question about DVD camcorders

[Brian MacWhinney]

Dear Aarre and Info-CHILDES,

    Let me get a bit more technical, since this stuff is actually  
quite complicated.   First, the material Dave Touretzky has collected  
is designed to decrypt  the CSS (content scrambling system) used for  
Hollywood DVDs.  This is not the problem for us, since the DVD videos  
that are produced by home cameras or home computer programs do not  
use CSS.  Our goal is to play a homemade DVD video through  
QuickTime.  You would think this would be easy, but unfortunately it  
is not. The video on a home DVD video is stored in MPEG-2 files and  
you can navigate about the DVD to locate these files.  The problem is  
that the MPEG2 plugin that Apple sells for Quicktime has not been  
seriously updated for years.  Once Apple produced iDVD, it appears to  
have lost interest in the MPEG2 plugin as a product.  We can see this  
easily by playing the MPEG2 files on the DVD in the separate VCL or  
MPEG2Player applications.
      The problem is that CLAN uses QuickTime to play media.  To  
rewrite CLAN to play directly using VCL would take months of  
programming, if it is possible.  I spent the whole afternoon trying  
to find a way around this barrier with no luck.  I wish I could  
report better news on this front, but for now I have to just repeat  
my warning that people who want to use CLAN should not record to DVD  
video format.

--Brian

On Jun 15, 2006, at 10:26 AM, Aarre Laakso wrote:

> Brian MacWhinney wrote:
>>    Please please don't record to the DVD format, if you plan to do  
>> further analysis of your data.  It is a highly proprietary  
>> format.  Someday, we will probably be able to "crack" the code for  
>> the DVD format in terms of linking to programming, but who knows  
>> when?
>
> This is a bit off-topic, but I feel compelled to note that software  
> to "crack" the DVD encoding was released in 1999 by a 15-year old  
> Norwegian named Jon Johansen. The original and many other  
> implementations are still widely available, although usually not in  
> a particularly "user friendly" form, for legal reasons. Dave  
> Touretzky maintains a "gallery" of examples at:
>     http://www.cs.cmu.edu/~dst/DeCSS/Gallery/index.html
> and some further information at:
>     http://www.cs.cmu.edu/~dst/DeCSS/index.html
> that together provide a fascinating case study of the both the  
> necessity and the ongoing difficulty of redefining such basic  
> notions as "property" and "speech" some 60 years after the dawn of  
> the information age.
>
> I agree with Brian: do not record your original data to DVD.
>
> Regards,
> Aarre Laakso
>
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