NAME

       dsp - Open Sound System audio devices

DESCRIPTION

       /dev/dsp  is  the  default audio device in the system. It's connected to the main speakers
       and the primary recording source (such as microphone). The system  administrator  can  set
       /dev/dsp  to  be a symbolic link to the desired default device. The ossinfo utility can be
       used to list the available audio devices in the system.

       /dev/dsp_mmap, /dev/dsp_ac3, /dev/dsp_multich  and  /dev/dsp_spdifout  are  default  audio
       devices for specific applications such as games or media (DVD) players.

DIRECT ACCESS AUDIO DEVICE FILES

       OSS  4.0  (and  later)  will  create audio devices under /dev/oss/<device> directory.  For
       example /dev/oss/sblive0/pcm0 is the first audio device that belongs to  the  first  Sound
       Blaster  Live!  or  Audigy  card  in  the  system.  These  direct devices are used when an
       application needs to access specific audio device (instead of the default one).

       You can use the ossinfo(1) utility with the -a option to get a list of the available audio
       devices in the system.

LEGACY AUDIO DEVICE FILES

       Traditionally  OSS  has  created  device  files like /dev/dsp0 to /dev/dspN for each audio
       device in the system. OSS 4.0 still supports this legacy naming.  These files are symbolic
       links  to  the  actual  device files located under /dev/oss. The ossdevlinks(8) utility is
       used to manage these links and it will be automatically invoked when OSS is started.

COMPATIBILITY

       •  The /dev/dsp (default() audio device file will be supported by all OSS  implementations
          and versions.

       •  The special purpose audio default devices (such as /dev/dsp_mmap) are only supported by
          OSS 4.0 and later.

       •  The legacy audio device files (such as /dev/dsp1) are supported by all OSS versions and
          implementations.

       •  New  style audio device files (under /dev/oss) are only supported by OSS 4.0 and later.
          However some independent OSS implementations may only support the  legacy  naming  even
          they are otherwise OSS 4.0 compatible.

       •  /dev/dsp0  doesn't  exist in all Linux systems which use /dev/dsp for the same purpose.
          In such systems /dev/dsp points to the first audio device and /dev/dsp1 to the second.

PROGRAMMING INFORMATION

       See the Audio Programming section of the OSS Programmer's Guide (DSP(2)) for more info.

OPTIONS

       None

FILES

       o /dev/dsp
              Default audio device

       o /dev/dsp_mmap
              Default audio device for applications using mmap(2)

       o /dev/dsp_ac3
              Default audio device for applications sending  Dolby  Digital  (AC3)  audio  to  an
              external receiver.

       o /dev/dsp_multich
              Default multichannel (4.0-7.1) audio output device

       o /dev/dsp_spdifout
              Default digital audio (S/PDIF) output device

       o /dev/oss/<driver>/pcmN
              Direct access device files for individual audio devices.

       o /dev/dsp0 to /dev/dspN
              Legacy style direct access audio device files.

AUTHOR

       4Front Technologies