From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: Maintaining sound card at a specific frequency Date: Tue, 18 Jan 2005 20:51:48 +0100 Message-ID: References: <1105938846.41eb499ec3527@www3.webhosting.cx> <5bdc1c8b05011809454b58899c@mail.gmail.com> Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <5bdc1c8b05011809454b58899c@mail.gmail.com> 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: Mark Knecht Cc: Giuliano Pochini , alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Tue, 18 Jan 2005 09:45:41 -0800, Mark Knecht wrote: > > On Tue, 18 Jan 2005 18:31:28 +0100 (CET), Giuliano Pochini > wrote: > > > > > > On Tue, 18 Jan 2005, Takashi Iwai wrote: > > > > > > IMHO we should think on a good solution for this problem. Some > > > > cards have many channels/voices but the sample rate is common > > > > for all of them. Currently the only clean way to manage it is > > > > a control that locks the sample rate at a given frequency, but > > > > it isn't a nice solution because it requires explicit user > > > > intervention. In the echoaudio driver I implemented a kludge > > > > that automatically locks the sample frequency in order to avoid > > > > unwanted rate changes. > > > > > > You can add a control to lock the sample rate (e.g. ICE1712). > > > > Yep, I know, but it's not part of the pcm API: applications do not > > lock the sample rate themselves. The user has to do it manually. This is > > why I choosed an alternate solution. If apps were able to lock the rate it > > would be very useful. It may need some help from the driver, though. > > > But that sort of application level control is actually what's causing > me problems. Mozilla browses around and changes the frequency of the > card, independent of what the overall system architecture requires. > > Again, I think you're probably right about this issue for a completely > stand-alone system, but for a multi-PC system I think some sort of > plughw solution that resamples in software when necessary would work > better for me and Mozilla. When the rate is locked in the system (as in my patch), plughw should work as you expected. Takashi ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt