as Charles ( charlesproxy.com) or Apple’s Network Link Conditioner control panel, which is
available as an optional download from Xcode.
Live Broadcast: Next Steps
Comparatively, it’s easier to prep your content for a Flash-free VOD world than it is to transition to a Flash-free live-streaming world. While
CDN vendors have deployment options that can
point to HTTP origin manifests and segments,
every live streaming deployment I’ve built or optimized for my clients in the last 12 months utilizes an RTMP push to a CDN or a streaming server such as Wowza Streaming Engine or Adobe
Media Server. In this respect, I don’t foresee any
major changes in 2017 to the publishing side of
live streaming deployment.
With live streaming encoders, you can control the keyframe interval (or GoP) just as you
do with VOD encoding. Most hardware encoders
have a default GoP duration of 1 or 2 seconds.
If you notice an overall degradation of quality in
your live stream that is at or near the same duration of your GoP (or “keyframe flash,” as I call
it), you need to increase the video bitrate applied
to the stream.
If you’re performing live transcodes on a CDN
or a streaming server such as Wowza Streaming
Engine, your transcoder should use the same
keyframe interval as the incoming stream for all
bitrate renditions. This type of encoding is called
“transrating” instead of “transcoding,” and usually it requires less CPU on the server. As with
VOD streams, your segment duration can be a
multiple of the frame rate and GoP duration.
Your CDN may have predetermined segment
durations; make sure you’re using a GoP duration that is compatible.
Real-Time Video Interaction:
Is the Flash-less World Ready?
Now this is where the momentum toward a
Flash-less world bumps up against reality. As
mentioned earlier in this article, the only pro-
posed specifications—not yet ratified as W3C
standards—for real-time communication are
WebRTC and ORTC. Real-time video may com-
prise just a segment of the overall online video
market, but it includes important businesses
like video chat, security feed monitoring, and
online auctions, just to name a few.
Like it or not, the Flash plug-in serves to fill
a very real gap in consistent technology avail-
able across HTML5 browsers. For this reason,
I believe the foreseeable online video land-
scape will include a growing number of hybrid
approaches that gradually embrace WebRTC,
ORTC, or whatever the final “RTC” spec be-
comes. Current solutions include the Open Tok
Platform from TokBox and the WebRTC Pre-
view Release available for Wowza Streaming
Engine 4. 4 or higher customers. Open Tok only
works on Chrome and Firefox and requires a
plug-in installation to work on IE, and it has no
support for Safari. Wowza Streaming Engine’s
WebRTC capabilities can enable WebRTC-con-
nected clients to send/receive video, audio,
and data more efficiently by reducing the out-
bound data rates in many-to-many use cases.
In a one-to-many scenario, Wowza Streaming
Engine can take a WebRTC origin live feed and
transmux it into more universally adopted for-
mats such as RTMP, HLS, and DASH. While
such a scenario means having stricter brows-
er requirements for the publisher, subscribers
to the real-time stream can have more flexible
The real financial pain for real-time video
business needs is native app development. With
a browser and plug-in world, you could keep
technical development focused on a web-based
platform. Now, the additional costs of iOS and
Android application development on top of
browser stack development continues to be a
drain on budgets for companies everywhere,
notably SMB markets.
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