From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Courtier-Dutton Subject: Re: Delay channel X by one sample Date: Fri, 25 Mar 2005 14:05:41 +0000 Message-ID: <42441AB5.7030005@superbug.co.uk> References: <4243FFFC.9040907@ybb.ne.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <4243FFFC.9040907@ybb.ne.jp> 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: Edson Pereira Cc: alsa-devel List-Id: alsa-devel@alsa-project.org Edson Pereira wrote: > > Greetings, > > I am in the process of implementing a small software defined radio > receiver using the PCM2903 codec and have a question for the > alsa-developers. > > The ALSA USB-Audio interface is working very well. The audio quality of > the chip is quite good, but the chip has a bug! The audio stream of one > channel is delayed by one sample in respect to the other channel. This > is drastic for the mentioned application since the phase correlation > between channels is critical. I have contacted Burr Brown technical > support and they have acknowledged the problem. The error is in the FIFO > addressing hardware and is present in the ADC as well in the DAC (but in > reversed channels). > > The problem is quite easy to get around in the application, but this > prevents the hardware interface being used with other programs (testing > software for example). My question is: Where in the system software > chain could a work around be implemented? In the ALSA snd-usb-audio? Or > is there any other more appropriate place? > > Thanks and best regards, > > -- Edson > I think adding this "delay channel X by one sample" feature would be a nice feature to add to alsa-lib. We are going to need it in order to support 96khz SPDIF out on the Audigy 2 cards via the P16V chip. So, if other cards also need it, it would be good to add. James ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click