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MPEG-4 Part 2

MPEG-4 Part 2 is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand MPEG-4 Part 2 rather than just read about it. In short: MPEG-4 Part 2, MPEG-4 Visual (formally ISO/IEC 14496-2) is a video encoding specification designed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC family of encoders.

Key takeaways

  • MPEG-4 Part 2 belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect MPEG-4 Part 2 to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of MPEG-4 Part 2 from memory before moving on to harder problems.

Reference excerpt

MPEG-4 Part 2, MPEG-4 Visual (formally ISO/IEC 14496-2) is a video encoding specification designed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC family of encoders. It uses block-wise motion compensation and a discrete cosine transform (DCT), similar to previous encoders such as MPEG-1 Part 2 and H.262/MPEG-2 Part 2. Examples of popular implementations of the encoder specifications include DivX, Xvid and Nero Digital. MPEG-4 Part 2 is H.263 compatible in the sense that a basic H.263 bitstream is correctly decoded by an MPEG-4 Video decoder. (MPEG-4 Video decoder is natively capable of decoding a basic form of H.263.) In MPEG-4 Visual, there are two types of video object layers: the video object layer that provides full MPEG-4 functionality, and a reduced functionality video object layer, the video object layer with short headers (which provides bitstream compatibility with base-line H.263). MPEG-4 Part 2 is partially based on ITU-T H.263. The first MPEG-4 Video Verification Model (simulation and test model) used ITU-T H.263 coding tools together with shape coding.

History The MPEG-4 Visual format was developed by the Moving Picture Experts Group (MPEG) committee. The standard was developed using patents from over a dozen organizations, listed by MPEG LA in a patent pool. The majority of patents used for the MPEG-4 Visual format were from three Japanese companies: Mitsubishi Electric (255 patents), Hitachi (206 patents), and Panasonic (200 patents). See Patent holders below for a full list of patent holders.

Editions

Profiles

To address various applications ranging from low-quality, low-resolution surveillance cameras to high definition TV broadcasting and DVDs, many video standards group features into profiles and levels. MPEG-4 Part 2 contains approximately 21 profiles. The most commonly deployed profiles are the Advanced Simple Profile (ASP or AS Profile) and the Simple Profile (SP), which is a subset of the ASP. Other profiles include the Advanced Coding Efficiency Profile (ACEP or ACE Profile), the Advanced Real Time Simple Profile (ARTSP or ARTS Profile), the Core Profile (CP), the Main Profile (MP), and the Simple Studio Profile (SStP or SSt Profile). Most of the video compression schemes standardize the bitstream (and thus the decoder) leaving the encoder design to the individual implementations. Therefore, implementations for a particular profile (such as DivX or Nero Digital which are implementations of Advanced Simple Profile and Xvid that implements both profiles) are all technically identical on the decoder side. A point of comparison would be that an MP3 file can be played in any MP3 player, whether it was created through iTunes, Windows Media Player, LAME, or the common Fraunhofer encoder.

Simple Profile (SP) The Simple Profile is mostly aimed for use in situations where low bit rate and low resolution are mandated by other conditions of the applications, like network bandwidth, device size etc. Examples are mobile phones, some low end video conferencing systems, electronic surveillance systems etc.

Levels

Advanced Simple Profile (ASP) The Advanced Simple Profile was not included in the original standard. Its notable technical features relative to the Simple Profile, which is roughly similar to H.263, include:

Support for "MPEG"-style quantization Support for interlaced video Support for B pictures (a.k.a. B-frames) Quarter Pixel motion compensation (Qpel) Global motion compensation (GMC) The MPEG quantization and interlace support are designed in basically similar ways to the way it is found in MPEG-2 Part 2. The B picture support is designed in a basically similar way to the way it is found in MPEG-2 Part 2 and H.263v2. The quarter-pixel motion compensation feature of ASP was innovative, and was later also included (in somewhat different forms) in later designs such as MPEG-4 Part 10, HEVC, VC-1 and VVC. Some implementations of MPEG-4 Part 2 omit support for this feature, because it has a significantly harmful effect on the speed of software decoders and it is not always beneficial for quality. The global motion compensation feature is not actually supported in most implementations although the standard officially requires decoders to support it. Most encoders do not support it either, and some experts say that it does not ordinarily provide any benefit in compression. When used, ASP's global motion compensation has a large unfavorable impact on speed and adds considerable complexity to the implementation.

Levels

Simple Studio Profile (SStP) The Simple Studio Profile has six levels, ranging from SDTV to 4K resolution. SStP allows for up to 12-bit bit depth and up to 4:4:4 chroma subsampling, using intra-frame coding only. SStP is used by HDCAM SR.

Levels

Patent holders MPEG-4 Part 2 patents have expired worldwide. The last US patent expired on November 14, 2023, while the last worldwide patent (in Brazil), PI0109962B1, expired on July 19, 2026. The following organizations held patents for MPEG-4 Visual technology, as listed in the patent pool administered by MPEG-LA and later by Via-LA.

Criticisms MPEG-4 Part 2 has drawn some industry criticism. FFmpeg's maintainer Michael Niedermayer has criticised MPEG-4 for lacking an in-loop deblocking filter, GMC being too computationally intensive, and OBMC being defined but not allowed in any profiles among other things. Microsoft's Ben Waggoner states "Microsoft (well before my time) went down the codec standard route before with MPEG-4 part 2, which turns out to be a profound disappointment across the industry - it didn't offer that much of a compression advantage over MPEG-2, and the protracted license agreement discussions scared off a lot of adoption. I was involved in many digital media projects that wouldn't even touch MPEG-4 in the late 1990s to early 2000s because there was going to be a 'content fee' that hadn't been fully defined yet."

Popular software implementations DivX HDX4 libavcodec Nero Digital QuickTime Xvid

See also High Efficiency Video Coding Advanced Video Coding Quantization (image processing) FourCC MP3 ISO/IEC JTC 1/SC 29

Notes

External links MPEG-4 Part 2: Visual "Levels for MPEG-4 Visual Profiles". Archived from the original on 2010-01-08. Retrieved 2006-03-02. Official MPEG web site MPEG-4 Visual Patent List (MPEG LA)

Worked examples

Example 1 — a first encounter with MPEG-4 Part 2

Start with the simplest possible case. Write down what MPEG-4 Part 2 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to MPEG-4 Part 2 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about MPEG-4 Part 2 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of MPEG-4 Part 2

In research
MPEG-4 Part 2 appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses MPEG-4 Part 2 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
MPEG-4 Part 2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1999 software, 20th-century inventions, MPEG-4, so understanding it makes those chapters shorter.
In everyday life
Look for MPEG-4 Part 2 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study MPEG-4 Part 2 in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what MPEG-4 Part 2 means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain MPEG-4 Part 2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MPEG-4 Part 2 in simple terms?

MPEG-4 Part 2, MPEG-4 Visual (formally ISO/IEC 14496-2) is a video encoding specification designed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC family of encoders.

Why does MPEG-4 Part 2 matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study MPEG-4 Part 2?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on MPEG-4 Part 2.

Tags

  • 1999 software
  • 20th-century inventions
  • MPEG-4
  • Open standards covered by patents
  • Videotelephony

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