| pcm.4 (119893) | pcm.4 (122741) |
|---|---|
| 1.\" 2.\" Copyright (c) 1998, Luigi Rizzo 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 9 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" | 1.\" 2.\" Copyright (c) 1998, Luigi Rizzo 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 9 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" |
| 26.\" $FreeBSD: head/share/man/man4/pcm.4 119893 2003-09-08 19:57:22Z ru $ | 26.\" $FreeBSD: head/share/man/man4/pcm.4 122741 2003-11-15 06:08:57Z trhodes $ |
| 27.\" | 27.\" |
| 28.Dd June 3, 1998 | 28.Dd November 14, 2003 |
| 29.Dt PCM 4 30.Os 31.Sh NAME 32.Nm pcm , 33.Nm snd | 29.Dt PCM 4 30.Os 31.Sh NAME 32.Nm pcm , 33.Nm snd |
| 34.Nd FreeBSD PCM audio device driver | 34.Nd FreeBSD PCM audio device infrastructure |
| 35.Sh SYNOPSIS 36For a card with bridge driver support, and a PnP card: 37.Cd "device pcm" 38.Pp 39For a card without bridge driver support, and a non-PnP card, 40the following lines may be required in 41.Pa /boot/device.hints : 42.Cd hint.pcm.0.at="isa" 43.Cd hint.pcm.0.irq="5" 44.Cd hint.pcm.0.drq="1" 45.Cd hint.pcm.0.flags="0x0" 46.Sh DESCRIPTION 47The 48.Nm | 35.Sh SYNOPSIS 36For a card with bridge driver support, and a PnP card: 37.Cd "device pcm" 38.Pp 39For a card without bridge driver support, and a non-PnP card, 40the following lines may be required in 41.Pa /boot/device.hints : 42.Cd hint.pcm.0.at="isa" 43.Cd hint.pcm.0.irq="5" 44.Cd hint.pcm.0.drq="1" 45.Cd hint.pcm.0.flags="0x0" 46.Sh DESCRIPTION 47The 48.Nm |
| 49driver provides support for PCM audio play and capture. 50This driver 51also supports various PCI and WSS/MSS compatible ISA sound cards, and 52AC97 mixer. | 49driver provides support for 50.Tn PCM 51audio play and capture. 52This driver also supports various 53.Tn PCI , 54.Tn WSS/MSS 55compatible, 56.Tn ISA 57sound cards, and AC97 mixer. 58Once the 59.Nm 60driver attaches, supported devices provide audio record and 61playback channels. 62The 63.Fx 64sound system provides dynamic mixing 65.Dq VCHAN 66and rate conversion 67.Dq soft formats . |
| 53True full duplex operation is available on most cards. 54.Pp | 68True full duplex operation is available on most cards. 69.Pp |
| 55If your sound card is supported by a bridge driver, | 70If the sound card is supported by a bridge driver, the |
| 56.Nm | 71.Nm |
| 57driver works 58in conjunction with the bridge driver. | 72driver works in conjunction with the bridge driver. |
| 59.Pp 60Apart from the usual parameters, the flags field is used to specify | 73.Pp 74Apart from the usual parameters, the flags field is used to specify |
| 61the secondary DMA channel (generally used for capture in full duplex 62cards). Flags are set to 0 for cards not using a secondary DMA | 75the secondary 76.Tn DMA 77channel (generally used for capture in full duplex cards). 78Flags are set to 0 for cards not using a secondary 79.Tn DMA |
| 63channel, or to 0x10 + C to specify channel C. 64.Pp | 80channel, or to 0x10 + C to specify channel C. 81.Pp |
| 65The driver works best with WSS/MSS cards, which have a very clean | 82The driver works best with 83.Tn WSS/MSS 84cards, which have a very clean |
| 66architecture and an orthogonal set of features. 67They also happen to be 68among the cheapest audio cards on the market. 69.Pp 70The driver does its best to recognize the installed hardware and drive | 85architecture and an orthogonal set of features. 86They also happen to be 87among the cheapest audio cards on the market. 88.Pp 89The driver does its best to recognize the installed hardware and drive |
| 71it correctly, so that you don't have to give too many details in | 90it correctly so the user is not required to add several lines in |
| 72.Pa /boot/device.hints . | 91.Pa /boot/device.hints . |
| 73For PCI and ISA PnP cards this is actually easy | 92For 93.Tn PCI 94and 95.Tn ISA 96.Tn PnP 97cards this is actually easy |
| 74since they identify themselves. | 98since they identify themselves. |
| 75For legacy ISA cards, the driver looks 76for MSS cards at addresses 0x530 and 0x604 (obviously, unless overridden | 99For legacy 100.Tn ISA 101cards, the driver looks for 102.Tn MSS 103cards at addresses 0x530 and 0x604 (unless overridden |
| 77in 78.Pa /boot/device.hints ) . | 104in 105.Pa /boot/device.hints ) . |
| 79.Sh IOCTL 80The driver supports most of the Voxware ioctls(), and most 81applications work unmodified (including popular mpeg players and linux 82binaries). A few 83differences exist (the most important one is the ability to use 84memory-mapped access to the audio buffers). As a consequence, some 85applications may need to be recompiled with a slightly modified 86audio module. | 106.Ss Boot Variables 107In general, the module 108.Pa snd_foo 109corresponds to device foo and can be 110loaded by the boot loader via 111.Pa boot/loader.conf 112or from the command line using the 113.Xr kldload 8 114utility. 115Options which can be specified in 116.Pa /boot/loader.conf 117include: 118.Bl -tag -width snd_emu10k1_load -offset indent 119.It Va snd_driver_load 120.Pq Dq NO 121If set to 122.Dq YES , 123this option loads all available drivers. 124.It Va snd_emu10k1_load 125.Pq Dq NO 126If set to 127.Dq YES , 128Only the SoundBlaster 5.1 driver and dependent modules will be loaded. 129.It Va snd_foo_load 130.Pq Dq NO 131If set to 132.Dq YES , 133load driver for card/chipset foo. 134.El 135.Ss VCHANS 136Each device can optionally support more playback channels 137that physical hardware provides by using 138.Dq virtual channels 139or 140.Tn VCHANs . 141.Tn VCHAN 142options can be configured via the 143.Xr sysctl 8 144interface but can only be manipulated while the device is inactive. 145.Ss Runtime Configuration 146The following 147.Xr sysctl 8 148tunables are available: 149.Bl -tag -width ".It Va hw.snd.report_soft_formats" -offset indent 150.It Va hw.snd.pcm%d.buffersize 151Configure the amount of 152.Tn DMA 153bufferspace available for a device. 154.It Va hw.snd.targetirqrate 155Set the default block size such that continuous 156playback will achieve this 157.Tn IRQ 158rate. 159This value can be tuned to improve application performance. 160Increase this value when the sound lags and decrease 161it if sound stutters or breaks up. 162.It Va hw.snd.unit 163When using 164.Xr devfs 5 , 165the default device for 166.Pa /dev/dsp . 167Equivalent to a symlink from 168.Pa /dev/dsp 169to 170.Pa /dev/dsp${hw.snd.unit} . 171.It Va hw.snd.report_soft_formats 172Controls the internal format conversion if it is 173available transparently to the application software. 174When disabled or not available, the application will 175only be able to select formats the device natively supports. 176.It Va hw.snd.verbose 177Level of verbosity for the 178.Pa /dev/sndstat 179device. 180Higher values include more output and the highest level, 181three, should be used when reported problems. 182Other options include: 1830 - Installed devices and their allocated bus resources. 1841 - The number of playback, record, virtual channels, and 185flags per device. 1862 - Channel information per device including the channel's 187current format, speed, and pseudo device statistics such as 188buffer overruns and buffer underruns. 1893 - File names and versions of the currently sound loaded modules. 190.It Va hw.snd.maxautovchans 191Global 192.Tn VCHAN 193setting that only affects devices that have only one playback channel. 194The sound system will dynamically create up this many 195.Tn VCHANs . 196Set to 197.Dq 0 198if no 199.Tn VCHANS 200are desired. 201.It Va hw.snd.pcm%d.vchans 202The current number of 203.Tn VCHANs 204allocated per device. 205This can be set to preallocate a certain number of 206.Tn VCHANs . 207Setting this value to 208.Dq 0 209will disable 210.Tn VCHANs 211for this device. 212.El 213.Ss Recording Channels 214On devices that have more than one recording source (ie: mic and line), 215there is a corresponding 216.Pa /dev/dspr%d.%d 217device. 218.Ss Statistics 219Channel statistics are only kept while the device is open. 220So with situations involving overruns and underruns, consider the output 221while the errant application is open and running. 222.Ss IOCTL Support 223The driver supports most of the 224.Tn OSS 225.Fn ioctl 226functions, and most applications work unmodified. 227A few differences exist, while memory mapped playback is 228supported natively and in Linux emulation, memory mapped recording is 229not due to 230.Tn VM 231system design. 232As a consequence, some applications may need to be recompiled 233with a slightly modified audio module. |
| 87See 88.In sys/soundcard.h | 234See 235.In sys/soundcard.h |
| 89for a complete list of the supported ioctls. 90.Sh SUPPORTED CARDS | 236for a complete list of the supported 237.Fn ioctl 238functions. 239.Ss SUPPORTED CARDS |
| 91Below we include a list of supported codecs/cards. 92If your sound card 93is not listed here, it may be supported by a bridge driver. 94.Bl -tag -width 2m 95.It CS4237, CS4236, CS4232, CS4231 (ISA) 96All these cards work perfectly in full duplex using the MSS mode. 97This chipset is used, among others, on the A/Open AW35 and AW32, on 98some Intel motherboards, and (the CS4231) on some non-PnP cards. --- 18 unchanged lines hidden (view full) --- 117Creative Labs SoundBlaster PCI is supported as well. 118.It ESS Solo-1/1E (PCI) 119.It NeoMagic 256AV/ZX (PCI) 120.El 121.Sh FILES 122The following commonly used symbolic links to real device nodes 123should be present: 124.Pp | 240Below we include a list of supported codecs/cards. 241If your sound card 242is not listed here, it may be supported by a bridge driver. 243.Bl -tag -width 2m 244.It CS4237, CS4236, CS4232, CS4231 (ISA) 245All these cards work perfectly in full duplex using the MSS mode. 246This chipset is used, among others, on the A/Open AW35 and AW32, on 247some Intel motherboards, and (the CS4231) on some non-PnP cards. --- 18 unchanged lines hidden (view full) --- 266Creative Labs SoundBlaster PCI is supported as well. 267.It ESS Solo-1/1E (PCI) 268.It NeoMagic 256AV/ZX (PCI) 269.El 270.Sh FILES 271The following commonly used symbolic links to real device nodes 272should be present: 273.Pp |
| 125.Bl -tag -width /dev/sequencer -compact 126.It Pa /dev/audio 127Sparc-compatible audio device 128.It Pa /dev/dsp 129Digitized voice device 130.It Pa /dev/dspW | 274.Bl -tag -width "/dev/dspr%d.%dXXX" -compact 275.It Pa /dev/audio%d.%d 276Sparc-compatible audio device. 277.It Pa /dev/dsp%d.%d 278Digitized voice device. 279.It Pa /dev/dspW%d.%d |
| 131Like 132.Pa /dev/dsp , | 280Like 281.Pa /dev/dsp , |
| 133but 16 bits per sample 134.It Pa /dev/midi 135Raw midi access device 136.It Pa /dev/mixer 137Control port mixer device 138.It Pa /dev/music 139Level 2 sequencer interface 140.It Pa /dev/sequencer 141Sequencer device 142.It Pa /dev/pss 143Programmable device interface | 282but 16 bits per sample. 283.It Pa /dev/dspr%d.%d 284Should be connected to a record codec. 285.It Pa /dev/sndstat 286Current 287.Nm 288status, including all channels and drivers. |
| 144.El 145.Pp 146Each symbolic link refers to a device node of the same name, 147but with a unit number appended. 148The unit number for each device matches the unit number of the 149device probed at boot time. 150Device probe messages can be examined with the 151.Xr dmesg 8 152utility. | 289.El 290.Pp 291Each symbolic link refers to a device node of the same name, 292but with a unit number appended. 293The unit number for each device matches the unit number of the 294device probed at boot time. 295Device probe messages can be examined with the 296.Xr dmesg 8 297utility. |
| 153.Sh DIAGNOSTICS AND TROUBLESHOOTING | 298.Sh DIAGNOSTICS |
| 154.Bl -tag -width 2m 155.It ac97: dac not ready 156AC97 codec is not likely to be accompanied with the sound card. 157.It unsupported subdevice XX 158A device node is not created properly. 159.El 160.Sh BUGS 161Some features of your cards (e.g. global volume control) might not 162be supported on all devices. 163.Sh HISTORY 164The 165.Nm 166device driver first appeared in | 299.Bl -tag -width 2m 300.It ac97: dac not ready 301AC97 codec is not likely to be accompanied with the sound card. 302.It unsupported subdevice XX 303A device node is not created properly. 304.El 305.Sh BUGS 306Some features of your cards (e.g. global volume control) might not 307be supported on all devices. 308.Sh HISTORY 309The 310.Nm 311device driver first appeared in |
| 167.Fx 2.2.6 , | 312.Fx 2.2.6 written by Luigi Rizzo. 313It was later |
| 168rewritten in | 314rewritten in |
| 169.Fx 4.0 . | 315.Fx 4.0 by Cameron Grant. 316The API evolved from the VOXWARE 317standard which later became OSS standard. |
| 170.Sh SEE ALSO 171.Xr csa 4 , 172.Xr gusc 4 , 173.Xr sbc 4 , | 318.Sh SEE ALSO 319.Xr csa 4 , 320.Xr gusc 4 , 321.Xr sbc 4 , |
| 174.Xr devfs 5 | 322.Xr devfs 5 , 323.Xr loader.conf 5 , 324.Xr dmesg 8 , 325.Xr kldload 8 , 326.Xr sysctl 8 327.Rs 328.%T "The OSS API" 329.%O "http://www.opensound.com/pguide/oss.pdf" 330.Re |
| 175.Sh AUTHORS | 331.Sh AUTHORS |
| 332.An -nosplit |
|
| 176.An Luigi Rizzo Aq luigi@iet.unipi.it 177initially wrote the 178.Nm 179device driver and this manual page. 180.An Cameron Grant Aq gandalf@vilnya.demon.co.uk | 333.An Luigi Rizzo Aq luigi@iet.unipi.it 334initially wrote the 335.Nm 336device driver and this manual page. 337.An Cameron Grant Aq gandalf@vilnya.demon.co.uk |
| 181totally revised the device driver. | 338later revised the device driver for 339.Fx 4.0 . |
| 182.An Seigo Tanimura Aq tanimura@r.dl.itc.u-tokyo.ac.jp 183revised this manual page. | 340.An Seigo Tanimura Aq tanimura@r.dl.itc.u-tokyo.ac.jp 341revised this manual page. |
| 342It was then rewritten for 343.Fx 5.2 . |
|