[MacDV] Re: AE Stupid question...probably

[Mark M. Florida]

On 4/30/03 12:16 AM, "Charles Martin" <chasm at mac.com> wrote:

>> From: Matthew Guemple <mo.og at verizon.net>
>> 
>> Yeah my bad.
>> 640X480
>> 29.7 fps...
>> Full/Best
>> No compression.
>> 
> Could it be an issue with the video card or the speed/fragmentation of
> the hard drive?

Probably not.  This is the equivalent of uncompressed video -- 27 MB (that's
megaBYTES) per second.  Although hard drives can *theoretically* push that
much data, streaming it from the hard drive and simultaneously drawing 30
frames every second to a computer screen is something that is (currently)
only able to be handled by dedicated uncompressed capture/playback cards and
video RAID disk arrays.  That's 9,216,000 pixels refreshing every second
(640x480x30).

So... To address the original issue -- your computer just can't keep up.  If
you have a Dual 1.42 GHz G4 with a RAID 0 disk array, you *might* be able to
play it back... But it would probably start to stutter at some point...  If
you use another high-quality but lossy codec like MJPEG-A/B (anyone know the
difference between those?) at full quality, you will most likely not notice
any difference visually on-screen.  If your final delivery will be via
DV/FireWire, then just save yourself some hassle down the line and work in
the DV codec at highest quality.

Or... If you want the highest-quality output for broadcast purposes, you can
render a preview version either at a lower resolution or with a high-quality
lossy codec like MPEG-4 or Sorensen (or both smaller frame size and with a
lossy codec), and when it comes time to send the rendered clip to the post
house, use the "None" compression setting (the "Animation" codec is also
visually lossless -- it compresses the data instead of the image to achieve
a smaller file size).

Anyway, hope all that mumbo-jumbo helps.

- Mark