On Wed, Jan 04, 2006 at 03:12:33PM -0500, Kyle Moffett wrote:
> Software mixing in the kernel probably _IS_ FPU ops in the kernel.
> We already do video mixing (think X) in userspace, I see no reason
> why audio should be different.
Bad comparison. X as it is is so good that if you want something
remotely looking like performance you end up with a proprietary kernel
module the size of Cleveland.
Software mixing in practice could be in the kernel, it's for instance
way less complex than say the network stack. I mean, even with an
helper thread, it fits in 20-30 lines of kernel code or so. But what
happens is that you quickly want much more than that. To give you
some examples:
- resampling (with a wide array of algorithms with a different cpu
usage/result quality mix), especially since a number of chips are
48KHz only.
- AC3/DTS encoding for multichannel output on spdif.
- spatialisation (virtual or real, depending on the hardware
available).
- dynamic range compression.
So as soon as you build some decent infrastructure to allow for that
in userspace, having software mixing specifically in the kernel does
not make much sense.
I have 3 main problems with ALSA, but using userspace for flexibility
is definitively not one of them.
OG.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
