Thanks to hard drive size increasing at a rapid pace, digital video is beginning to find its way to direct download distributors and consumers are becoming less reliant on those thin round discs that seem to scratch and become useless fairly easily. Even with hard drive space becoming more abundant, you may find yourself running out of space when you need it the most. This is one problem that can be solved with the right encoder and understanding of how digital video works.
It’s important to know the two biggest components of a modern digital video. The first and most recognizable is the container. The container can go by several names the most common of which are AVI, MP4, MOV, FLV, etc. In addition to holding the video data, it also contains the audio and extra information such as chapters and other advanced features.
If the video file were an actual physical file full of data, the container would be the manilla envelope the pages of data are contained within. Some players are only able to deal with certain containers, so it’s important to find out which container format is best considering where and how you intend to play the file.
Some containers are flexible and can work with multiple codecs while others are more specialized. The MP4 container doesn’t just work with MPEG-4, which seems like an exact match due to their similar names. It also works very well with H.264
The second major component of a digital video file is the codec. If the container is the folder the data is located in, the codec is most certainly the data. This is the chief determiner of file size within a video file and, in general, is the most important to consider when converting a file from one format to another. Some codecs offer better compression than others, giving you a quality image with as little space taken up as possible. The most popular lossy codecs include H.264, WMV, DivX, FFmpeg, VP8, MPEG-4, etc.
Of these, my personal favorite is H.264 due to its adoption rate among mobile devices and usability with HTML5 video embedding. There are several adaptations of the codec out there, but to keep things simple just look for H.264 in the video encoder to simplify the process.
One drawback to converting any video file for a smaller file size is you have to deal with lossy formatting that will degrade your video quality to some degree. No matter how good the codec and compression settings you choose, encoding video degrades the quality each time you do it, like making a copy of a copy on the office copier.
Finding the Right Software
Now that you have an idea of exactly what impact your codec and container selections have on a video file, it’s important to take a look at which program you’d like to use to achieve solid video compression. You may want to keep in mind that video compression utilities of professional quality doesn’t come cheap. The suggested options below are simply some of the better known and reliable programs currently being distributed at no charge.
Handbrake is a popular option that allows you to take video off a DVD or even load up a video file currently on your drive. In addition to being free, it offers you a wide range of options including the ability to set a goal file size. This means that it will determine how much it needs to compress the file to reach your goal, or something close to it. Handbrake sends video out in two primary container formats, MP4 and MKV. Both of these formats are widely accepted by a broad range of media playback devices. The MP4 file comes out as an M4V which allows it a more complete compatibility with the Apple TV, but it is still an MP4 file.
Miro Video Converter is free for the Mac and gives users the ability to take one video file and convert it depending on which device you prefer to play it back on. While it is more of a converter than a utility targeted at compressing files, it does a fair job of making videos optimized for specific devices and formats without leaving them too bulky.
VirtualDub is a great free program that also assists with video formatting and compression. Though it doesn’t give you much in terms of video editing, it does give you a suite of features for post-production processing allowing you to make sure the file you get is what you want.
If you want something a bit more professional and aren’t afraid to spend some cash, some of the best compression utilities include Compressor for the Mac and Adobe Media Encoder for Windows. These utilities come with Final Cut and Adobe Premiere, respectively, and offer a multitude of rendering and encoding options with professional quality. Quicktime Pro / Quicktime paired with iMovie can be a powerful solution at a very low cost.
Stay away from changing frame rates, as that can result in jerky movement or very long processing times. The more you shrink the files, the less reliable the results will be.
No matter what you decide on, what’s important is that the files you are compressing end up looking and sounding the way you want them to. The fight between encoding systems has waged on for years and will continue to do so as long as audiophiles and video enthusiasts have anything to say about it. Fact is, if you can’t tell the difference between before and after, you’ve probably landed on a great solution.