Elementary question: What characterizes a compressible source?

[moviefan]

Hi guys,

on my way to understanding video processing and getting best quality out of least file size, I have just asked myself what characteristics a source must have to be compressible. More clearly: Is e.g. a very grainy source with theoretically extreme grain stableness also compressible? Or is a source only compressible when it's grainless. So does compressibility only arise from stableness or also from the complexity of the source? So less complex = more compressible.

Thanks for helping me understand video compression :)

[unskinnyboy]

less grainy = more compressible
less motion = more compressible
less colorful (i.e., more uniform colors) = more compressible
low resolution = more compressible
...you get the idea.

Why is this in the Avisynth Development forum?

[moviefan]

Because I didn't know where else to put it and it somehow concerns my script development ;)

[thetoof]

Yeah, a source with no grain at all and with crappy gradients will be more compressible, but being able to stabilize the grain would help a lot (but not as much as having none)

[unskinnyboy]

Because I didn't know where else to put it and it somehow concerns my script development ;) Unless this is about writing/modifying/compiling an Avisynth filter or Avisynth core itself, this doesn't belong here. If your question is about the development of your script, it should go to the Avisynth Usage forum, but with specifics about it. The way the thread is currently, it belongs to the General Discussion forum.

[Biggiesized]

High frequency detail compresses worse.

[Soulhunter]

Enemys of compression: Spatial complexity -> High frequencys [fine details, sharp edges, strong contrasts... so, everything that makes a image non flat / even] and temporal complexity -> The alteration between frames... The characteristics of a compressible source is a low amount of both!


Bye