HLS ffmpeg script

hls.sh

#!/bin/bash

# Function to display usage information
usage() {
    echo "Usage: $0 /path/to/input.mp4 [ /path/to/output_directory ]"
    exit 1
}

# Check if at least one argument (input file) is provided
if [ $# -lt 1 ]; then
    usage
fi

# Assign input file and output directory from arguments
INPUT_FILE="$1"

# Check if input file exists
if [ ! -f "$INPUT_FILE" ]; then
    echo "Error: Input file '$INPUT_FILE' does not exist."
    exit 1
fi

# Check for required commands
for cmd in ffmpeg ffprobe; do
    if ! command -v $cmd &> /dev/null; then
        echo "Error: $cmd is not installed or not in PATH."
        exit 1
    fi
done

# Get the base filename without extension
FILENAME=$(basename "$INPUT_FILE")
BASENAME="${FILENAME%.*}"

# Determine input directory
INPUT_DIR=$(dirname "$INPUT_FILE")

# Assign output directory: second argument or default to current directory
if [ $# -ge 2 ]; then
    OUTPUT_BASE_DIR="$2"
    # Create the output base directory if it doesn't exist
    mkdir -p "$OUTPUT_BASE_DIR"
else
    OUTPUT_BASE_DIR="$PWD"
fi

# Create specific output directory within the base output directory using the base filename
OUTPUT_DIR="$OUTPUT_BASE_DIR/$BASENAME"

# Remove existing output directory if it exists
if [ -d "$OUTPUT_DIR" ]; then
    echo "Output directory '$OUTPUT_DIR' already exists. Removing it to avoid unused .ts files."
    rm -rf "$OUTPUT_DIR"
fi
mkdir -p "$OUTPUT_DIR"

# Get the frame rate of the input video
FRAME_RATE=$(ffprobe -v 0 -of default=noprint_wrappers=1:nokey=1 \
    -select_streams v:0 -show_entries stream=avg_frame_rate "$INPUT_FILE")

# Convert frame rate to a number
IFS='/' read -r num denom <<< "$FRAME_RATE"
if [ -z "$denom" ] || [ "$denom" -eq 0 ]; then
    denom=1
fi
FRAME_RATE=$(echo "scale=2; $num/$denom" | bc)
FRAME_RATE=${FRAME_RATE%.*}

# Calculate GOP size (number of frames per 4 seconds)
GOP_SIZE=$((FRAME_RATE * 4))

# Define resolutions, bitrates, and output names
RESOLUTIONS=("1280x720" "1920x1080" "3840x2160")
BITRATES=("1200k" "2500k" "8000k")
OUTPUTS=("720p" "1080p" "2160p")
PLAYLISTS=()

# Loop over the variants
for i in "${!RESOLUTIONS[@]}"; do
    RES="${RESOLUTIONS[$i]}"
    BITRATE="${BITRATES[$i]}"
    OUTPUT_NAME="${OUTPUTS[$i]}"
    PLAYLIST="${OUTPUT_NAME}.m3u8"
    PLAYLISTS+=("$PLAYLIST")

    # Set profile and level based on resolution
    if [ "$OUTPUT_NAME" == "2160p" ]; then
        PROFILE="high"
        LEVEL="5.1"
    elif [ "$OUTPUT_NAME" == "1080p" ]; then
        PROFILE="high"
        LEVEL="4.2"
    else
        PROFILE="main"
        LEVEL="3.1"
    fi

    echo "Processing $OUTPUT_NAME..."

    if ! ffmpeg -y -i "$INPUT_FILE" \
    -c:v libx264 -preset veryfast -profile:v "$PROFILE" -level:v "$LEVEL" -b:v "$BITRATE" -s "$RES" \
    -c:a aac -b:a 128k -ac 2 \
    -g $GOP_SIZE -keyint_min $GOP_SIZE -sc_threshold 0 \
    -force_key_frames "expr:gte(t,n_forced*4)" \
    -hls_time 4 -hls_list_size 0 -hls_flags independent_segments \
    -hls_segment_filename "$OUTPUT_DIR/${OUTPUT_NAME}_%03d.ts" \
    "$OUTPUT_DIR/$PLAYLIST"; then
        echo "Error: Failed to process $OUTPUT_NAME."
        exit 1
    fi
done

# Generate master playlist
MASTER_PLAYLIST="$OUTPUT_DIR/playlist.m3u8"

echo "Generating master playlist..."
{
    echo "#EXTM3U"
    echo "#EXT-X-VERSION:3"

    for i in "${!RESOLUTIONS[@]}"; do
        RESOLUTION="${RESOLUTIONS[$i]}"
        OUTPUT_NAME="${OUTPUTS[$i]}"
        PLAYLIST="${OUTPUTS[$i]}.m3u8"
        BITRATE="${BITRATES[$i]}"
        BANDWIDTH=$(( ${BITRATE%k} * 1000 + 128000 )) # Video bitrate + audio bitrate in bits per second

        echo ""
        echo "#EXT-X-STREAM-INF:BANDWIDTH=$BANDWIDTH,RESOLUTION=$RESOLUTION"
        echo "$PLAYLIST"
    done
} > "$MASTER_PLAYLIST"

echo "Processing completed successfully."
echo "Output directory: $OUTPUT_DIR"

Usage: ./hls.sh /path/to/input.mp4 [ /path/to/output_directory ]

@stenuto awesome! I wrote something similar in TypeScript because bash is hard - I only specify the height and let the width of the video be detected in case I ever have videos that are different aspect ratios: https://github.com/wesbos/R2-video-streaming/blob/main/transcode.ts

@wesbos yep, good idea on the different aspect ratios! It'd be cool if the bitrates also adjusted based on the resolution/actual pixel count. For example, a square 1080p video should have a higher bitrate than a 16:9 1080p video. Splitting hairs, but these are the things we think about. 🤷‍♂️

Pretty quickly you realize why people pay for a service haha :D

Awesome work @stenuto

This is awesome! Thanks for sharing @stenuto. I made a python version which is slightly faster due to preset: ultrafast | threads: 0 config options.

https://gist.github.com/nwaughachukwuma/ad42141a8c0ab37bdf95ad15abad0b20

Pretty Awesome Neat . Thanks for sharing , I have made something similar using JavaScript but I generate a dynamic ffmpeg hls command based input video and audio quality and ratio and so all in just one command .

Thank you for sharing. Awesome work.

Thanks!

Thank you very much for sharing, this is really awesome and helpful .

@stenuto thanks for the script :)

I believe the framerate part can be done a bit more simply with

FRAME_RATE=$(ffprobe -v 0 -select_streams v:0 -show_entries stream=avg_frame_rate \
    -of csv=p=0 "$INPUT_FILE" | awk -F'/' '{printf "%.0f", ($1 / ($2 ? $2 : 1))}')

The of flag does what you need in your case.

Btw, the awk part is only needed if the denom is zero, if you are sure it doesn't happen, you could just pipe this to bc

Cool script, but no support for 480? :(