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Archiving strategy for old tape library.

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Nathan Tinsley
Archiving strategy for old tape library.
on Feb 18, 2009 at 6:42:43 pm

I would like to put forth an archive plan for comment and suggestion.

Hardware: Apple G5 dual quad core. AJA-Kona LHe. Final Cut Pro 6.

Application: Take old One Inch, ¾ inch and Betacam originals (30-60 minute edited TV shows) and capture them with the Kona LHe in a lossy codec with a 4:2:2 color space. Store the video files on an external firewire drive. I’m aware of the risks in the storage and am willing to take them. These programs are mostly old shows and features that my TV station has done over the past 30 years.

Option 1: Make a capture preset with the following specs – AJA 10bit Digitizer, Compression H.264 at 100%, Audio 48 kHz stereo PCM. This creates an overall data rate of about 30 megabits/sec. The results are good with a little bit of blooming in the whites. It renders out on a 10 bit uncompressed timeline well and looks fine in the program monitor.

Questions: Is this H.264 codec really 10bit 4:2:2? According to wikepedia there is a profile level called Hi422P that supports 10 bit 4:2:2 but I can’t seem to figure out if it’s really happening with the Quicktimes I make. I’m using Quicktime 7.5. Also in theory couldn’t H.264 be written STRAIGHT to the firewire drive?

Option 2: DVCPro50. This definitely is a 4:2:2 color space and previews in real time on the timeline. Results are very similar to H.264 and handle detail better in high exposure areas. Quicktime Movie inspector puts the datarate for these files at about 60 megabits/sec. So double the H.264 spec.

Questions: Can DVCpro50 video be written STRAIGHT to the firewire drive during capture? How do you all feel about the legacy support of DVCpro50 into the future?

Option 3: Apple Prores422. This is also 4:2:2 and is practically identical in datarate to DVCpro50 (64 megabits for ProresHQ). As to quality I can’t tell the difference when it is side by side on a 10bit uncompressed timeline with DVCpro50.

Questions: Between this and DVCpro50 I think the only question would be legacy support in the future and opinions on quality. I’m guessing ProRez has newer algorithms than DVCpro50? Also can Prores422 video be written STRAIGHT to the firewire drive during capture?

FINAL QUESTIONS: Is 4:2:2 overkill on the color space? Would 4:1:1 color space have enough chroma resolution for One Inch and ¾ inch? Should I consider photo-jpeg? Is 10bit sampling too much? Should I consider the 8 bit digitizer? Am I way out in left field wanting to capture straight to the firewire drive?

Many thanks in advance.


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walter biscardi
Re: Archiving strategy for old tape library.
on Feb 18, 2009 at 7:21:57 pm

Personally I would capture everything to Apple ProRes HQ

Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.

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gary adcock
Re: Archiving strategy for old tape library.
on Feb 19, 2009 at 3:21:21 pm

[Nathan Tinsley] " AJA 10bit Digitizer, Compression H.264 at 100%, "

no. the Kona cards cannot capture into h.264.

"Questions: Is this H.264 codec really 10bit 4:2:2?"
no 8bit, no iframe convention in H.264- this is a delivery codec not an archive.

"Should I consider photo-jpeg? Is 10bit sampling too much? Should I consider the 8 bit digitizer?"
Yes photojeg at 75% should about equal your original-and offer the smallest file size.

while 10bit is great - chances are none of your originals are at 10bit
8 bit capture will maintain the data integrality for archive use.



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Nathan Tinsley
Re: Archiving strategy for old tape library.
on Feb 19, 2009 at 3:29:00 pm

Gary thanks for that critical info. H.264 is out. I will conduct tests with Photo Jpeg.

Walter thanks for your tip. Could you elaborate just a bit on your choice? =)

How do either of you feel about selecting the external firewire drive as the capture scratch location?

Nate



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gary adcock
Re: Archiving strategy for old tape library.
on Feb 19, 2009 at 7:29:55 pm

[Nathan Tinsley] "How do either of you feel about selecting the external firewire drive as the capture scratch location?"

I prefer to capture to a disk array, then move the content via FW.

I always want to make sure that my storage is faster than it needs to be for capture purposes, it is a lets always be safe kinda thing.







gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Nathan Tinsley
Re: Archiving strategy for old tape library.
on Feb 20, 2009 at 2:43:23 pm

Thanks Gary. I understand the point. I'd had to have dropped frames!

Nate




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