Messages in this thread | | | Date | Sun, 8 Jan 2006 14:32:40 +0100 (CET) | From | Jaroslav Kysela <> | Subject | Re: [OT] ALSA userspace API complexity |
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On Sun, 8 Jan 2006, Olivier Galibert wrote:
> On Sun, Jan 08, 2006 at 03:26:18AM +0100, Martin Drab wrote: > > On Sun, 8 Jan 2006, Olivier Galibert wrote: > > > > > > And if the application doesn't support, who and where converts it? > > > > With OSS API, it's a job of the kernel. > > > > > > Once again no. Nothing prevents the kernel to forward the data to > > > userland daemons depending on a userspace-uploaded configuration. > > > > I think that the point was, that switching from userspace to kernelspace > > then to userspace again and back to kernelspace in order to do something, > > that could have been done directly in the userspace, and though could save > > those two unnecessary switches, is an unnecessary overhead, which may not > > necessarily be that insignificant if it's done so often (which for > > streaming audio is the case). > > You all seem to forget that dmix is in userspace in a different task > too.
Because it is really not. The mixing is done directly to the mmaped DMA buffer.
> > Why doing things complicated when there is no evident gain from it, > > or is there? > > No evident gain? Wow. What about: > - stopping crippling the OSS api
We're not doing that. We're just showing that OSS API and useability has it's own problems, too.
> - having a real kernel api for which you can make different libraries > depending on the need of the users > > - stop making a fundamentally unsecure shared library mandatory
ALSA kernel API is real and binary compatible. If someone require to write an own library, we will document this API, of course, too.
> - opening the possibility of writing plugins to people without a PhD > in lattice QCD.
Already done. We have official plugin SDK in alsa-lib to create user space drivers. If you have some questions or bug-reports (missing docs etc), please, fill a bug report.
Also, you can use very simple LADSPA plugin style, because alsa-lib can use LADSPA plugins directly, too.
Jaroslav
----- Jaroslav Kysela <perex@suse.cz> Linux Kernel Sound Maintainer ALSA Project, SUSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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