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From: Jim on 12 Aug 2010 11:20
On 2010-08-12, Woody <usenet(a)alienrat.co.uk> wrote:
>>>
>>> I believe you but the issue is not technical, it is more political.
>>> Jpeg2000 was always viewed as being encumbered by patents, which
>> > pretty
>>> well kills anything being used.
>>
>> Is JPEG2000 /really/ so encumbered?
>
> Actually, not as far as I can see. However in the early days it was
> viewed that way which prevented it's large scale adoption.

From the 'Legal Issues' section of the Wikipedia entry for JPEG2000:
-----
JPEG 2000 is by itself licensed, but the contributing companies and
organizations agreed that licenses for its first part . the core coding
system . can be obtained free of charge from all contributors.

The JPEG committee has stated:
It has always been a strong goal of the JPEG committee that its
standards should be implementable in their baseline form without payment
of royalty and license fees... The up and coming JPEG 2000 standard has
been prepared along these lines, and agreement reached with over 20
large organizations holding many patents in this area to allow use of
their intellectual property in connection with the standard without
payment of license fees or royalties.

However, the JPEG committee has also noted that undeclared and obscure
submarine patents may still present a hazard:
It is of course still possible that other organizations or individuals
may claim intellectual property rights that affect implementation of the
standard, and any implementers are urged to carry out their own searches
and investigations in this area.[24]

Because of this statement, controversy remains in the software community
concerning the legal status of the JPEG 2000 standard.
-----

Jim
--
Twitter:@GreyAreaUK

"If you have enough book space, I don't want to talk to you."
Terry Pratchett
From: Rowland McDonnell on 12 Aug 2010 21:29
Jim <jim(a)magrathea.plus.com> wrote:

> Woody <usenet(a)alienrat.co.uk> wrote:
> >>>
> >>> I believe you but the issue is not technical, it is more political.
> >>> Jpeg2000 was always viewed as being encumbered by patents, which
> >> > pretty
> >>> well kills anything being used.
> >>
> >> Is JPEG2000 /really/ so encumbered?
> >
> > Actually, not as far as I can see. However in the early days it was
> > viewed that way which prevented it's large scale adoption.
>
> From the 'Legal Issues' section of the Wikipedia entry for JPEG2000:
[snip]

> Because of this statement, controversy remains in the software community
> concerning the legal status of the JPEG 2000 standard.
> -----

Wikip ain't quite right - again.

It's hardly because of that statement - more because of the patent
sharks out there. The JPEG committee is simply warning people of what
they ought to know anyway.

Whatever the `thing' in use might be, there's always the risk of being
eaten by patent sharks these days, unless your lawyers are leaner and
hungrier than theirs...

Rowland.

--
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From: Jim on 13 Aug 2010 07:06
On 2010-08-13, Woody <usenet(a)alienrat.co.uk> wrote:
>
> I don't understand what there is to interpret MIME types. It is just a
> label to refer to something. It is just a name for a thing, it conveys
> no information beyond that. In the same way as my name identifies me,
> and my surname identifies my family, but it conveys no other information
> about me.

A bit like the extension on a filename - it gives an idea of what the
file contains and allows the OS (or browser in this cse) to decide what
programme (or plugin) to use to handle the contents.

Jim
--
Twitter:@GreyAreaUK

"If you have enough book space, I don't want to talk to you."
Terry Pratchett
From: Rowland McDonnell on 13 Aug 2010 09:18
Woody <usenet(a)alienrat.co.uk> wrote:

> Rowland McDonnell wrote:
> > Woody<usenet(a)alienrat.co.uk> wrote:
[snip]

> >> The full
> >> list is actually quite large. You can see it In firefox in the
> >> application tab of the preferences.
> >
> > I know about that. What I don't know is how to interpret the contents
> > of the list. How is it parsed by the machine?
>
> OK, sorry, I don't understand what you need to know here, so I dont know
> if I can really help. I am really not sure what you mean by parsed in
> this context. As I said it is just a label, so there is no real parsing
> to be done.

SO you say - so tell me how to read the label, then. What the hell does
it mean, an entry in a MIME type table? How are they used?

> OK, for some types, you could look at the text before the '/', ie, for
> 'image/jp2' you would take the 'image' part and use that as a fallback
> in case 'image/jp2' doesn't come up with anything, but there is no
> actual parsing to be done.

What do you mean?

> The label could just as easily by 'owiejfow234moij##' or 'kipper' - it
> is just a piece of text which is used as an index value.

How is it so used?

> the code looking at it will go down the list, looking for a match (for
> 'image/jp2' or 'kipper' or whatever you want to call it), until it finds
> one.

Looking for a match with what, and what makes the code do this in the
first place?

> If it finds one, the entry at that index location is the path to a chunk
> of code which will be run to process that file.

Huh?

> >> It's a bit messy, but the types are (I believe) on the left, so you
> >> would look down that list for image/jp2, and on the right should be the
> >> name of the plugin that handles it. On mine it was QuickTime
> >> 7.something, but I don't know how new my firefox is.
> >
> > Yes, okay, but how are MIME types parsed?
> >
> > You clearly know so you don't see any need to explain. But I don't, so
> > I can't interpret MIME types at all.
>
> Its not that I don't see a need to explain, I am happy to explain, if
> you could let me know what it is that you don't understand.

I understand precisely nothing at the moment.

I'd like to understand how MIME types are used. I don't understand them
*at all* at the moment.

[snip]

Rowland.

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From: Woody on 13 Aug 2010 10:08
On 13/08/2010 14:18, Rowland McDonnell wrote:
> Woody<usenet(a)alienrat.co.uk> wrote:
>
>> Rowland McDonnell wrote:
>>> Woody<usenet(a)alienrat.co.uk> wrote:
> [snip]
>
>>>> The full
>>>> list is actually quite large. You can see it In firefox in the
>>>> application tab of the preferences.
>>>
>>> I know about that. What I don't know is how to interpret the contents
>>> of the list. How is it parsed by the machine?
>>
>> OK, sorry, I don't understand what you need to know here, so I dont know
>> if I can really help. I am really not sure what you mean by parsed in
>> this context. As I said it is just a label, so there is no real parsing
>> to be done.
>
> SO you say - so tell me how to read the label, then. What the hell does
> it mean, an entry in a MIME type table? How are they used?

as a keyed value, such as various programing languages variously
describe as a dictionary, lookup table, hashtable, map, keyed map etc.
Depending on language. Whatever they call it the principle is the same.
You have a key (a label) and a value (the path of a bit of code).

So there is a lookup table (using the one from my firefox for pc, as I
use firefox on windows):

key value
audio/3gpp npqtplugin4.dll
audio/ac3 npqtplugin3.dll
audio/acc npqtplugin3.dll
image/pict npqtplugin6.dll
image/png npqtplugin6.dll
image/jp2 npqtplugin7.dll
application/futuresplash NPSWF32.dll
application/pdf nppdf32.dll
application/xaml+xml NPWPF.dll
application/x-java-bean npjp2.dll
....

and continuing, a very long way.

then at the end of the list there is one special entry:
* npnul32.dll

which is what to do if you don't find anything else.

On requesting a file from the server, it responds saying that the mime
type of the file the browser has requested from the server is the text
label "image/jp2", so the software in the browser lists the value
associated with that label. Literally that label, no processing of it.

in a c based language the code would be of the form

plugin = mimeLookupTable["image/png"];
where the result would be npqtplugin6.dll


--
Woody
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