Transcode 720 to 1080 with ffmpeg

trans.sh

#!/bin/bash

# This script downsizes video files from 1080 to 720 resolution using ffmpeg.
# It expects input files in ./movies and an output dir ./720.

transcode ()
{
file=$1
indir=$2
outdir=$3

quality=23 # 0 - 51 (best - worst). default: 23.

ffmpeg -i $indir/$file \
	-map 0:0 -map 0:1 -map 0:2 -map 0:3 -map 0:4 \         # channel map for 2 audio and 2 sub titles
	-vf scale=-1:720 -c:v libx264 -crf $quality -preset fast \
	-c:a:0 copy -c:a:1 copy -c:s copy $outdir/720-"$file"  # copy channels

}


inputdir="movies"
outputdir="720"
for f in `ls -1 $inputdir`; do
  transcode $f $inputdir $outputdir
done