Game Development Reference
In-Depth Information
I do not recommend), I am going to cover the basics of digital video compression and
optimization next.
Digital Video Compression Concepts: Bit Rate, Data
Streaming, SD, HD, UHD
Let's begin with the primary or standard resolutions that are used in commercial video.
These also happen to be common device screen resolutions, probably because if the
screen pixel resolution matches the video pixel resolution that is being played full
screen on a screen, there will be zero scaling, which can cause
scaling artifacts
. Be-
fore high definition came along, video was
standard definition
(
SD
) and used a ver-
tical resolution of
480 pixels
. VGA is an SD resolution, and
720 × 480
could be called
wide SD
resolution.
High definition
(
HD
) video comes in two resolutions,
1,280 ×
720
, which I call
pseudo HD
, and
1,920 × 1,080
, which the industry calls
true HD
.
Both HD resolutions feature a
16:9
aspect ratio and are used in TVs and iTVs, smart-
phones, tablets, e-book readers, and game consoles. There is also an
ultra high defini-
tion
(
UHD
) resolution out now that features 4,096 × 2,160 pixels.
Video streaming is a more complicated concept than resolution, as it involves play-
ing back video data over a wide expanse, such as the one between your Java 8 game
application and the remote video data server that will hold your potentially massive di-
gital video assets. Furthermore, the device that your Java game application is running
on will be communicating in real time with remote data servers, receiving
video data
packets
as the video plays (it is termed streaming because the video is streaming from
the video server, over the Internet, and into the hardware device). Video streaming is
supported by the MPEG-4 H.264 AVC format codec (encoder-decoder pair).
The last concept that you need to understand is
bit rate
. Bit rate is the key setting
used in the video compression process, as bit rates represent your
target bandwidth
,
or the
data pipe size
that is able to accommodate a
certain number of bits streaming
through it every second
. The bit-rate setting should also take into consideration the
CPU processing power that exists within any given Java-capable device, making your
digital video's data optimization even more challenging. Fortunately, most devices
these days feature dualcore or quadcore CPUs!
Once the bits travel through a data pipe, they also need to be
processed
and
dis-
played
on the device screen. Thus, bit rates for digital video assets must be optimized
not only for bandwidth, but also in anticipation of variances in CPU processing power.
Some single-core CPUs may not be able to decode high-resolution, high-bit rate digital
