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How can I strip the audio track out of a video file with FFmpeg?

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6 Answers 6

778

You remove audio by using the -an flag:

input_file=example.mkv
output_file=example-nosound.mkv

ffmpeg -i $input_file -c copy -an $output_file

This ffmpeg flag is documented here.

7
  • 5
    I'm a bash and ffmpeg newbie but I put this answer together with some other pieces to create function ffsilent { ffmpeg -i $1 -c copy -an "$1-nosound.${1#*.}" } which you can use in your profile to quickly create a silent version of any video file.
    – Aaron
    Commented Dec 16, 2019 at 15:18
  • 10
    @Aaron nice, but should be function ffsilent { ffmpeg -i "$1" -c copy -an "${1%.*}-nosound.${1#*.}" } or you'll end up with "file.mp4-nosound.mp4" when using it on "file.mp4". Commented Jul 7, 2020 at 8:52
  • 1
    This doesn't carry over GPS coordinates.
    – Donny V
    Commented Dec 8, 2020 at 16:43
  • 4
    @rlittles Yes, -c copy always avoids re-encoding, If it can't it will fail with an error. Commented Jul 10, 2022 at 0:35
  • 2
    Be sure to put the -an flag before $output_file
    – Jan
    Commented Apr 12, 2023 at 14:11
139

You probably don't want to reencode the video (a slow and lossy process), so try:

input_file=example.mkv
output_file=example-nosound.mkv

ffmpeg -i $input_file -vcodec copy -an $output_file

(n.b. some Linux distributions now come with the avconv fork of ffmpeg)

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  • 2
    This didn't make any difference to me compared to the accepted solution.
    – nidi
    Commented Dec 29, 2017 at 0:49
  • 8
    vcodec is an alias for -c:v, so specifically it'd copy the video stream only. The only data you're preventing with this would be subtitles, metadata, etc from what I can see.
    – Rogue
    Commented Mar 8, 2018 at 15:48
  • 3
    In other words, this solution can conceivably lose more information than the accepted solution.
    – Alex
    Commented Feb 25, 2020 at 15:12
  • 2
    We can call this "only video" solution :+1: Commented Nov 1, 2021 at 10:44
  • 3
    I agree: This here is the "copy video only" solution, whereas the accepted answer is the "copy everything but audio" solution.
    – porg
    Commented Nov 9, 2022 at 19:03
13
avconv -i [input_file] -vcodec copy -an [output_file]

If you cannot install ffmpeg because of existing of avconv try that .

3

I put together a short code snippet that automates the process of removing audio from videos files for a whole directory that contains video files:

FILES=/{videos_dir}/*
output_dir=/{no_audio_dir}
for input_file in $FILES
do
  file_name=$(basename $input_file)
  output_file="$output_dir/$file_name"
  ffmpeg -i $input_file -c copy -an $output_file
done

I hope this one helps!

2
  • Out of interest, how would I use this snippet when there are spaces in the video dir (and output dir)? Commented Aug 12, 2022 at 14:26
  • @PaulSkinner adding quotes should be enough eg: file_name=$(basename "$input_file")
    – George
    Commented Jan 6, 2023 at 13:27
3

You can also use the -map option of ffmpeg to get better control on what exactly will be put into the final video container.

Lets say for example that your video file my_video.mp4 is composed this way:

Input #0
  Stream #0:0 Video: h264
  Stream #0:1 Audio: English
  Stream #0:2 Audio: German
  Stream #0:3 Audio: Japanese
  Stream #0:4 Audio: Spanish
  Stream #0:5 Audio: Italian

To remove all audio tracks (like the -an option does):

ffmpeg -i my_video.mp4 -map 0 -map -0:a -c copy my_video.noaudio.mp4`

-map 0 grabs the entire input (videos, audios, subtitles, metadata, chapters, etc.).
-map -0:a removes all audio tracks from input 0 (notice the - sign).
-c copy copies as it is without re-encoding.

To remove the Japanese and Spanish tracks:

ffmpeg -i my_video.mp4 -map 0 -map -0:3 -map -0:4 -c copy my_video.nojap.noesp.mp4`

-map -0:3 removes the 3rd track from input 0, which is the Japanese audio.
-map -0:4 removes the 4rd track from input 0, which is the Spanish audio.

To remove all audio tracks but Italian:

ffmpeg -i my_video.mp4 -map 0 -map -0:a -map 0:5 -c copy my_video.ita.mp4`

-map -0:a removes all audio tracks from input 0.
-map 0:5 inserts the 5th track from input 0, which is the Italian audio (notice NO - sign in this case).


This is also very useful also when dealing with more than one file.
For example when:

  • grabbing audio from one file
  • audio tracks from another one
  • subtitles and metadata from a third one
-2

I have taken @apolak's answer and turned it in to a recursive loop for all folders underneath the input folder. It will retain the directory layout of the input folder, and you can set a max-depth for it to recurse through. The output directory must not be a child of the input directory or it will error, to stop accidental infinite recursion. It should also be fine with spaces in filenames and paths.

NOTE: all files within the input directory will be attempted to be processed, so make sure they're all video files.

#!/bin/bash

process_files() {
    local current_dir="$1"
    local output_dir="$2"
    local max_depth="$3"
    local depth="${4:-0}" # Set default value of 0 if $4 is not set
    if [ "$depth" -gt "$max_depth" ]; then
        return
    fi
    # Check if output directory is a subdirectory of the input directory and error
    # This should stop accidental recursive loops
    if [[ "$output_dir" == "$current_dir"* ]]; then
        echo "Error: Output directory is a subdirectory of the input directory"
        exit 1
    fi
    mkdir -p "$output_dir"
    for input_file in "$current_dir"/*
    do
        if [ -d "$input_file" ]; then
            # If the input file is a directory, recurse into it
            process_files "$input_file" "$output_dir/$(basename "$input_file")" "$max_depth" "$((depth+1))"
        elif [ -f "$input_file" ]; then
            # If the input file is a regular file, process it
            local file_name=$(basename "$input_file")
            local output_file="$output_dir/$file_name"
            ffmpeg -i "$input_file" -c copy -an "$output_file"
        fi
    done
}

# Call function with input and output directories and maximum depth
process_files "/Volumes/Storage/ORIGINAL" "/Volumes/Storage/MUTED" 2 # Set the maximum recursion depth to 2

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