For those who don't know the default location for ffmpeg encoder on their server (administrator/index.php?option=com_easysocial&view=settings&layout=form&page=audios), a few lines php might clarify things. I used the following script to find my path. Perhaps integrate it with a button?

<?php
// Use 'which' or 'type -P' to find the absolute path
$ffmpeg_path = trim(shell_exec('which ffmpeg'));
if (empty($ffmpeg_path)) {
$ffmpeg_path = trim(shell_exec('type -P ffmpeg'));
}

if (!empty($ffmpeg_path)) {
echo "FFmpeg gevonden op: " . htmlspecialchars($ffmpeg_path) . "\n";
// You can now use this path in your further FFmpeg commands
// Example:
// shell_exec($ffmpeg_path . ' -i input.mp4 output.avi');
} else {
echo "FFmpeg not found in system PATH.\n";
}
?>