Thanks for replying. I am writing an application that is generic enough to a number of different drivers. If thats possible! I am trying to achieve a 2 second of buffer for a number of different sample rates. This means that for a sample rate of 44.1KHz I require a buffer size of 88.2K frames!!!! For all the different types of sound cards that I have used I havent seen a buffer size > 16K frames : ( I have noticed that various drivers have certain behaviour which makes writing a application that is generic for all drivers very difficult. For example for an intel chipset I have found that the driver was very versatile and allowed me to choose various period sizes for different buffer sizes. Whilst the driver for the CS4299 chipset, although allows a buffer size of upto 16K the period size has to be half that value. Therefore this makes it impossible for me to use with the ALSA callback mechanism, which I need to use for the design to work! By the way how do I find out which driver is assigned to a chipset? I understand that I can use 'lsmod'. Can a driver be used on multiple chipsets? You will have to excuse my knowledge on this : ) On 8/29/07, Clemens Ladisch <cladisch@xxxxxxxxxxxxxx> wrote: > paul blakeley wrote: > > Is it possible to increase the buffer size of a ALSA driver? > > Yes. No. Er, maybe. > > Each driver has a certain limit for the buffer size. The ALSA framework > preallocates memory for the buffer, but usually only half the limit. > You can increase the amount by writing a new value into > /proc/asound/cardX/pcm*/sub*/prealloc. > > The limit is sometimes just an arbitrary value invented by the driver > writer, but in many cases a hard limit of the hardware. > > What driver are you using? > > > Regards, > Clemens > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
