Your Mac’s Finder has a built-in feature called “Quicklook” that gives you thumbnail previews of many types of files. It’s particularly helpful for skimming through graphic files since you can see in Cover Flow view if the image is a house, a horse, or a horsefly. For video files, however, Apple skimped a bit; the factory-stock Quicklook previews only .mov and MPEG-related formats. When you browse Cover Flow-style through .flv or other types, all you get is a generic video file icon. The good news is you can extend Quicklook’s capabilities with QLVideo, a free plug-in software program that adds video types to Quicklook.
The QLVideo plug-in works on Macs running OS X/macOS versions 10.9 (Mavericks) or later. The installation package file weighs in at a trim 14MB, so the plug-in is easy on your Mac’s resources.
Where to Get It
QLVideo installs much like any Mac app. Locate the .pkg file (e.g. QLVideo_187.pkg) you just downloaded, then double-click it. The installer will walk you through a few steps such as agreeing to the software license and selecting a destination drive to install to. Enter your administrator password when prompted. The installer will display a message when the plug-in has installed successfully.
After installing QLVideo and before using it for the first time, restart the Finder by logging out, then logging back in again. Click the Finder icon in the Dock and browse to a folder of video files, especially .flv and others not native to the Mac world. In the Finder click the “Cover Flow” icon to change the view, if necessary. At first you may see only generic icons. After a few minutes, Quicklook generates preview images from the videos which will appear in place of the generic icons. Flip back and forth through the images as you would for any Cover Flow view.
The Finder can play .mp4 and related files in Cover Flow. As you browse the files in Cover Flow, a play button appears in the video thumbnail. However, even with the QLVideo plug-in, to play .flv and other non-native video formats, you need a separate player app such as VLC or MplayerX. The play button will not appear in the Quicklook preview for non-native formats.
Some video files use a trick called “interlacing” which gives the appearance of smooth motion while reducing the amount of data needed. With the QLVideo plug-in, thumbnails of interlaced videos may appear blurry or distorted.
How to Remove
Chances are you’ll never have to remove the QLVideo plug-in from your Mac. However, should you find it necessary, the developer has made the process fairly straightforward, if a little technical. First, open a window in the Terminal app. Next, copy and paste the following text into the Terminal window, then press Enter:
sudo rm -rf "/Library/Application Support/QLVideo" "/Library/QuickLook/Video.qlgenerator" "/Library/Spotlight/Video.mdimporter"
Enter your Mac’s system administrator password when prompted.
When it comes to video thumbnails, the Finder’s Quicklook covers only a handful of file types. However, you can extend its capabilities with third-party plug-in files. One such plug-in, called QLVideo, adds avi, flv, and several other video types to Quicklook’s repertoire. With QLVideo, file browsing becomes easier for those with large video libraries.