Streaming videos are fun to watch, but you can only view them when you're connected to the Internet. There are various ways you can attempt to save these videos for offline use on your Mac. Some methods will give better-quality results, but may not work with some websites.
What Is Streaming?
In the early years of personal computers, multimedia content like videos was stored as files on hard drives and distributed on CDs or DVDs. Streaming video refers to video content that is played over a network, typically the Internet, without a video file being stored on your computer. Given a suitably fast Internet connection, the video can start playing quickly, before most of the video is actually downloaded. This near-instant playback capability is the great advantage of streaming video, and it has driven the success of sites like YouTube in concert with the proliferation of broadband Internet connections. It does mean, however, that you must be connected to the Internet to see these videos, unless the website offers an option for you to download as well as stream it.
Accessing Streaming Video Files With Safari
There are various protocols used by websites to deliver streaming video to you. In some cases, a regular video file stored on the website's server is accessed by your browser in a "behind-the-scenes" way. It is sometimes possible to discover the URL of the video file itself using Safari's developer tools so you can download it like any other file. After activating the "Develop" menu in Safari's preference panes, navigate to the website with the streaming video. Before playing the video, choose "Start Timeline Recording" from the "Develop" menu. When you play the video, the player connects to the server to access the video file, and this access is logged in the timeline. Video files typically have extensions like MP4, AVI, or FLV, and have a relatively large size, so you can sometimes find the URL of the video by examining the timeline (sorting by size helps). The full URL of the video is revealed in the right side of the timeline when you select it, and you can paste this URL into Safari's location bar to download it.
Third Party Websites and Plugins
There are various services which attempt to automate the exploit described in the previous section, so you don't have to do the work yourself. Different services work with certain popular streaming sites like YouTube or Vimeo. Some, like Offliberty, are websites that gives you a download link for the video given the URL of the page you stream it from. Other services take the form of browser plugins that will embed a download link into the streaming page itself. Finally, there are some standalone programs you can install, like the Wondershare YouTube Downloader, which download streaming videos when given the URL of the streaming page. These services won't work with every streaming video out there, but for some popular websites they can be very convenient.
Capturing With Quicktime
The preceding techniques for saving streaming videos will yield the best quality possible, since you download the original video file itself. However, you can also capture the content on-the-fly as it appears on your screen using the QuickTime player that came with your Mac. With this method, the quality of the captured video will only be as good as it appears while streaming, but the advantage is that you can capture any video content this way, regardless of the website, and can record live streaming video as well. Choose "New Screen Recording" from the File menu and click the Record button to get started. You can capture the entire screen or just a portion, so you can target the video itself for your capture. To record the audio as well, use a an audio routing program like SoundFlower to use the Mac's audio output as an input source for the capture.