From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: Lowest latency: JACK, or ALSA directly? Date: Thu, 18 Nov 2004 13:38:33 +0100 Message-ID: References: <20041111144152.GA12443@stud.ntnu.no> <87mzxozahr.fsf@sulphur.joq.us> <20041112090416.GA3167@stud.ntnu.no> <87oei3xbly.fsf@sulphur.joq.us> <87k6srx9wi.fsf@sulphur.joq.us> <87oehwv0tc.fsf@sulphur.joq.us> <87d5ybvria.fsf@sulphur.joq.us> Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <87d5ybvria.fsf@sulphur.joq.us> 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: Jack O'Quin Cc: =?ISO-8859-1?Q?Asbj=F8rn_S=E6b=F8?= , alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At 17 Nov 2004 20:07:57 -0600, Jack O'Quin wrote: > > > Untested as usual :) > > I'll try it here with my Delta-66. > > That won't test any of the strange cases where -nperiods=2 but the > device actually requires a three-period buffer. Which cards do you > know of that are affected by this? rme32, rme96 and korg1212 have the fixed buffer size. ymfpci has 3 periods as minimum, too. > > (BTW, the jack code is still based on the older ALSA API. > > Is this intentional?) > > It was intentional last year so JACK would work with all ALSA > versions. A patch was recently submitted to use the newer interfaces. > The consensus on jackit-devel was that it is time to do that now, but > the patch has not yet been committed to CVS. > > (Patch follows for your review...) > > [2. text/x-patch; 2004-11-02.0.patch]... > @@ -620,19 +621,15 @@ (snip) > + err = snd_pcm_hw_params_get_period_size ( > + driver->playback_hw_params, &p_period_size, &dir); > + err = snd_pcm_hw_params_get_periods ( > + driver->playback_hw_params, &p_nfragments, &dir); > + err = snd_pcm_hw_params_get_format ( > + driver->playback_hw_params, &(driver->playback_sample_format)); > + snd_pcm_access_t access ; ^^^ the variable declaration should be moved in the beginning of the block. Otherwise it looks fine. You could check the return value of snd_pcm_hw_params_get_*, but it's usually ok. Takashi ------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8