On-demand streaming services have transformed how we consume media in staggering ways. According to Sandra Pattison of Cloudwards, approximately 85% of the U.S. population subscribes to at least one video streaming platform. As a whole, the industry is projected to be worth over $300 billion by the year 2030. This is an astounding number that confirms the platform’s ever-increasing popularity.
Most consumers typically wouldn’t delve into the technical complexities that drive the video streaming industry. However, for videographers, editors, broadcasters, content creators, and other professionals, there are some important considerations. One of these is understanding video codecs and how they’re related to digital video in the streaming age.
What is a Codec?
If you’re wondering what a codec is, we’ll aim to clarify that now. A video codec is a software algorithm that compresses and decompresses digital video for distribution. The word “codec” itself blends the words “encoder” and “decoder.” An encoder is responsible for compressing data and a decoder is responsible for decompressing it. In short, codec’s meaning is “coder-decoder.”
Why are Codecs Important?
Uncompressed video files require a tremendous amount of storage space, to the tune of nearly two terabytes for a 120-minute movie. You can imagine the challenges storage alone would pose for a service like Netflix. Part of what makes a video codec so important is the necessity to shrink file sizes to more manageable loads.
Not only is storage an issue, but transmitting uncompressed video data would demand huge amounts of network bandwidth as well. Video codecs squash, or compress, raw digital data into compact chunks for transmission and delivery of on-demand media.
How Does a Codec Work?
Video codecs are responsible for compressing raw data for storage and transmission. Subsequently, it is also responsible for decompressing it on the consumer end for streaming and playback. At the core of a codec are complex algorithms that make the process possible, with the viewer none the wiser to what’s going on behind the scenes.
Video encoding falls into two broad categories: lossless compression and lossy compression. Lossless compression preserves all of the data present in the file, while lossy compression discards excess information that the algorithm deems unimportant. It may help to consider recognizable audio formats such as WAV files and MP3s to understand the difference between lossless and lossy data encoding. MP3s are lossy formats with slightly degraded quality in exchange for very small file size. WAV files retain data and generally sound better at the cost of additional size.
It’s largely the same with video codecs and how they encode (compress) raw data into a more manageable format. With regards to streaming, most services will employ lossy compression to maximize file shrinkage. The good news is that, despite streaming relying on lossy compression, the visual quality remains quite high.
What are the Different Types of Codecs?
We’ve covered the term “codec” in general terms, and now it’s time to explore the actual types of codecs that exist. There are many different kinds out there. Although, there only several in any sort of widespread usage. The gap is further narrowed by the longtime universal standard, H.264/AVC (Advanced Video Coding).
H.264 was developed in the early 2000s and maintains a roughly 80% international usage rate for video content. The reason H.264 remains so prevalent is for its universal compatibility for streaming, DVD/Blu-Ray, and cable broadcasting, in addition to its efficiency as a compression algorithm.
Another codec with increasing viability is the successor to AVC, H.265/HEVC (High Efficiency Video Coding). Unlike AVC, HEVC supports resolutions up to 8K, making it a suitable standard for high-resolution, high dynamic range (HDR) video delivery to home theater systems. Most smart TVs currently support the HEVC codec. It also boasts more efficient compression and smaller file sizes than its predecessor, but it’s yet to make a meaningful push toward taking over H.264 entirely.
Several of the world’s top tech companies partnered to form the Alliance for Open Media, in turn producing an open-source codec known as AV1. These companies included Netflix, Google, Mozilla, and Microsoft in an attempt to get around some of the headaches associated with H.265 (namely, problems with royalty payments from using the codec). AV1, being open-source and highly capable, is steadily becoming more adopted.
Wrapping up, in terms of overall performance and compatibility, Google’s own VP9 codec makes a suitable alternative to H.264. It supports 4K resolution, putting it right up against H.265 in that regard. VP9 is compatible with YouTube, Chrome, Firefox, Safari, Android and iOS mobile devices, and most household smart TVs. VP9 is one of the faster growing codecs.
How to Choose the Right Codec
For video production, content creation, and live streaming, the most important thing to understand is what these video codecs mean for the final stage of delivery and distribution. After all, a codec ultimately just makes it possible for creators to package huge amounts of data and make it available to a wider audience.
With this in mind, the optimal codec is going to be the one with the greatest compatibility, so that consumers on any platform can enjoy your content. For example, YouTube still recommends uploading videos encoded with the H.264 codec because of its near universal compatibility. Consumers watching online in any browser, watching from the YouTube app on their mobile device, or watching from the app on their smart TV can all stream video without issue. The only drawback to H.264 is for creators shooting at higher resolutions such as 4K. H.264 can compromise the quality, in which case a different codec would be better suited to the task.
For ultra high-resolution projects, a codec like VP9 works incredibly well to preserve video quality — especially for YouTube uploads, given the codec was developed by Google. Since VP9 also offers impressive compatibility across devices, it’s a fantastic codec for projects that want to retain next-gen visuals.
In other situations, such as live streaming to platforms like Twitch, your outgoing codec will be subject to what your streaming software offers. The most widely used open-source streaming software, OBS Studio, utilizes the H.264 codec to compress live streaming data for web delivery to streaming platforms. Again, we see H.264 leading the pack as one of the most balanced codecs for its efficiency, file size, bandwidth usage, compatibility, and quality.
Conclusion
A video codec makes it possible stream visual content on the web, whether it’s from on-demand services like Netflix, from content platforms like YouTube, or from live streaming sites like Twitch. As creators, you’ll want to have at least a working knowledge of codecs so you can ensure your content reaches the widest audience possible. While the future is yet undetermined, H.264 remains one of the most widely used codecs for digital video.
