From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick Shirkey Subject: Re: AW: usb quattro Date: Sat, 21 Sep 2002 17:02:04 +0900 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <3D8C277C.2070808@boosthardware.com> References: <3D77A319.3010703@boosthardware.com> <3D7912A2.1000908@boosthardware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Takashi Iwai Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org Takashi Iwai wrote: > the resolution of usb-audio device is 1ms. this value is fixed. > thus you need to adjust the period size according to the sample rate > if you want to achieve the real-time response with a small period > size. > > that means: > - the sample rate should be 48kHz (or 32kHz), which can be divided by > 1000, and should not be 44.1kHz. > - the period size should be aligned to (rate / 1000). > in the case of 48kHz, the period size should be 48, 96, 192, ... > > please try this combination. > This is not working properly here. Using 48khz with the above or higher sample rates I get many xruns from jackd and it is impossible to connect ardour. However if I use 44100/48000 with the default period size of 1024 then it takes jack a while to warm the card up (about 5-10 seconds) and then I get no xruns. However the sound quality is scratchy. -- Patrick Shirkey - Boost Hardware Ltd. For the discerning hardware connoisseur Http://www.boosthardware.com Http://www.boosthardware.com/LAU/guide/ ======================================== "Um...symbol_get and symbol_put... They're kindof like does anyone remember like get_symbol and put_symbol I think we used to have..." - Rusty Russell in his talk on the module subsystem ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf