From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Davis Subject: Re: I/O Error in mmapping ES 1969 Date: Fri, 10 Oct 2003 08:55:56 -0400 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <200310101255.h9ACturd017106@oud> References: <200310101427.43458.Safari.Doktor@addcom.de> Return-path: In-reply-to: Your message of "Fri, 10 Oct 2003 14:29:48 +0200." <200310101427.43458.Safari.Doktor@addcom.de> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: "Dr. med. =?iso-8859-15?q?G=FCnther?= Montag" Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org >I mentioned my ham radio realtime program with mmap >in a posting on 3. Oct and before. >It works now with ALSA 0.9.7 with AC97 and maybe some other cards, thanks!!! >With ESS ES1969 mmap(ibuf, isize, PROT_READ, MAP_FILE | MAP_SHARED | >MAP_FIXED, fd_audio, 0) >(and I tried also all other MAP_ options) it breaks with I / O error. >Do You know some help about mmap besides man, IIRC, mmap with OSS doesn't work unless you use the LD_PRELOAD hack. this loads a library that intercepts all standard system calls and routes them through alsa-lib. your app will not run without this. why? mmap provides direct access to the DMA buffer of the hardware, and thus bypasses most of what alsa-lib does. ALSA does support such direct access, but not in the simplistic way that OSS provides. or can I do something with "Scatter Gather" in ALSA API, >or does it help if i work myself into JACK for this problem? >hints welcome, tnx!!! either use ALSA natively, or use JACK, or use the LD_PRELOAD hack. ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. SourceForge.net hosts over 70,000 Open Source Projects. See the people who have HELPED US provide better services: Click here: http://sourceforge.net/supporters.php