From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Revell Subject: Re: Re: alsa driver, repeat playback of buffer contents Date: Mon, 14 Mar 2005 19:20:19 -0500 Message-ID: <1110846019.15588.28.camel@mindpipe> References: <200503141530.20339.random.bits@rogers.com> <1110836720.15088.3.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable In-Reply-To: Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: =?ISO-8859-1?Q?M=E5ns_Rullg=E5rd?= Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Mon, 2005-03-14 at 23:20 +0100, M=E5ns Rullg=E5rd wrote: > Lee Revell writes: >=20 > > On Mon, 2005-03-14 at 15:30 -0500, random.bits wrote: > >> I have been reading up on the alsa driver. I would like=20 > >> to have the alsa driver play a small pcm sound bite=20 > >> over and over without have to re-write it to the=20 > >> device. > >>=20 > >> By small, I mean 1.9K in length. I have followed the=20 > >> examples enough to get it to play the sound bite once,=20 > >> but I cannot figure out how to get it to play it=20 > >> multiple times without having to make another call to=20 > >> snd_pcm_writei() again. > > > > Why in the heck are you using write() instead of mmap()? >=20 > snd_pcm_writei() often uses mmap() behind the scenes. >=20 Right, but AFAICT mmap() should not call write() behind the scenes (unless you use the plug layer?). So if you want to be sure to avoid unnecessary copying you should just use mmap() directly. Or am I wrong? Anyway, the JACK ALSA driver always uses mmap() for example. Lee ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick