Video Profiles and Levels
MPEG-2 video supports a wide range of applications from mobile to high quality HD editing. For many applications, it's unrealistic and too expensive to support the entire standard. To allow such applications to support only subsets of it, the standard defines profile and level.
The profile defines the subset of features such as compression algorithm, chroma format, etc. The level defines the subset of quantitative capabilities such as maximum bit rate, maximum frame size, etc.
A MPEG application then specifies the capabilities in terms of profile and level. For example, a DVD player may say it supports up to main profile and main level (often written as MP@ML). It means the player can play back any MPEG stream encoded as MP@ML or less.
The tables below summarizes the limitations of each profile and level. There are many other constraints not listed here. Note that not all profile and level combinations are permissible.
| Abbr. | Name | Picture Coding Types | Chroma Format | Aspect Ratios | Scalable modes | Intra DC Precision |
|---|---|---|---|---|---|---|
| SP | Simple profile | I, P | 4:2:0 | square pixels, 4:3, or 16:9 | none | 8, 9, 10 |
| MP | Main profile | I, P, B | 4:2:0 | square pixels, 4:3, or 16:9 | none | 8, 9, 10 |
| SNR | SNR Scalable profile | I, P, B | 4:2:0 | square pixels, 4:3, or 16:9 | SNR (signal-to-noise ratio) scalable | 8, 9, 10 |
| Spatial | Spatially Scalable profile | I, P, B | 4:2:0 | square pixels, 4:3, or 16:9 | SNR- or spatial-scalable | 8, 9, 10 |
| HP | High profile | I, P, B | 4:2:2 or 4:2:0 | square pixels, 4:3, or 16:9 | SNR- or spatial-scalable | 8, 9, 10, 11 |
| 422 | 4:2:2 profile | I, P, B | 4:2:2 or 4:2:0 | square pixels, 4:3, or 16:9 | none | 8, 9, 10, 11 |
| MVP | Multi-view profile | I, P, B | 4:2:0 | square pixels, 4:3, or 16:9 | Temporal | 8, 9, 10 |
Exempting scalability (a rarely used feature where one MPEG-2 stream augments another), the following are some of the constraints on levels:
| Abbr. | Name | Frame rates (Hz) | Max horizontal resolution | Max vertical resolution | Max luminance samples per second (approximately height x width x framerate) | Max bit rate in Main profile (Mbit/s) |
|---|---|---|---|---|---|---|
| LL | Low Level | 23.976, 24, 25, 29.97, 30 | 352 | 288 | 3,041,280 | 4 |
| ML | Main Level | 23.976, 24, 25, 29.97, 30 | 720 | 576 | 10,368,000, except in High profile, where constraint is 14,475,600 for 4:2:0 and 11,059,200 for 4:2:2 | 15 |
| H-14 | High 1440 | 23.976, 24, 25, 29.97, 30, 50, 59.94, 60 | 1440 | 1152 | 47,001,600, except that in High profile with 4:2:0, constraint is 62,668,800 | 60 |
| HL | High Level | 23.976, 24, 25, 29.97, 30, 50, 59.94, 60 | 1920 | 1152 | 62,668,800, except that in High profile with 4:2:0, constraint is 83,558,400 | 80 |
| Profile @ Level | Resolution (px) | Framerate max. (Hz) | Sampling | Bitrate (Mbit/s) | Example Application |
|---|---|---|---|---|---|
| SP@LL | 176 × 144 | 15 | 4:2:0 | 0.096 | Wireless handsets |
| SP@ML | 352 × 288 | 15 | 4:2:0 | 0.384 | PDAs |
| 320 × 240 | 24 | ||||
| MP@LL | 352 × 288 | 30 | 4:2:0 | 4 | Set-top boxes (STB) |
| MP@ML | 720 × 480 | 30 | 4:2:0 | 15 (DVD: 9.8) | DVD, SD-DVB |
| 720 × 576 | 25 | ||||
| MP@H-14 | 1440 × 1080 | 30 | 4:2:0 | 60 (HDV: 25) | HDV |
| 1280 × 720 | 30 | ||||
| MP@HL | 1920 × 1080 | 30 | 4:2:0 | 80 | ATSC 1080i, 720p60, HD-DVB (HDTV).
(Bitrate for terrestrial transmission is limited to 19.39Mbit/s) |
| 1280 × 720 | 60 | ||||
| 422P@LL | 4:2:2 | ||||
| 422P@ML | 720 × 480 | 30 | 4:2:2 | 50 | Sony IMX using I-frame only, Broadcast "contribution" video (I&P only) |
| 720 × 576 | 25 | ||||
| 422P@H-14 | 1440 × 1080 | 30 | 4:2:2 | 80 | |
| 1280 × 720 | 60 | ||||
| 422P@HL | 1920 × 1080 | 30 | 4:2:2 | 300 | Sony MPEG HD422 (50 Mbit/s), Canon XF Codec (50 Mbit/s), Convergent Design Nanoflash recorder (up to 160 Mbit/s) |
| 1280 × 720 | 60 |
Read more about this topic: H.262/MPEG-2 Part 2
Famous quotes containing the words video and/or levels:
“We attempt to remember our collective American childhood, the way it was, but what we often remember is a combination of real past, pieces reshaped by bitterness and love, and, of course, the video past—the portrayals of family life on such television programs as “Leave it to Beaver” and “Father Knows Best” and all the rest.”
—Richard Louv (20th century)
“The only inequalities that matter begin in the mind. It is not income levels but differences in mental equipment that keep people apart, breed feelings of inferiority.”
—Jacquetta Hawkes (b. 1910)