View Full Version : Compare HDV/miniDV scratch disk and storage needs


Scott Shuster
February 12th, 2005, 11:55 PM
There was a great post last month about the storage needs for HDV:
http://www.dvinfo.net/conf/showthread.php?s=&threadid=37241

...however now that growing numbers of small producers are making the shift from miniDV to HDV production, I wonder if anyone can do a direct comparison of miniDV vs. HDV (FX1, Z1U) storage needs:

Such as, "a minute of miniDV requires 'x'-amount of storage, while a minute of HDV requires 'y'-amount. A direct comparison of this nature would be very useful.
Thanks in advance,
Scott

Kevin Shaw
February 13th, 2005, 12:31 AM
Scott: looks like that was covered somewhat in the previous thread, but with maybe a few details left out.

Native HDV 720p (JVC) = ~19 Mbps = 142 MB/minute
Native HDV 1080i (Sony) = ~25 Mbps = 187 MB/minute
Canopus HQ, low quality= ~50 Mbps = 374 MB/minute
Canopus HQ, medium quality = ~75 Mbps = 562 MB/minute
Cineform Aspect HD: ~75 Mbps = 562 MB/minute
Canopus HQ, high quality = ~100 Mbps = 750 MB/minute

Both Canopus HQ and Aspect HD have some variables which will affect these numbers.

David Newman
February 13th, 2005, 12:01 PM
Yes, CineForm also has three compression modes for bit-rate/quality selection. Plus the option for progressive vs interlaced encoding which is very useful for progressive cameras like HD10U and Sony's CF25 and CF30 modes (it offers additional compression without quality loss.) All bit-rate numbers for a constant quality codec will depend on the material being encoded, data rate will rise and fall as needs to maintain quality. So numbers like Kevin has shown are very approximate for CineForm and Canopus codecs. The import thing is maintaining quality (CineForm approach) has priority over maintaining bit-rate (the native HDV approach.) This link compares quality over generation of CineForm vs Native HDV: http://www.cineform.com/technology/HDVQualityAnalysis/HDVQualityAnalysis.htm

So back on subject. Storage needs will be between 3 and 4 times higher for an intermediate format vs a native format. The benefits for this are higher quality and dramatic performance increases.