From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: I thought it would simple.... Date: Thu, 24 Jul 2003 15:48:08 +0200 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: <20030723110750.GA2492@alinoe.com> <20030724050325.3325.qmail@web21501.mail.yahoo.com> Mime-Version: 1.0 (generated by SEMI 1.14.4 - "Hosorogi") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <20030724050325.3325.qmail@web21501.mail.yahoo.com> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: tsw@johana.com Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Wed, 23 Jul 2003 22:03:25 -0700 (PDT), Tom Watson wrote: > > OK, here is more data. The enclosed files are: > 1) The "minimal playback program" described in the original message, > modified to clear the buffer, and do the "dump" of the parameters. The > buffer size is lengthened a bit (maybe this makes a difference??) in general, it'd better to specify proper period and buffer sizes in hw_params. (you can use *_near() for that purpose, too, in the case the hardware doesn't support the request size.) note that the configuration of buffer and period sizes is often sensitive to the card type. and they define the stability and the latency of the application. that's why many applications have options to set up these things. also, calling snd_pcm_prepare() is not necessary. it's called automatically after hw_params(). it's needed only after xrun/suspend occurs. many programs have the xrun recovery. in the playback direction, if a buffer underrun occurs, snd_pcm_writei() returns -EPIPE (and -ESTRPIPE if the suspend occurs). and ALSA drivers don't recover this status automatically as default. you need to call snd_pcm_prepare() to recover the status. so, Takashi ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01