In this age of digital media, there are many different ways of consuming video – and just as many methods of delivering it.
The formats we’ve listed below are split between codecs and containers. A codec – short for compression/decompression – refers to the method of compressing raw footage into a lightweight form, which can be more easily stored and distributed, and then decompressed at the point of engagement.
Essentially, an encoder removes large amounts of redundant information – huge swathes of blue sky, for example (spatial redundancy), or consecutive frames that are similar to one another (temporal redundancy). What’s left is then packaged up and sent over the internet, TV cable or airwaves, where a receiving decoder uses the remaining data to reconstruct the imagery.
Containers – also known as ‘wrappers’ – are packages that can hold multiple bitstreams, with video and audio compressed using different codecs. Information in the container tells the receiving system how to deal with the bitstreams inside, but the appropriate decoders are still needed to decompress and play back the media.
With all that in mind, let’s look at the top 10 video formats in use today across sport, media and enterprise.
Digital Nonlinear Extensible High Definition is an open-standard codec developed by Avid, primarily for use in post-production (much like Apple’s ProRes codec). This ‘intermediate codec’ provides an image quality comparable to uncompressed video, but with smaller file sizes and bandwidth requirements, and it preserves its observable quality even after multiple generations. Crucially for editing environments, it’s an intra-frame format meaning each frame is encoding independently so edits can take place quickly at any point.
A newer version, DNxHR (Digital Nonlinear Extensible High Resolution) has been designed to help editors and compositors deal with the demands of 4K and 8K content captured on a variety of devices. We are yet to see this gain any significant traction in the wild.
Pros: High quality HD imagery with low file size/bandwidth, retains mastering quality even after multiple generations of effects or composites
Cons: Intended for editing and post production.
Also known as MPEG-4/AVC, this codec was developed to cope with the increasingly varied needs of digital video, able to scale from low-bitrate content for internet streaming, up to 8K ultra-high-definition TV. It’s also able to deliver the same image quality while using between 50% and 25% of the data rate of its predecessors. In the sports world, the intra-frame version is frequently used for digital archiving and distribution of legacy Standard Definition video, principally with AVC-Intra 100 variant.
Pros: Offers three times smaller file sizes than MPEG-2, very high compression rates, highly scalable, ubiquitous hardware acceleration available in all modern devices.
Cons: Primarily a distribution format, optimised for linear playback and not as convenient for editing, low bandwidth image quality can be inconsistent
High Efficiency Video Coding (or H.265) was developed as the successor to H.264 for use with the latest generation of ultra-high resolution video, and delivers up to 50% better data compression with the same level of image quality.
HEVC relies on very sophisticated algorithms and is therefore processor intensive, but most CPUs and GPUs from 2014 onwards have dedicated HEVC decoding built in. The codec also supports efficient parallel processing, which is more suited to modern processors.
Pros: Very efficient compression, supports UHD resolutions
Cons: Does the same job as H.264, but nowhere near as much adoption. Computationally expensive, slow to encode, requires a license fee
First introduced in 1995, MPEG-2 (also known as H.262) is one of the most popular video codecs, and, despite its age, is still being used in DVDs and in digital TV broadcasts. The standard has been tweaked and improved over the years, but it struggles with the low bitrates needed for digital multimedia and has been superseded by more efficient codecs.
In sports, MPEG-2 is widely incorporated among Sony’s range of XDCAM digital recorders and cameras.
Pros: Mature and reliable, generally good picture quality
Cons: Not optimised for low bitrates, limited to HD (1080p)
ProRes is an ‘intermediate codec’ format developed by Apple and intended for use during video editing rather than for final delivery, where higher compression will probably be used. As such, it’s designed for fast encoding/decoding and for real-time editing of multiple streams.
ProRes supports 10-bit colour for better colour correction, a range of resolutions and frame rates, and VBR (Variable Bitrate) encoding maintains high image fidelity even with busy action scenes.
Pros Supported by all major editing apps, relatively small file sizes, real-time editing performance, supports up to 8K resolutions
Cons Designed for use as an intermediate codec in post production environments, lossy compression, large file size, only best for Final Cut Pro shops.
This Google-developed codec is a competitor to HEVC, developed initially for YouTube, and later adopted by Netflix. It’s designed to be used with resolutions greater than 1080p and supports lossless compression, reducing file sizes by 50% without a loss of image quality.
As a native format in HTML5, it’s supported by the majority of web browsers and has an installed base roughly twice that of HEVC. VP9 will be superseded by AOMedia AV1, a state-of-the-art codec currently in development.
Pros: High compression efficiency, highly scalable from mobile to 4K, royalty-free open standard
Cons: Slow to encode, 4K playback not currently supported on Apple Safari
Developed by Apple as an alternative to Flash video, HLS (HTTP Live Streaming) is one of the most popular formats for live streaming. While not technically a container format, HLS is a protocol that describes what format the video uses, how it’s compressed and so on. It supports Adaptive Bitrate Delivery, which adjusts image quality depending on the available bandwidth.
HLS normally employs H.264 video compression, split into chunks, plus AAC or MP3 for audio, and transmits streams using an MPEG-TS container. Alternatives to HLS include MPEG-DASH, Microsoft Smooth Streaming (MSS) and the Real-Time Messaging Protocol (RTMP).
Pros: Dynamically adjusted video quality, cheap and easy to implement, supported on most devices, efficiently handles multiple streams
Cons: A high degree of latency means HLS isn’t ideal for live, super-fast streaming; HLS is a ‘subscriber-only’ protocol for playing streams
MPEG transport stream is another container format, designed to store and carry multiple media over one bitstream. It’s primarily used for live streaming via digital broadcast TV, IPTV and HTTP, but has also been adapted for use in video cameras/players and Blu-ray discs.
A transport stream is a multiplex of ‘elementary streams’ (e.g. audio and video bitstreams) with error correction and synchronisation data to ensure the integrity of the transmission. MPEG-TS is often used for things like video-on-demand sports events, delivering multiple camera feeds and audio tracks.
Pros: Carries multiple streams at once, widely supported, better error protection than other containers
Cons: Aging technology, does not offer Adaptive Bit Control, designed mainly for live streaming
MXF (Material Exchange Format) is a container that references several different media formats – multiple video and audio streams, metadata, subtitles, playlists and so on.
MXF was developed as an industry standard for professional video and audio, able to contain a variety of different compressed bitstreams with full timecode support. It’s primarily used in TV production for content interchange and archiving and is referred to as the digital equivalent of videotape.
Pros: Packages multiple clips into one file, extensive metadata support, can use any codecs, open and easily extensible
Cons: Not a consumer playback format.
QuickTime File Format
Developed by Apple back in 1991, the QuickTime file format is for the delivery of multiple media tracks, including audio, video, subtitles, still images and interactive content.
Over the years it has incorporated many different video and audio codecs – it was among the first to support H.264, for example – and is the basis of the MP4 format. Its ability to handle multiple tracks makes it useful for video editing. Media packaged in the QuickTime file format use the extension .mov.
Pros Flexible and supports a variety of codecs, compatible with lots of apps and media players
Cons Not as ubiquitous as the .MP4 variant.