MPEG-2
MPEG-2 is a video and audio compression standard from the mid-1990s that powered DVDs and digital broadcast television. MPEG-2 is far less efficient than H.264 or HEVC, so files are much larger at the same quality. Many cable, satellite and over-the-air TV systems still use it. The MPEG-2 standard also defines the transport stream format used in broadcasting.
Why it matters
MPEG-2 still sits behind many TV channels, so any service that brings broadcast content online meets it. Because it needs far more bandwidth than modern codecs, streaming it as is would be costly; it usually has to be converted first.
How it works
- The encoder splits each frame into 16 by 16 pixel macroblocks.
- Each block is predicted from earlier or later frames, and only the difference is kept.
- The difference is rounded and compressed into a bitstream.
- Video and audio are carried in an MPEG transport stream for broadcast or a program stream for DVDs.
Is MPEG-2 still used?
Yes, MPEG-2 is still used in many cable, satellite and over-the-air TV systems and on DVDs. It is the standard video format for ATSC broadcasts in the United States. Online streaming services rarely deliver it directly and instead convert it to H.264 or HEVC.
MPEG-2 vs H.264: what is the difference?
H.264 compresses video far more efficiently than MPEG-2, so it delivers similar quality at a much lower bitrate. MPEG-2 is older, simpler to decode and entrenched in broadcast and DVD equipment. For streaming to phones and browsers, H.264 is the practical choice.
Where it's used
OTT services and FAST channel operators take broadcasters' MPEG-2 feeds and convert them to H.264 or HEVC so channels stream on phones and smart TVs.
By the numbers
- MPEG-2 Part 1 (Systems) and Part 2 (Video) were first released in 1996, and Part 3 (Audio) in 1995. (Wikipedia: MPEG-2)
