FYI: i didn't see this email on ALSA-DEVEL, so i'm posting here too.. don't know if useful to anyone.. but it's a real pity to see the cirrus dsp couldn't be exploited to its "real" power by lack of a single cirrus people! :-(
bye andrea venturi ================================ From: "Woller, Thomas" <[EMAIL PROTECTED]> To: "'David Ford'" <[EMAIL PROTECTED]>, "Woller, Thomas" <[EMAIL PROTECTED]>, linux-kernel <[EMAIL PROTECTED]> Subject: RE: 2.4.3+ sound distortion Date: Wed, 6 Mar 2002 10:43:53 -0600 david, et al a) i am very sorry about the tinny sound you are experiencing. we no longer have any DSP pc audio engineers working at cirrus, and pc audio products are no longer developed or supported here at cirrus. i have talked this problem over with the only person that might help, and the debugging effort involved is extensive and may not yield results. we do not fully understand the issue, but believe that several internal points in the DSP become misaligned resulting in the tinny sound. b) the static DSP image that is currently used with the linux cs46xx driver, is not capable of any of the fancy extensive feature set, and the work involved would require an engineer with intimate knowledge of the DSP which no longer is present. c)see b d) i am always willing to assist the linux effort, it's just difficult due to the lack of any support at cirrus for pc audio any longer. i am working on embedded RTOS in my official job, but always try to fix any linux pc audio related bugs as i am able. also, without any DSP engineers we can not create another static DSP image with the additional tasks necessary to take advantage of the wonderful features of cards with the cs46xx controller. we are stuck with the current DSP images that are available. there is a small glimmer of light concerning secondary codec support and SPDIF support. i had found 2 other "test" static DSP images that might be useful. i placed 2 piles of code out on a cirrus ftp site (see below). the first is a cs46xx driver with an untested static DSP image that snoops the data to the primary codec and pumps it to the secondary, so that there is sound coming from the rear speakers, although the same as the the front. the second pile of code (EOLT) contains a set of tests that we used for testing the cs4630. the static image used in these tests contained in this directory functioned with SPDIF in/out. i am unsure whether the other tasks are loaded in this image to support the general audio data paths, so this static image may not support more than spdif. i tried using the static "spdif" image on the latest cs46xx linux driver, but it did not work with a simple static image replacement in the source. specific problem definition and resolution using the spdif EOLT static image with the linux cs46xx sources, has not been determined. anyone and everyone are welcome to look over these 2 piles of source, but my time is very limited concerning any new development for spdif and/or secondary codec. here is the ftp site info. the cs46xx code is based on an older version of the 2.4 kernel. server: ftp1.cirrus.com login: ftppclink password: cSPxQMd thanks Tom Woller _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel