HTML and CSS Reference
In-Depth Information
Terminology Review
I've covered a lot of new terminology and acronyms this chapter. To better provide you with a quick reference,
I'll outline some of the ones I've touched on in detail; see Table
7-2
.
Table 7-2.
HTML5 Media Terminology Review
Word
Definition or Meaning
Encoding
This is the preparation of a video project for output according to different playback specifications.
Transcoding
This is the conversion process from one format into another according to different playback
specifications.
CBR
This is the rate at which a codec's output bitrate data should be set, and it's a constant value.
VBR
This varies the amount of output data to be consumed per time segment. VBR allows for higher
bitrate in complex scenes and lower in less complex.
Bitrate
This is the number of bits used per unit of playback time to represent audio or video.
FPS
This is the number of frames of video rendered to the screen within one second.
Aspect ratio
This is the proportional relationship between a video or image's width and its height; typically this
is 16:9 or 4:3, but other ratios exist.
Codec
This is a device or software capable of encoding or decoding digital data.
GOP
This is a group of successive pictures within an encoded video file.
Alpha channel
This is a pixel's data that is reserved for transparency information. This is typically used for
overlaying or compositing graphics on top of each other.
Summary
We're at a huge turning point in the industry in that online audio and video delivery is more confusing and important
than ever. Clients expect to have their produced video spots delivered to every screen with optimal quality and clear
audio, and users expect quick-starting video with great quality and no hiccups in playback. However, with only certain
video formats playing nicely in certain browsers, operating systems, and devices, creating a ubiquitous and high-
quality cross-screen experience is challenging and often very time-consuming.
This chapter covered a lot, but it's important to understand the large landscape and digest all the moving parts
that go into creating, delivering, and optimizing video and audio for the Web, especially for online advertising using
HTML5. Your potential customers won't give you the time of day if you're using poor-quality video assets and delivery
mechanisms that the user can't even play. I suggest reviewing this chapter if your next campaign requires some
form of media so you can make sure you understand the overall process that goes into video creation, compression,
and delivery. But even more so, make sure your clients understand. Video, like a lot of things on the Web currently,
is super-fragmented, but the process is getting easier to work with, and you'll have a firm grasp on the competition
because you were working through it now. Don't be afraid to start using HTML5 video with your next advertising
campaign and look for integration points with VAST and VPAID to help speed up your campaign needs. This will
ensure that your video will work across media buys, while the technology I covered will ensure that it will work across
browsers and devices. Play around with different compression techniques and start getting familiar with working
with the JavaScript APIs. Also, be sure to test your creatives and video on different devices including mobile devices,
tablets, and operating systems under varying network conditions. And if it's too hard to take it all into consideration
under compressed timelines, remember the online services I've covered to help you get started quickly.
The next few chapters in this topic are geared toward working with mobile, and I'll talk more about video in those
chapters. Take what you've learned here and apply it going forward.
