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<SegmentTemplate timescale="1000" duration="9750" media="vid.mp4" startNumber="1"/>
<Representation id="5" mimeType="video/mp4" codecs="avc1.64001f" width="1280" height="720"
startWithSAP="1" bandwidth="3861547">
<SegmentTemplate timescale="1000" duration="9750" media="vid.mp4" startNumber="1"/>
<ContentComponent id="1" contentType="audio" lang="en"/>
<SegmentTemplate initialization="vid.mp4"/>
<Representation id="1" mimeType="audio/mp4" codecs="mp4a.40.02" sampleRate="44100"
numChannels="2" lang="en" startWithSAP="1" bandwidth="257141">
<SegmentTemplate timescale="1000" duration="9980" media="audio.m4s" startNumber="1"/>
In the previous example, you can see that the MPD file is really just straight XML outlining the instructions for
the video player to ingest. You'll notice in the XML that certain nodes outline the representation of instructions for
the DASH player to interpret. DASH is video codec agnostic, and ideally through browser and device adoption,
MPEG-DASH will become the de facto standard for delivering HTML5 video over HTTP. If this adoption takes, as
I believe it will, you will see very good uses of dynamic video advertising handled completely on the client side.
Basically, the manifest files are really just a playlist or description file; as a viewer begins to view the first few segments,
the later segments in the description could be reserved for targeted advertising. This will eliminate the need for
rendering hundreds upon thousands of custom video permutations on a server in order to target them to the correct
audience. With DASH, truly addressable video content can be achieved rather simply.
You'll learn more about dynamic advertising in Chapter 11.
Cloud Services
You may be asking, “With all the talk about encoding, transcoding, and delivery issues with video, how can an
organization make sense of it all operationally and turn a profit?”
Fear not, there are a lot of cloud encoding services such as (, Wowza, Zencoder, Akamai,
and others that are aiming to ease this video fragmentation for businesses and content owners. These services allow
you to upload your source media asset to their cloud-based services; then you select what devices and browsers you
want to target, and they handle the transcoding and delivery process. You can even open up the “hood,” so to speak,
and really customize the video encoding parameters that you've learned in this chapter, that is, if you feel comfortable
enough to do so. These cloud services typically sit on top of an Amazon cloud server where, as more requests come
in, they spin up more servers to process the transcoding jobs. This greatly reduces the overhead of running and
maintaining several servers that could or could not be working at that given moment. If you're building a content site
for a major media network or are a content owner looking to deploy across all screens, you'll want to take a look at one
of these white-label solutions. Having an external service handle your video conversions into all the correct formats is
a blessing; it allows you to “pass the buck” to your clients and spares you from the operational nightmare of managing,
converting, and hosting all of your video assets. This process works with YouTube, Vimeo, Ooyala, Brightcove, and
others. I believe as more solutions like open source WebM encoding and player-agnostic MPEG-DASH delivery
become available, we as an industry will work our way out of the fragmentation woes. I hope we all reflect on this a
few years from now and shake our heads at the crazy hoops we had to jump through to deploy video across.
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