From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Sakamoto Subject: Re: [RFC][PATCH 00/15 v4] OXFW driver, a succesor to firewire-speakers Date: Thu, 14 Aug 2014 07:55:06 +0900 Message-ID: <53EBECCA.6010908@sakamocchi.jp> References: <1399991272-5807-1-git-send-email-o-takashi@sakamocchi.jp> <53E795BD.1070100@ladisch.de> <53E957EA.3030601@sakamocchi.jp> <53E9BDC2.3000801@ladisch.de> <53EA9901.40306@sakamocchi.jp> <53EB0E5E.40004@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp310.phy.lolipop.jp (smtp310.phy.lolipop.jp [210.157.22.78]) by alsa0.perex.cz (Postfix) with ESMTP id 62F8326557D for ; Thu, 14 Aug 2014 00:55:18 +0200 (CEST) In-Reply-To: <53EB0E5E.40004@ladisch.de> 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: Clemens Ladisch Cc: alsa-devel@alsa-project.org, stefanr@s5r6.in-berlin.de, fenlason@redhat.com List-Id: alsa-devel@alsa-project.org On Aug 13 2014 16:06, Clemens Ladisch wrote: > When I wrote the driver, Jay tested which combinations did actually > work (without any stream format information command; I don't have the > spec), so that's what the driver ended up supporting: > - 6ch at 32/44.1/48/96 kHz > - 2ch at 48/96 kHz > > If snd-oxfw also does not send the stream format information command, > then I guess that 2ch at 32/44.1 kHz will not work either. If so, Jey's test included something wrong. I hope someone to test these combinations again, especially 2ch/96kHz. >> [...] >> Instead, we should consider the 2ch modes. This mode seems to be used >> for Dolby Pro Logic II and Dolby Digital but I don't know about the >> specification of Dolby something. If we drop these modes, the work to >> develop OXFW driver becomes simpler. > > The driver does not need care about the format itself; the data is just > sent as 16-bit words that pretend to be samples. All the driver has to > do is to handle the "non-audio" bit in the "IEC958 Playback Default" or > "IEC958 Playback PCM Stream" mixer controls; this can be added later. Hm. So the driver just transfers 2ch 16bit words in IEC 60958 compliant data channels, then the device handles them for surround channels. I misunderstand that Dolby something is a functionality in driver side. Regards Takashi Sakamoto (In summer vacation) o-takashi@sakamocchi.jp