The StreamSpot Blog

Insight, news and reviews from the StreamSpot staff

The Right Fit: Next-Generation Compression

Posted by Michael Wilson on Nov 9, 2018 4:48:45 PM
Find me on:


Sizing Up the Situation

In today's digitally connected world, everyone and anyone can watch, create, and share content with others. Whether the goal is to entertain or educate, to motivate or inspire, it's easier than ever to watch and share your creations.

But this raises the question: With 3.5 billion global internet users, continuously growing bandwidth requirements, and a reliance on affordable infrastructure, how does all of this data (especially high-quality HD video) get exchanged so quickly and reliably without overloading... well, everything? 

The Answer is Compression 

As it turns out, the process art of compression is a key part of what makes our modern digital experiences possible. Making large things smaller, and finding more efficient ways to store and convey information, is imperative to transmitting any kind of images, video, or other complex audio/visual content.

About the only thing you can reliably distribute over the internet fully uncompressed is text, but even that gets reduced in size these days before it appears on your screen.

How Does Compression Optimize Video

To exemplify the impact of compression on high-definition video, let's look at it mathematically. We'll examine the difference in space required to store and the bandwidth required to transmit one one minute of HD video in both native and compressed formats.


Native, Uncompressed Video: 2.99 Gbit/s - (1.3 Terabytes @ 1 hour)

Web-Video: 3.0 Mbps - (1.3 Gigabytes @ 1 hour)

(1080p60 Camera Signal, 24 Bit Color. In real-world applications, a bit-rate of 5 Mbps or higher should be used for 1080p60 web-video for maximum quality.)


This 99.9% reduction in size was made possible by the use of H.264, a lossy compression format that has proven extremely popular for web and internet related applications, it's also one of the encoding standards for Blu-Ray discs. It's been around for a while, and done very well for itself. It's the successor in a long line of compression schemes dating back to H.261, ratified in 1988 - but what we're here to talk about today is H.264's successor: H.265 / HEVC (High Efficiency Video Codec), as well as it's competition.

The Future of Video Compression

While H.264 and VP8 power much of the internet's video today, their market dominance is not likely to continue. Several new compression codecs have been introduced and are gaining market share.  H.265 (HEVC) and VP9 are among the latest compression codecs available for high-definition video compression. 

H.265 extends and improves the immensely popular H.264 format, offering much superior compression and smaller file sizes without sacrificing quality. Google's VP9 format offers similar compression benefits, and is much less tied up in patents and licensing fees, making it generally perceived to be a more 'open' format. Much of VP9 is now powering YouTube and other streaming platforms. Meanwhile, H.265 (HEVC) can still be found implemented all over the web, but is also well-known for being one of the official formats of 4K BluRay.

Now, both of these formats are seeing support and use on the web (though VP9 is arguably seeing much larger-scale market penetration, due to the previously mentioned open-nature of the format) - But why? If H.264 was so good, why does it need a successor?

Size. That's really it. H.265 HEVC offers up to a 50% reduction in file-size over H.264 while retaining identical quality. So...that's a pretty good reason.

Benefits

There is a variety of practical benefits as a result of better compression. In the live streaming industry specifically, two areas of particular importance are:

Reducing on-site transmission bandwidth requirements

Minimizing the upload bandwidth, and amount of data that needs to be sent, for broadcasts from their origin point. This is great for rural venues with limited internet access, or for mobile broadcasters relying on 4G internet. Contractors that pay-per-gigabyte for rented internet access or CDN usage will also be relieved by the savings.

Reducing user's viewing bandwidth requirements

Allowing your users to watch the same quality stream on a potentially slower connection, and also consume less data. This is particularly helpful for areas with slower internet, or users on plans with bandwidth caps.


Codec Comparison - Which is Best?

To properly demonstrate the improved efficiency of these next-gen encoding schemes, we need some examples. But we weren't really satisfied with any of the example videos we could find comparing compression codecs. So we made our own:

 

 
Note: The higher the viewing quality, the better the differences will be demonstrated - so we recommend watching the above video in 1080p. (The maximum quality video is available in our case study.)

For further analysis, we've compiled a detailed case study, which we're giving away free to our readers, our gift to you.

Download Free Case Study Download FREE Case Study


Big Ideas, Big Challenges, Big Potential

Clearly there are some massive space-saving benefits to H.265 and VP9. Better quality, less space, higher numbers: But why are older compression algorithms still dominant? The biggest reasons are compatibility, and processing power. The increased complexity of these next-gen codecs means that it takes more processing power to encode high-definition video.  In fact, most new compression codecs recommend or require using GPUs (Graphics Processing Units) instead of CPU (Central Processing Unit) for their superior performance benchmarks.  

There are considerations for playback of video using new compression codecs as well as any mobile processors aren't powerful enough to decode H.265 or VP9 in software, and need special hardware chips alongside the main CPU.  Apple appears to be leading the way by officially supporting HEVC (H.265) for many of their latest iOS and MacOS devices.

Plus, let's not forget, there isn't yet 'one format to rule them all." When it comes to H.265 and VP9 - There's still a huge amount of competition between formats, and those involved with them. Not every browser and device supports one or the other natively.

Netflix has also added support for HEVC.  However, this article outlines the challenges they face for royalty payments for the use of HEVC and how the move to royalty-free VP9 or AV1 (another very powerful codec that was not included in this blog entry due to testing limitations), may be more appealing.

Conclusion

High-definition video compression is a complex, processor intensive process that is here to stay.  As consumer demand grows for high-quality, HD video content, so does the price tag to create, store and deliver.  As our testing demonstrates, there is a dramatic improvement of quality at lower-bitrates when using the new compression codecs.  Just as H.264 replaced legacy MPEG and VP6 codecs in the past, HEVC, VP9 and AV1 will also continue to gain market share and will eventually render previous codecs obsolete.

Topics: encoding, compression, hevc, vp9, h.264, h.265, case study, streaming basics