Page 285 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

274 CHAPTER 10 Video
Table 10.3 Various Video Compression Standards over Time
Year Standard Issuer Description of Main Feature
1984 H.120 ITU-T 1990 H.261 ITU-T 1993 MPEG-1 ISO
1995 H.262/MPEG-2 ITU-T/ISO
1996 H.263 ITU-T
1999 MPEG-4 Part 2 ISO
2003 H.264/MPEG-4 AVC ITU-T/ISO 2008 VC-2 ISO
First video encoding standard
Video conferencing
Video CD
DVD, DVB, Blue-Ray, SVCD
Expanded video conferencing with cellular Video over Internet protocol
HD DVD over digital video broadcasting HDTV broadcast
FIGURE 10.30
I-frame P-frame B-frame I-frame
The basic concept of video compression with I, P, and B frames.
the manufacturers’ common display interfaces, breaking down the wide acceptance of digital con- sumer video in its early stages. MPEG-2 was introduced to extend the MPEG-1 to a deeper pool of applications and produce commonality in the display algorithms. The MPEG-4 and H.264 standards further extended the MPEG-2 protocol by allowing deeper data compression (higher quality per unit time at a constant bit rate) and support for video interactivity. To summarize, MPEG-1 pro- vided low-quality video in a CD-based environment, MPEG-2 (still in use today with typical con- sumer DVDs) tightened the deficiencies of MPEG-1 with medium compression. Then the MPEG-4 followed, allowing deep compression algorithms with interactions such as easy overlaying of graph- ical and textual information (such as displaying the latest score of other ballgames while watching your favorite game or synthetically overlaying the next down marker into the “field layer” while a player on the field in the “player layer” steps on the synthetic yard marker within the frame).
The MPEG standard is an ISO-based standard while the H.26x standard is an ITU standard. As with most separate standards that gain a wider audience, the separate standards tend to merge over time. The current MPEG-4 and H.264 standards are essentially the same. Various video codec stan- dards over time are shown in Table 10.3.
The basics of video compression are simply to repeat portions of a previous frame into the next frame by comparing two sequential frames and then predicting the frame into the space in between (Figure 10.30).
The concept for this video referencing scheme is to repeat common objects within a frame and predict the occurrence of another object within the next frame. The frame types are termed