As law enforcement equipment is used in critical missions, it must be rugged, capable, easy to use and based on proven technologies. These days, it must also feature open standards, along with technology that is cost-effective and flexible enough to allow users to future-proof their investment. The MPEG-4 technology that is now becoming ubiquitous to this type of gear brings a new level of capability to digital video downlinks, including improved delivery of critical, time-sensitive and actionable data to police officers, firefighters and emergency medical teams on the ground. Before you make an investment in new downlinks and receive sites, however, consider both the technology trends and your installed legacy MPEG-2 video systems.
The MPEG-4 advantage
Both MPEG-2 and MPEG-4 video compression standards are used for the same applications: video from helicopters, drop cameras or surveillance robots. The video is compressed in an encoder before it is transmitted or stored and decompressed in a decoder for playback.
The majority of legacy installed video downlink systems going back at least five years use MPEG-2 video compression. The quality of MPEG-2 video is quite good, but the format has a lot of limitations, especially for such in-demand applications as one-to-many multicasting, streaming of videos to phones, laptops and other types of end-user equipment, and automatic ingestion into video archiving systems.
Over the last several years, more law enforcement agencies have been requesting the higher-quality video that comes with high definition. It is a standard requirement for crowd surveillance at major events such as the G-20 summits and conventions, as well as for search-and-rescue operations. But HD video contains about four times as much information as standard definition. While MPEG2 has low data rates with SD video, the HD data rates are much higher. Using MPEG2 for HD video will invariably reduce the range of your video downlink system’s transmission.
For storage and archiving, MPEG-4 files take up less memory compared to MPEG-2. Additionally, most of today’s archiving tools and disc systems use MPEG-4 to natively ingest MPEG-4 compressed video and audio, saving you from buying additional equipment to transcode MPEG-2 video.
H.264 is the next-generation video compression technology in the MPEG-4 standard. MPEG-4 H.264 delivers incredible video quality at data rates one-fourth to one-half the size of previous video formats. Better video at a lower bit rate translates into less storage required as well, providing additional savings.
In addition to its efficiency and better image quality, another important advantage of MPEG-4 H.264 video is the reliability of the video stream. Rather than breaking down into distinct blocks and jagged objects as seen in MPEG-2 video, the video is consistently crisp and clear. It also degrades gradually, softening an image without losing the detail critical to many situational-awareness scenarios.
The importance of open standards
The success of law enforcement response operations often depends on the ability to receive crisp, detailed video information in real time and exchange it in one-to-many dispatches. This is so other units, agencies and responders are aware of the situation, can coordinate their response operations and prepare to assist as needed. In the past several years, interoperability, including that of video downlink systems has become a cornerstone requirement for the Department of Homeland Security, state law enforcement agencies and fire departments.
To ensure interoperability and share information with other jurisdictions and disciplines in a cost-effective and future-proof way, law enforcement agencies need to take into account the standards of the legacy equipment in state and local partners’ helicopter downlinks and receive sites. One of the major benefits of MPEG-4 is that it is an open standard that has been adopted by organizations across the globe. Many products and devices now support MPEG-4.