Profiles and levelstMyn1 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.

Profiles and levelstMyn2 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.

Profiles and levelstMyn3 Table 1 shows the upper limits of resolution and temporal parameters in MPEG-2. Main Level is targeted for SDTV applications, while Main Level is targeted for HDTV

Profiles and levelstMyn4 Level Spatial Resolution Layer Parameter Samples per line Lines per frame Frames per second Profile 4:2:2 Simple Main Multiview High SNR Spatial High 1440 Main Low Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Samples per line Lines per frame Frames per second Lower Enhancement Lower Table 1. MPEG-2 upper limits of resolution and temporal parameters.

Profiles and levelstMyn5 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 Mbits/sec.

Profiles and levelstMyn6 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 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 Mbits/sec.

Profiles and levelstMyn7 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

Profiles and levelstMyn8 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.

Profiles and levelstMyn9 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.

Profiles and levelstMyn10 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.

Profiles and levelstMyn11 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.

Profiles and levelstMyn12 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.

Profiles and levelstMyn13 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).

Profiles and levelstMyn14 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.

Profiles and levelstMyn15 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.

Profiles and levelstMyn16 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:

Profiles and levelstMyn17 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).

Profiles and levelstMyn18 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:

Profiles and levelstMyn19 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.