Creating a video is as simple as taking out your phone or turning on your webcam, but sharing, storing and compressing that video is where things can get complicated. This blog post is designed to give you a better understanding of why and when video compression is necessary, as well as how to do it yourself! If video compression has ever intimidated or frustrated you in the past, read on and leave those hang ups behind.
1. The Why
If video is such a great medium, why do we have to worry about compressing it in the first place? The reason modern digital video looks as impressive as it does is because of the sheer amount of information digital cameras can capture. This informational data is what creates the crisp details and vivid saturation of modern video. The problem is that it takes a ton of data to capture these beautiful images. So much data that you may find your computers and hard drives filling up quickly due to the hefty storage demands of your video, not to mention the extremely long wait times for uploading or sharing these videos to online platforms.
Luckily, compression offers the solution of taking the vast amounts of data that cameras generate and interpreting it in a way that is more efficient, creating new files that are only a fraction of the file size! The only way you’ll be able to share, upload, stream and store all of your great video content with any regularity is by compressing it. The trick is to know “good” compression from “bad” compression. The objective of “good” compression is to minimize the file size as much as possible with the least amount of image quality reduction by removing things like redundant or non-functional data from your video file.
2. The What
There have been a lot of compression technology breakthroughs since the digital revolution of video, and there is bound to be more and more every year. While compression technology is always evolving, here are a few key concepts to give you a better idea of what compression actually does to your video.
Numbers like 720p, 1080p, and 4k are all measurements of a video’s resolution. These numbers actually refer to the length and width dimension of videos in terms of pixels (see the chart below). The “p” stands for “progressive” by the way. This refers to the way fields are scanned when watching video. Progressive scan technology is also present for 4k resolutions, people just don’t like to say 4kp for some reason…
Basically, the higher the number of total pixels used in capturing your video, the crisper and more detailed the image looks. However, videos with higher resolution come with the caveat of much larger file sizes. So, one way we can compress video is to simply lower its resolution.
Sure, lowering a video from a UHD resolution like 4k to something like 1080p will technically be lowering the image quality, but the difference will be negligible unless you are projecting your video onto a giant movie theater screen. Always keep in mind where your final video is going to be viewed and on what kind of screen. For example, If you plan on posting a video to social media, most people will be watching this video on their phone, which is a very small screen! The smaller the screen, the more diminishing the returns will be for higher resolution video in terms of noticeable image quality. 720p is a fine resolution for most small screens and only very trained eyes will be able to tell the difference.
It’s more important that you can actually post, share, and store your awesome videos easily than getting every bit of resolution out of it as possible, so reduce that resolution and watch your file size become much more manageable!
Codec is a high tech sounding word that refers to the specific algorithms that are used to compress video efficiently. Identifying and separating these processes by calling them codecs gives us the ability to name different methods of compression without having to go into too much detail about how they work. Codecs are what are applied to your video file during the actual act of compressing it when using software such as imovie, media encoder, or handbrake.
This may seem like a lot to take in, but all you really need to know is that some codecs compress more efficiently than others. While some codecs like ProRes 422 can be great for archival purposes, the standard compression codec for online video is called H264. Seriously, you really can’t go wrong with H264 compression for almost any type of online video.
H264 is a quintessential “good” compression option in that it offers great image quality and seriously reduces the file size of your video. This also changes your video file’s extension to the widely used .mp4 format. If you are ever facing a complicated menu of codec options to choose from, go with H264.
C) Bitrate (Mbps)
Here is another aspect of your video that can contribute to needlessly large file sizes. Like with resolution, the higher the bitrate number, the higher the overall video quality. This most noticeable difference between a video with a low bitrate versus that of a high bitrate is in the way fast moving objects look. Because bitrate is the measurement of maximum data being transferred at any given second, a low bitrate makes fast moving objects look choppy, jittery and overly digitized. High bit rates on the other hand can transfer enough data at once to show the full motion of quick movements smoothly and with greater detail. The trade-off for having a high bit rate is, you guessed it, enormous file sizes!
Luckily, knowing a bit about efficient bit rates can help determine how much is too much. Take a look at the image below. The clips with .19 and 1 Mbps don’t look great, but it’s hard to tell much of a difference between the 4 and 8 Mbps frames. This is another example of diminishing returns. Pumping a video up to 200 Mbps will most likely net you the same visual results as a video with a 40 Mbps bitrate, but your video will be five times the size!
Determining an efficient amount of Mbps for your video depends on its resolution, higher resolutions need higher bitrates. Our rule of thumb is that you typically do not need to go any higher than 10 Mbps for compressing HD video (1080p). If you need the video to be as small as possible without losing too much quality, you can definitely compress below 10 Mbps as well. Here is a helpful chart of Youtube’s recommended bitrate settings depending on the frame rate and resolution of your video.
3. The How
Now that we understand some different concepts of video compression we can get our hands dirty with some practical solutions for how you can compress videos yourself!
A WORD OF WARNING: be weary of free online compression tools that can be found with a hasty google search. While we can’t speak to the validity of all of them, there are lots of free, proven digital tools that you can use to get high quality video compression without putting your computer or video files at risk.
Quicktime is a free video player that comes bundled with Mac computers so it’s easily accessible for any mac user. Quicktime doesn’t give you a lot of compressing options but it does allow you to change the resolution of your video very easily.
Right click your video file and select Open With > Quicktime Player.
Once your video is open, navigate to the top menu bar and select File > Export As > Choose your resolution!
Using Quicktime to compress your video file doesn’t offer a comprehensive set of options, but it’s a fast and easy way to cut your file size in half by changing its resolution.
HandBrake is a free encoder tool that offers a lot more flexibility, customization and optimization for video compression. HandBrake generates compressed files by using a special H264 encoding method that is designed to achieve very small file sizes while retaining as much image quality as possible.
To start compressing with HandBrake, first download HandBrake and launch the app. Once opened, the app should automatically present you with a navigation window. Use this window to navigate the video file you want to compress and select open.
Next, select the presets drop down menu in the top left and choose either Fast 1080p30 or Fast 720p30 depending on your video’s original resolution.
You should never attempt to change a smaller resolution size into a larger one if you are trying to compress your video, for obvious reasons. If your video file’s resolution is 720p for instance, don’t use any compression preset higher than 720p, such as 1080p. If you are on mac, simply press Command+I while your video file is selected or select File > Get Info from the top bar to get a run down of your video’s specs, including its resolution.
In order to further customize your compression settings, you’ll want to navigate to the Video Tab.
Once there, you can drag the Encoder Options slider to the right for a slower setting. This will make it take longer for the video to encode but you get a more optimized video file in the end, resulting in an even smaller file size, and thats kind of the point, right?
We also recommend that you set the Framerate (FPS) option to Same as Source to avoid any frame rate translation issues for your new export.
Lastly in the video tab, you can change the value of the Quality slider for varying levels of compression. Set this slider to 23 or less depending on your compression needs.
Finally, you can name your compressed video file with the text bar near the bottom of the UI and select the Browse button to determine where your new video will be saved.
When you are ready to encode your video, select the green play button near the top of the page and enjoy your newly compressed video!
C) Creative Cloud
If you want to make video content a regular part of your business or marketing pipeline and have not yet invested in creative cloud software, do it! Post Production software used to be costly and difficult to understand but Adobe has made their essential creative toolkit more accessible than ever. We are not affiliated with Adobe in any way, so trust us when we say that their suite of digital software is a no brainer subscription solution to solve almost any video or photo workflow you can imagine for your business. One such software that is offered by Adobe’s Creative Cloud suite is Media Encoder.
Media Encoder is a straight forward tool for managing your exports and renders that comes bundled with both the full suite of creative cloud services, as well as the more specific video workflow bundles revolving around Premiere Pro. Your first step to compress video using media encoder is to, well…open media encoder.
Once opened, you should see something like the image below. The first thing you’ll need to do is point Media Encoder to where the video file that you want to compress is located. Do this by pressing Command + I on mac, or by selecting File > Add Source… from the top navigation bar.
Next, you’ll want to click the first drop down menu that is under your media, this controls your desired format. Set this format to, you guessed it, H.264!
Once H.264 has been selected, move on to the next drop down menu where you can select a preset. Match Source – Medium bitrate is a good starting point to really shrink your overall file size. Notice in this drop down menu there are also presets specifically designed for video platforms like Youtube and Vimeo as well, pretty handy!
Finally, just set your output name and determine where you’d like your video to be saved by clicking on the blue letters in the output file column. Then, hit the green arrow in the top right corner and you’re done!
There is a lot to wrap your head around when it comes to digital video, but it’s a necessary skill set for any successful business to have. Hopefully this blog has at least given you a much better understanding of the Why, What, and How of video compression! Stop by Explainly.com for many more insights into digital video production from your friendly, neighborhood video experts!