Overview - MPEG-4 profiles
MPEG-4 was introduced to give users the chance to deliver content to a wide range of delivery mediums like personal computer, PDAs, mobile phones or settop boxes. Since MPEG-4 offers such a broad spectrum of possibilities profiles were defined. They contain specific features of MPEG-4 that have to be supported by a delivery plattform to be compatible to this profile.
Additionally, Levels specify fixed limitations of MPEG-4 like maximum resolution or bitrate. If a device is labeled to be e.g. Advanced Simple@Level3 you can be definitely sure that it can render content encoded according to the Advanced Simple Profile Level3.
To understand profile definitions completely we should take a look at the ’Common Intermediate Format (CIF)’ specifications. They were defined by the MPEG as standard resolution between the PAL and NTSC standard.
|
Resolution |
QCIF |
176x144 |
CIF |
352x288 |
2CIF |
352x576 |
3CIF |
720x576 |
So what are the important MPEG-4 profiles today?
The Simple Profile
...is the easiest most popular implementation of MPEG-4 technology today. It can be encoded and rendered even on low-power devices such as PDAs or mobile phones.
|
Level | Max. resolution | Max. bitrate | |
| 0 | QCIF | 64 | |
| 1 | QCIF | 64 | |
| 2 | CIF | 128 | |
| 3 | CIF | 384 | |
The Advanced Simple Profile
...is downwardly compatible to the Simple Profile. The advanced features additionally supported provide a better visual quality.
|
Level | Max. resolution | Max. bitrate | |
| 0 | QCIF | 128 | |
| 1 | QCIF | 128 | |
| 2 | CIF | 384 | |
| 3 | CIF | 768 | |
| 3b | 2CIF | 3000 | |
| 4 | 2CIF | 3000 | Interlace support |
| 5 | 4CIF | 8000 | Interlace support |
The Simple Scalable Profile
...adds another powerfull feature to the Simple Profile. Similar to SureStream/MBR streaming the server uses scalability to react to a decreasing bandwidth through lowered resolution, framerate or image quality.
|
Level | Max. resolution | Max. bitrate | |
| 1 | CIF | 128 | |
| 2 | CIF | 256 | |
Overview - H.264, AVC or MPEG-4 part 10
Although MPEG-4 offers highly efficient video coding, its scientific bascis were defined in the middle 90th. So compared to proprietary commercial solutions parts of the MPEG-4 video compression is already outdated.
1997 the Video Coding Experts Group (VCEG) of the ITU-T started to develop an even more efficient video compression technology called H.26L. 2001 VCEG and the MPEG started to cooperate in the completion of the codec. This year it will be become an international standard named ’Recommendation H.264’ (ITU) or ’MPEG-4 Part 10/ Advanced Video Coding (AVC)’ (MPEG).
Due to a very slow reference implementation the complexity of H.264/AVC was first overrated. The first commercial implementations indicate that in the future H.264/AVC can be encoded in realtime on consumer PCs and be decoded even on low power devices.
H.264/AVC provides a highly increased coding efficiency that is needed for IP-streaming, GPRS/UMTS-videoconferencing, digital HDTV and many other applications. Compared to MPEG-2, H.263 and MPEG-4 video compressed with H.264/AVC offers a significant better image quality at even lower bitrates.
A test by the German magazin c’t shows that the coding efficiency of H.264/AVC is twice as high as every other open standard available today. Compared to MPEG-2 H.264/AVC offers the same image quality at half of the bitrate. The decoding is 2-3 time as complex as the decoding of MPEG-2, the encoding 3-5 times.
Links: MPEG-4 Part 10 (AVC) or H.264
|
H.264/AVC Software Coordination
H.264 reference implementation of the Heinrich-Hertz-Institute Berlin.
Go
|
|
|
VSS H.264 Codec
Vanguard Software Solutions was the company that presented a fast implementation of H.264.
Go
|
|
|
Project: Hdot264 video codec
Open source project that wants to implement H.264 (no code released officially yet).
Go
|
Links: MPEG-4 information and resources
|
|
MPEG.org
The home page of the Moving Picture Experts Group (MPEG) with links, resources and all the official MPEG-4 specifications.
Go
|
|
|
MPEG-4 Industry Forum
This non-profit organisation has the goal to get the MPEG-4 standard widely adopted.
Go
|
|
|
Internet Streaming Media Alliance (ISMA)
The ISMA is a non-profit corporation provides a forum for the creation of specifications that define an interoperable implementation for streaming media.
Go
|
|
|
Fraunhofer AEMT
Description of the scope and the features of MPEG-4.
Go
|
|
|
MPEG-4 Tutorial
Tutorial Issue on the MPEG-4 Standard by the Image Communication Journal.
Go
|
Links: MPEG-4 implementations
|
|
Apple MPEG-4
Apple’s MPEG-4 implementation today is the biggest chance for MPEG-4 to become a widely adopted streaming media technology in the internet.
Go
|
|
|
Envivio
Provider of complete end-to-end MPEG-4 broadcast and streaming solutions for encoding, editing, protecting and distributing of MPEG-4 content.
Go
|
|
|
iVAST
The iVAST Platform is a suite of software products that enable the creation, delivery and presentation of interactive and enhanced streaming media experiences.
Go
|
|
|
mpegable AVI
Free MPEG-4 codec for Video for Windows.
Go
|
|
|
Philips
Philips was the first to present a commercial MPEG-4 implementation...
Go
|
|
|
Sorenson Squeeze 3 for MPEG-4
Built for the Sorenson MPEG-4 Pro codec, Sorenson Squeeze 3 is the first Variable Bit Rate (VBR) compression application for novice and pro users.
Go
|
|
|
HappyMachines 3ivx
3ivx Delta 4 is a high quality MPEG-4 codec that allows content creators to effectively deliver video at all levels of the video spectrum from High Definition Television (HDTV) down to video for mobile phones and embedded devices.
Go
|
|
|
Sigma Designs MPEG-4 codec
Sigma Designs offers a free ISO-compliant MPEG-4 codec.
Go
|
|
