I'm a bit confused as to why on my 550d I can get 45mb/s video bitrate (fullHD PAL / 1080p 25fps) yet the max card write speed is only 21mb/s (and then my card probably doesn't even write half that).
Is this a case of me confusing megabit with megabyte?
Where does the first number come from?
Ciao
Walter
Quote from: Walter Schulz on December 09, 2013, 10:12:51 AM
Where does the first number come from?
I played back the video on my computer and checked out the average bitrate.
Quote from: ItsMeLenny on December 09, 2013, 09:58:54 AM
Is this a case of me confusing megabit with megabyte?
It is.
@ItsMeLenny: Yes, that's the confusion. 45mb/s is 45 MegaBITS per second, which is less than 6 MegaBYTES per second. The SD card limit is about 21MegaBYTES per second. Probably the bitrate viewer you used to check the average "bitrate" shows you just that, not the "byte"-rate.
Cheers!
Quote from: NedB on December 09, 2013, 10:27:13 AM45mb/s is 45 MegaBITS per second, which is less than 6 MegaBYTES per second.
And that's why a decent Class 10 card will be sufficient recording Canon's h.264 implementation at 1080p/30 without any hickups.
Ciao
Walter
Ok, my bad :P
While on the subject though, which uses lower case b?
Mb = megabit/megabyte
MB = megabit/megabyte
And I should get myself a faster card and see how much I can ramp the bitrate up.
http://en.wikipedia.org/wiki/Megabit
Faster card? 21 MByte/s is interface limit. Nothing you can do about.
Ciao
Walter
Quote from: Walter Schulz on December 09, 2013, 10:57:28 AM
Faster card? 21 MByte/s is interface limit. Nothing you can do about.
Yes but my card only writes at about 12.
So in that case, something I can do about ;) :P