#!/bin/sh

DestVolume="-33.0"

cd /sdcard/DCIM/ScreenRecorder
[ ! -z "$1" ] && File="$1" || File="$(ls *.mp4 -t | head -n1)"

ffmpeg \
	-i "$File" \
	-af volumedetect -f null /dev/null \
	> ffmpeg.volumedetect.log 2>&1
StartVolume="$(grep mean_volume ffmpeg.volumedetect.log | tail -n1 | rev | cut -d' ' -f2 | rev)"

Volume="$(echo "0 - ($StartVolume - $DestVolume)" | bc)"
ffmpeg \
	-i "$File" \
	-af volume="${Volume}dB" \
	-vf crop=600:450:60:463 \
	"New-$File"