No longer maintained here. Use now for issues, pull requests, etc.
Objective-C C C++ CMake Makefile M4
Latest commit c0ea860 Nov 12, 2016 @ddennedy committed on GitHub Merge pull request #9 from sofian/master
Fixed: blend_factor was uninitialized in blend plugin.


   ___________              ._________
   \_   _____/______   ____ |__\   _  \_______
    |    __) \_  __ \_/ __ \|  /  /_\  \_  __ \
    |     \   |  | \/\  ___/|  \  \_/   \  | \/
    \___  /   |__|    \___  >__|\_____  /__|
        \/                \/          \/

  Minimalistic plugin API for video effects  v1.5
		by the Piksel Developers Union

  Updated info on


What frei0r is 

Frei0r is a minimalistic plugin API for video effects.

The main emphasis is on simplicity for an API that will round up the
most common video effects into simple filters, sources and mixers that
can be controlled by parameters.

It's our hope that this way these simple effects can be shared between
many applications, avoiding their reimplementation by different

What frei0r is not 

Frei0r is not meant as a competing standard to more ambitious efforts
that try to satisfy the needs of many different applications and more
complex effects.

It is not meant as a generic API for all kinds of video applications,
as it doesn't provides things like an extensive parameter mechanism or
event handling.

Eventually the frei0r API can be wrapped by higher level APIs
expanding its functionalities
(for instance as GStreamer, MLT, FFmpeg and others do).

Current status 

Developers are sporadically contributing and we are happy if more
people like to get involved, so let us know about your creations! Code
and patches are well accepted, get in touch with us on the
mailinglist (see the section Communication below).


Frei0r has been around since 2004, born from yearly brainstormings
held at the Piksel conference with the participation of various free
and open source video software developers.

It works on all hardware platforms without the need for any particular
hardware acceleration (GNU/Linux, Apple/OSX and MS/Win) and consists
of more than 100 plugins. Among the free and open source video
application supporting frei0r are: KDEnLive, FFmpeg, MLT, PureData,
Open Movie Editor, DVEdit, Gephex, LiVES, FreeJ, VeeJay, Flowblade, and
Shotcut among the others.

Wikipedia page about frei0r:

[Open  Movie  Editor]:


Source code 

Stable frei0r releases are packaged periodically and distributed on

Frei0r sourcecode is released under the terms of the GNU General
Public License and, eventually other compatible Free Software

The latest source for frei0r plugins can be attained using our
revisioning system *GIT*

 git clone git://

A repository is also maintained on Gitlab

Make sure to get in touch with our mailinglist if you like to

Build dependencies 

Frei0r can be built on GNU/Linux, M$/Windows and Apple/OSX platforms,
possibly in even more environments like embedded devices.

For details see the INSTALL file, short and to the point.

GNU / Linux

Binary packages are mantained on various distributions.

For an overview see

Apple / OSX 

MacPorts provides packages for OSX:
          $ sudo port install frei0r-plugins

Pre-compiled binaries are also uploaded on our website.

We encourage Apple/OSX application distributors to compile the plugins
directly and to include frei0r within their bundle.

Microsoft / Windows

Pre-compiled binaries are often provided by third-parties

We encourage MS/Win application distributors to compile the plugins
directly and to include frei0r within their bundle.

If you  are new to frei0r (but  not to programming) the  best thing is
probably to  have a look at  the [frei0r header], which  is quite simple
and well documented, or the doxygen code documentation in doc/

API explanation 

While  the main  source of  documentation for  the frei0r  API  is the
header, the  sourcecode is  well commented so  you can study  its full
[doxyfied documentation] online.

[doxyfied documentation]:

C++ Filter example 

A simple skeleton for a frei0r video filter looks like this:

  #include <frei0r.hpp>
  typedef struct {
    int16_t w, h;
    uint8_t bpp;
    uint32_t size;
  } ScreenGeometry;
  class MyExample: public frei0r::filter {
    MyExample(int wdt, int hgt);
    virtual void update();
    ScreenGeometry geo;
    void _init(int wdt, int hgt);
  MyExample::MyExample() { /* constructor */ }
  MyExample::~MyExample() { /* destructor */ }
  void MyExample::_init(int wdt, int hgt) {
    geo.w = wdt;
    geo.h = hgt;
    geo.bpp = 32; // this filter works only in RGBA 32bit
    geo.size = geo.w*geo.h*(geo.bpp/8); // calculate the size in bytes
  void MyExample::update() {
    // we get video input via buffer pointer (void*)in 
    uint32_t *src = (uint32_t*)in;
    // and we give video output via buffer pointer (void*)out
    uint32_t *dst = (uint32_t*)out;
    // this example here does just a copy of input to output
    memcpy(dst, src, geo.size);
          plugin("MyExample", "short and simple description for my example",
                 "Who did it", 1, 0);


You  can get  in touch  with our  developer community,  send  your new
effects and share your intentions with us.

We have a free mailinglist open to [subscription] and we provide
[public archives] of the discussions there that are also searchable
and indexed online.

For bug reporting the mailinglist is preferred, but is also possible
to use an [issue tracker].

[public archives]:
[issue tracker]:


Frei0r is the result of a collective effort in coordination with
several software developers meeting to find a common standard for
video effect plugins to be used among their applications.

For a full list of contributors and the project history, see the file
AUTHORS, the ChangeLog and the project web page