Remove unnecessary audio streams from video files using ffmpeg.

ffmpeg-singleaudiostream.sh

#!/bin/bash

files=${1-"*.avi"};
audio_stream=${2-"0:1"};
video_stream=${3-"0:0"};
output_dir=${4-output};

echo -e "\e[0;33m";
echo "       Files: $files";
echo "Video stream: $video_stream";
echo "Audio stream: $audio_stream";
echo "  Output dir: $output_dir";
echo -e "\e[0m";

read -p "Continue? (y/n)" continue
case "$continue" in
	y*)  break;;
	n*)  exit;;
esac

mkdir $output_dir;

for f in $files;
	do ffmpeg -i "$f" -map $video_stream -map $audio_stream -vcodec copy -acodec copy "$output_dir/$f";
done

Usage:

ffmpeg-singleaudiostream.sh [files] [audio_stream] [video_stream] [output_dir]

ffmpeg-singleaudiostream.sh "*.avi" 0:1 0:0 output

@muchbetterbig 30 bucks to replace a one liner command is not a good deal if you ask me :)