HMC150 PH Data Rate

D

dvdell

New member
Hello Everyone,

Long time DVX user here and recent HMC150 buyer. I love the camera and I have found lots of great info here, but I do have one question about the data rate in PH mode. I have shot in most of the modes available, but plan on on using 720/60p in PH mode, and 1080/30p in PH mode. I am using FCP 6.0.5 to log and transfer my files. I was expecting to get date rates at around 21mb, as described for PH mode shooting, but everything is coming in at around 17mb. I am diffenitly shooting in PH mode so I am wondering what the problem is? Anyone out there have an idea why my data rates aren't higher?

Thank you in advance,
dvdell
 
yeah I use FCP and transcode with Toast 9. I have noticed some of my data rates to AIC are below the data rate of the PH mode depending on the footage etc. A locked down landscape shot has a much lower data rate after transcode then say a handheld shot with tons of motion.
 
Hmmm... that doesn't seem likely; no intraframe format of any decent quality will be anywhere near the small size of AVCHD footage. I don't know about AIC, but footage transcoded to ProRes in FCP often has a data rate of 17MBps (megaBYTES)... NOT 17Mbps (megaBITS)... are you sure you're not confusing bits and bytes?

How big are the actual files, and how long? Divide the file size by the length in seconds, you'll get the average data rate.


EDIT: I searched the web, and data rates for AIC derived from 1080i HDV is 14MB/s; so it wouldn't be strange if full-raster AVCHD-derived AIC is around 17MB/s... so, around 8.5x the size of PH footage....
 
Last edited:
ullanta said:
Hmmm... that doesn't seem likely; no intraframe format of any decent quality will be anywhere near the small size of AVCHD footage. I don't know about AIC, but footage transcoded to ProRes in FCP often has a data rate of 17MBps (megaBYTES)... NOT 17Mbps (megaBITS)... are you sure you're not confusing bits and bytes?

How big are the actual files, and how long? Divide the file size by the length in seconds, you'll get the average data rate.


EDIT: I searched the web, and data rates for AIC derived from 1080i HDV is 14MB/s; so it wouldn't be strange if full-raster AVCHD-derived AIC is around 17MB/s... so, around 8.5x the size of PH footage....
Click to expand...

Thanks for looking into that Ullanta, I appreciate your efforts. And yes I am talking about MB/sec. I attached a jpg of the browser window in FCP so you can see.

:dankk2:
 

Attachments

  • AVCHD_window.jpg
    AVCHD_window.jpg
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Right.... so your ProRes files have about 6.6 times the data rate of your PH mode AVCHD (that is, about 142 mbps). Hope you got your big drives ready!
 
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