dotfiles/bin/compress-video-with-crf

#!/usr/bin/env bash

if which tput >/dev/null 2>&1; then
    ncolors=$(tput colors)
fi
if [ -t 1 ] && [ -n "$ncolors" ] && [ "$ncolors" -ge 8 ]; then
    RED="$(tput setaf 1)"
    GREEN="$(tput setaf 2)"
    YELLOW="$(tput setaf 3)"
    BLUE="$(tput setaf 4)"
    MAGENTA="$(tput setaf 5)"
    CYAN="$(tput setaf 6)"
    BOLD="$(tput bold)"
    NORMAL="$(tput sgr0)"
else
    RED=""
    GREEN=""
    YELLOW=""
    BLUE=""
    MAGENTA=""
    CYAN=""
    BOLD=""
    NORMAL=""
fi

use_gpu=$1
use_crf=$2
output_name="$4"
start_time="$5"
end_time="$6"

if [[ $use_gpu == "" || $use_crf == "" || $3 == "" || $output_name == "" || ($start_time != "" && $end_time == "") ]]; then
    printf "${BOLD}${RED}Usage: $0 <use-gpu (1|0)> <crf value> <filename> <output name> <optional start time HH:MM:SS> <optional end time HH:MM:SS>\n\nIf you want to encode a range of CRF values then use -1 as the crf value.${NORMAL}\n"
    exit 1
fi


filename=$(basename -- "$3")
extension="${filename##*.}"
filename="${filename%.*}"

function encode() {
    crf=$1
    output="${output_name}.$extension"

    printf "\n${YELLOW}${BOLD}Encoding '$filename.$extension' | GPU: $use_gpu | CRF $crf | output: $output | start: $start_time | end: $end_time${NORMAL}\n"

    timing_args=""
    if [[ $start_time != "" ]]; then
        timing_args+="-ss $start_time -to $end_time"
    fi

    if [[ $use_gpu -eq 1 ]]; then
        # File will be slightly larger than CPU encoding, but it's much faster to transcode and doesn't max out the CPU cores.

        #ffmpeg version N-103152-gef54590f83-20210806
        # This version of ffmpeg results in larger files than version 4.3.1 command below.
        #ffmpeg -y -stats -loglevel level+error $timing_args -vsync 0 -hwaccel_output_format cuda -c:v h264_cuvid -i "$filename.$extension" -c:a copy -c:v h264_nvenc -profile:v high -rc:v vbr -cq:v $crf -b:v 5M -maxrate 5M -max_muxing_queue_size 9999 "$output"

        #ffmpeg version 4.3.1-2020-11-08
        ffmpeg -y -stats -loglevel level+error $timing_args -vsync 0 -hwaccel cuvid -c:v h264_cuvid -i "$filename.$extension" -c:a copy -c:v h264_nvenc -profile:v high -rc:v vbr_hq -cq:v $crf -b:v 5M -maxrate 5M -max_muxing_queue_size 9999 "$output"

    else
        ffmpeg $timing_args -i "$filename.$extension" -c:v libx264 -crf $crf -preset veryfast -profile:v baseline -level 3.0 -strict -2 "$output"
    fi
    printf "\n${GREEN}${BOLD}Finished encoding '$filename.$extension' (CRF $crf) | output name '$output'${NORMAL}\n\n"
}

if [[ $use_crf -ne -1 ]]; then
    encode $use_crf
else
    printf "\n${YELLOW}${BOLD}Encoding using a range of CRF values.${NORMAL}\n"

    # Bigger crf values == bigger compression.
    for crf in {25..28}
    do
        encode $crf
    done
fi