From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Gruber Subject: Buffer underrun in a not empty playback buffer Date: Wed, 25 Jul 2012 08:33:05 +0200 Message-ID: <500F9321.30305@voiceinterconnect.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from dd14716.kasserver.com (dd14716.kasserver.com [85.13.136.34]) by alsa0.perex.cz (Postfix) with ESMTP id 500BE2652AF for ; Wed, 25 Jul 2012 08:29:06 +0200 (CEST) Received: from server-a.vic.site (146-52-60-185-dynip.superkabel.de [146.52.60.185]) by dd14716.kasserver.com (Postfix) with ESMTPSA id 0DCE566C23B for ; Wed, 25 Jul 2012 08:29:08 +0200 (CEST) Received: from kepler.vic.site ([192.168.13.149]) by server-a.vic.site with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1Stv5l-0000N0-3K for alsa-devel@alsa-project.org; Wed, 25 Jul 2012 08:29:07 +0200 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org I had a problem with an ALSA-driver, which causes an underrun in the playba= ck stream = before the playback buffer was completely empty (snd_pcm_avail() < playback= buffer size). = The driver developer told me, that this is correct, since for correct DMA t= ransfer a = minimum buffer filling level is required. Is this an allowed ALSA-driver behaviour or does the ALSA-driver developer = has to hide all = DMA internals to the application developer so that an underrun just occurs,= when the = playback buffer is empty? If yes, how can I get to know about the required = minimum buffer = filling level before an underrun occurs? Regards, Christian -- = --------------------------------------------------------------- Dipl.-Ing. Christian Gruber voiceINTERconnect GmbH Ammonstra=DFe 35 01067 Dresden Germany Tel.: +49 (0) 351 - 407 526 67 Fax.: +49 (0) 351 - 407 526 55 --------------------------------------------------------------- www.voiceinterconnect.de ... smart signal processing for electronic devices Gesch=E4ftsf=FChrung: Eingetragen im Handelsregister: Dr.-Ing. Diane Hirschfeld, Amtsgericht Dresden HRB 19466 Ludwig Linkenheil