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

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5 Answers 5

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703

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.

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  • 3
    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
    Dec 16, 2019 at 15:18
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    @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".
    – Alexander Revo
    Jul 7, 2020 at 8:52
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    This doesn't carry over GPS coordinates.
    – Donny V
    Dec 8, 2020 at 16:43
  • Using -c copy -an works on most video files but it won't strip audio from SWF (Shockwave Flash) files. The solution is to shorten it to just -an then it works.
    – bat_cmd
    Apr 4, 2021 at 0:18
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    @rlittles Yes, -c copy always avoids re-encoding, If it can't it will fail with an error.
    – TheRandomGuyNamedJoe12
    Jul 10, 2022 at 0:35
131

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
    Dec 29, 2017 at 0:49
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    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
    Mar 8, 2018 at 15:48
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    In other words, this solution can conceivably lose more information than the accepted solution.
    – Alex
    Feb 25, 2020 at 15:12
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    We can call this "only video" solution :+1:
    – Vladimir Vukanac
    Nov 1, 2021 at 10:44
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    I agree: This here is the "copy video only" solution, whereas the accepted answer is the "copy everything but audio" solution.
    – porg
    Nov 9, 2022 at 19:03
12 
avconv -i [input_file] -vcodec copy -an [output_file]

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

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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!

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  • Out of interest, how would I use this snippet when there are spaces in the video dir (and output dir)?
    – PaulSkinner
    Aug 12, 2022 at 14:26
  • @PaulSkinner adding quotes should be enough eg: file_name=$(basename "$input_file")
    – George
    Jan 6 at 13:27
0

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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