[Free-sklyarov-uk] Identifying Corrupt Media and Tools

Jim Peters jim at uazu.net
Sat Dec 21 19:42:31 UTC 2002


Seth Johnson wrote:
> I got a request from a member of the C-FIT Community list,
> asking for information on identifying corrupt tools and
> media.  The problem being how does one check whether a piece
> of hardware has DRM in it or in any way restricts one's
> freedoms -- preferably before buying it?
> 
> Thought I'd start by asking if any of you have specific
> pointers or ideas.

That is an incredibly broad question, and it seems impossible to
answer without talking about specific types.  Perhaps as a general
guide -- did you have to click on any licence agreements too long to
read fully?

I know CD 'copy-protection' isn't really a true DRM technology, but I
thought I'd just point out that some corrupt CDs *used* to have
obvious gaps between the tracks, or between the audio session and the
data session (which provided some guide for making your marker-pen
modifications), but these have now been eliminated, and the play-side
looks just like any other CD.

So, there is no easy way to detect a corrupt ('copy-protected') CD in
the shop unless there is a warning of some sort on the packaging.
Regarding warnings -- checking for areas of fine-print or unusual
symbols used on the packaging might be an idea.  Some corrupt CDs do
have relatively obvious warnings, but others still do not make this at
all clear, if a warning is used at all.  

The presence or absence of the original "compact disc digitial audio"
logo is not reliable, since many corrupt discs still come with this
logo on the packaging somewhere (e.g. the CD tray), and many standard
non-corrupt discs fail to display it.

You can see some of the symbols/labelling in use here:

  http://ukcdr.org/issues/cd/warnings/

Hope this helps --

Jim

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