From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davy Durham Subject: buffers, periods, cycles.. oh my! Date: Sat, 28 Aug 2004 00:46:40 -0500 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <41301C40.10609@davyandbeth.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org Hi, Something I don't seem to grasp is exactly what the difference is between, and min/max ranges of, periods and buffers. I know that a sound card uses a buffer to which it reads/writes data (via DMA) and that an interrupt can be configured to trigger n times during that buffer's filling (these are periods and period count?) Well, then there's API functions for buffer time and sizes (I assume you can set by time OR by size in frames, whichever you please, but you don't need to set by both). I've looked but to no avail.. is there some higher level documentation that explains the big picture here? When I fist started using the API I had a 1/4 second latency or so for playback.. I tried and tried to figure out why but couldn't. Finally I coped JACKs use of the lib and eliminated that. Now, I'm working on capture, but I can't seem to set the buffering time to more than 2*8192 frames. I'd like to set it as high as possible to avoid studders in the recording and would rather not buffer the data myself if ALSA can already do that. Thanks, Davy ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click