From owner-svn-src-all@FreeBSD.ORG Sun Jul 12 03:40:04 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B6F84106564A; Sun, 12 Jul 2009 03:40:04 +0000 (UTC) (envelope-from minimarmot@gmail.com) Received: from ey-out-2122.google.com (ey-out-2122.google.com [74.125.78.24]) by mx1.freebsd.org (Postfix) with ESMTP id 8AD2C8FC13; Sun, 12 Jul 2009 03:40:03 +0000 (UTC) (envelope-from minimarmot@gmail.com) Received: by ey-out-2122.google.com with SMTP id 9so374350eyd.3 for ; Sat, 11 Jul 2009 20:40:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=jOZnx93KOS+npQm76AUmNeaF+CUuErUvuSkluXbCXdc=; b=f9pPBATI4TAZ3vcf6lqhNpSaIG4dTjaSx/erIG9csKPwUXFLEQypu55/lVTyrTuTiY liFYvh5S06IRlTQv2m3camPuqfQ0kwDopCHjrDbo5LEfLCzWiif6BnnSUxDcuC9M70/q GnI8sM1hq1oFZy1Pp2br7c2ZEMszEvrLH4Z2g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=ajj0fULdEkKXSn/Zk+xm3ulWbfYA4cJp+yU6FyWtJqvFLnLXCk+6EzEu5YSnR3lA3y 3i8UbtMfEZNPuT0SsUQBJYc3pLBFbK2psMTfQThhLQjkgjrTEHaxxKeTV6OPmfDJOoYj Icr8cjYU7QbzPfDEeu2nbTPxQE/y33xPqsOc8= MIME-Version: 1.0 Received: by 10.210.142.6 with SMTP id p6mr3179170ebd.76.1247370002575; Sat, 11 Jul 2009 20:40:02 -0700 (PDT) In-Reply-To: <200907111525.n6BFPDrY056196@svn.freebsd.org> References: <200907111525.n6BFPDrY056196@svn.freebsd.org> Date: Sat, 11 Jul 2009 23:40:02 -0400 Message-ID: <47d0403c0907112040v785b6f4se7e927809035b3b5@mail.gmail.com> From: Ben Kaduk To: Joel Dahl Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, ariff@freebsd.org Subject: Re: svn commit: r195619 - head/share/man/man4 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Jul 2009 03:40:05 -0000 On Sat, Jul 11, 2009 at 11:25 AM, Joel Dahl wrote: > Author: joel (doc committer) > Date: Sat Jul 11 15:25:13 2009 > New Revision: 195619 > URL: http://svn.freebsd.org/changeset/base/195619 > > Log: > Document the new multichannel support. > > Reviewed by: ariff > Approved by: re (blanket) > > Modified: > head/share/man/man4/pcm.4 > > Modified: head/share/man/man4/pcm.4 > ============================================================================== > --- head/share/man/man4/pcm.4 Sat Jul 11 15:02:45 2009 (r195618) > +++ head/share/man/man4/pcm.4 Sat Jul 11 15:25:13 2009 (r195619) > @@ -25,7 +25,7 @@ > .\" > .\" $FreeBSD$ > .\" > -.Dd July 9, 2009 > +.Dd July 11, 2009 > .Dt SOUND 4 > .Os > .Sh NAME > @@ -141,6 +141,30 @@ To define default values for the differe > set the channel to the preferred value using hints, e.g.: > .Va hint.pcm.0.line Ns = Ns Qq Li 0 . > This will mute the input channel per default. > +.Ss Multichannel Audio > +Multichannel audio, popularly referred to as > +.Dq surround sound > +is supported and enabled by default. > +The FreeBSD multichannel matrix processor supports up to 18 interleaved > +channels, but the limit is currently set to 8 channels (known as 7.1). The expression "known as 7.1" is a bit odd. Maybe "as commonly used for 7.1"? > +The internal matrix mapping can handle reduction, expansion or > +re-routing of channels. > +This provides a base interface for related multichannel > +.Fn ioctl > +support. > +Works with or without > +.Tn VCHANs . This sentence has no subject. Is the intent to say "multichannel audio works with both software VCHANs and hardware channels"? > +Most bridge device drivers are still missing multichannel matrixing support > +, but in most cases this should be trivial to implement. > +Use the > +.Va dev.pcm.%d.[play|rec].vchanformat > +.Xr sysctl(8) Pedantically, this is a sysctl node, though the meaning is probably clear enough with the current text. > +to adjust the number of channels used. > +The current multichannel interleaved structure and arrangement was > +implemented by inspecting various popular UNIX applications. > +There were no single standard, so much care has been taken to try > +to satisfy each possible scenario, despite the fact that each > +application has its own conflicting standard. > .Ss EQ > The Parametric Software Equlizer (EQ) enables the use of > .Dq tone > @@ -407,6 +431,32 @@ Format for > mixing. > All playback paths will be converted to this format before the mixing > process begins. > +By default only 2 channels are enabled. > +Available options include: > +.Bl -tag -width 2n > +.It s16le:1.0 > +Mono > +.It s16le:2.0 > +Stereo, 2 channels, (left, right). The second comma is probably spurious (cf. quadrophonic, below). > +.It s16le:2.1 > +3 channels (left, right, LFE). > +.It s16le:3.0 > +3 channels (left, right, rear center). > +.It s16le:4.0 > +Quadraphonic, 4 channels (front/rear left and right). > +.It s16le:4.1 > +5 channels (4.0 + LFE). > +.It s16le:5.0 > +5 channels (4.0 + center). > +.It s16le:5.1 > +6 channels (4.0 + center + LFE). > +.It s16le:6.0 > +6 channels (4.0 + front/rear center). > +.It s16le:6.1 > +7 channels (6.0 + LFE). > +.It s16le:7.1 > +8 channels (4.0 + center + LFE + left and right side). > +.El It would be nice to be consistent about using "and", "+" or neither for the parentheticals. Also, "LFE" does not appear to be expanded to "low frequency enhancement" anywhere .... Documentation nits aside, I'm really glad to have this audio work hit the tree -- my primary audio setup is currently based on a box running -current. -Ben Kaduk