Convert AVI to MP4 with ffmpeg

avi2mp4.sh

#! /bin/bash
timestamp=$( date +"%Y%m%d" )
base=${file%.*}
a1=$(ffprobe -i $VID 2>&1 |grep 'Stream #0:1'.| sed 's/\s.*$//') 
a2=$(ffprobe -i $VID 2>&1 |grep 'Stream #0:2'.| sed 's/\s.*$//')
dir=$(pwd)

for VID in /media/gp/*.avi
do
                #create folder
		echo "Found ${VID}... Starting ffmpeg."
		mkdir `basename ${VID%%.*}`
		chmod -R 0777 `basename ${VID%%.*}`
		cp $VID `basename ${VID%%.*}`
		cd `basename ${VID%%.*}`
		
		#check if video has two audio streams
		if [ "$a1"="Stream #0:1: Audio: pcm_" ] && [ "$a2"="Stream #0:2: Audio: pcm_" ]
		then
	        ffmpeg -i $VID -map 0:1 -c copy audio0.wav -map 0:2 -c copy audio1.wav
	        ffmpeg -i audio1.wav -vn -ss 00:00:00 -t 00:00:01 noiseaud.wav
	        sox noiseaud.wav -n noiseprof noise.prof
	        sox audio1.wav audio1_clean.wav noisered noise.prof 0.21
	        fi
	        
	        if [ -f /media/gp/`basename ${VID%%.*}`/audio0.wav ] && [ -f /media/gp/`basename ${VID%%.*}`/audio1.wav ] 
	        then
	        echo "Two audio files present"
	           ffmpeg -i $VID -crf 17 -preset veryfast -codec:v libx264 -threads 2 -strict experimental -b:a 256k -ac 2 -an `basename $VID avi`'mp4'
	           rm *.prof noiseaud.wav audio1.wav *.avi
	        else
	        echo "One audio file present"
	           ffmpeg -i $VID -crf 17 -preset veryfast -codec:v libx264 -threads 2 -strict experimental -b:a 256k -ac 2 `basename $VID avi`'mp4'
               fi
done

process_ffmpeg.sh

#!/bin/bash

pipe=/tmp/ffmpeg

trap "rm -f $pipe" EXIT

# creating the FIFO    
[[ -p $pipe ]] || mkfifo $pipe

while true; do
    # can't just use "while read line" if we 
    # want this script to continue running.
    read line < $pipe

    # now implementing a bit of security,
    # feel free to improve it.
    # we ensure that the command is a ffmpeg one.
    [[ $line =~ ^ffmpeg ]] && bash <<< "$line"
done