Encodes and segments an MP4 video for adaptive streaming over various network conditions.

adapt.sh

#!/bin/bash

# Encodes and segments an MP4 video for adaptive streaming over various network conditions.
# It supports resolutions ranging from 360p to 1080p and creates both HLS and MPEG-DASH playlists.
# Assumes ffmpeg is installed and in the path. Usage: ./encode.sh <video_file>

set -euo pipefail

if [ -z "$1" ]; then
  echo "Usage: $0 <video_file>"
  exit 1
fi

input="$1"
if [ ! -f "$input" ]; then
  echo "Error: File '$input' not found!"
  exit 1
fi

input_type=$(file --brief --mime-type "$input")
if [ "$input_type" != "video/mp4" ]; then
  echo "Error: File '$input' is not a valid MP4 video!"
  exit 1
fi

output_dir="${input%.*}_streaming_output"
if [ -d "$output_dir" ]; then
  echo "Error: Output directory '$output_dir' already exists!"
  exit 1
fi
mkdir -p "$output_dir"

# Encoding profiles for various network conditions.
resolutions=("640x360" "854x480" "1280x720" "1920x1080")
bitrates=("400k" "800k" "1500k" "3000k")
profiles=("360p" "480p" "720p" "1080p")

# Encode and segment the video for each profile.
for i in "${!resolutions[@]}"; do
  resolution=${resolutions[$i]}
  bitrate=${bitrates[$i]}
  profile=${profiles[$i]}
  ffmpeg -i "$input" -vf "scale=$resolution" -c:v libx264 -profile:v main -level 3.1 -b:v "$bitrate" -c:a aac -b:a 128k -g 48 -keyint_min 48 -sc_threshold 0 -hls_time 4 -hls_playlist_type vod -hls_segment_filename "$output_dir/${profile}_%03d.ts" "$output_dir/${profile}.m3u8"
  ffmpeg -i "$input" -vf "scale=$resolution" -c:v libx264 -profile:v main -level 3.1 -b:v "$bitrate" -c:a aac -b:a 128k -g 48 -keyint_min 48 -sc_threshold 0 -dash 1 -f dash "$output_dir/${profile}.mpd"
done

# Create master HLS playlist.
echo "#EXTM3U" > "$output_dir/master.m3u8"
for i in "${!profiles[@]}"; do
  profile=${profiles[$i]}
  bitrate=$((${bitrates[$i]%k} * 1000 + 128000)) # Remove the "k" suffix, multiply by 1000, and add 128000
  echo "#EXT-X-STREAM-INF:BANDWIDTH=$bitrate,RESOLUTION=$profile" >> "$output_dir/master.m3u8"
  echo "${profile}.m3u8" >> "$output_dir/master.m3u8"
done

echo "Done"