sparaig wrote:
> --- In [email protected], Bhairitu <[EMAIL PROTECTED]> wrote:
>
>> sparaig wrote:
>>
>>> --- In [email protected], Bhairitu <noozguru@> wrote:
>>> [...]
>>>
>>>
>>>>> Most of the features included in MPEG-4 are left to individual
>>>>>
>>>>>
>>>> developers to decide whether to implement them. This means that there
>>>> are probably no complete implementations of the entire MPEG-4 set of
>>>> standards. To deal with this, the standard includes the concept of
>>>> "profiles" and "levels", allowing a specific set of capabilities to be
>>>> defined in a manner appropriate for a subset of applications."
>>>>
>>>> --- cut---
>>>> Do you see anything about QuickTime here? Do you really know anything
>>>> about video programming? Have you ever written a demuxer or muxer? Do
>>>> you know the MPEG format, sequence headers, etc? Have you ever written
>>>> a stream parser?
>>>>
>>>> Dream on.
>>>>
>>>>
>>>>
>>> Why so hostile?
>>>
>>>
>>>
>> I'm not being hostile but some of the stuff you're saying is like
>> someone who's never been to India telling me what India is all about
>> when I've been there. I've been on the steering committees for these
>> consortiums (not the MPEG-4 but some others). I've been to Apple
>> developer conferences and worked with Apple developer support. I've
>> developed on the Mac and in fact at the moment looking to pick up a used
>> Mac that can run OS X so that I can port some products to it. I have an
>> iMac here but I can't put OS X on it. The company I used to work for
>> started out very Mac centric.
>>
>> I also do some video development and had to even write a player for the
>> last product I did. I've also been working with digital video since
>> 1991 when I bought my first camcorder and capture box for the Amiga.
>>
>
> My first programming job was for Dave McClain, who helped finish AmigaDOS 1.0
> for
> Commodore. We were doing software support for a video/accelerator card for
> Mac Plus
> and Mac SE.
>
>
>
>> Now if you want to talk about a superior computer, the Amiga was way
>> ahead of it's time (and the Lisa before that until Jobs killed it).
>>
>>
>
> Eh. At $10,000 per box, the original Lisa was a tad expensive for most
> people. NeXT was
> far better, but still too expensive at $7000 per box. The Mac Mini is many
> times more
> powerful and versatile than either machine except on expansion slots, and
> only costs 1/10
> of the NeXT cube.
>
>
>> 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.
> MPEG-2 described how to store multi-channel audio and visual information.
> Basically, the
> options available with many DVD movies, such as different camera view,
> subtitles,
> dubbed/alternate audio, etc, as well as screen resolution and shape (although
> there's no
> built-in limit in MPEG-2 as to how many such options could be made available,
> the
> implementations put up hard limits due to space considerations). The MPEG-2
> compression/decompression algorithm implements such things, but the DESIGN of
> MPEG-2 is the important issue. The implementation is secondary.
>
> In fact, no-one has thus far implemented every aspect of MPEG-4 in the same
> package,
> and many/most of the designers believe that no-one ever will--its just TOO
> versatile.
>
> Here's an overview of MPEG-4's design. Check out the figure on page 7 of the
> pdf and
> recall that MPEG-4 isn't limited JUST to visual/audio data. Computer data,
> such as
> instructions for arbitrary computers or Java programs or HTML webpages or
> whatever is
> inherently supported in MPEG-4, just as it is in QuickTIme. That's the reason
> why the
> QUickTime file format was chosen: The design of QT anticipated MPEG-4 in many
> ways so
> Apple had already done the design work for a file format to support
> MPEG4-like features,
> even though Apple hadn't implemented all of them at that time (and still
> hasn't):
>
> http://www.bbc.co.uk/rd/pubs/presentations/pdffiles/mpeg4gat.pdf
>
> [page 7]
>
> "This figure explains the way in which an audiovisual scene in MPEG-4 may be
> desribed as
> composed of individual objects. The figure contains compund media objects
> that group
> primitive media objects together. Primitive media objects correspond to
> leaves in the
> descriptive tree while compound medial objects encompass entire sub-trees. As
> an
> example: the visual object corresponding to the talking person and the
> corresponding
> voice are tied together to form a new compound media object, containing both
> the aural
> and visual compoonents of that talking person.
>
> "Such grouping allows authors to construct complex scenes, and enables
> consumers to
> manipulate meaningful (sets of) objects.
>
> "More generally, MPEG-4 provides a standardized way to describe a scene,
> allowing for
> example to:
> * place media objects anywhere in a given coordinate system;
> * apply transforms to change the geometrical or acoustical appearance of a
> media object;
> * group primitive media objects in order to form compound media objects;
> * apply streamed data to media objects, in order to modiy their attributes
> (e.g. a sound, a
> moving texture belonging to an object; animation parameters driving a
> synthetic face);
> * change, interactively, the user's viewing and listening points anywhere
> in the scene."
>
>
>> As Barry pointed out you're doing the same groundless thing for Apple
>> you do for TM. If anything I'm trying to help you get a better grasp on
>> how the computer industry works and how they develop technology. It's
>> not any ego trip for me, I'm just one of the many who worked "in the
>> valley" and have "been there, done that." I try to do the same thing in
>> explaining how mantra shastra works.
>>
>>
>
> I hope you have a better grasp of THAT then of the difference between MPEG-2
> and
> MPEG-4. Sheesh.
I think you could get a great gig at tech seminars.... as a geek
comedian. They'd have a great laugh at how you grasp technology.
