From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?Ville_Syrj=E4l=E4?= Subject: Re: GUS Classic driver, PLUGHW problems Date: Thu, 10 Jul 2003 00:17:33 +0300 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <20030710001733.A13484@sci.fi> References: <20030704091249.GA1692@catfish.dhs.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20030704091249.GA1692@catfish.dhs.org>; from jlunder@catfish.dhs.org on Fri, Jul 04, 2003 at 02:12:49AM -0700 Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Fri, Jul 04, 2003 at 02:12:49AM -0700, Joseph Lunderville wrote: > I'm trying to get a 486 with a GUS Classic working through ALSA, and I'= ve > run into a couple of problems: >=20 >=20 > 1. plughw doesn't know how to convert from interleaved data to > noninterleaved data. in fact, as far as I can see, nothing at all excep= t the > GUS driver knows what to do with noninterleaved data. I ran into this problem with my GUS PnP some time ago. You should be able to find the discussion from alsa-devel archives. Apparently the conversion works for some other non-interleaved cards like RME Hammerfall. The GUS driver doesn't support mmap which may cause problems but even using alsa-lib's mmap emulation didn't fix the problem for me :( > I imagine that the only > reason this hasn't been fixed yet is that nobody wants to use a GUS wit= h > ALSA :) I will resurrect my GUS PnP when (if?) MIDI emulation gets implemented... > 2. the GUS driver seems to have a problem with outputting PCM data. I h= ad to > test it using my own code (since the example uses interleaved data), bu= t I'm > reasonably confident that the problem's in the driver. >=20 > the problem I'm observing is that there are frequent clicks in the audi= o > output (coincidentally, they arrive at a frequency corresponding exactl= y to > the size of the ring buffer -- I've confirmed this by looking at the ou= tput > on an oscilloscope. the click looks like one or two samples are being > skipped). this is when I use a buffer size that's a multiple of my peri= od > size -- when I use other combinations of buffer size and period size, t= hings > get worse. some combinations of buffer & period size cause I/O errors. >=20 > 3. finally, the example doesn't start the audio output. it's difficult = for > me to tell whether you're supposed to call snd_pcm_start() in order to = get > output from the speakers (in which case the example is wrong), or wheth= er > the gus driver requires this when it's not supposed to, but either way > something's not right. I don't remember seeing this with my GUS PnP but then again I mostly used the codec instead of the synth for PCM. Also GUS PnP doesn't have the channel count vs. frequency limitation of the original GUS. I have a GUS MAX buried somewhere but I don't think I've tried it with ALSA. --=20 Ville Syrj=E4l=E4 syrjala@sci.fi http://www.sci.fi/~syrjala/ ------------------------------------------------------- This SF.Net email sponsored by: Parasoft Error proof Web apps, automate testing & more. Download & eval WebKing and get a free book. www.parasoft.com/bulletproofapps