[TAG] .SWF files (Flash)
Kapil Hari Paranjape
kapil at imsc.res.in
Sat Feb 11 04:07:17 MSK 2006
On Fri, 10 Feb 2006, Mike Orr wrote:
> One comment and then I'll shut up. How is accepting Flash documents
> different from accepting Word documents?
I did some more googling^H^H^H^H^H^H^H^Hresearch and found out a bit.
Sorry for the rather long mail. I hope it serves to inform rather
than wake up the trolls.
1. The official Flash specification is in fact only available under a
strange licensing agreement which specifically *forbids* the licensee
from developing a Flash Player. Its sole purpose is to help people
develop Flash Writers.
+1 to AFA (= Anti-Flash-Advocacy)
2. There are currently at least 5 projects under way to develop a
Flash Player without reading the specification. Actually, one of
them (gplflash) has merged into gnash. http://www.gnu.org/software/gnash/
and http://www.schleef.org/swfdec/ seem to be the most promising.
As said earlier the latter already "seems to work".
-1 to AFA
3. The projects seem to be based on the time-honoured technique used
by Samba, Abiword et al---"Reverse Engineering" in its
completely legal sense.
+1 to AFA if you believe Samba and OpenOffice are doomed to play
catch-up all the time.
4. There are a number of SWF content generators that are FLOSS. After
all the writers of such generators are encouraged to read the official
Flash specification as published. See www.osflash.org for details.
-1 to AFA
Frankly, I am confused by MacroMedia's bizarre license but it isn't
the first time someone has given a new and strange twist to software
Mike also wrote comparing this to Word/SMB/CSS DVDs/PDF and postscript.
"You are in a maze of twisty passages all different"
As far as I can see all these caes are different. I personally never
thought of Postscript and PDF as being proprietary formats since I
never used proprietary PS/PDF generators and none of my
correspondents ever did so.
A rather long postscript(*) follows on what I understand to be the
"restrictive usage" issues dealing with these formats.
Executive summary: I think Ben is right in calling Flash a lesser
evil than either Word or RealPlayer but then that is a matter of
opinion and a lesser evil is nonetheless an evil.
(*) Couldn't resist the pun :)
In order of Evilitude or is it Evility (which is the opposite of
I recall that one could buy the RGB books of postscript that described
the language in great detail; and there was no clause in those
books that said "thou shalt not write something called ghostscript
that implements this language". What *did* happen is that there
was a section of postscript that allowed each printer to have its
own proprietary PS dictionary. A "driver" for that printer then used
operators from that dictionary to enhance printing and the resulting
postscript files did not work well with ghostscript of course.
Postscript files that were generated using tools like "dvips" which
were based on the RGB books alone, worked fine with ghostscript *and*
with most PS printers. As people started exchanging PS files over the
net these proprietary extensions became a hindrance and were mostly
Maybe I'm wrong but PDF was Adobe's "network"-if-ied version of
Postscript. They tried to build in the proprietary extensions in a
way that they would be network transparent but again were largely
unsuccessful. There is of course, the "default 16 fonts" issue (that
was in some sense an issue with PS as well) but as long as you had
reasonable substitutes for those fonts everything worked just fine.
Again documents that were generated using tools like "pdflatex" that
included all the fonts/glyphs used worked fine with all readers.
What "xpdf" cannot currently do are the fancy "transitions" like
"Dissolve"---I don't know why this is so, but it has not bothered
me since I don't care for it. To me encrypted PDF is like encrypted
DVD's---if someone doesn't want me to enjoy their creativity---I
Andrew Tridgell and folks (a big salute to them) patiently gathered
network traffic in order to decode the way in which SMB was spoken
and wrote clients/servers in some ways better than the original. Of
course, the MicroSoft will continue to improve/modify(:)) their
protocol but existing deployment prevents them from introducing
incompatibilities that would break Samba as it would probably break
Windows 95/98 as well. Note that Samba has (always had?) some security
features over and above that offered by the proprietary version so
in principle a number of people *did* switch over to Samba servers
instead of proprietary servers. When enough people do that the
proprietary protocol is under pressure to be more compatible with the
"discovered" specification and avoid proprietary "enhancements".
Some major effort of catch-up was required here but it does seem as
if the current version of OpenOffice can deal with many MicroSoft
generated documents. Again OO has added features to its software
(like incorporation of LaTeX) which are not automatically available
with the default MS offering. This and its slightly better security
status could lead to enough people using it to pressurise MS to keep
to "discovered" specs.
They disclose so little I don't think there is anything to say here.
To use a phrase from Joerg Schilling out of context "RealPlayer is
the most self-incompatible piece of software that I know".
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