Convert mp4 to h.265

convert.ps1

# Assumes all videos are in a folder called "video" sitting alongside ffmpeg
# Note conversion is likely lossy, but not noticeable in my experience and the >50% space savings were worth it to me personally
# See more detailed notes below for tuning and options

$videosToConvert = Get-ChildItem -Filter '*.mp4'

foreach ($video in $videosToConvert) {
    $destination = Join-Path 'output' $video.Name
    
    If ((Test-Path -Path $destination -PathType Leaf) -ne $true) {
        Write-Host "Processing '$($video.Name)'"

        # Choosing a different 'preset' can save you lots of time for little cost in quality
        # See also: https://streaminglearningcenter.com/blogs/cut-clients-encoding-costs-75-30-minute-phone-call.html
        .\bin\ffmpeg.exe -i $video -y -c:v libx265 -preset slower -c:a copy $destination -map_metadata 0

        # Additional options:
        # -x265-params lossless=1 (combine with `-preset veryslow` to get as close to lossless as you can, as I understand it)
        # -hwaccel cuda (try gfx acceleration)
        # -vf "transpose=1" (rotate 90 degress, for old phone videos, etc.)
    }
    else {
        Write-Host "Skipping '$($video.Name)'"
    }
}