Pal? NTSC? HDV? Prores422? 23.98p? 60i? 50i? This is what I am dealing with right now.
What I am trying to accomplish sounds quite simple. I want to make a
16x9 NTSC DVD from the PAL HDV master QuickTime for my new documentary
Legacy of the Great Aletsch. However this is not as simple as it
sounds. There are several thing to consider.
First is the frame rate. I need to convert the original frame rate of
50i (50 interlaced frames per second) to either 60i or 24p. However
both options have their problems. Increasing the framerate means that
we need to create new frames out of no where. This is not a simple
process and often introduces stutter artifacts. Lowering the frame rate
means we lose some frames here and there. This can introduce a
different kind of stutter.
The next thing I need to consider is frame size. HDV has a framesize of
1920x1080. NTSC 16x9 has a frame size of 720x404 Actually, even this is
not so simple because both of these formats use non-square pixels. So
HDV's real dimensions are 1440x1080 with wide rectangle pixels and NTSC
is 720x480 with squished pixels. So I have to go from one non-square
pixel format to another.
The final problem is interlacing. HDV is an interlaced format, meaning
that each frame is seperated into two fields made up of the odd and
even lines of the frame. With NTSC we have two choices. I have to
choose interlaced or progressive.
So I have a multitude of choices to make. Do I convert from 1080i to
480p or 480i? Do I change the framerate first and then downconvert or
the other way around? I also have to decide which piece of software to
use during the conversions and which codecs to use. It is maddening to
figure out which gives the best results. I will update when I have
found the best workflow.