From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Channel map API patches: to be 3.7 or not to be? Date: Tue, 11 Sep 2012 14:19:49 +0200 Message-ID: <504F2C65.1090204@ladisch.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by alsa0.perex.cz (Postfix) with ESMTP id B697A2602C4 for ; Tue, 11 Sep 2012 14:19:51 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org, pulseaudio-discuss@lists.freedesktop.org List-Id: alsa-devel@alsa-project.org Takashi Iwai wrote: > BTW, this reminds me of an open question: > is it useful to add SND_CHMAP_MONO, or is it just redundant? > > It's nothing but indicating a mono channel without any channel > position, so I supposed SND_CHMAP_UNKNOWN being sufficient. OTOH, > SND_CHMAP_MONO would give a clear sign of mono streams while > SND_CHMAP_UNKNOWN could be used for any other exceptional purposes. What would it be used for? Labeling surround channels is necessary for reordering them or for doing up/downmixing. A "mono" channel, however, does not appear to have any semantic difference from a single "unknown" channel. Regards, Clemens