diff options
author | joel <joel@FreeBSD.org> | 2007-05-31 20:26:39 +0000 |
---|---|---|
committer | joel <joel@FreeBSD.org> | 2007-05-31 20:26:39 +0000 |
commit | 2e12909782c9809e92b1cdc707a8130946b634b3 (patch) | |
tree | d30d692b54d2eb5ceb4136dad753f8e1e619a9ad /share | |
parent | 663d795614ab33044d0f6fb24e8291c82cbfdfbf (diff) | |
download | FreeBSD-src-2e12909782c9809e92b1cdc707a8130946b634b3.zip FreeBSD-src-2e12909782c9809e92b1cdc707a8130946b634b3.tar.gz |
Document recent improvements to the sound infrastructure (virtual recording
channels, changed sysctl's and device nodes etc).
Reviewed by: ariff
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/pcm.4 | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/share/man/man4/pcm.4 b/share/man/man4/pcm.4 index a30d813..8d466bd 100644 --- a/share/man/man4/pcm.4 +++ b/share/man/man4/pcm.4 @@ -25,7 +25,7 @@ .\" .\" $FreeBSD$ .\" -.Dd November 29, 2006 +.Dd May 31, 2007 .Dt SOUND 4 .Os .Sh NAME @@ -152,7 +152,7 @@ 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 VCHANs -Each device can optionally support more playback channels +Each device can optionally support more playback and recording channels than physical hardware provides by using .Dq virtual channels or @@ -226,7 +226,7 @@ Various messages intended for debugging. .It Va hw.snd.maxautovchans Global .Tn VCHAN -setting that only affects devices with only one playback channel available. +setting that only affects devices with at least one playback or recording channel available. The sound system will dynamically create up this many .Tn VCHANs . Set to @@ -234,7 +234,7 @@ Set to if no .Tn VCHANS are desired. -Maximum value is 255. +Maximum value is 256. .It Va hw.snd.default_unit Default sound card for systems with multiple sound cards. When using @@ -245,7 +245,7 @@ Equivalent to a symlink from .Pa /dev/dsp to .Pa /dev/dsp Ns Va ${hw.snd.default_unit} . -.It Va dev.pcm.%d.vchans +.It Va dev.pcm.%d.[play|rec].vchans The current number of .Tn VCHANs allocated per device. @@ -256,13 +256,13 @@ Setting this value to will disable .Tn VCHANs for this device. -.It Va dev.pcm.%d.vchanrate +.It Va dev.pcm.%d.[play|rec].vchanrate Sample rate speed for .Tn VCHAN mixing. All playback paths will be converted to this sample rate before the mixing process begins. -.It Va dev.pcm.%d.vchanformat +.It Va dev.pcm.%d.[play|rec].vchanformat Format for .Tn VCHAN mixing. @@ -322,8 +322,10 @@ but 16 bits per sample. Playback channel. .It Pa /dev/dsp%d.r%d Record channel. -.It Pa /dev/dsp%d.v%d -Virtual channel. +.It Pa /dev/dsp%d.vp%d +Virtual playback channel. +.It Pa /dev/dsp%d.vr%d +Virtual recording channel. .It Pa /dev/sndstat Current .Nm @@ -343,6 +345,15 @@ Additional messages are sometimes recorded when the device is probed and attached, these messages can be viewed with the .Xr dmesg 8 utility. +.Pp +The above device nodes are only created on demand through the dynamic +.Xr devfs 5 +clone handler. +Users are strongly discouraged to access them directly. +For specific sound card access, please instead use +.Pa /dev/dsp +or +.Pa /dev/dsp%d . .Sh DIAGNOSTICS .Bl -diag .It pcm%d:play:%d:dsp%d.p%d: play interrupt timeout, channel dead |