🚀 go-pugleaf

In article <4b9hd3$jrm@news.unicomp.net> ray@optibase.com "Ray Harris" writes:

> MPEG Compression can vary depending upon the quality you want.  This
> quality is comprised of the following issues:
> 1. Frame Rate - 30 frames per second is preferred but you will often
> see reduced frame rates used to store more video in a given amount of
> space.
> 2. Resolution - The nominal MPEG resolution is 352 x 240.  However,
> many people distribute MPEG on the net at lessor resolution, often 160
> x 120.  Again, a big space saver.
> 3. Compression Ratio - The more you compress, the smaller the file.  A
> good encoder can compress from a full BTSC/CCIR601 video stream
> representing over 30 MB/S to around 150K per/second and still maintain
> very good quality.  However quality is subjective.
> 4. Audio - MPEG1 can use CD quality 16 bit audio or lower quality 11
> KHz, mono audio.  Mono uses less space.
> 
> So, to figure out what will fit where, just do some math.
> 
> At 150K per second (pretty high quality video at MPEG1) you get 72
> minutes on a CD ROM and around 9 seconds on a floppy.
> 
> Change the above facters to fewer frame rates, lower resolution and
> mono audio and get a LOT more.  In reality, your application will
> determine your quality requirements.
> 

Excellent,  just what I needed to begin thinking practically  and 
constructively about a project. 

The card I am using is a MIRO DC1 which offers JMPEG compression, 
but  unless  someone  else has such a card  it's  not  much  use. 
Instead,  what I tend to do is select 'cinepak' and opt for  100% 
quality.   That  produces  a  good  file,  but  minimal   to   no 
compression.  In Adobe Premiere on a P120, 32MB EDO and 256  CELP 
with  1.2GB EIDE drive and Windows for Workgroups set to  32  bit 
file  and disk access, that still took 8 hours to convert  a  raw 
capture  file of 60MB (15 fps at 160 x 120 with audio turned  off 
in output) to a file of about 50MB). 

My main question is this. When I capture video from a VHS source, 
is  any  compression  being  done  at  that  stage,  or  is   the 
compression  only  done  at the stage that I 'make  a  movie'  in 
Premiere?  
-- 
David Longley