What is in this article?:
- MPEG HEVC compression not ready for primetime
- The need for HEVC encoding is clear, but at what cost?
- Addressing legacy infrastructure
- Advanced data rate reduction
- Targeting multiplatform delivery
The delivery of HD, 4K and even higher image quality content to support multichannel platforms is on the horizon. It’s just a matter of how long it will take to deploy in the field.
At the 2013 NAB Show, the proliferation of next-generation MPEG compression technology, namely HEVC-compatible (aka, H.265) software and hardware encoders and decoders, gave the impression that the technology necessary to move and then display large data files containing the highest quality HD (1080p/60) and 4K (3840 x 2160 pixels for delivery or 4096 x 2160 pixels for production) content was ready to be deployed. This would clearly improve the value of bandwidth-constrained networks. However, a lack of an industry standard, the need for significantly more processing power to accurately compress such files and the ongoing move towards the current state-of-the-art (and standardized in January) AVC (H.264) technology to distribute full HD 1080p files would seem to make High Efficiency Video Coding (HEVC) a far off reality.
This is not to say that it won't happen, but don't hold your breath, as most people we spoke to at the show say it’s at least five years off. The benefits to multiplatform delivery associated with the new HEVC is said to be a 50-percent improvement in bit-rate efficiency when compared to the Advanced Video Coding (AVC) scheme, while maintaining the same image quality or better.
Like H.264 before it, HEVC is the latest version of the MPEG standard. It’s uses the same idea of recognizing the difference in motion between frames and finding near-identical areas within a single frame. With HEVC, these similarities are subtracted from subsequent frames, and whatever is left in each partial frame is mathematically transformed to reduce the amount of data needed to store each frame. This results in smaller files with nearly the same quality as the 4K original, for example, which makes them easier to distribute and saves operators in content storage costs.
At the NAB Show, companies such as Elemental Technologies, Ericsson, Fraunhofer Institute, Harmonic, Media Excel, Motorola, Rovi Corp. and Vanguard Video showed hardware and software solutions (in prototype form) and side-by-side demonstrations of H.265 and H.264 encoding to compare image quality results. In all cases the H.265 decode looked visibly better, even at bit rates as low as 5Mb/s (at the Fraunhofer exhibit booth). Each seemingly challenged the other to a compression/image quality contest comparison.
Elemental — which showed the ability to encode 1080p/60 content to HEVC in real time — went so far as to issue a highly public “HEVC Throwdown.” The contest dared competitors and customers to bring content on a USB drive and have it encoded in H.265 by Elemental and then see it simultaneously streamed live (at 500Kb/s) to a tablet device and at 1080p resolution to a high-definition television. Participants were encouraged to visit other video processing companies at NAB to request the same demonstration of capabilities. It wasn’t clear how many participated, but it was a small number.
“Those that only had DVD sources weren’t able to attempt the challenge because we didn’t have input for that, but those that had USB drives were able to load onto our server and see the transcode process at real-time (say 30fps), and now they have those transcoded files for evaluation in their labs,” said Keith Wymbs, vice president of marketing at Elemental.