Extending fffw
==============

The aim of ``fffw`` library is to provide mechanics for preparing ``ffmpeg``
command line arguments, not to cover all possible ``ffmpeg`` parameters.
It provides all necessary base classes to extend input file handling, filtering
and output configuration.

Before writing code it's useful to read section :ref:`command-line-structure`.

Extending FFMPEG
----------------

If you need to add more flags to common section of ``ffmpeg``, just extend
main wrapper:

.. literalinclude:: ../../examples/extending.py

Alternate inputs
----------------

Files are not the only sources for ``ffmpeg``. Audio/video streams could be read
from network or hardware devices. Below there is a sample implementation of
`screen grabbing input <http://ffmpeg.org/ffmpeg-all.html#X11-grabbing>`_.

.. literalinclude:: ../../examples/grabbing.py

Implement filters
-----------------

There are many useful filters in ``ffmpeg``. I.e. you may use
`scale2ref <http://ffmpeg.org/ffmpeg-all.html#scale2ref>`_ to scale one video
to fit another one.

.. literalinclude:: ../../examples/filters.py

Configure muxer
---------------

There are lot's of formats supported by ``ffmpeg``. Internet video streaming
often uses HLS protocol to provide better experience. HLS muxer has a bunch of
options to tune.

.. literalinclude:: ../../examples/hls.py