From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ctirad Fertr Subject: emu10k1, how to setup DMA for 24bit playback? Date: Thu, 21 Feb 2008 00:09:33 +0100 Message-ID: <200802210009.33259.c.fertr@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp2.vol.cz (smtp2.vol.cz [195.250.128.75]) by alsa0.perex.cz (Postfix) with ESMTP id A111B24568 for ; Thu, 21 Feb 2008 00:10:46 +0100 (CET) Received: from [10.16.3.4] (dsl-tn-6-43.static.adsl.vol.cz [83.148.7.43]) by smtp2.vol.cz (Postfix) with ESMTP id 43AF629956 for ; Thu, 21 Feb 2008 00:10:46 +0100 (CET) Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hello, I'm trying to add 24bit playback for E-mu cards into emu10k driver. These cards use an FPGA, which is 32bit internally and it is feeded via 10k2 EMU32 BUSes. Unfortunatelly, the emu10k DMA cannot handle more than 16bit samples, so kind of tricky stuff is needed. The already working 24bit multichannel capture uses an DSP code, which splits an 32 bit sample into two halfs, sent it over two DMA channels and then alsa lib (???) joins it back into S32_LE sample. I'm trying to use same technique in reverse way using a pair of A_FXBUSes for one playback chanel, but I'm not able to set the DMA the way I need. Can someone with emu10k knowledge help me? ---- Ctirad