--- In [email protected], Bhairitu <[EMAIL PROTECTED]> wrote: > > sparaig wrote: > >>> <snip> > >>> > >>>> Answer me this: what is the primary difference between MPEG-2 and > >>>> MPEG-4? It's a very simple engineering idea which overcomes a > >>>> limitation of MPEG-2 and in itself gave MPEG-4 (also h.263) more > >>>> compression. > >>>> > >>>> > >>>> > >>> The primary difference between MPEG-4 and MPEG-2 is NOT the compression- > >>> decompression algorithm (codec). That's just crazy. I.. mean... > >>> literally... crazy. > >>> > >>> > >> Nope, on the average an MPEG-4 file compresses about 1/3 the size of > >> MPEG-2 and you can use a lower bitrate. The first comparison I found > >> was unlike MPEG-2 you could have one frame repeat as much as 300 times > >> without repeating that frame in the file. If you have a static title > >> image that saves a lot of space in the file. That's just one simple > >> difference in the GOP structure and of course there is a lot more. > >> > > > > Er, um.... That's NOT the primary difference between MPEG-4 and MPEG-2. > > That's a > > relatively minor difference. If that was all that was important, they could > > have come up > > with MPEG-2 rev B or something. > > > No, the major benefit between MPEG-2 and 4 *is* the compression. Having > flexibe GOP structures really helps compression. The rev was MPEG-4. I > would recommend "Video Demystified" 4th Edition by Keith Jack as a > reference. Or maybe you ought to spend less time on FFL and more time > on some AV forums.
Sigh. No, the major difference between MPEG-2 and MPEG-4 is the purpose for which the two standards were designed. MPEG-2 is a standard for a relatively simple multi-channel audio-visual presentation, while MPEG-4 goes lightyears beyond that, potentially incorporating all sorts of things besides multi-channel video and audio. And which AV forum do you want to move this discussion to?
