue on debian using ekiga can be seen here : http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=367524 Portage 2.1_rc2-r2 (default-linux/x86/2006.0, gcc-3.4.6, glibc-2.4-r3, 2.6.15-gentoo-r5 i686) ================================================================= System uname: 2.6.15-gentoo-r5 i686 Intel(R) Pentium(R) M processor 1.86GHz Gentoo Base System version 1.12.0 dev-lang/python: 2.3.5, 2.4.3-r1 dev-python/pycrypto: 2.0.1-r5 dev-util/ccache: [Not Present] dev-util/confcache: [Not Present] sys-apps/sandbox: 1.2.18.1 sys-devel/autoconf: 2.13, 2.59-r7 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2 sys-devel/binutils: 2.16.1-r2 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.11-r5 ACCEPT_KEYWORDS="x86 ~x86" AUTOCLEAN="yes" CBUILD="i686-pc-linux-gnu" CFLAGS="-march=pentium-m -pipe -g2 -O2" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/X11/xkb" CONFIG_PROTECT_MASK="/etc/gconf /etc/revdep-rebuild /etc/terminfo /etc/texmf/web2c /etc/env.d" CXXFLAGS="-march=pentium-m -pipe -g2 -O2" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks metadata-transfer nostrip sandbox sfperms strict" GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo" PKGDIR="/usr/portage/packages" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude='/distfiles' --exclude='/local' --exclude='/packages'" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="x86 X a52 aac accessibility acpi adns alsa apache2 apm atm avahi avi bash-completion berkdb bitmap-fonts bzip2 cairo cdr clamav cli crypt cups daap dbus dhcp dri dts dv dvb dvd dvdr dvdread edl eds emacs emboss encode exif ffmpeg firefox flac foomaticdb fortran freetts gdbm gif glitz gnome gnutls gphoto2 gpm gstreamer gtk gtk2 gtkhtml hal ieee1394 imlib ipv6 isdnlog java joystick jpeg libclamav libg++ libwww lirc live mad matroska mikmod mmx mono motif mp3 mpeg musicbrainz nautilus ncurses network nfs nls nntp nptl nptlonly nsplugin ogg oggvorbis opengl oss pam pcmcia pcre pdf pdflib perl png pppd python quicktime readline real reflection samba sdl session silc snmp speex spell spl sse sse2 ssl svg tagwriting tcpd theora tiff truetype truetype-fonts type1-fonts udev unicode v4l vorbis win32codecs x264 xml xmms xorg xv xvid zlib elibc_glibc input_devices_evdev input_devices_joystick input_devices_keyboard input_devices_mouse input_devices_synaptics kernel_linux userland_GNU video_cards_fbdev video_cards_fglrx video_cards_ati video_cards_vesa video_cards_vga video_cards_v4l" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS, MAKEOPTS, PORTAGE_RSYNC_EXTRA_OPTS
I can confirm this bug, and believe the patch should be in our alsa packages.
Thanks Edward, thanks Zaheer, patch added to alsa-lib 1.0.11-r1.