How to Extract Audio from Video Using FFmpeg (MP4 to MP3)

Ever wanted to convert a video lecture into an audio file to listen to on your commute? Or maybe save the song from a music video as an MP3? With FFmpeg, you don't need any complex software—just a single command line to extract audio perfectly.

🚀 Quick Path: The FFmpeg Command

To extract the full audio track from a video file (e.g., lecture.mp4) and save it as an MP3, use this command:

ffmpeg -i lecture.mp4 -vn audio.mp3

After running this, you will get a file named audio.mp3 containing only the sound from the original video.

🧠 The Breakdown: What Each Parameter Means

The key to this command is the -vn parameter. Let's break it down:

Parameter	Explanation	Example
ffmpeg	The command to start the FFmpeg program.	ffmpeg
-i lecture.mp4	-i stands for "input," followed by your source video file.	-i music_video.mp4
-vn	This is short for "Video No." It tells FFmpeg to completely discard the video stream and not process it.	-vn
audio.mp3	The output audio filename. FFmpeg uses the .mp3 extension to automatically apply the MP3 encoder.	podcast_episode.mp3

FAQ & Variations

Q: Can I control the quality of the output MP3?

A: Absolutely! You can use the -ab (audio bitrate) parameter to specify the bitrate for the audio. A higher bitrate results in better quality and a larger file. 192k is a great choice for general use, while 320k is often considered standard for high-quality MP3s.

For example, to extract a high-quality 320kbps MP3:

ffmpeg -i music_video.mp4 -vn -ab 320k song.mp3

Q: How can I extract a specific segment of the audio instead of the whole thing?

A: That's just as easy! You can combine the -ss (start time) and -to (to time) or -t (duration) parameters.

For example, to extract only 60 seconds of audio starting from the 10-second mark of the video:

ffmpeg -i video.mp4 -ss 00:00:10 -t 00:01:00 -vn extracted_clip.mp3

• -ss 00:00:10: Starts the process at 10 seconds in.
• -t 00:01:00: Sets the duration to 60 seconds.