ffmpeg commands

This page contains ffmpeg commands that I find useful. ffmpeg is super powerful and can sometimes be enough for quick media manipulations. For more commands check the ffmpeg documentation page.

Cut a part of a video :

• use ss to select the starting and ending time
• to avoid re-enconding the video, use stream copy via -c, define the video with v and the codec (libx264 in the example)
• use -crf to define quality (lesser is better)

Concatenate videos

Create a text file with the files you want to concatenate into a single video or audio file.

file 'video1.mp4'
file 'video2.mp4'
file 'video4.mp4'

• Use -c copy to avoid re-enconding the videos (they need to have the same base codec)

Add audio to video

• the -c copy avoid re-encoding the streams
• the first -map defines where to start the audio in the video file
• the second -map defines where to start the audio in the audio file

Encode audio file to mp3

• -ar defines the frequency (here it's 44100)
• -ac sets the number of audio channels (here 2)
• -b:a defines the bitrate of the file (here 128k)

Add metatags to audio file

• -i img.jpg adds an image to the audio file
• -c copy to avoid re-encoding the image file
• -map 0 -map 1 position the image
• -metadata title="title" defines the title of the file in the metadatas