How to recursively convert files in all folders and subfolders?

Question

Windows

How to execute this code in Windows (not 10) cmd

find . -type f -iname "*.webm" -exec bash -c 'FILE="$1"; ffmpeg -i "${FILE}" -vn -ab 128k -ar 44100 -y "${FILE%.webm}.mp3";' _ '{}' \;

???
source

Answer 1

By default, do nothing. There is no find command in Windows - this is a purely nix command.
But you can install some ported set of Linux utilities (for example, msys2 or something else) and run this command from under it.
In general, this is not difficult to rewrite for cmd:

@echo off
for /f "tokens=* delims=" %%a in ('dir /b /s *.webm') do ffmpeg -i "%%a" -vn -ab 128k -ar 44100 -y "%%~dpna.mp3"

Save the code in a batch file in the directory with files and run.
ffmpeg must be available to run from the command line, if not available, then you need to specify the full path to it.
The code has not been tested.

Answer 2

Through powershell:

$files = Get-ChildItem -Recurse -Include *.webm
foreach ($f in $files){
   $inFile = '"' + $f.Fullname + '"'
   $outFile = $infile.replace('.webm','.webm.mp3')
   ffmpeg -i $inFile -vn -ab 128k -ar 44100 -y $outFile
}