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

OSS Devices                                                                                  7(11 February 2015)