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Dummy modules are the VLC equivalent of /dev/null on GNU/Linux: they represent doing nothing.


Overview of dummy modules
Type Description Shortcut(s)
Access Dummy input dummy, vlc
Access output Dummy stream output dummy
Audio output Dummy audio output dummy
Decoder Dummy decoder dummy, dump
Encoder Dummy encoder dummy
Control interface Dummy interface (none)
Muxer Dummy/Raw muxer dummy, raw, es
Stream output Dummy stream output dummy, drop
Text renderer Dummy font renderer (none)
Video output Dummy video output dummy, stats
Video output (legacy video plugins) Dummy window dummy



A dummy interface works well with command-line usage. It consumes fewer computing resources, something that can be used to reduce a bottleneck effect during transcoding, or simply when opening a window makes little sense.

This will play an Ogg file with no interface:

$ vlc -I dummy audio.ogg vlc://quit

No window is launched, and control is returned to the calling application after the file plays.

This will play a Schroedinger file with a minimalist interface:

$ vlc -I dummy video.drc vlc://quit

A window with no buttons or toolbars is launched (no skin), because video output requires a window. Hotkeys may be used to control playback by default, something that can be disabled if necessary with --no-keyboard-events.

Stream output

Doesn't do anything. Can be used to test other stream output chain modules without actually streaming anything.


Dummy decoder

  • dummy-save-es <boolean> : Save the raw codec data if you have selected/forced the dummy decoder in the main options. default value: disabled

Video output

  • dummy-chroma <string> : Force the dummy video output to create images using a specific chroma format instead of trying to improve performances by using the most efficient one. default value: NULL

Source code

This page is part of official VLC media player Documentation (User GuideStreaming HowToHacker GuideModules)
Please read the Documentation Editing Guidelines before you edit the documentation
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.