MPEG-2 vs MPEG-4

[skorpinok]

Hi, is the video qaulity of MPEG-2(DVD MOVIE) is equal to MPEG-4? what is the main purpose of releasing movies in MPEG-4 i,e the blu-ray ? & what about those millions of movies already released in DVD Format ? iam very much confused regarding this Goddamn formats, if you got any little knowledge please suggest me, GREAT THANKS IN ADVANCE !

Thanks
Skorpinok

[jagabo]

MPEG 4 can deliver better quality than MPEG 2 at the same file size. Or MPEG 4 can deliver the same quality with a smaller file size.

[PuzZLeR]

MPEG-2 is pretty much the only video format on DvD. (Some players support MPEG-1, the older VCD format, but that's another story).

MPEG-4 is newer in technology and typically two things:

MPEG-4 Part 2, usually MPEG-4 ASP (Advanced Simple Profile) is more efficient than MPEG-2. Typical formats of MPEG-2 ASP are DivX and Xvid.

MPEG-4 Part 10, also called MPEG-4 AVC (Advanced Video Coding), or H.264, is even more efficient than MPEG-4 ASP and estimated, on average, to be twice as efficient than MPEG-2.

What I mean by more efficient is similar quality for less file size. And that is encoding from the same source, not MPEG-2 -> MPEG-4.

Blu-ray supports MPEG-2, MPEG-4 AVC and VC-1 (the latter of which is a higher profile of WMV and also very efficient like MPEG-4 AVC and more efficient than MPEG-4 ASP and MPEG-2).

[PuzZLeR]

Just to add: there is no video format called "MPEG-3" and it should not be confused with the audio format MP3. "MPEG-3" was a project began about 10 years ago to make MPEG-2 more efficient for HD. It was scrapped when it was realized that significant improvements would only be apparent with a new format, hence MPEG-4.

[lordsmurf]

MPEG-2 was also expanded quite a bit through the years.
More profiles, etc.

[PuzZLeR]

MPEG-2 was also expanded quite a bit through the years.
More profiles, etc.

You know, I do believe that formats like H.264/AVC, or even the upcoming H.265/HEVC, were concepts thought out decades ago, but "delayed" till the "astronomical" processing muscle needed became "realistic" processing muscle, as subsequent new video formats typically demand. Hence the reason for adjustments and improvements on an incumbent format before totally entering a new format era.