All You Need to Know About Video File Types
What’s the difference between MP4, MOV, MKV, and any of the other video file types? Good question. And the simple answer is that each file type will end up giving your video a different kind of compatibility and overall size. Which file type is right for you all depends on what you’re using it for. So let’s jump right on in and get you up to speed on the fundamentals of exporting optimized video.
Basics: Codecs and Containers
Two major factors influence how large the video file is and where it can be played. These are codecs and containers.
Most of the videos you’ll come across will have been compressed, meaning the files are modified to take up less space on your computer. That’s exactly what a codec does. It interprets the video and determines how to either compress it (for storage space and transport) or decompress them (for viewing or editing) Every codec does this differently: Some prioritize quality (lossless codecs), and others will sacrifice quality to achieve smaller files (lossy codecs).
The majority of modern cameras capture footage in some compressed format; generally, only professional filmmakers and videographers work with uncompressed video codecs. In a perfect world, one with unlimited storage, you’d always store video captured in the original format as it gives you the most options when editing and it can fit on larger screen sizes. Once you transcode or export the video, you can then minimize to the desired file size using lossy compression.
Then we have containers. You’ll recognize these a little easier because unlike codecs which are ‘under the hood,’ video containers will appear as a suffix at the end of a video file name, for example, .mp4 or .mkv.
So, what do containers do? Since video files will often make use of both a video and audio codec — as well as the occasional subtitles track, the video container is designed to bundle all these assets together and package the video as one single file.
Think of the container as the box and the codecs are the goods that are packaged inside. Certain containers work best for the web; others work exclusively on Apple devices, and others work only on windows. Choosing the right container will help you achieve the optimum balance between quality and ‘stream-ability’ – especially if you’re uploading to the web.
So let’s run through the most popular codecs and what they’re primarily used for.
Most Popular Codecs For: Video Capture and Archiving
H.264 / MPEG-4 AVC:
Without a doubt, H.264 is the most frequently used codec in digital cameras and modern camcorders — devices that capture to file-based storage, like memory cards, hard drives etc. It’s important to note that H.264 is the codec, not to be confused with the container format, which is typically AVCHD (see the container section below.) H.264 has a number of different functions. It offers a robust image quality at relatively low bitrates and high compression ratios. It’s very scalable, which means you can also have a high bitrate H.264 video that looks stunning on larger screens. This is what’s typically used for Blu-ray playback.
MJPEG (Motion JPEG):
MJPEG was developed by the Joint Picture Experts Group — the same genius’ who developed the JPEG image compression codec, thus the name. MJPEG is an older format used by some digital cameras and older devices to capture video, but not so commonly found now.
DV and HDV:
Developed by an assortment of consumer electronics companies that manufacture and sell camcorders, DV is a tape-based standard and is commonly utilized by camcorders that employ mini cartridges of DV tape. As a codec, DV is limited to plain standard definition, so HDV was invented to allow for the recording high-definition video onto mini-DV tape cartridges. DV and HDV are a little special in that they are the names of the codec being used and the container as well.
Most Popular Codecs For: Streaming From the Web
When uploading video onto the web, most believe it’s all about making compromises; trading off image quality for lower bit rates. And, this is true to a degree — smaller file sizes will load quicker on the internet, and this is especially important if the majority of your viewers have a slow internet connection. But as of late, we now have to take into account a video’s playability across mobile and tablet devices, seeing as a vast portion of video consumers are now watching content on portable devices, and not all video formats are going to be supported on the,. So it’s safe to say, you’ll ideally want to strive for an optimal balance between small file size, high-quality and compatibility.
H.264 / MPEG-4 AVC:
If you’re looking for those above three criteria, then H.264 will be able to satisfy most of your needs. When kept at lower bit rates, H.264 delivers fairly high-quality video, and due to its widespread compatibility, It’s likely that H.264 will continue to be the most frequently used codec. For example, Adobe supports it in Flash, the HTML5 canvas can use it with ease, Apple offers full support for it already, and YouTube is steadily progressing to H.264 while I write this very article. With H.264, you’re betting on the future: While it may not play on older devices, it’s sure as hell going to play on most devices in the years to come.
While video content giants such as YouTube and Netflix have moved away from MPEG-1, plenty of MPEG-1 standard-definition video is still accessible on other sites. MPEG-1 is known to be the old, rugged warhorse that first brought us video over the web. Great if you’re in a hurry or working collaboratively, or even if you simply want to communicate an idea to a colleague, but if the quality is of paramount importance and you plan on using high definition, you’ll want to steer well clear of our old friend MPEG-1.
WMV (Windows Media Video):
You wouldn’t think so, but there is still a lot of WMV content available. And remember, we’re not talking about the windows media container here, just the codec for now. While WMV is not as commonly utilized as MPEG-1, they still come under the same category of ‘most likely avoid’.
MPEG-2 is primarily used as the compression standard for DVD video and to compress video for over-the-air HDTV broadcast. Its additional use was present in the early days of Blu-ray Disc creation. However, as technology progressed, the majority of Blu-ray movies have discontinued the use of MPEG-2.
Most Popular Containers
Unlike codecs, the ‘unique’ qualities of container formats tend to overlap with one another. So here are the most common formats you’ll find:
MP4 is the recommended container when uploading video to the web. Even services like Vimeo and Youtube list it as their preferred format. The great thing about the MP4 container is that it’s widely supported on most devices around the world. Although sometimes confused with QuickTime files, MP4’s are actually quite different. Again, MP4 was developed by the Motion Pictures Expert Group, with a more technical name of MPEG-4 Part 14. Videos inside of an MP4 container are encoded with H.264, while audio is generally encoded with AAC, but other audio standards can also be used.
MKV is fast growing in its popularity and widespread use as it’s the container that was designed to be future-proof. MKV supports just about any audio or video codec which makes it versatile, efficient, and well renowned as one of the best ways to store video and audio files. On top of this, MKV supports a number of video, audio and subtitle files even if they’re encoded in different formats. Due to the amount of option MKV brings to the table, as well as how it handles error recovery (which allows you to play corrupted files), it has fast become one of the best containers available.
QuickTime is Apple’s own proprietary container format. This container can occasionally cop some criticism as its codec support (of both video and audio) is limited to whatever Apple supports. However, like MP4, QuickTime still supports a large array of codecs for audio and video offering a wide spread of versatility. In addition, Apple is a strong proponent of everyone’s favourite codec; H.264, which means QuickTime containers can support it. However, if you’re looking to maximise compatibility, Quicktime videos won’t playback on devices such as the Sony PSP and various DVD players, where MP4 will. This won’t be an issue for many, but it’ worth considering.
Flash is Adobe’s proprietary container, which supports a range of different codecs. Currently, more recent Flash video is primarily encoded with H.264 and AAC audio codecs, but you may come across older Flash sites that use completely different codecs which were encoded in years previous.
This is a conventional container used by the majority of camcorders around the globe. When video is captured with these devices, it is automatically compressed with the H.264 AVC codec. On the other hand, audio is encoded as Dolby Digital or alternatively, uncompressed linear PCM.
Advanced Systems Format: (WMV / WMA / ASF)
You may come across a few ASF files from time to time, or even some of its other file extension names as listed above. The impressive thing about ASF is that in theory, it can contain video and audio files compressed with just about any codec. But for ASF, it’s
playback that can become an issue across a wide array of devices, especially with compressed H.264 video codecs. So, if you’re planning on staying within the world of Microsoft, ASF will do you just fine, but you might have problems elsewhere.
Audio Video Interleave (AVI)
AVI is an older Microsoft container format developed in 1992 and is still decent for audio quality retention while supporting a fair number of codecs. Yet, AVI won’t fair too well on Apple devices, so you’ll likely need a media player like VLC to support it in those situations. Still, it’s quite commonly found, but as time moves on, probably less so. With current and future projects, it’d be advisable to give this one a miss.
What Format is Right For You?
The right codec and container really depend on what you’re using it for. If you’re looking for widespread compatibility, a great balance of both quality and file size, you can’t go wrong with the H.264 codec and the MP4 container, with the containers of MKV and QuickTIme deserving a definite mention. Since their creation, these formats have been able to withstand the test of time, and continuously manage to keep up with the ever-growing demands of high-quality visuals, low file size and evolving consumers devices. Plus, if you store your videos in these formats, transcoding to another format such as AVI, Flash and QuickTime is a relatively simple process.
There’re mountains of information on codecs, file formats and their specific uses — forums and debates about which reigns triumphant. While they’re incredibly insightful, and you’ll likely learn a great deal, for beginners they can tend to be a little overwhelming. Ultimately it’s helpful to have a basic grasp of the fundamentals as surprisingly; a little knowledge can take you a long way in the vast world of media.
Lunamik loves to inform our viewer base on all the cumbersome technicalities that accompany digital media, because when you’re just starting out, there can be alarming amount of information to take on. So, now that you’ve got a solid grip on Video File Types check out our artcile on Image File Types.