What is MPEG?

MPEG is the Motion Picture Expert Group team designated by ITU to develop compression tools for DTV Tx. and Rx. Although ATSC did not adhere to ITU regulations for DTTB, it did accept the MPEG -1 & MPEG -2 compression system.

The first step for transmitting a digital signal using terrestrial networks is to deliver the digital signal using terrestrial networks is to deliver the digital signal duly compressed and multiplexed to the transmitter exciter, for it to fit in the relatively small bandwidth assigned in the radioelectrical space.

Compression is done pursuant to the ITU MPEG Team regulations, which ensures at least that the ITU.R 601 BT signal is coded in a standard system to enter into the transmitter through the exciter.

In the system DVB, the digital video encoding process to feed a digital terrestrial transmission transmitter, cable system, satellite link or any other form of transport is the same.

There are different versions of the MPEG system: 1, 2, 4, 7, and 21. MPEG 1 was not apt for television broadcasting so it was enhanced and complemented. The result was MPEG 2 that is the standard used nowadays and that will be used for many more years to come. This is mainly due to cost because, although MPEG 4 is much more efficient, it costs more than twice what MPEG 2 does.

MPEG 7 and MPEG 21 are still being developed. MPEG 3 disappeared when MPEG 4 appeared on the scene.

MPEG Standards

• ISO/IEC Draft International Standard 13818-2, a criteria guideline for digital motion video.

• 13818-1. Systems.

• 13818-2. Video.

• 13818-3. Audio.

• 13818-4. Conformance.(Symbiosis and synergy correlation of the standards applied.

As has been mentioned, MPEG is an international Standard; therefore, it adheres to International Standardization Organization (ISO) guidelines.

Organizations such as European Broadcasting Union (EBU), Society of Motion Pictures and Television Engineers (SMPTE), and European Technical Standards Institute (ETSI), to name a few, all follow ISO standards. Thanks to that mentality, significant progress has been made in achieving certain uniformity in the standards.

International standardization brings benefits, such as economy due to a reduced number of equipment models, less effort, ease of communication, program exchanging leading to lower program prices, and many more.

Compression

• Compression is reducing the amount of data needed to give information.

• Per se, information is not random.

• Due to its essence, it requires less data for encoding.

• There are several compression technologies, very different one from another, which take up the same time because they complement each other.

Information is ordered; therefore, its elements are correlated. This characteristic means that less data is required to code a text message than a noise because the level of entropy for noise is much higher.

Each one of the technologies used to reduce the amount of data needed to transmit information is different from the others.

As they are different, all of these technologies can be used within one sole system, each one operating on its own, achieving a set of processes that provide an efficient end result.

Data compression – data reduction – is not information reduction. It is the elimination of unnecessary redundant data. It does not affect the comprehension of the message, so it will not lead to the message being misinterpreted.

Most data compression techniques have been around for over fifty years due to economic reasons of patent payment. The most used are Huffman, Discrete Cosine Transform (DCT), Markov series, several works by Shannon, and others. Arithmetic Encoding was patented by IBM but is not used.

The DVB system uses open systems.

Colombian Association of Engineers 
ACIEM