ramdom scattered color blocks in P2 footage... at DVinfo.net

Kevin McRoberts · February 24th, 2011, 03:39 PM

Noticing them now on a recent project... every so often, there's some corruption as a small batch of pixels in random parts of the frame are scrambled to primary monochromatic nonsense. The video clips aren't unreadable, just messed up in certain single scattered frames.

Where does this corruption typically happen? On the card end or the camera end?

Daniel Epstein · February 25th, 2011, 07:51 AM

More Info Kevin. What camera? What cards? How are you viewing? Show a still of the problem. Can you look at the footage with a different program an still see the problem?

Kevin McRoberts · February 25th, 2011, 06:40 PM

Hm, yes.

HVX200 (non-A), 32 and 8gb Pan A-series cards. Problem visible when previewing clips via FCP Log n Xfer, and P2CMS (mac).

Actually dont' have an account handy to dump stills, but I'll get that and will eventually try previewing the problem clips via the camera's comp out on a large-screen TV.

Daniel Epstein · February 27th, 2011, 01:08 PM

Kevin,
If the data is recorded on the P2 cards with the errors and it is on multiple cards then the problem is most likely in the camera. If the camera can playback the footage without error then you have to look at your computer harddrive system. When you play back a clip is the error always in the same place or is it more random? You should be able to identify on the same clip whether the error is in the recording. Good Luck

Joe Lawry · February 28th, 2011, 05:30 PM

Its due to the fact the cards haven't been write protected when downloaded to a mac computer.

write protect your cards before you download them with P2CMS and you should be fine.

the footage you have currently with the issue cannot be saved however.

Robin Probyn · March 1st, 2011, 07:05 PM

wow thats a worry?

Is that just with Mac and using P2CMS..(as opposed to say shotput pro),or for all situations..?

Joe Lawry · March 1st, 2011, 07:07 PM

its been a known issue for many years now.

Its to do with the fact Mac's write files to external drives when connected.. and a p2 card is effectively an external drive.

write protect it and you'll have no problems..

Robin Probyn · March 1st, 2011, 08:47 PM

Ok thanks.. surprised I,d never heard of it.. so you mean pull the write protect tap on the card..?

Joe Lawry · March 1st, 2011, 08:51 PM

Yup thats the one! :)

Robin Probyn · March 1st, 2011, 09:41 PM

Ok thanks.. good tip..

Kevin McRoberts · March 6th, 2011, 02:53 AM

Interesting...

Now that you mention it, previously I'd been using a cheap windows laptop to offload P2 to a USB HDD, and then transporting to the Mac from that. Probably why I never noticed it before, and a mighty good thing I asked

Philip Fass · March 6th, 2011, 06:57 AM

Can we ignore write-protect when downloading from camera to external hard drive?

Kevin McRoberts · March 6th, 2011, 01:49 PM

Probably... I know the MacOSX tendancy he's talking about. OSX places small "invisible" reference files on any attached drive, which apparently are mungy enough to corrupt P2 data streams. No OSX involved, no need to write-protect.

Come to think of it, perhaps that's why I'm having so much trouble with my MRC1K as well...

Robin Probyn · March 6th, 2011, 07:29 PM

But were you not pulling the write protect on the cards after you filled them up..? if you were it would have to be something else ?

Kevin McRoberts · March 7th, 2011, 12:16 PM

No, I'd never flipped the switch.

Tested the theory out, filled a card and write-protected it, mounted and captured on the Mac, and the wee villainous pixels were not summoned, evoking gladness and mirth within my soul.

February 24th, 2011, 03:39 PM	#1
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	ramdom scattered color blocks in P2 footage... Noticing them now on a recent project... every so often, there's some corruption as a small batch of pixels in random parts of the frame are scrambled to primary monochromatic nonsense. The video clips aren't unreadable, just messed up in certain single scattered frames. Where does this corruption typically happen? On the card end or the camera end?

February 25th, 2011, 07:51 AM	#2
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Re: ramdom scattered color blocks in P2 footage... More Info Kevin. What camera? What cards? How are you viewing? Show a still of the problem. Can you look at the footage with a different program an still see the problem?

February 25th, 2011, 06:40 PM	#3
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	Re: ramdom scattered color blocks in P2 footage... Hm, yes. HVX200 (non-A), 32 and 8gb Pan A-series cards. Problem visible when previewing clips via FCP Log n Xfer, and P2CMS (mac). Actually dont' have an account handy to dump stills, but I'll get that and will eventually try previewing the problem clips via the camera's comp out on a large-screen TV.

February 27th, 2011, 01:08 PM	#4
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Re: ramdom scattered color blocks in P2 footage... Kevin, If the data is recorded on the P2 cards with the errors and it is on multiple cards then the problem is most likely in the camera. If the camera can playback the footage without error then you have to look at your computer harddrive system. When you play back a clip is the error always in the same place or is it more random? You should be able to identify on the same clip whether the error is in the recording. Good Luck

February 28th, 2011, 05:30 PM	#5
Joe Lawry Major Player Join Date: Jul 2004 Location: Auckland, New Zealand Posts: 418	Re: ramdom scattered color blocks in P2 footage... Its due to the fact the cards haven't been write protected when downloaded to a mac computer. write protect your cards before you download them with P2CMS and you should be fine. the footage you have currently with the issue cannot be saved however.

March 1st, 2011, 07:05 PM	#6
Robin Probyn Major Player Join Date: Jan 2010 Location: Tokyo Posts: 590	Re: ramdom scattered color blocks in P2 footage... wow thats a worry? Is that just with Mac and using P2CMS..(as opposed to say shotput pro),or for all situations..?

March 1st, 2011, 07:07 PM	#7
Joe Lawry Major Player Join Date: Jul 2004 Location: Auckland, New Zealand Posts: 418	Re: ramdom scattered color blocks in P2 footage... its been a known issue for many years now. Its to do with the fact Mac's write files to external drives when connected.. and a p2 card is effectively an external drive. write protect it and you'll have no problems..

March 1st, 2011, 08:47 PM	#8
Robin Probyn Major Player Join Date: Jan 2010 Location: Tokyo Posts: 590	Re: ramdom scattered color blocks in P2 footage... Ok thanks.. surprised I,d never heard of it.. so you mean pull the write protect tap on the card..?

March 1st, 2011, 08:51 PM	#9
Joe Lawry Major Player Join Date: Jul 2004 Location: Auckland, New Zealand Posts: 418	Re: ramdom scattered color blocks in P2 footage... Yup thats the one! :)

March 1st, 2011, 09:41 PM	#10
Robin Probyn Major Player Join Date: Jan 2010 Location: Tokyo Posts: 590	Re: ramdom scattered color blocks in P2 footage... Ok thanks.. good tip..

March 6th, 2011, 02:53 AM	#11
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	Re: ramdom scattered color blocks in P2 footage... Interesting... Now that you mention it, previously I'd been using a cheap windows laptop to offload P2 to a USB HDD, and then transporting to the Mac from that. Probably why I never noticed it before, and a mighty good thing I asked

March 6th, 2011, 06:57 AM	#12
Philip Fass Major Player Join Date: Jan 2005 Location: Charlotte, VT Posts: 397	Re: ramdom scattered color blocks in P2 footage... Can we ignore write-protect when downloading from camera to external hard drive?

March 6th, 2011, 01:49 PM	#13
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	Re: ramdom scattered color blocks in P2 footage... Probably... I know the MacOSX tendancy he's talking about. OSX places small "invisible" reference files on any attached drive, which apparently are mungy enough to corrupt P2 data streams. No OSX involved, no need to write-protect. Come to think of it, perhaps that's why I'm having so much trouble with my MRC1K as well...

March 6th, 2011, 07:29 PM	#14
Robin Probyn Major Player Join Date: Jan 2010 Location: Tokyo Posts: 590	Re: ramdom scattered color blocks in P2 footage... But were you not pulling the write protect on the cards after you filled them up..? if you were it would have to be something else ?

March 7th, 2011, 12:16 PM	#15
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	Re: ramdom scattered color blocks in P2 footage... No, I'd never flipped the switch. Tested the theory out, filled a card and write-protected it, mounted and captured on the Mac, and the wee villainous pixels were not summoned, evoking gladness and mirth within my soul.