From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] ALSA: ASoC: CS4270: export de-emphasis filter as ALSA control Date: Thu, 29 Oct 2009 10:15:13 +0000 Message-ID: <20091029101512.GA3902@rakim.wolfsonmicro.main> References: <1256779472-30754-1-git-send-email-daniel@caiaq.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 7A8B024664 for ; Thu, 29 Oct 2009 11:15:14 +0100 (CET) Content-Disposition: inline In-Reply-To: <1256779472-30754-1-git-send-email-daniel@caiaq.de> 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: Daniel Mack Cc: alsa-devel@alsa-project.org, Timur Tabi List-Id: alsa-devel@alsa-project.org On Thu, Oct 29, 2009 at 02:24:32AM +0100, Daniel Mack wrote: > The CS4270 codec features an de-emphasis filter for compensation of > audio material filtered by an 50/15 uS algorithm. Not sure whether we > should always enable it for 44100Hz sampling frequency, but it should at > least be configurable by the user. It shouldn't be automatically enabled - historically some sources put some preemphasis on the recording in order to compensate for poor playback technologies but it's vanishingly rare to encounter any such sources these days. I'll apply this.