---
name: "dsp"
section: "7"
platform: "linux"
package: "oss4-base"
version: "4.2-build2010-2"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/dsp/7"
---

# dsp(7)

Open Sound System audio devices

## 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)](/ossinfo/1.md) 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)](/ossdevlinks/8.md) 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)](/mmap/2.md)**

- **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**