Profiles and levelstMyn1 Profiles and levels MPEG-2 is intended to be generic, supporting a diverse range of applications Different algorithmic elements

Profiles and levels tMyn 1

Profiles and levels

• MPEG-2 is intended to be generic, supporting a diverse range of applications

• Different algorithmic elements or ”tools”, developed for many applications, have been integrated into a single bit-stream syntax.

• To implement the full syntax in all decoders is unnecessary complex, so a small number of subsets or profiles of the full syntax have been defined.


• Also, within a given profile, a ”level” is defined which describes a set of constraints such as maximum sampling density, on parameters within the profile.

• The profiles defined to date fit together such that a higher profile is a superset of a lower one.

• A decoder which supports a particular profile and level is only required to support the corresponding subset of the full syntax and a set of parameter constraints.

• To restrict the number of options which must be supported, only selected combinations of profile and level are defined as conformance points.


• Table 1 shows the upper limits of resolution and temporal parameters in MPEG-2.

• Main Profile@Main Level is targeted for SDTV applications, while Main Profile@High Level is targeted for HDTV applications.

mailto:Profile@Main

mailto:Profile@High


LevelSpatialResolutionLayer

Parameter

Samples per lineLines per frameFrames per second

Profile

4:2:2Simple Main Multiview HighSNRSpatial

High

High1440

Main

Low








Lower

Enhancement

Enhancement

Enhancement

Enhancement

Lower

Lower

Lower

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

72057630

72057630

72057630

72057630

72057630

72057630

72057630

35228830

35228830

35228830

1920108860

1920108860

1920108860

96057630

72060830

1440108860

1440108860

1440108860

Table 1. MPEG-2 upper limits of resolution and temporal parameters.


• MPEG-2 supports four levels, which specify resolution, frame rate, coded bit rate and so on for a given profile.

Low Level (LL)– MPEG-1 Constrained Parameters Bitstream (CPB) supports

up to 352*288 at up to 30 frames per second.– Maximum bit rate is 4 Mbits/sec.

Main Level (ML)– MPEG-2 CPB supports up to 720*576 at up to 30 frames per

second and is intended for SDTV applications.– Maximum bit rate is 15-20 Mbits/sec.


• High 1440 Level– This level supports up to 1440*1088 at up to 60 frames per

second and is intended for HDTV applications.– Maximum bit rate is 60-80 Mbits/sec.

• High Level (HL)– High level supports up to 1920*1088 at up to 60 frames per

second and is intended for HDTV applications.– Maximum bit rate is 80-100 Mbits/sec.


• MPEG-2 supports six profiles, which specify which coding syntax (algorithms) is used.

Simple Profile (SP)– This is main profile without the B frames, intended for

software applications and perhaps digital cable TV.

Main Profile (MP)– Supported by most MPEG-2 decoder chips, it should satisfy

90% of the SDTV applications


Multiview Profile (MVP)– By using existing MPEG-2 tools, it is possible to encode

video from two cameras shooting the same scene with a small angle between them.

4:2:2 Profile (422P)– Previously known as ”studio profile” this profile uses

4:2:2 instead of 4:2:0, and with main level, increases the maximum bit rate up to 50 Mbits/sec (300 Mbits/sec with high level).

– It was added to support pro-video SDTV and HDTV requirements.

YC Cb r


• SNR and Spatial Profiles– Adds support for SNR scalability and/or spatial scalability

• High Profile (HP)– Supported by MPEG-2 decoder chips targeted for HDTV

applications.


• The MPEG-2 SNR, Spatial and High Profiles support four scalable modes of operation.

• These modes break MPEG-2 video into layers for the purpose of prioritizing video data.

• Scalability is not commonly used since efficiency decreases by about 2 dB, or about 30% more bits are required.


• The H.264/MPEG-4 AVC standard includes the following sets of capabilities, which are referred to as profiles, targeting specific classes of applications:

• Constrained Baseline Profile (CBP) • Primarily for low-cost applications this profile is used

widely in videoconferencing and mobile applications. It corresponds to the subset of features that are in common between the Baseline, Main, and High Profiles described below.


• Baseline Profile (BP) • Primarily for low-cost applications that requires

additional error robustness, while this profile is used rarely in videoconferencing and mobile applications, it does add additional error resilience tools to the Constrained Baseline Profile. The importance of this profile is fading after the Constrained Baseline Profile has been defined.


• Main Profile (MP) • Originally intended as the mainstream consumer

profile for broadcast and storage applications, the importance of this profile faded when the High profile was developed for those applications.

• Extended Profile (XP) • Intended as the streaming video profile, this profile

has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching.

• High Profile (HiP) • The primary profile for broadcast and disc storage

applications, particularly for high-definition television applications (this is the profile adopted into HD DVD and Blu-ray Disc, for example).


• High 10 Profile (Hi10P) • Going beyond today's mainstream consumer product

capabilities, this profile builds on top of the High Profile, adding support for up to 10 bits per sample of decoded picture precision.

• High 4:2:2 Profile (Hi422P) • Primarily targeting professional applications that use

interlaced video, this profile builds on top of the High 10 Profile, adding support for the 4:2:2 chroma subsampling format while using up to 10 bits per sample of decoded picture precision.


• High 4:4:4 Predictive Profile (Hi444PP) • This profile builds on top of the High 4:2:2 Profile,

supporting up to 4:4:4 chroma sampling, up to 14 bits per sample, and additionally supporting efficient lossless region coding and the coding of each picture as three separate color planes.

• High Stereo Profile • This profile targets two-view stereoscopic 3D video

and combines tools from the High profile with inter-view prediction capabilities of Multiview Video Coding extension.


• In addition, the standard contains four additional all-Intra profiles, which are defined as simple subsets of other corresponding profiles. These are mostly for professional (e.g., camera and editing system) applications:


• High 10 Intra Profile • The High 10 Profile constrained to all-Intra use. • High 4:2:2 Intra Profile • The High 4:2:2 Profile constrained to all-Intra use. • High 4:4:4 Intra Profile • The High 4:4:4 Profile constrained to all-Intra use. • CAVLC 4:4:4 Intra Profile • The High 4:4:4 Profile constrained to all-Intra use and

to CAVLC entropy coding (i.e., not supporting CABAC).


• As a result of the Scalable Video Coding extension, the standard contains three additional scalable profiles, which are defined as a combination of the H.264/AVC profile for the base layer (2nd word in scalable profile name) and tools that achieve the scalable extension:


• Scalable Baseline Profile • Primarily targeting video conferencing, mobile, and

surveillance applications, this profile builds on top of a constrained version of the H.264/AVC Baseline profile to which the base layer (a subset of the bitstream) must conform. For the scalability tools, a subset of the available tools is enabled.

• Scalable High Profile • Primarily targeting broadcast and streaming

applications, this profile builds on top of the H.264/AVC High Profile to which the base layer must conform.

• Scalable High Intra Profile • Primarily targeting production applications, this profile

is the Scalable High Profile constrained to all-Intra use.

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Profiles and levelstMyn1 Profiles and levels MPEG-2 is intended to be generic, supporting a diverse range of applications Different algorithmic elements