Re: Movie Corruption Issue & Codecs

Posted by Urs Utzinger on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Movie-Corruption-Issue-tp591691p591702.html

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I suggest well documented standards such as MPEG4 and JPEG2000.

Open source encoders such as Xvid or x264 where you have access to the
software code might be useful, however once the movie is encoded any player
adhering to the standard can decode it. The encoders differ in their ability
to compress and maintain quality but store data into a standard format.

Open source decoders are available for both MPEG4 and JPEG2000. It is likely
that in 20 years you will still find example source code.

Lossless encoding is often not entirely lossless and testing if a particular
configuration really did not change a single bit is time consuming.

Making a ZIP archive of the original data seems to be the way to go.

You might also want to check virtual machines such as VMWare where you can
build a virtual computer (appliance) that has all your image processing
software installed and at later time you can run it on another computer and
redo your analysis. The advantage would be that you can archive your virtual
computer and revive it in the future when there is no support for it anymore
(assuming a program playing your virtual machine still exists). There are
programs that create a virtual machine from a real hardware installed
operating system.

Urs Utzinger
University of Arizona


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On
Behalf Of Stephen Bunnell
Sent: Friday, January 25, 2008 2:32 PM
To: [hidden email]
Subject: Re: Movie Corruption Issue & Codecs

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http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

I agree that my short-term solution poses a security risk, but the inability
to play my archived movies had effectively deleted my work product from
1999-2004. This was not recoverable without reinstalling an earlier version
of the OS in order to downgrade Quicktime. Obviously, this is not the best
strategy.

Apple explicitly advertises legacy support for _all_ previous Quicktime
codecs. This is an extremely appealing feature when legacy access to old
scientific data is at issue. However, this is currently false. If Apple
intends to discontinue/disable old codecs, they should make this apparent in
the upgrade notes, so that users may convert their movies _before_ their
ability to convert them is deleted.

I cannot imagine any sane individual who would enjoy the prospect of
retroactively re-encoding 5 years worth of compiled imaging data solely to
maintain legacy access.

So, I seek advice: Are there industry-standard lossless codecs that are
expected to be supported for 10-20 years? What are the best options for
long-term storage of imaging data? What resources are available that discuss
the costs and benefits of various formats vis a vis scientific data?

    Best regards,

    Steve Bunnell

 



On 1/25/08 1:16 PM, "Mathieu Marchand" <[hidden email]> wrote:

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> To comment the previous post,
>
> Everybody should be aware that using any other version than the latest
> available Quicktime is a major security risk, on both Mac and Windows.
>
> The last 7.3, 7.3.1 and 7.4 updates of Quicktime corrected some CRITICAL
> flaws:
> http://secunia.com/advisories/28502/
> http://secunia.com/advisories/28092/
> http://secunia.com/advisories/27755/
> http://secunia.com/advisories/27523/
> and these are the flaws for only the past 3 months
>
> These flaws are rated "extremely critical" and could give an attacker
> remote access on your system just by visiting a malicious website with
> your favorite browser.
> Since Quicktime 7.2 and later does not support Windows 2000 any more,
> I recommend to uninstall Quicktime on computers running Windows 2000.
>
> Support for old codecs like "animation" for quicktime or "cinepak" for
> vista is broken or problematic and people should stop using them, and
> plan to convert old movies to more recent codec. "Codec Packs" can
> sometimes solve your problem, but they usually have major stability /
> legality / security risks attached to them. They can introduce new
> problems, too (for example: the Perian codec pack for MacOS brakes the
> play out of 'ARAW' coded avi files including avi files generated by
> ImageJ).
>
> Picking a codec is a complex issue and there is no easy choice.  It is
> something worth discussing with a specialist to make the best decision
> for your situation.

****************************************************************************
Stephen C. Bunnell, Ph.D.
Assistant Professor
Tufts University Medical School
Department of Pathology
Jaharis Bldg., Room 512
150 Harrison Ave.
Boston, MA 02111

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