<p>FFmpeg's segment muxer is designed for this.</p>

<pre><code>ffmpeg -i in.mp4 -c copy -f segment -segment_time 1200 -reset_timestamps 1 in%d.mp4
</code></pre>

<p>Output files will be <code>in0.mp4</code>, <code>in1.mp4</code>...</p>

<p>Since the video keyframes in the source file may not be present exactly at the start of each 20 minute interval, the output segments won't be exactly 20 minutes each. Expect a deviation of a few seconds.</p>

CC BY-SA 3.0
2018-04-23T06:32:29.767Z
2018-04-23T06:32:29.767Z
Gyan
<p>Try <a href="http://avidemux.sourceforge.net/" rel="nofollow noreferrer">avidemux</a>. Alternatively, if you're comfortable with command-line tools, you can use <code>ffmpeg</code>. Here's an answer from <a href="https://askubuntu.com/questions/35605/splitting-an-mp4-file?utm_medium=organic&amp;utm_source=google_rich_qa&amp;utm_campaign=google_rich_qa">Ask Ubuntu</a> that shows how to do it.</p>

CC BY-SA 3.0
2018-04-23T05:02:28.617Z
2018-04-23T05:02:28.617Z
0x9dedbaf9
<p>Does anyone know of software (preferably free) which can be used to divide up a video or audio file into a number of smaller sized pieces at regular intervals? (e.g. to turn a 3-hour video file into nine 20-minute video files)?</p>

<video><editing><freeware>
Splitting files automatically
Andy
# Splitting files automatically

(Asked by: username_0 on 2018-04-22)

Does anyone know of software (preferably free) which can be used to divide up a video or audio file into a number of smaller sized pieces at regular intervals? (e.g. to turn a 3-hour video file into nine 20-minute video files)?

**Tags:** video, editing, freeware


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## 2 answers

### Answer by username_1 on 2018-04-23. Score: 2

FFmpeg's segment muxer is designed for this.
ffmpeg -i in.mp4 -c copy -f segment -segment_time 1200 -reset_timestamps 1 in%d.mp4

Output files will be in0.mp4, in1.mp4...
Since the video keyframes in the source file may not be present exactly at the start of each 20 minute interval, the output segments won't be exactly 20 minutes each. Expect a deviation of a few seconds.


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### Answer by username_2 on 2018-04-23. Score: 0

Try [avidemux](http://avidemux.sourceforge.net/). Alternatively, if you're comfortable with command-line tools, you can use `ffmpeg`. Here's an answer from [Ask Ubuntu](https://askubuntu.com/questions/35605/splitting-an-mp4-file?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa) that shows how to do it.


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