From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Smietanowski Date: Fri, 06 Jan 2006 15:03:26 +0000 Subject: Re: [OT] ALSA userspace API complexity Message-Id: <43BE86BE.3010203@stesmi.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------enig9B277B93160D1B757F2CDE18" List-Id: References: <20050726150837.GT3160@stusta.de> <20060103193736.GG3831@stusta.de> <20060104030034.6b780485.zaitcev@redhat.com> <1136504460.847.91.camel@mindpipe> In-Reply-To: To: Hannu Savolainen Cc: Lee Revell , Takashi Iwai , linux-sound@vger.kernel.org, LKML This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig9B277B93160D1B757F2CDE18 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hannu Savolainen wrote: > On Thu, 5 Jan 2006, Lee Revell wrote: > > >>On Fri, 2006-01-06 at 01:06 +0200, Hannu Savolainen wrote: >> >>>We have not received any single bug report that is caused >>>by the concept of kernel mixing. >>>Kernel mixing is not rocket science. All you need to do is picking a >>>sample from the output buffers of each of the applications, sum them >>>together (with some volume scaling) and feed the result to the >>>physical >>>device. >> >>Hey, interesting, this is exactly what dmix does in userspace. And we >>have not seen any bug reports caused by the concept of userspace mixing >>(just implementation bugs like any piece of software). > > Having dmix working in user space doesn't prove that kernel level mixing > is evil. This was the original topic. Wasn't there a thread a few years ago (3-5?) about sound mixing in the kernel? I've tried searching for it but have been unsuccessful so I could be remembering wrong. I can't remember if it was about OSS, ALSA or anything else but I believe the conclusion was that sound mixing does NOT belong in the kernel and SHOULD be done in userspace. I have a faint memory of that being written by Alan Cox, but since it was a while ago I could very well be mistaken there (too?). // Stefan --------------enig9B277B93160D1B757F2CDE18 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFDvobBBrn2kJu9P78RAykCAKCiyP/4h/9Hfm32u234hOkDAQqRXACdHb0t wxf3EgLQpV+ZoI259URZcRU= =Gg3n -----END PGP SIGNATURE----- --------------enig9B277B93160D1B757F2CDE18--