From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emmanuel Milou Subject: Plugin default and sw_params Date: Wed, 26 Mar 2008 09:38:49 -0400 Message-ID: <47EA51E9.6070007@savoirfairelinux.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from xenon.savoirfairelinux.net (unknown [199.243.85.90]) by alsa0.perex.cz (Postfix) with ESMTP id F03C224474 for ; Wed, 26 Mar 2008 14:38:17 +0100 (CET) Received: from [192.168.1.216] (dyn216.inside.savoirfairelinux.net [192.168.1.216]) by xenon.savoirfairelinux.net (Postfix) with ESMTP id 557D4F68CC for ; Wed, 26 Mar 2008 09:38:16 -0400 (EDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi all, I have some questions about the /default/ plugin. I am developping a softphone based on ALSA on Ubuntu 7.10. I use read/write IO. When I open a device with the /plughw /plugin, quite everything works fine, the quality sound is good. But with the /default/ plugin or the /dmix/ plugin ( the user can choose one of them ), I can't set my own hw parameters or sw parameters. Actually I set my own value of period size, buffer size, start threshold, stop threshold, but when I check in /proc/asound/cardx/pcm0p/sub0/sw_params or /proc/asound/cardx/pcm0p/sub0/hw_params, the values are totally different. For instance, the start threshold is set to 1 even if I set it to period_size. As a result, I get crackling sound. I suspect this is due to buffer underrun. Maybe if I could change the start threshold or the period size, the sound would be better. So my question: is it possible to modify this values for /default/ plugin without changing the alsa config file ( asoundrc ) ? Thank you very much Manu