Re: [streaming] OT: H.264 support and .3gp
Warren Young <[email protected]> Mon, 28 Jul 2008 11:08:06 -0600
| Newsgroups | gmane.comp.video.videolan.vls.general |
|---|---|
| Message-ID | <[email protected]> |
Yusuf Mayet wrote: > > What does MPEG-4 refer/mean to? MPEG-4 is a huge, unruly bag of technologies. I don't know of a single software package that implements *all* of MPEG-4. See: http://en.wikipedia.org/wiki/Mpeg-4 http://www.chiariglione.org/mpeg/achievements.htm Colloquially, when you see "MPEG-4" given with no other qualifiers in a video context, MPEG-4 typically refers to MPEG-4 Part 2, the original video encoding method defined for the MPEG-4 family. Part 2 was a mess, from a standards perspective. It specified far more than has ever been actually put into practice, and the video only parts splintered through proprietary extensions like DivX and Microsoft's MPEG-4v3, perhaps because as-is it isn't dramatically better than MPEG-2. H.264 was added to the MPEG-4 family a few years after the initial parts of MPEG-4 were standardized; it is also called MPEG-4 Part 10. Part 10 is a much more focused standard than Part 2, covering just video. It takes the ideas in the video parts of MPEG-4 Part 2 and extends them further, making it valuable enough in terms of coding efficiency to woo many more people away from MPEG-2 and proprietary codecs than Part 2 could. It is likely that over the next few years, H.264 will crush Part 2: it won't be used for new products, and old Part 2 products will either be updated to use H.264 instead, or will be allowed to slide into obsolescence. > Is'nt is just the container, That's yet another confusing part about MPEG-4: it defines at least three different "container" formats. There are program and transport streams (Part 1) similar to those of MPEG-2, then there is the QuickTime variant defined in Part 12, which is often associated with H.264, but not actually tied to it. > Can anyone explain the difference between MPEG-4 and H.264. John Watkinson can: http://www.amazon.com/MPEG-Handbook-Second-John-Watkinson/dp/024080578X/ _______________________________________________ streaming mailing list To unsubscribe or modify your subscription options: http://mailman.videolan.org/listinfo/streaming