From mboxrd@z Thu Jan 1 00:00:00 1970 From: sbenno@gardena.net Date: Thu, 05 Aug 1999 17:03:36 +0000 Subject: Re: MPEG Support Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org On Thu, 05 Aug 1999, Thomas Sailer wrote: > "Jonathan C. Masters" wrote: > > > > I have to disagree with you here. I believe that MPEG audio decoding/encoding > > and MPEG video decoding/encoding optional devices such as /dev/mpad /dev/mpae > > /dev/mpvd /dev/mpve would be emensely useful. It would save so much rewritten > > code (libraries are never quite as good as they sound) and my programs would > > Why should a library be worse than kernel code? > > Furthermore, in the kernel, you can't use: > - MMX > - Floating point > - KNI or ISSE or 3dNOW. Tom, could you please explain why we can't use these instructions in kernel mode ? I thougth that Linux don't use FP due to performance reasons, but not because it's not allowed. RT Linux seems to have some FP restrictions as well, but I think this is due to the fact that FP instructions could cause exceptions, which might ruin RT responsiveness by a few usecs. :-) > > So kernel code will be slower than usermode code. > > > instantaneously become much more enhanced. Besides, since MPEG decoding/encoding > > cards are popular these days, you begin to see the speed required (so much so > > Please name one that does MPEG _AUDIO_, I don't know one. (I know > about MPEG video cards...) Agreed, just provide a standard mpeg library with a well defined API , that every audio app can use easily. > > Tom Benno.