Re-encode every FLAC above 16 bits or 44100 hz

flac-convert.ps1

param(
    [string]$Path = "."
)

Get-ChildItem -Path $Path -Recurse -Filter "*.flac" | ForEach-Object {
    $file = $_.FullName
    
    $sampleRate = [int](ffprobe -v error -select_streams a:0 -show_entries stream=sample_rate -of default=noprint_wrappers=1:nokey=1 "$file")
    $bitsStr = ffprobe -v error -select_streams a:0 -show_entries stream=bits_per_raw_sample -of default=noprint_wrappers=1:nokey=1 "$file"
    
    if ([string]::IsNullOrWhiteSpace($bitsStr) -or $bitsStr -eq "N/A") {
        $bitsStr = ffprobe -v error -select_streams a:0 -show_entries stream=bits_per_sample -of default=noprint_wrappers=1:nokey=1 "$file"
    }
    $bits = [int]$bitsStr

    if ($sampleRate -gt 44100 -or $bits -gt 16) {
        Write-Host "Re-encoding: $file ($sampleRate Hz, ${bits}-bit)"
        $tmpFile = [System.IO.Path]::ChangeExtension($file, "tmp.flac")
        
        ffmpeg -v error -i "$file" -af "aformat=sample_fmts=s16:sample_rates=44100" -map 0 -c:a flac -c:v copy "$tmpFile"
        
        if ($LASTEXITCODE -eq 0) {
            Move-Item -Path $tmpFile -Destination $file -Force
        } else {
            Write-Error "Error processing $file"
            Remove-Item -Path $tmpFile -ErrorAction SilentlyContinue
        }
    }
}