FFmpeg Window
=============

.. figure:: ../../image/ffmpeg_window.png
   :alt: ffmpeg_window
   :width: 900

   FFmpeg camera viewer window.

Overview
--------

In the screenshot above, the left panel lists available video topics, while the
right panel renders selected streams in a grid. A column slider controls how
many streams appear per row.

Layout
------

* **Topic list**: remote topics (from the active connection) and local topics
  (published on the GUI machine).
* **Grid controls**: slider to set the number of columns in the video grid.
* **Video tiles**: one tile per selected topic, rendered with a fixed aspect
  ratio.

Controls and Indicators
-----------------------

* **Refresh topics** repopulates the topic list from the connection and local
  publishers.
* **Checkboxes** create or remove camera widgets for each selected stream.
* **Video column** slider adjusts the grid layout from 1 to 3 columns.

Data Sources
------------

* Remote topics support ``raisin_interfaces::msg::FfmpegPacket`` and
  ``sensor_msgs::msg::Image``.
* Local topics are discovered through the local publisher registry.

Notes
-----

* Remote topics require an active connection; local topics do not.
* Use fewer columns for larger previews when inspecting fine detail.