<?php
return [
    
    // image
    'image/jpeg' => 'jpg',
    'image/bmp' => 'bmp',
    'image/x-ms-bmp' => 'bmp',
    'image/png' => 'png',
    'image/gif' => 'gif',
    
    // audio
    'audio/mp3' => 'mp3',
    'audio/mpeg' => 'mp3',
    'application/ogg' => 'ogg',
    'audio/ogg' => 'ogg',
    'audio/mp4' => 'm4a',
    'audio/x-m4a' => 'm4a',
    'audio/x-wav' => 'wav',
    'audio/flac' => 'flac',
    'audio/x-flac' => 'flac',
    'audio/x-ape' => 'ape',
    
    // video
    'video/mp4' => 'mp4',
    'video/mpeg' => 'mpg',
    'video/quicktime' => 'mov',
    'video/x-matroska' => 'mkv',
    'video/x-flv' => 'flv',
    'video/x-msvideo' => 'avi',
    
    // compress
    'application/zip' => 'zip',
    'application/x-rar-compressed' => 'rar',
    'application/x-rar' => 'rar',
    'application/x-7z-compressed' => '7z',
    
    // doc
    'application/msword' => 'doc',
    'application/vnd.ms-excel' => 'xls',
    'application/vnd.ms-powerpoint' => 'ppt',
    'application/vnd.openxmlformats-officedocument.wordprocessingml.document' => 'docx',
    'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' => 'xlsx',
    'application/vnd.openxmlformats-officedocument.presentationml.presentation' => 'pptx',
    'application/pdf' => 'pdf'
];