From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Revell Subject: Re: emu10k1 latency / capture period Date: Thu, 17 Jun 2004 14:37:27 -0400 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <40D1E4E7.8000704@joe-job.com> References: <200406170906.i5H9604W013076@www1.pobox.sk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200406170906.i5H9604W013076@www1.pobox.sk> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Alsa-devel@lists.sourceforge.net Cc: pzad@pobox.sk List-Id: alsa-devel@alsa-project.org Peter Zubaj wrote: >Hi, > >I don't well understand ALSA concepts, but I think, that minimum >period size for emu10k1 is 384. > > True, it is actually 512 not 384. This still results in input to output latency that is 5-10x worse than using ASIO drivers on Windows. >Emu10k1 has actually 3 capture devices. >0 - standard capture, stereo 16 bit / 8000 - 48000 Hz >1 - mic capture - (implemented, not very used under ALSA) mono 16 bit >/ 8000 Hz >2 - fx capture - (implemented, not very used under ALSA) 1 - 32 >channels 16 bit / 48000 Hz > >All have same minimal period size, but 2 has 32 channels and then I >think it is better for low latency and multichannel recording. > > Yes, the kX ASIO drivers on Windows work this way, by mapping directly onto the (16 for SBLive, 32 for Audigy) FXBus channels. You cannot directly capture line or mic in, you have to connect it to an FXBus channel and then the signal is available on the corresponding ASIO device. I would imagine that to provide low latency in an ALSA driver it would work the same way. I am starting to reach the conclusion that this will require major changes to the guts of the emu10k1 ALSA driver. I would love it if some ALSA developer would correct me but so far my inquirues have met with deafening silence. To reiterate the situation: currently the ASIO drivers for this card provide an order of magnitude better latency than the ALSA driver. I am constantly hearing claims that ALSA is superior to ASIO, but no one can tell me why the ALSA drivers for this *very* common device provide 5-10x worse latency than the ASIO drivers. As I see it, this is a glaring deficiency. Lee >Peter Zubaj >====================== REKLAMA ======================== >Spolocnost SUN Microsystems uviedla na trh novy server Sun Fire V20z >zalozeny procesoroch AMD Opteron. >Viac informacii najdete na : http://www.somi.sk/sun/v20z.php >======================================================= > > > >------------------------------------------------------- >This SF.Net email is sponsored by The 2004 JavaOne(SM) Conference >Learn from the experts at JavaOne(SM), Sun's Worldwide Java Developer >Conference, June 28 - July 1 at the Moscone Center in San Francisco, CA >REGISTER AND SAVE! http://java.sun.com/javaone/sf Priority Code NWMGYKND >_______________________________________________ >Alsa-devel mailing list >Alsa-devel@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/alsa-devel > > > > ------------------------------------------------------- This SF.Net email is sponsored by The 2004 JavaOne(SM) Conference Learn from the experts at JavaOne(SM), Sun's Worldwide Java Developer Conference, June 28 - July 1 at the Moscone Center in San Francisco, CA REGISTER AND SAVE! http://java.sun.com/javaone/sf Priority Code NWMGYKND