encode.sh

#!/bin/bash
# Usage: ./encode.sh input.mp4 output_dir
set -e

INPUT="${1:-input.mp4}"
OUT="${2:-output}"

mkdir -p "$OUT"/{720p,480p,270p,audio}

ffmpeg -i "$INPUT" \
  -filter_complex "
    [0:v]split=3[v720raw][v480raw][v270raw];
    [v720raw]scale=720:1280:force_original_aspect_ratio=decrease,pad=720:1280:(ow-iw)/2:(oh-ih)/2[v720];
    [v480raw]scale=480:854:force_original_aspect_ratio=decrease,pad=480:854:(ow-iw)/2:(oh-ih)/2[v480];
    [v270raw]scale=270:480:force_original_aspect_ratio=decrease,pad=270:480:(ow-iw)/2:(oh-ih)/2[v270]
  " \
  -map "[v720]" -map "[v480]" -map "[v270]" -map 0:a \
  \
  -c:v:0 libx264 -b:v:0 1800k -maxrate:v:0 1861k -bufsize:v:0 3722k \
    -profile:v:0 high -level:v:0 4.0 \
  \
  -c:v:1 libx264 -b:v:1 800k -maxrate:v:1 837k -bufsize:v:1 1674k \
    -profile:v:1 high -level:v:1 3.1 \
  \
  -c:v:2 libx264 -b:v:2 350k -maxrate:v:2 371k -bufsize:v:2 742k \
    -profile:v:2 high -level:v:2 3.0 \
  \
  -c:a:0 aac -b:a:0 128k -ac 2 -ar 48000 \
  \
  -f hls \
  -hls_time 6 \
  -hls_playlist_type vod \
  -hls_flags independent_segments \
  -hls_segment_type fmp4 \
  -hls_fmp4_init_filename "init.mp4" \
  -hls_segment_filename "$OUT/%v/%03d.m4s" \
  -master_pl_name "master.m3u8" \
  -var_stream_map "v:0,agroup:audio-hi-0,name:720p v:1,agroup:audio-hi-0,name:480p v:2,agroup:audio-hi-0,name:270p a:0,agroup:audio-hi-0,language:und,default:yes,name:audio" \
  "$OUT/%v/rendition.m3u8"

echo "Done → $OUT/master.m3u8"