<p>Commands allow you to change the parameters <em>during</em> execution of the command. This is primarily useful when working with streaming media e.g. if the volume gets too loud during a broadcast, send a command to the volume filter to lower it.</p>

<p>To issue commands to filters which support it from outside, ffmpeg has to be compiled with libzmq support. See the <a href="https://ffmpeg.org/ffmpeg-filters.html#zmq_002c-azmq" rel="nofollow noreferrer">docs</a> for the zmq filter for details.</p>

<p>To issue commands from the terminal, press <kbd>c</kbd></p>

<p>The 'command prompt' will be shown :</p>

<pre><code>Enter command: &lt;target&gt;|all &lt;time&gt;|-1 &lt;command&gt;[ &lt;argument&gt;]
</code></pre>

<p>Enter a command as per the given format and press <kbd>Enter</kbd>.</p>

<p>e.g. <code>overlay@logo -1 x 100</code></p>

CC BY-SA 3.0
2017-04-27T08:12:12.640Z
Thank you very much, I intensively searched for it without a success.
MarianD
CC BY-SA 4.0
2017-04-27T07:45:29.893Z
2018-11-18T15:09:51.117Z
2018-11-18T15:09:51.117Z
Gyan
<p>In the <a href="http://ffmpeg.org/ffmpeg-filters.html" rel="nofollow noreferrer">FFmpeg Filters Documentation</a> some filters have a subsection "Commands" which begins with the sentence</p>

<blockquote>
  <p>This filter supports the following commands:</p>
</blockquote>

<p>e. g. in the section <a href="http://ffmpeg.org/ffmpeg-filters.html#volume" rel="nofollow noreferrer">6.68 volume</a>.</p>

<p>Filters have <em>parameters</em>; it is understandable. But what is the meaning of filter <em>commands</em> and how and when are they used?</p>

<ffmpeg>
What does it mean "This filter supports the following commands"?
MarianD
# What does it mean "This filter supports the following commands"?

(Asked by: username_0 on 2017-04-27)

In the [FFmpeg Filters Documentation](http://ffmpeg.org/ffmpeg-filters.html) some filters have a subsection "Commands" which begins with the sentence

> This filter supports the following commands:

e. g. in the section [6.68 volume](http://ffmpeg.org/ffmpeg-filters.html#volume).

Filters have *parameters*; it is understandable. But what is the meaning of filter *commands* and how and when are they used?

**Tags:** ffmpeg


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## 1 answers

### Answer by username_1 on 2017-04-27. Score: 3 | Accepted answer

Commands allow you to change the parameters during execution of the command. This is primarily useful when working with streaming media e.g. if the volume gets too loud during a broadcast, send a command to the volume filter to lower it.
To issue commands to filters which support it from outside, ffmpeg has to be compiled with libzmq support. See the docs for the zmq filter for details.
To issue commands from the terminal, press c
The 'command prompt' will be shown :
Enter command: |all |-1 [ ]

Enter a command as per the given format and press Enter.
e.g. overlay@logo -1 x 100

> **Comments:**
> **username_0**: Thank you very much, I intensively searched for it without a success.  

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