From time to time I need to rip a DVD, due to my fascination with
compression I'm interested in knowing about how they work and
which codec is the best. I began looking for a visual
comparison between XviD and X264 and couldn't find anything
so I thought it would be fun to create my own comparison.
In the encoding community a PNSR represents the mathematical
measurement for how much loss occurs during encoding, and there
are plenty of ways to automate this analysis but I am more interested in
how things look visually once decoded.
Normally if I had some encoding to do I would simply open
but I've had
issues with XviD at low bit rates which made me interested in comparing
it to newer alternatives. XviD is an MPEG4
encoder, which many consider to be the best ASP codec. There is
another profile in the MPEG4 spec however called AVC
which HD-DVD and Apple's QuickTime use. For
testing MPEG4 AVC I decided to use the wildly popular X264
distributed as a command line tool that takes AVISynth input and
outputs MP4 files. AVC has advanced compression algorithms that go
beyond what ASP offers, and XviD generally suffers from the constraints
of the commonly used AVI container for things like encoding B-frames.