On Fri, Dec 30, 2005 at 05:36:28PM -0500, Ross Vandegrift wrote: > [...] > Say I have two sound cards in my box. Each sound card has an > independent crystal that generates a clock for timekeeping. The > crystals are rated to resonate at some fixed frequency, but there will > always be a margain of error. Even two "identical" parts from the > same manufacturer will produce different errors in their clock. > [...]
We can always find a way to measure the difference in sample frequencies. But that is only half the solution, we have to use this knowledge to get the cards in synch. Adjusting the data rate to the sampling frequency by dropping (or reusing) samples is BAD(TM). Although it may not be very easily heard if done seldom, it does lower audio quality. (Yes, I know, I do it myself.) Sample rate conversion is better. It does take some processing, though. What I really would like is a sound card with adjustable sampling frequency. That is, small scale tunable on an almost continous scale. Practiaclly, I think that one possible way to do it would be to use a temperature sensitive clock crystal in combination with some form of controllable heating element (e.g. a resistor). Asbjørn ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_idv37&alloc_id865&op=click _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
