On Mon, Mar 28, 2016 at 10:37:57PM -0400, [email protected] wrote
> I'm involved in beta testing Gstreamer 1.x support for HTML5 under
> Pale Moon (a Firefox fork). So far so good; it works. I use a QEMU VM
> for some building and testing. Things work great on a real physical
> machine, but audio absolutely sucks in the QEMU VM. I get an annoying
> warble-stutter and the playback seems a bit slower than it should be.
> The same thing also happens with mplayer playing a .wav file, so it's
> definitely not a Pale Moon browser problem.
>
> The VM gets 3 gigs of RAM (host has 8), 4 gigs of swap space, and 3 of
> the host's 4 cores. Resources should not be a problem. Has anybody got
> better performance? If so, what are your kernel and sound card settings?
The problem appears to be the "sdl" flag. It slows down things by
adding one more layer of middleware and overhead. I also got rid of the
"gtk2" flag, for the same reason. By building QEMU with "-sdl" and
"-gtk2", I get playback that is indistinguishable from playback on the
host. Here is the build that works properly "emerge -pv qemu"...
[ebuild R ] app-emulation/qemu-2.5.0-r1::gentoo USE="aio alsa curl
fdt gtk jpeg ncurses opengl pin-upstream-blobs png snappy ssh threads
usb vhost-net vnc -accessibility -bluetooth -caps -debug -filecaps
(-glusterfs) -gnutls -gtk2 -infiniband -iscsi -lzo -nfs -nls -numa
-pulseaudio -python -rbd -sasl -sdl -sdl2 -seccomp (-selinux) -smartcard
-spice -static -static-softmmu -static-user -systemtap -tci {-test}
-usbredir -uuid -vde -virgl -virtfs -vte -xattr -xen -xfs"
PYTHON_TARGETS="python2_7" QEMU_SOFTMMU_TARGETS="i386 x86_64 -aarch64
-alpha -arm -cris -lm32 -m68k -microblaze -microblazeel -mips -mips64
-mips64el -mipsel -moxie -or32 -ppc -ppc64 -ppcemb -s390x -sh4 -sh4eb
-sparc -sparc64 -tricore -unicore32 -xtensa -xtensaeb"
QEMU_USER_TARGETS="i386 x86_64 -aarch64 -alpha -arm -armeb -cris -m68k
-microblaze -microblazeel -mips -mips64 -mips64el -mipsel -mipsn32
-mipsn32el -or32 -ppc -ppc64 -ppc64abi32 -ppc64le -s390x -sh4 -sh4eb
-sparc -sparc32plus -sparc64 -tilegx -unicore32"
--
Walter Dnes <[email protected]>
I don't run "desktop environments"; I run useful applications
