e r y if you plan on working with the HEVC or any newer advanced codec. Companies have been
quick to fill this need, and you can find HEVC
as an option on the Teradek Cube 755/855 or
the BoxCaster Pro (Figure 4). BoxCaster also
supports HEVC on its webcast CDN, which is
powered by Amazon AWS.
On the software side, vMix does support the
both H.264 and HEVC codecs for 4K recordings,
but only H.264 for webcast. But before you can
start working with 4K content, you first need to
pair your webcast computer with a 4K capture
card. Desktop and workstation webcast encod-ers can install PCIe 4K capture cards like the
AJA KONA 4 or KONA 3G/Quad, Blackmagic
Mini Recorder 4K or DeckLink 4K Extreme, and
Magewell AIO 4K Plus.
If you don’t have a desktop or workstation
system and you’re working from a laptop, you
might still be able to use a PCIe 4K capture card,
but you will need to install it in a Thunderbolt
enclosure, like the Sonnet Echo Express. Just
be careful to consider that the Thunderbolt 2
connector is the same as a mini DisplayPort
connector, while the newer Thunderbolt 3 connector is same as the USB-C connector.
Laptop users can also employ 4K USB capture cards like the Magewell USB Capture 4K
Plus or the Epiphan AV.io 4K. These USB models have an added benefit: They can also scale
the 4K input to a different resolution and frame
rate if you don’t want to webcast a 4K stream but
still want to record the signal in 4K on a recorder like the Atomos Ninja Flame, Shogun Flame,
Shogun Inferno, or Blackmagic Video Assist 4K.
It goes without saying that processing 4K
signals in any workflow requires a fast system.
Last year, the Intel Core i7-7700K was a very
common quad-core processor for webcast laptops, but this year the sweet spot is going to be
the hexacore Intel i9-8950HK mobile processor that Intel claims will deliver a 59% boost in
speed for 4K video editing.
Before you rush out and buy yourself the newest HEVC hardware, keep in mind that HEVC is
becoming more accepted by on-demand video
hosting companies like Vimeo and You Tube, but
adoption by webcast companies is much more
limited. At the time of this writing, pre-NAB
2018, I am aware of only one workflow with Amazon EC2 and Wowza that can support HEVC,
but I have not personally had the opportunity
to test this out.
A more important long-term consideration
against rushing out to cobble together a reliable
HEVC workflow is that the Alliance for Open
Media has just frozen the AV1 bitstream and
released an unoptimized software encoder and
decoder. AV1 is a competitor of HEVC with two
distinct advantages. The first advantage is 30–
40% better quality, and the second is that AV1
is a royalty-free codec, whereas HEVC requires
licencing. If you can hang on another year or
two, AV1 hardware implementations will likely
be released or announced at NAB 2019 and AV1
hardware around NAB 2020.
The 4K live-streaming workflows are still a
work in progress. Most likely, if you need to deliver a 4K live stream today, you might want to start
with a 2160/30P H.264 stream at 15–30Mbps on a
webcast service like IBM Cloud Video, Wowza
Streaming Cloud, You Tube Live, or DaCast. It
remains to be seen whether HEVC or AV1 will
be the next dominant codec and which hardware
and software solutions will be released to support either or both of these two next-generation
codecs for resolutions of 4K and beyond. Ultimately, wider support of either of these codecs
is needed from webcast providers before 4K live
streaming at lower bitrates and higher quality
becomes a reality.
Shawn Lam ( firstname.lastname@example.org) is an award-winning video
producer and technical director. His Vancouver-based video
production company, Shawn Lam Video Inc., specializes in
corporate and event video production, including online video,
video switching, webcasting, and video SEO.
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