You may have found yourself in a situation where you have to modify a video or extract its audio. Firing up a complete editor for such simple tasks could be a waste of energy and time.

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Here are some basic tips for FFmpeg that can sometimes make your workflow more efficient:

Change the aspect ratio of a video without re-encoding

This can be useful when the only thing we want to do is changing the proportions of a video without losing quality.

For example for converting a 4:3 video to an stretched 16:9:

ffmpeg -i in.mp4 -aspect 16:9 -c copy out.mp4

The -c copy option allows setting up the codec to a copy mode where ffmpeg doesn’t reencode the video and the results are done immediately.

Extracting audio from a file

ffmpeg -i in.mp4 out.mp3

Note: the extensions shown here are completely arbitrary, ffmpeg supports a wide variety of codecs and formats which can be seen with the commands ffmpeg -codecs and ffmpeg -formats

Cutting a video file without reencoding

ffmpeg -i in.mp4 -ss 00:00:25.0 -codec copy -t 30 out.mp4

In this case the cut starts on second 25 and the video lasts 30 seconds

Converting a video to other format

ffmpeg -i in.ogv -c:v libx264 out.mp4

• -c:v libx264 sets the video codec
• -c:a vorbis sets the audio codec
• -r 25 sets the framerate to 25fps
• -s <1280x720|hd720> sets the video resolution to 720p
• -b:v 1M sets the video bitrate to 1MB/s