Roy Schestowitz <newsgroups@xxxxxxxxxxxxxxx> espoused:
> ____/ Mark Kent on Wednesday 09 January 2008 08:11 : \____
>
>> Roy Schestowitz <newsgroups@xxxxxxxxxxxxxxx> espoused:
>>> ____/ chrisv on Tuesday 08 January 2008 16:59 : \____
>>>
>>>> Roy Schestowitz wrote:
>>>>
>>>>>____/ chrisv on Tuesday 08 January 2008 13:57 : \____
>>>>>
>>>>>> Mark Kent wrote:
>>>>>>
>>>>>>>Roy Schestowitz <newsgroups@xxxxxxxxxxxxxxx> espoused:
>>>>>>>>
>>>>>>>> The higher definition is for Hollywood. It helps when they can make old
>>>>>>>> content 'expire' (no longer be playable). They are drying people up, so
>>>>>>>> to speak, and people then have to go out and get some more. Same
>>>>>>>> situation with Microsoft Office...
>>>>>>
>>>>>> I don't think so, Roy. DVD's will always be playable. Unless you
>>>>>> have evidence to the contrary?
>>>>>
>>>>>VCRs and gramophones are getting harder to find and also become more
>>>>>expensive. It's gradual phasing out of technology that won't last forever.
>>>>>The solution is to make backward compatible technology (like ODF).
>>>>
>>>> Sure, eventually, the whole "optical disk" thing will be past it's
>>>> "use by" date. But, since HD video-disk players also play DVD disks,
>>>> they themselves cannot be a force to "expire" DVD disks.
>>>
>>> Yes, but one key issue here (among more) is DRM, which has been described by
>>> many as the monster that will eat digital preservation and spit it out. You
>>> see, with tapes you could still trivially digitise, then put on a hard
>>> drive, pass over to SSD, and so on. Another issue (among more) are formats
>>> that are designed to spur 'upgrades' (monetary considerations over
>>> integrity). Will be be able to open your Word files 20 years from now? 100
>>> years? Is there sufficient documentation? Is it elegant? Will known bug be
>>> understood at that time? There's a good video in YouTube about "Digital
>>> curation". It's a one-hour long lecture, but it's worth finding and
>>> watching.
>>>
>>
>> There are also basic issues around entropy which cannot be ignored. All
>> data eventually reduces to random noise unless energy is applied to it
>> in some way. DVDs will surely be no exception to this, although it
>> could take decades or more in some cases. Similarly, for how long the
>> playback technology will be available is not necessarily clear. It's
>> virtually impossible to buy new drives for 8" and 5.25" floppies now,
>> and even 3.5" ones are disappearing fast.
>
> The first point that you make reminds me of the dangers of encryption in this
> context. A few corrupt bits (signals) of distortion ruin the whole chunk
> rather than lead to random noise. You can't handle 'lossy' encrypted packets,
> can you?
>
Of course, a ruined chunk becomes random noise anyway. The action of
encryption here is something we used to call "error extension" in the
early days of plesiochronous and then synchronous digital hierarchies
for telcos (the stuff the internet /actually/ runs on!).
Error extension is a function of framing algorithms where, if a key bit
is corrupted, say, then framing can be lost, and all the data in those
frames also becomes errored.
In this context, encryption can be considered to be similar to a framing
algorithm, since if an error occurs then it will probably be "extended"
to cover a whole block of data, which is analogous to a frame in PDH
terms.
The fundamental point is that entropy is natural.
--
| Mark Kent -- mark at ellandroad dot demon dot co dot uk |
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