View Full Version : HD-space on hard disk


Marcus Martell
April 13th, 2009, 03:07 PM
Could you explain me guys the basical things about HD?
I mean:1 hour of hdv equals......
1 hour of Sd equals.....

thx

Martin Mayer
April 13th, 2009, 03:26 PM
...13 GB
...13 GB as well!

(The HDV contains more information, but is more highly compressed.)

Giroud Francois
April 13th, 2009, 04:01 PM
you simply have to convert the bandwith to disk space.
DV=25Mbit/sec , need 8 bits to make one byte, so 25/8=3.125 MBytes/sec.
HDV is the same.
multiply by 3600 to get one hour. 3.125x3600 =11250 Mbytes or 11.250 Gig.
Since there is always some discrepancie with calculation (sometime 1meg=1024K, sometime 1Meg=1000K, you never know).

XDCAM Ex =35Mbit/sec
AVCHD , MPEG2 are more tricky since each camera can use its own speed and sometimes several speed (low/mid/high quality setting)

Bradley Ouellette
April 13th, 2009, 04:09 PM
Martin, would it not depend on which camcorder you are using. Some have 25mb/s. DV are more like 6mb/s? The HV30 used 11.32GB for an hour of raw footage. I'm sure SD footage would be much less...

Marcus Martell
April 13th, 2009, 04:40 PM
Ok thank u guys; what about if i have to edit 1 hour in dv-avi,and what about 1 hour in m2t hdv?

Ron Evans
April 13th, 2009, 05:26 PM
DV and HDV are CBR 25mbps so will use exactly the same time on tape. About 12GB for the hour. The codec is different so the data is different but both are recorded CBR 25mbps. That's also true of DV LP speed too its just using less tape to record( higher bit density on the tape) and this is why LP is more susceptible to drop outs and head alignment. Doesn't matter whether you record or edit its still the same. It will only change if you change the codec that you render to from the NLE.

Ron Evans

Tripp Woelfel
April 13th, 2009, 09:06 PM
Ok thank u guys; what about if i have to edit 1 hour in dv-avi,and what about 1 hour in m2t hdv?

About 13 Gb for both. HDV and DV have exactly the same data rate/storage size. Once transcode, for example to BD or DVD format that will change. But to answer your question both have a data rate of 25 mbps.

Bradley's a little off the mark, or maybe misunderstood your question. All the other answers are correct and saying the same thing in different ways.