From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=50311 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PGAcF-0004nF-Pk for qemu-devel@nongnu.org; Wed, 10 Nov 2010 08:21:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PGAcB-0005Kf-Op for qemu-devel@nongnu.org; Wed, 10 Nov 2010 08:21:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39677) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PGAcB-0005KQ-GJ for qemu-devel@nongnu.org; Wed, 10 Nov 2010 08:21:27 -0500 Message-ID: <4CDA9C52.9090308@redhat.com> Date: Wed, 10 Nov 2010 14:21:22 +0100 From: Gerd Hoffmann MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH] spice: add audio References: <20101109211021.45EC22A34D@zimbra14-e2.priv.proxad.net> <817F9C5B-1459-444F-9E4D-A06C7420CBC8@free.fr> <4CDA6A77.1050806@redhat.com> <20101110103611.GC11830@redhat.com> <4CDA83E0.1070704@redhat.com> <20101110115023.GM11830@redhat.com> In-Reply-To: <20101110115023.GM11830@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: =?ISO-8859-1?Q?Fran=E7ois_Revol?= , qemu-devel@nongnu.org On 11/10/10 12:50, Daniel P. Berrange wrote: > On Wed, Nov 10, 2010 at 12:37:04PM +0100, Gerd Hoffmann wrote: >> Do you know where the dropouts come from? > > Not entirely, it is still rather work in progress to debug it. > Part of the issues is that even QEMU + one of the standard > pulseaudio/alsa/sdl audio backends doesn't seem very reliable > to me, so I've not got a reliable benchmark to compare VNC > audio against. Well, on a standard fedora install alsa ends up being routed to pulseaudio anyway. Not sure what happens with SDL, I suspect it goes via alsa to pulseaudio too. So I've bothered with pulseaudio (and spice) only in my testing. Came up with these patches for pulseaudio: http://cgit.freedesktop.org/spice/qemu/log/?h=pulse These patches make pulseaudio work alot better for me. They are waiting to be reviewed by Fengguang right now. > Just testing with mpg123 in the guest, audio > will often simply stop after a few seconds of playback to the > host. Fedora 14 + rhythmbox works rock solid for me. Win7 + media player works too but has dropouts now and then, I think this is because win7 uses a very small dma buffer for the audio data. I don't see the sound stopping altogether. > Is there a particular audio device that is considered to work 'best' ? > I've been using ac97 mostly, but if your new ICH6 device is thought > to be significantly better I'll try that instead. Naturally I'm testing with the new intel-hda device ;) It has some advantages, for example it just got MSI support so it doesn't has to share the IRQ line with other devices (when the guest supports it). I think there is nothing which makes a major difference compared to ac97. I don't know ac97 that well though. cheers, Gerd