MPEG-2  (also called H.262 or MPEG-2 Part 2/Main Profile@High Level, Main Profile@Medium Level), jointly created in 1995 by Video Coding Experts Group (VCEG) and Moving Picture Experts Group (MPEG) is the same video codec used on DVD but with good HD picture quality. 

MPEG-2 includes three basic types of coded frames: intra-coded frames (I-frames), predictive-coded frames (P-frames), and bidirectionally-predictive-coded frames (B-frames). It uses Intra-DC Precision that indicates the number of bits for quantized DC coefficients of intra-coded blocks; it takes one of the values of 8, 9, 10, or 11 bits. The more bits used, the more precise quantization is achieved. Higher DC precision is better quality but requires more space for higher bitrates. So, using a lower precision for lower bitrates is recommended. The reason why developers use MPEG I-frame for slideshows instead of JPEG and PNG is to save space on the graphics memory and cache. For a slideshow, a single MPEG stream, that contains many I-frames (images), is loaded from the disc to the primary memory buffer for fast performance and quicker loading.

In the early days of Blu-ray, MPEG-2 was used for the Primary Video and often for bonus feature content, but it's aged and not as advanced as AVC and VC-1. It takes alot more disc space because of the lack of better compression, so as a result, it only holds at least 2 hours of HD video. However, it is still used today for browseable slideshow images using I-frame, mainly for photos, art galleries, and readable pages.

 

Here's an example of a browsable slideshow using the MPEG-2 I-frame format.

 MPEG-2 has one advantage over the other two codecs - all its patents have expired, which means it can be used for commercial purposes without any restrictions. It is under the .mpv extension name in the M2TS container.

MPEG-2 Profiles  Green = Supported by Blu-ray

Abbr.	Name	Picture Coding Types	Chroma Format	Scalable modes	Intra DC Precision
SP	Simple profile	I, P	4:2:0	none	8, 9, 10
MP	Main profile	I, P, B	4:2:0	none	8, 9, 10
SNR	SNR Scalable profile	I, P, B	4:2:0	SNR	8, 9, 10
Spatial	Spatially Scalable profile	I, P, B	4:2:0	SNR, spatial	8, 9, 10
HP	High-profile	I, P, B	4:2:0 or 4:2:2	SNR, spatial	8, 9, 10, 11
422	4:2:2 profile	I, P, B	4:2:0	none	8, 9, 10, 11
MVP	Multi-view profile	I, P, B	4:2:0	Temporal	8, 9, 10

MPEG-2 Levels  Green = Supported by Blu-ray

Abbr.	Name	Frame rates (Hz)	Max resolution	Max luminance samples per second (approximately height x width x framerate)	Max bit rate MP@ (Mbit/s)
LL	Low Level	23.976, 24, 25, 29.97, 30	352 x 288	3,041,280	4
ML	Main Level	23.976, 24, 25, 29.97, 30	720 x 576	10,368,000, except in High-profile: 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 x 1152	47,001,600, except in High-profile: constraint is 62,668,800 for 4:2:0	60
HL	High Level	23.976, 24, 25, 29.97, 30, 50, 59.94, 60	1920 x 1152*	62,668,800, except in High-profile: constraint is 83,558,400 for 4:2:0	80*

*On Blu-ray, the maximum video bitrate is 40 Mbit/s

MPEG-2 Combination Limits Green = Supported by Blu-ray

Profile @ Level	Resolution (px)	Framerate max. (Hz)	Sampling	Bitrate (Mbit/s)
SP@LL	176 × 144	15	4:2:0	0.096
SP@ML	352 × 288	15	4:2:0	0.384
	320 × 240	24
MP@LL	352 × 288	30	4:2:0	4
MP@ML	720 × 480	30	4:2:0	15
	720 × 576	25
MP@H-14	1440 × 1080	30	4:2:0	60
	1280 × 720	30
MP@HL	1920 × 1080	30	4:2:0	80*
	1280 × 720	60
422P@ML	720 × 480	30	4:2:2	50
	720 × 576	25
422P@H-14	1440 × 1080	30	4:2:2	80
422P@HL	1920 × 1080	30	4:2:2	300
	1280 × 720	60

*On Blu-ray, the maximum video bitrate is 40 Mbit/s

Author(s) : Æ Firestone