From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benny Sjostrand Subject: Re: SPDIF and cs46xx ? Date: Mon, 17 Mar 2003 00:23:10 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <3E75075E.7030401@cucumelo.org> References: <14a4584ea6cb4a6894e70d84e717abc6.peter599@gotnet.net> 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: Peter Heatwole Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org > > >2) A clicking sound (described by another user as "cards in a bike") For the > times I get this sound, it's normally about 4-6 beats-per-second (or so), but > if I unmute "IEC958 Input" it nearly doubles (about 8-12 beats-per-second). > > Sounds like your receiver don't detect the AC3 stream, and inteprets it like PCM instead. There can be many reasons why this hapen, right now I can mention: - The AC3 is altered in some how, DSP applies gain's, roundings, while procesing stream (operation that are audible while playing PCM, and probably improbes sound), then when the data reach the receiver it's not detected as AC3 anymore. In the current cs46xx driver there's a special treatment for 48khz streams through IEC958, to prevent the DSP process the stream in any way. - The magic status bit's, I'm not sure if the current implementation in the cs46xx that set's the IEC958 is correct. I have not found any way to verify ... /Benny ------------------------------------------------------- This SF.net email is sponsored by:Crypto Challenge is now open! Get cracking and register here for some mind boggling fun and the chance of winning an Apple iPod: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en