From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kris Modrak Subject: Re: Rate Conversion Date: Fri, 28 Jun 2002 13:30:24 +1000 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <3D1BD850.C59C43C2@anu.edu.au> References: Reply-To: u9514439@anu.edu.au Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: Jaroslav Kysela Cc: "alsa-devel@lists.sourceforge.net" List-Id: alsa-devel@alsa-project.org Jaroslav Kysela wrote: > > On Thu, 27 Jun 2002, Kris Modrak wrote: > > > I am writing a PCM application and wish to play a .wav file that has a > > sampling rate of 8kHz on a hardware setup that only supports sampling > > frequencies of 44.1 or 48kHz. > > > > Does anyone know how to implement this? > > You don't need to do this. Use the 'plughw' device which should do all > conversions from you. I am a little confused about your advice. I am not sure how to access the 'plughw' device from my application. I have a full duplex application that can play a file at 44.1kHz and record at the same rate but I want it to operate at lower sampling frequencies. I am not sure of how I should be setting up my PCM devices. How do I tell them to convert, say, 8kHz audio data to 44.1kHz audio data so my hardware can play it at the correct speed? I tried using aplay with plughw to play an 8kHz file and got the following results >aplay -Dplughw s1.wav Playing WAVE 's1.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono Segmentation fault However it worked when using a 441.kHz file. Regards Kris Modrak ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Bringing you mounds of caffeinated joy. http://thinkgeek.com/sf