From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John L. Utz III" Subject: Re: Controling wave amplitude using alsa api !! (pcm interface ???????) Date: Tue, 04 Aug 2009 10:08:12 -0700 Message-ID: <4A786AFC.3030809@dmx.com> References: <4A7863EB.5090207@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dmxmusic.com (mail.dmxmusic.com [199.201.237.35]) by alsa0.perex.cz (Postfix) with ESMTP id 0DBA8244BD for ; Tue, 4 Aug 2009 19:08:25 +0200 (CEST) In-Reply-To: <4A7863EB.5090207@gmail.com> 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: Guilherme Longo Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Guilherme Longo wrote: > Hi all! > > Mates, I am following the example PCM.C that I found at alsa web site. > its a sine wave generator. > I am looking for a control that alsa provides to control the amplitude > of the wave. > > As I could found so for, there is just frequency control... I didn't > find any amplitude control. This line int pcm.c is not amplitude control? unsigned int maxval = (1 << (snd_pcm_format_width(format) - 1)) - 1; it's an int, so you probably need to alter this a bit to allow you to have arbitrary control over the amplitude (ie: multiply by a float less than 1.0) HTH johnu > * I don't want to control the volume using alsamixer or even my sound... > I want to generate a wave with predefined amplitude. > > Does anyone could give me a little help?? > > Thanks a lot! > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel >