As the way we consume video evolves, moving from standard definition (SD) to high-definition (HD) and eventually from 4K to 8K, the video encoding process is also evolving. To keep up with the changing video landscape, the broadcast industry has had no choice but to explore new video compression techniques – after all, video compression is integral for broadcasters and pay TV operators to deliver content to audiences. Consequently, the industry has begun looking to new solutions to produce further advances in compression. So as new codecs are developed, which are proving the most popular, and what does this mean for existing codecs?
The current codec landscape
There are currently two mainstream codecs. Firstly, MPEG-2, the historic codec used for SD and initially the first digital deployment, while the second, H.264, otherwise known as Advanced Video Coding (AVC), was established for the transition to HD. These standards-based codecs have proved to be the two most successful so far and were both primarily formulated for the broadcast market. ITU standards like AVC were designed with television in mind and have subsequently been extended to over-the-top (OTT) video. Therefore, neither lend themselves to use for streaming, but they could be the answer for converged services.
With streaming overtaking traditional broadcast, it’s become apparent that there’s a need for new codecs. However, while it’s natural for broadcasters to look to the future, it’s crucial that they don’t forget the huge number of people still consuming HD and continue to pay attention to existing codecs. As the industry develops new codecs, it should use what it learns and new technologies to improve existing codecs to ensure that broadcasters can continue to meet the needs of all audiences.
Although originally slated to be the ITU successor of AVC, High Efficiency Video Coding (HEVC) hasn’t been adopted as widely as initially expected due to limited 4K penetration and royalty issues. Compared to AVC, HEVC delivers high-quality 4K video that is at least 50% smaller. However, an additional option has emerged in the form of AV1. AV1 is a royalty-free alternative to HEVC, supported by giant tech groups including FAANG through the Alliance for Open Media, and was designed primarily with OTT, and therefore progressive scan, in mind. As a result, it is the optimized choice for this type of service.
As there are several similarities between the two, whether a broadcaster or pay TV operator uses AV1 or HEVC is almost entirely dependent on their needs and existing infrastructure. Currently, AV1 is seen as the "codec of choice" for streaming media distribution and is supported by the likes of Amazon, Google and Netflix.
Next generation codecs
Faced with increasing OTT consumption and technological advances, new standards are being developed to handle new resolutions and more sophisticated content types. One of the codecs currently in development is Versatile Video Coding (VVC) which the JVET expects to be finalised this year. VVC capabilities are expected to support immersive content, resolutions from 4K to 16K and 360-degree video. Meanwhile, Essential Video Coding (EVC) has been fast-tracked by MPEG to provide a “licensing-friendly” standardized video coding solution to address business needs, such as video streaming.
Beyond the usual commitment of reducing the bitrate by 30-50% compared to previous standards (in this case HEVC), it’s too soon to determine the exact benefits and advantages VVC and EVC could offer. However, regardless, these new codecs are likely to shake up the market in 2020 and beyond and bring with them a degree of complexity, particularly as each of them is due to be set in stone over the course of the next year. As a result, it may take until next year or even 2022 before it’s possible to ascertain if they will find their market.
Looking further ahead
During the next decade, H.264, HEVC and AV1 are likely to be among the most popular codecs in use. Due to the infancy of the standard, its core technology DNA and its supporters, AV1 might cement its position as the codec of choice for streaming media distribution. However, considering that each codec has different properties and every broadcaster or pay TV operator has different infrastructure in place, there is unlikely to be a clear "winner" in the codec domain. Rather, the more probable outcome is that there will be several dominant players per niche.
Ultimately, as work continues on next generation codecs, the learnings and technologies generated will be vital in improving not only new codecs, but also older ones. If broadcasters and OTT providers keep this in mind, in the future, all viewers will benefit from an enhanced experience, whether they are watching content in HD or 8K.
Remi Beaudouin is chief strategy officer for ATEME.