From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tanu Kaskinen Subject: Re: [RFC] Channel mapping API (take 2) Date: Wed, 05 Sep 2012 09:00:12 +0300 Message-ID: <1346824812.3629.29.camel@laptop> 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 55FA92652DB for ; Wed, 5 Sep 2012 08:00:15 +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 List-Id: alsa-devel@alsa-project.org On Tue, 2012-09-04 at 17:47 +0200, Takashi Iwai wrote: > The rest aren't so much changed. Only slight bug fixes. I have a couple of comments about "the rest". I haven't been following the development of the channel map API very closely, so I'm relying on the pcm.h file only. /** channel map list type */ enum snd_pcm_chmap_type { SND_CHMAP_NONE = 0, /** unspecified channel position */ SND_CHMAP_FIXED, /** fixed channel position */ SND_CHMAP_VAR, /** freely swappable channel position */ SND_CHMAP_PAIRED, /** pair-wise swappable channel position */ }; It's not clear to me what the VAR and PAIRED types actually mean. It would be nice to explain in more detail the concepts in the header. The snd_pcm_chmap_position enum doesn't contain an entry for mono. I think it would be a useful channel to have. Up/downmixing decisions may be different with mono than, for example, a single channel declared as front left. -- Tanu