#!/usr/bin/env bash
#
set -euo pipefail
IFS=$'\n\t'
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"



function main {
    local cmd
    cmd=$1
    shift
    if [ "$cmd" = "copy" ]; then
        copy "${@}"
    elif [ "$cmd" = "h264" ]; then
        h264 "${@}"
    elif [ "$cmd" = "software_h264" ]; then
        software_h264 "${@}"
    elif [ "$cmd" = "preprocess_h264" ]; then
        preprocess_h264 "${@}"
    elif [ "$cmd" = "preprocess_vp8" ]; then
        preprocess_vp8 "${@}"
    elif [ "$cmd" = "webcam" ]; then
        webcam "${@}"
    elif [ "$cmd" = "encode_webcam" ]; then
        encode_webcam "${@}"
    else
        (>&2 echo "Unknown command: $cmd")
        exit 1
    fi
}

function copy {
    local file_to_cast
    file_to_cast="$3"

    local USERNAME PASSWORD
    USERNAME="$1"
    PASSWORD="$2"

    exec ffmpeg \
        -re \
        -stream_loop -1 \
        -i "$file_to_cast" \
        -c copy \
        -f rtsp \
        -rtsp_transport udp \
        "rtsp://$USERNAME:$PASSWORD@172.16.16.251:8554/fetch"
}

function h264 {
    local file_to_cast
    file_to_cast="$3"

    local USERNAME PASSWORD
    USERNAME="$1"
    PASSWORD="$2"

    # -bf 0 :: Disable b-frames because webrtc doesn't support h264 streams with b-frames.
    exec ffmpeg \
        -re \
        -stream_loop -1 \
        -init_hw_device vaapi=foo:/dev/dri/renderD128 \
        -hwaccel vaapi \
        -hwaccel_output_format vaapi \
        -hwaccel_device foo \
        -i "$file_to_cast" \
        -filter_hw_device foo \
        -vf 'format=nv12|vaapi,hwupload' \
        -c:v h264_vaapi \
        -bf 0 \
        -c:a aac \
        -b:a 160k \
        -ar 44100 \
        -f rtsp \
        -rtsp_transport udp \
        "rtsp://$USERNAME:$PASSWORD@172.16.16.251:8554/fetch"
}

function software_h264 {
    local file_to_cast
    file_to_cast="$3"

    local USERNAME PASSWORD
    USERNAME="$1"
    PASSWORD="$2"

    # -bf 0 :: Disable b-frames because webrtc doesn't support h264 streams with b-frames.
    exec ffmpeg \
        -re \
        -stream_loop -1 \
        -i "$file_to_cast" \
        -c:v h264 \
        -bf 0 \
        -c:a aac \
        -b:a 160k \
        -ar 44100 \
        -f rtsp \
        -rtsp_transport udp \
        "rtsp://$USERNAME:$PASSWORD@172.16.16.251:8554/fetch"
}

function preprocess_h264 {
    local file_to_cast file_to_save
    file_to_cast="$1"
    file_to_save="$2"

    # -bf 0 :: Disable b-frames because webrtc doesn't support h264 streams with b-frames.
    exec ffmpeg \
        -i "$file_to_cast" \
        -c:v h264 \
        -bf 0 \
        -c:a aac \
        -b:a 160k \
        -ar 44100 \
        "$file_to_save"
}

function preprocess_vp8 {
    local file_to_cast file_to_save
    file_to_cast="$1"
    file_to_save="$2"

    # -bf 0 :: Disable b-frames because webrtc doesn't support h264 streams with b-frames.
    # -strict -2 :: Enable support for experimental codecs like opus.
    # -b:v 1M :: Target 1 megabit/s
    # -crf 10 :: Target a quality level and adjust bitrate accordingly. This should be preferred, but ideally both should be used.
    exec ffmpeg \
        -i "$file_to_cast" \
        -c:v vp8 \
        -b:v 1M \
        -crf 10 \
        -bf 0 \
        -c:a opus \
        -b:a 320k \
        -ar 48000 \
        -strict -2 \
        "$file_to_save"
}

function webcam {
    # Uses on-webcam h264 encoding.

    local USERNAME PASSWORD
    USERNAME="$1"
    PASSWORD="$2"

    exec ffmpeg \
        -re \
        -input_format h264 \
        -video_size 1920x1080 \
        -i /dev/video0 \
        -c:v copy \
        -an \
        -f rtsp \
        -rtsp_transport udp \
        "rtsp://$USERNAME:$PASSWORD@172.16.16.251:8554/fetch"
}

function encode_webcam {
    # Uses hardware accelerated gpu-based encoding.

    local USERNAME PASSWORD
    USERNAME="$1"
    PASSWORD="$2"

    exec ffmpeg \
        -re \
        -vaapi_device /dev/dri/renderD128 \
        -i /dev/video0 \
        -vf 'format=nv12,hwupload' \
        -c:v h264_vaapi \
        -an \
        -f rtsp \
        -rtsp_transport udp \
        "rtsp://$USERNAME:$PASSWORD@172.16.16.251:8554/fetch"
}

main "${@}"