How does DivX work?

[sturmie]

i was just curious how the DivX encoding actually works...a basic overview. i heard some where that DivX works by capturing only what's different from frame to frame, which is how you can get such good compression on videos, as opposed to writing each full frame...seems to make sense to me and it would explain why going from DivX to DVD creates such a pixelated'ish copy.


...but before i go spreading any rumors, i'd like to verify it ;).

thanks.


sturmie

[G_M_C]

Well first off:
Going from DivX to DVD has got nothing to do with pixelation, thats probably only caused by your conversion-method.

Secondly; Reading your post, I get the feeling that you think DVD codes frames individually. Thats not true, DVD also mainly codes the differences between frames. If you look at it; The coding DivX (MPEG4-ASP) does and DVD (MPEG2) does aren't that different, it's both based on the MPEG standard.

But let me say: Encoding video isn't as easy as you think. It's not only coding differences between frames, but it encompasses far ... far more.

But why dont you :search: on google ?

Video Compression on Wikipedia (http://en.wikipedia.org/wiki/Video_compression)

[unskinnyboy]

@sturmie, DivX being closed source, you can't hope to look at the actual code and figure it out for yourself, like you can with Xvid and x264. The underlying principles are mostly the same, it's just the implementation which is different.

This guide will give you a fair idea: http://download.divx.com/divx/DivXUserGuide521-en.exe

[sturmie]

But why dont you :search: on google ?

Video Compression on Wikipedia (http://en.wikipedia.org/wiki/Video_compression)

i did "google" it..."how divx works" gives you some good info about the old Divx Video On Demand stuff ;)...i really just wanted to see if my buddy's layman's term definition of how DivX works was accurate...that's all. i really don't need an ultra-technical answer :thanks:.

[G_M_C]

i did "google" it..."how divx works" gives you some good info about the old Divx Video On Demand stuff ;)...i really just wanted to see if my buddy's layman's term definition of how DivX works was accurate...that's all. i really don't need an ultra-technical answer :thanks:.

Yup, searching on "How DivX works" could give you some unwanted pages.

But remember; DivX is one of many video-compression methods falling under the MPEG cathegory. So searching on how MPEG compression works (http://www.google.com/search?hl=nl&q=how+MPEG+compression+works&lr=) might give more wanted pages ;)