#!/usr/bin/bash

file_path="$1"

# from: https://stackoverflow.com/questions/2869281/how-to-determine-video-codec-of-a-file-with-ffmpeg
current_codec="$(
    ffprobe -v error -select_streams v:0 \
    -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 \
    "$file_path"
)"
[ "$current_codec" = 'h264' ] && { echo 'Video is already in h264'; exit 1; }

# CUDA options: -hwaccel cuda -hwaccel_output_format cuda -c:v h264_nvenc
# seems slower on gpu tho
# There is also -c:v hvec_nvenc
#
# Options to reduce size: -b:v 5M -crf 28

ffmpeg -i "$file_path" \
    -map 0 -c:v libx264 -crf 18 -vf format=yuv420p -c:a copy \
    "${file_path%%.*}-h264.${file_path##*.}"