Humbly requested: Filter SDK / Easy filter sample

[pieter1976]

Can someone help me with a delphi(5) example of a filter plugin?
This because i have very little C++ experience and I don't have the tools to compile at home.


I hoop nobody minds me asking this question at this tread.

[Si]

In practical terms, what you ask for is not possible.:(

AFAIK no-one has ever made a plugin using anything other than MS VC++.

On the other hand, I'm sure a super-whizz programmer in another language could make one because nothing's impossible in the programming world and people always like challenges :)

regards
Simon

[morsa]

wrong!! :D

Kevin atkinson made his filters using C, also Fizick and....
Remember LoadCPlugin?

[Si]

I nearly used the phrase "normal plugin" but I thought, no-need, everyone will know what I mean :p

Simon

[Longinus]

Would it be possible to make a wrapper or something, to be able to use .Net languages like VB.net and C#?? I know very little about C++, not enough to do anything... But It would be much easier to play with a .Net implementation... It probably would be slow, but a solution for the simple mortals among us... and maybe a nice test bed for new plugins...

[bill_baroud]

it would be a lot more easier to learn c++ than writing a wrapper ;)

[ambrotos]

did someone could compile under dev-c++ (mingW)?
just a question because, if I could avoid to use a cracked version of visual studio...

in fact I do compile but the dll, if I try to use it, return : there is no function named simplesample ...

[Guest]

What do you mean by "cracked version of visual studio"?

[Fizick]

(cracked=pirated)
But you can use free MS VC Toolkit 2003 (I use it) or 2005.

[Guest]

@ambrotos

Do not discuss or mention warez here. It's against forum rules.

[ambrotos]

:eek: ooops I'm sorry ^^

I was just saying that I do not intend to use a warez version ^^
I don't even more intend to receive tips to crak it :)
on the contrary i'm trying to develop only with opensource tools

@fizick :thanks:
(but about mingW ? no positive feedback ?)

[Fizick]

I used MinGW for Avisynth_C plugins only.

[ShinSan]

I just want to say thanks to sh0dan for making those sample scripts (of course props goes out to the avisynth devs as well). I've looked at a few filter tutorials and just got daunted at the explanation and for some reason the sample scripts for avisynth made everything click.

[Fizick]

I try collect FilterSDK for v2.5.7 offline documentation.
Am I correctly understand, that SimpleSample license is strictly GPL, and not under exception of 'avisynth.h' ?
So any plugin based on SimpleSample must be open source.

[IanB]

Everything related to or derived from Ben's original Avisynth is strictly GPL apart from his avisynth.h exception.

The goal is to encourage others to contribute to the open source community, the exception clause is to allow authors to choose the licence terms for their work, hopefully they do the community spirited thing and release their source code.

Everything I have contributed is strictly GPL. I believe (hope)the other contributors also support this ideal.

Obeiwan got it wrong, he should have said "Luke use the Source.... "

[Fizick]

It is not easy question.

Here is Ben's words about plugins license:
http://forum.doom9.org/showthread.php?p=176734#post176734
Here's my view on this. When AVISource() opens an AVI file, it loads
appropriate audio and video codecs and asks them to decode the data in the file. For all practical purposes it's using the codecs as plug-ins. Clearly I can't require those codecs to be open source, even if they were written after Avisynth was. I think this applies equally to so-called "Avisynth plugins." They are not really part of Avisynth in any meaningful way; there just happens to be an Avisynth command which instructs Avisynth to load one of them and talk to it in a certain way. So regardless of my moral/ethical views, I don't think I have any legal basis for restricting the licensing terms of these plugins (and I never intended to do so).

I won't relicense Avisynth under the LGPL, but I will sign off on a
statement (or write one myself) to the effect that my license should not be construed as placing any restriction on plugin licenses, provided that Avisynth is not modified to *automatically* load a closed-source plugin and then bundled with that plugin (which is the situation the FSF is rightly concerned about). You should probably get a similar statement from Avery, because Avisynth proper contains VirtualDub code. Also, I hereby release avisynth.h (all versions created by me) into the public domain, although I'm not sure it qualified for copyright protection in the first place.

So, IMO, the various Ben's "Invert" plugins codes from Avisynth SDK is not strictly GPL (and all other Ben's examples).
The sh0dan's v2.5 "Invert" is probably too:
http://forum.doom9.org/showthread.php?p=176183#post176183

- Plugins do not need to be GPL. It's the author (and the users) own loss.
- All internal Avisynth should be GPL. I will not accept any avisynth that is distributed without source. No excuses here.
- If anyone releases a payware plugin. Let them. Let the users decide if they want to pay. I will not!
- If anyone can prove that a plugin uses code from GPL plugins, I will stand by your side, to help you get the source opened on such thieves.

But SimpleSample was firstly created by Simon Walters (v.1.0) under GPL as is noted in the head of source,
then was commented by sh0dan (v1.0b) without license change, and so on.

I do not know about various assembler parts by Avery and others (these parts have no any copyright notices and license).

IMHO, whole AviSynth Filter SDK must have one type of license, the same as avisynth.h.

But now part of code in AviSynth Filter SDK is under GPL.
May be we may ask Simon Walters re-release SimpleSample (may be some versions, for example 1.0b) under other license (the same as avisynth.h) for avisynth SDK?

[Si]

What is the problem with the SimpleSamples being GPL?

regards

Simon

[Fizick]

Hi, Simon,
SimpleSample as a real plugin must (may) be GPL without any problem.
But if SimpleSample is considered as 'official' part of Avisynth FilterSDK, than I see some license conflict.
For example if somebody take SimpleSample 1.1 as a base for you own (advanced) plugin, this plugin automatically must be GPL.
But SimpleSample does not contains many differences from Ben's Invert code (which is not strictly GPL, see above).

For example, the only different line of SimpleSample 1.0b from Ben's Invert is:

*(dstp + w) = *(srcp + w); // Copy each byte from source to destination.

Are you really has copyright on this statement ? :)
Any program with this line must be GPL? :)

As I understand, the SimpleSample was created for the purposes of illustration of using avisynth plugins interface,
with some basic commands.
It is exactly aim of Avisynth FilterSDK.

Simon, may you give (as an exception) a permission to use SimpleSample code as a part of AviSynth FilterSDK solely for creation of AviSynth plugins under any license?

I do not force you to change the license. And I very like GPL. I simply try make some things more clear to me and others.

Here is my current free interpretation (may be wrong):
1. Avisynth Filter SDK (avisynth.h, information, examples) may be used for creation of any software under GPL license.
2. Avisynth Filter SDK may be used for creation of AviSynth plugins (3rd-party filters, import and export plugins, or graphical user interfaces) under license of your choice.
3 (not 4). Avisynth Filter SDK may NOT be used for creation of any other non-GPL host program which is linked to (i.e. can directly call) AviSynth or AviSynth GPL plugins.
4. Avisynth Filter SDK may NOT be used for creation of non-GPL plugins for any program besides AviSynth.
5. AviSynth community friendly suggest to create any AviSynth plugin under GPL and will help in its development and improving.

[IanB]

Having the sample code GPL is a very good thing. It means that anyone who uses the sample code as a basis for a plugin is obliged to also release the source to that plugin under GPL and I think that is quite fair. They have used somebody else work. The same applies to any plugin that use avisynth internal source code or is based in avisynth internal source code.

It is the same case for most of the code for AviSource() It is straight from VirtualDub and as such conforms to that licence.

Now those who develope a plugin from scatch are entitled to do whatever they like. I don't have a problem with this, it's their work so their's to copyright as they see fit. And Ben's avisynth.h exception supports this model, and he is just being fair, after all it is pretty hard to write a plugin without using avisynth.h in your source.
Here is my current free interpretation (may be wrong):
1. Avisynth Filter SDK (avisynth.h, information, examples) may be used for creation of any software under GPL license.True. This is the straight forward case. GPL -> more GPL :D
2. Avisynth Filter SDK may be used for creation of AviSynth plugins (3rd-party filters, import and export plugins, or graphical user interfaces) under license of your choice.True. This is because of the avisynth.h exception and applies as long as no GPL code is used in it. The new original source belongs to the author.
3. Avisynth Filter SDK may NOT be used for creation of any other non-GPL host program which is linked to (i.e. can directly call) AviSynth or AviSynth GPL plugins.Half true. While definitly outside the avisynth.h exception, there is nothing to stop any program loading avisynth.dll and poking at the entry points. Even greyer is a program using avisynth plugins directly. It is against the spirit but is probably unenforcable. :(
4. Avisynth Filter SDK may NOT be used for creation of non-GPL plugins for any program besides AviSynth.Half true. Here intent is very hard to prove. E.G. Yes it is an original unique avisynth plugin, plus, yes it is NOT GPL. Is the author of this plugin in violation when a 3rd party uses it with a non GPL program. Probably not.
5. AviSynth community friendly suggest to create any AviSynth plugin under GPL and will help in its development and improving.This has nothing to do with GPL licencing other than being a very desirable goal.

[Fizick]

IanB,
thanks for fixing my enumeration bug! :)

A little corrected item 3:
3. Avisynth Filter SDK may NOT be used for creation of any other non-GPL host program which is linked to (i.e. can directly call) AviSynth or AviSynth plugins.

If it outside the avisynth.h exception, it is not legal,
especially if we explicitly write this text to FilterSDK doc (you are avisynth copyholder too).
And I say not only about avisynth.h, but about Invert plugin and other samples included in Avisynth FilterSDK.
I was really annoyed when I see some closesource VirtualDuB-compatible program (or module of some big program) which can load VirtualDub plugins. :(

About item 4:
I say about creating plugins for example for Adobe Premier, with using some code of SDK.

Item 5:
O.K., I will remuve its enumeration :)

[Si]

Its my opinion that the Invert and SimpleSample plugins are GPL.

As is the whole of Avisynth except for avisynth.h.

But I'm not a lawyer and I only do this for fun :-)

regards

Simon

[Si]

Fizick is PM'ing me with questions and suggestions that I am having great trouble in understanding :confused:

So I'd like to have this discussion in public (IF Fizick doesn't mind)

I think he wants to change the example plugins from GPL to the special license type that Ben granted to avisynth.h

I don't want to do this for the SimpleSample plugins because I don't understand the need for change or the repercussions if I did.

(And IMO they were a community created resource anyway - I just was the one that edited them :-) - without Shodan's comments they'd have been worthless :-) )

Help!!!!

regards
Simon

[IanB]

I am not sure what Fizick wants to achieve, perhaps he should restate his objectives or thoughts with regards to GPL restrictions.

I still stand by my opinion :-
All the resources to do with the filter SDK and example code should be full GPL!

Letting closed source shops freely reuse sample code is just not on.

[Wilbert]

@IanB,

I agree with the examples SimpleSample and Invert being GPL, but how can the other code snippets be GPL? It's just basic stuff which is used in almost very plugin. Since we allow plugins to be non-GPL, this implies that those code snippets can't be GPL.

[Fizick]

I do not want nothing besides clarity.
And sorry my poor English below:
I wanted to add FilterSDK to offline Avisynth.doc.
I start with page http://www.avisynth.org/FilterSDK
It is not available now - it is one of reasons to have off-line SDK.
really I start with this link:
http://www.avisynth.org/warpenterprises/avisynth_org_20050408.rar
I remove non-SDK files. Here is stripped SDK pages (temporary link):
http://avisynth.org.ru/FilterSDK0/FilterSDK.html
I reformated SDK a little, and added some information (about what it contains and compilers).
Then I begin think about: what is license of the SDK?
I thinked, that it was single (uni) license for all its parts.
Not I understand, that it is wrong.
Every parts of the SDK has own license.

Here is the parts list:

A. Header file avisynth.h
License: GPL with exception (to develop AviSynth plugins under license your choise), see avisynth.h.

B. Ben's "Writing Avisynth plugins" page,
see mirror at http://www.neuron2.net/www.math.berkeley.edu/benrg/avisynth-extensions.html
It contains 'Invert' plugin sample code and many comments on its every line.
This code is trivial and contains only basic calls. All them are contained in avisynth.h
No any plugin can be created for example without line PVideoFrame src = child->GetFrame(n, env);
and similar.
This page does not contain any license notes.
As we can read from later Ben's letter, he never say that plugins must be GPL.
The 'Invert' plugin was never existed (released) as a plugin (unlike SimpleSample).
Therefore, all Ben's code plugin samples and 'Invert' code is under the exception too.

C. 'TwoFiveInvert' sample code (for avisynth 2.5 with YV12).
probably by sh0dan.
The code is without comments and license notes.

D. SimpleSample source codes (various versions) by Simon Walters.
They all have clear license notes about GPL.


I. various topics about colorspaces, Changes framefrates,
how to invoke internall functions, with small fragments of code.

J. Assembler Optimizing part with many basic examples (various ? authors, in particular phaeron).
The code is very fragmentary.
No any license notes.
In my opinion, this part is very (very!) useful, but is not directly related to FilterSDK (but to general programming).
Probably it may be not included to FilterSDK.
(or be included, but as a separate non-official supplement)

And I forget about K parts: extra files like avisynth.lib, avisytnth.def, avisynth.map
Probably they are under GPL.

So, my (today) conclusion:
First: We must ask sh0dan separately about parts C, I and J.

Second: We must clearly to say, what is license for every parts of FilterSDK. The plugin authors must clearly know, what they can do, to not wake-up with "Oops! I am in GPL catched by IanB!" :) And probably we must not force them to say "No-no, I did not use SimpleSample for my closed source plugin"
(that is why I asked Simon - but let's forget about it).

In my opinion, the core part of SDK must give to authors the freedom to write any plugins for AviSynth (the more plugins, the better), but protect FilterSDK code fragments and samples from using in non-Avisynth programs (besides GPL-compatible programs).

[IanB]

@Wilbert, I express myself badly. I am not saying everything is GPL, I am stating my opinion that everything substantial contributed to the new Filter SDK documentation bundle be put under GPL, certainly anything I contribute will be under GPL, all I can hope is others do likewise.

Yes trivial coding expresions like PVideoFrame src = child->GetFrame(n, env); can never be under any sort of copyright for similar reasons that the wheel cannot be. There is nothing new, innovative or novel there to protect, it is simply general public information. I suppose if people are worried the copyright on the actual documentation can either explicitly allow free use of code snippets (assuming some ownership claim is valid) or more simply disclaim ownership because they are so generic that no-one could lay claim.

@Fizick, yes you are getting there ;)B. ...
Therefore, all Ben's code plugin samples and 'Invert' code is under the exception too.I think this is a wishful stretch, you really cannot say one way or the other. I think you are right that Ben might probably see it this way, but we cannot state this with any certainty. Best we simply acknowledge this as Ben's work and let anyone involved with an at risk commercial enterprise get a professional legal opinion.

C. 'TwoFiveInvert' sample codeThis is fairly obviously work based on the original Ben example. So sh0dan (the author) gets to say any extra copyright conditions but the core conditions must comply with those of the original work.

J. ...
Probably it may be not included to FilterSDK.Why??? We are conforming to the appropriate conditions. Subsequent use is not our problem. By all means get the attributions corrrect so it is easy to trace ownership, beyond that not our problem.

[Fizick]

IanB,
I do not see any problem with new contributions to SDK. Simply add license notice your choice to your text.
I see problem with existent content without license notice.
So waiting sh0dan :)

In my opinion above, the implied license of current SDK is the same as license of avisynth.h

Here is the my next draft of license block at the top of Ben's documentation page:
-------------------------------------------------------------------------------------------------------------
This is the original documentation written for AviSynth 1.0 by Ben Rudiak-Gould
(creator and developer of Avisynth up to v1.0beta3) - copied from
http://math.berkeley.edu/~benrg/avisynth-extensions.html
The current mirror is at:
http://www.neuron2.net/www.math.berkeley.edu/benrg/avisynth-extensions.html

License notes.
The original documentation page has no any special license statement.
AviSynth 1.0 was created and developed under GNU GPL license.
Here is Ben's words about AviSynth plugins license:
"...regardless of my moral/ethical views, I don't think I have any legal basis for restricting
the licensing terms of these plugins (and I never intended to do so)."
See http://forum.doom9.org/showthread.php?p=176734#post176734
We suppose that the license of plugin code samples in this page may be considered the same as
the license of the header file avisynth.h.
-----------------------------------------------------------------------------------------------------------
it is not clear, but probably it is what we have.

[Fizick]

Today I think, that the text above is too long :)
Next version of License notes (about Ben's article):
The original documentation page has no explicit license statement.
We believe that contained on this page code samples
that illustrate the syntax of interfaces defined in avisynth.h
are under GNU GPL plus license exception declared in avisynth.h.
-----------------------------
While waiting shodan, I try create GPL drafts of AviSynth FilterSDK license text
(partially taken from virtualDub filter SDK):
-------------------------------------------------------------------------------------------
The AviSynth external filter SDK is Copyright(c)2000 Ben Rudiak-Gould,
and Copyright(c)2002-2006 Klaus Post et al, All Right Reserved.
It is released with NO WARRANTY and freely usable/
distributable under the terms of the GNU General Public License (GPL).
It should have been included; if not, you may receive a copy by writing
to the Free Software Foundation, Inc., 675 Mass Ave., Cambridge, MA 02139,
USA.

Some files in this package (in particular avisynth.h)
contain license exeptions giving you additional permissions
besides those granted in the GNU General Public License.
Consult the license block at the top of files for information.

Fragments of AviSynth FilterSDK code samples
that illustrate the syntax of interfaces defined in avisynth.h only
are also under license exceptions declared in avisynth.h.

Any trademarks mentioned here are the property of their owners. To the
our knowledge no trademark or patent infringement exists in this
document or this distribution; any such infringement is purely
unintentional.

We suggest you to create and distrubute your plugins also under
GNU GPL license in the spirit of open source AviSynth project.
Whole AviSynth community will help you in plugin development and improving.
To do it, simply place your copyright statement and GNU GPL license
comment block at the top of your souce code (see SimpleSample code for example)
and release your plugin with the source code included.
(You may not act differently if your plugin contains some source code under GNU GPL.)
-----------------------------------------------------------------------------------------

Please correct my English.

[Wilbert]

That formulation is fine with me.

[IanB]

As these documents are to be long lived :) I suggest things like this be date referenced. It help down the track when trying to trace the history of something.The current mirror is at:The mirror as at November 2006 is at:
-------------------------------
In my opinion above, the implied license of current SDK is the same as license of avisynth.hWe suppose that the license of plugin code samples in this page may be considered the same as the license of the header file avisynth.h.We believe that contained on this page code samples that illustrate the syntax of interfaces defined in avisynth.h are under GNU GPL plus license exception declared in avisynth.h.Fragments of AviSynth FilterSDK code samples that illustrate the syntax of interfaces defined in avisynth.h only are also under license exceptions declared in avisynth.h.@Fizick,

Do you have some reason for needing the sample code to be explitly usable by closed source shops?

The forms above are all your opinion, yes, I do happen to agree with your opinion, BUT that does not make it fact.

We should not be encouraging people to risk using the sample code in a non GPL manner unless we have documented proof positive that it is in fact exempt. If we did have explicit documentation then these clauses would not be necessary, we would just include it.

The form text stands quite fine without including the guess. Apart from that the revisions are very good.

If you are still seriously worried, make the recomendation that those at risk should seek professional legal advice.

[stickboy]

I have some somewhat recent contact information for BenRG. I'll send him an email.

[Fizick]

stickboy,
may be we can invite him to AviSynth development this way?

my next wording version:
As a special exception, you may copy and modify
some portions of contained in this documentation code samples
and distribute such modifications
(independent modules that communicate with Avisynth
solely through the interfaces defined in avisynth.h)
under license terms declared in avisynth.h,
provided that these portions solely illustrate the syntax
of interfaces defined in avisynth.h.


And I discover one more implicit part of AviSynth SDK with code fragments: postings of various user to this forum. Licenses is various probably.

Finally, i have a suggestion to add a function 'bool IsPluginGPL() ' to Avisynth and give to plugin more cache memory if return value is 'true'. ;)

[IanB]

Again, @Fizick,

Do you have some reason for needing the sample code to be explitly usable by closed source shops?

[Fizick]

IanB,
Right now I try undersand license terms of existant SDK documentation, firstly from Ben.
As I write above, IMHO no any close source plugin can be written without using some fragments of code samples,
at least from Ben's 'Invert' plugin description.
So, my latest proposal above is related to existant (Ben's ?) part of SDK.
But may besome of these parts is public domain (remember Ben's word about avisynth.h) or strictly GPL. Will wait answer from Ben, then from sh0dan.

IMHO, the voluntary releasing of source is much more good thing than forced by 'PVideoFrame src->GetReadPtr()' copyright. But if you think, that this small fragments is trivial,
we can do not write general exception to new SDK.

[IanB]

If you get statements from Ben and sh0dan, then the problem is solved. If not, just fall back on advising to seek professional legal advise.

We can really see how all this legal crap can gum up the works. For all this time and effort a really nice SDK doco bundle could have been made now. ;)

[Fizick]

IanB,
Yes, I almost completely with you here
(regarging Ben, but sh0dan's part is not completely sh0dan's work)
And really I secretly work under its real content too ;)

EDIT: I put draft version to CVS tree. Developers can edit it :)


By the way, anybody has backup copy of the page from SDK:
http://www.avisynth.org/GettingStartedWithAudio
(I do not have it).
And who wrote it and under which license? :)

[photoguy123]

Hate to interrupt the legal discussions, but a quick question:

Is 1.7 still considered the most recent SimpleSample version?

Link to SimpleSample 1.7 Code (http://www.geocities.com/siwalters_uk/simplesample17.zip)

And I assume it's still one of the best simple samples out there for new plug-in writers?

Just wanted to clarify as this thread is pretty old now.

[Si]

Yes - SimpleSample 1.7 was the last one.

I wouldn't describe it as the best - the different versions are there to show how to progress from a very very simple operation to a simple one :-)

I would recommend looking at the (debugged and commented) previous versions first.

regards

Simon

[Fizick]

Response to my e-mail:

> you (at 2003) posted at www.avisynth.org WiKi some short
> articles about assembler opimization with small code fragments.
> What is license terms of this articles? May we re-distribute them in
> off-line AviSynth filter SDK at GPL (or GPL-compatible) license ?


You may consider the text added by me to that article to be freely
available for any use.

--
Avery Lee

[Fizick]

Here is an unforeseen (for me) result of our discussion about various aspects of VirtualDub SDK and Avisynth SDK (from next e-mail):

...
> May I (we) now ask your special permission to distribute code fragments
> of VirtualDub contained in Avisynth v.2.5.6 with any version of
> Avisynth under current license terms of Avisynth (with exception
> declared in avisynth.h)?

Yes, of course. I will authorize use of the existing VirtualDub-derived
elements in Avisynth under the current Avisynth license, which is GPL plus
a special exemption.

Note that use of any more VirtualDub code in Avisynth will require
additional permission.


--
Avery Lee

[IanB]

Poking sleeping bears has problems! :D

[Fizick]

Not all bears are hungry and angry :)

[redfordxx]

Why is all this etc. in the getframe fucntion?
const int dst_pitch = dst->GetPitch();
const int dst_width = dst->GetRowSize();
const int dst_height = dst->GetHeight();

That is like I am asking for every frame, how big is it. Is it enough in constructor? Or can it somehow change in Avisynth?

[squid_80]

Pitch can definitely have different values for different frames (for input frames at least). Width and height I'm not so sure about...

[redfordxx]

_aligned_malloc() is part of the platform SDK.
That means I should download this?
Microsoft ® Windows Server® 2003 R2 Platform SDK Web Install (http://www.microsoft.com/downloads/details.aspx?FamilyId=0BAF2B35-C656-4969-ACE8-E4C0C0716ADB&displaylang=en)

I have WinXP, VS6 C++ SP6... does that match?

I definitely won't spend money to upgrade from VS6 to VS2005, but I read Fizick's recommendation to use the free VS2005Express.
Can anybody tell, whether is better to stick with "old full version" VS6 or "new lite version" VS2005Express

[redfordxx]

I have to add a "thanks" for the simplesample too.
It raised my C++ knowledge from 0 to... something nonzero.;)

Could you add an explanation how adding optional parameters for the filter with default values?
And AsString comes like *BYTE?

[Fizick]

redfordxx,
this MS links says:
1. "The last SDK that will work with VC 6.0 is the February 2003 Edition".
And of course no download link for old version.
Nice M$ !
For 10$ you can get CD at
http://www.qmedia.ca/launch/psdk.htm
(or from some friend :) )
My recommedation was VC2005? No. It was option only!
Other free option is vctoolkit2003 (with your vc 6 IDE)
http://www.google.com/search?&q=vctoolkitsetup.exe
Every choice is subjective.

2. Download as many plugins with source code as you can and try read them. ;)

[redfordxx]

My recommedation was VC2005? No. It was option only!
Sorry for the wording;)
Other free option is vctoolkit2003
I understand Express is the next version of Toolkit
(with your vc 6 IDE)
IDE??? - You probably don't mean hard drive. What does it mean?
Every choice is subjective.
Of course, but any remarks what is missing or bothering compred to full VS (at least what's important for filters development)

[redfordxx]

"The last SDK that will work with VC 6.0 is the February 2003 Edition".
And of course no download link for old version.
Nice M$
This is it...(?)
http://www.microsoft.com/msdownload/platformsdk/sdkupdate/psdk-full.htm
It is full, so probably mostly unnecessary (because only few C++ header files / includes or how is it called etc. needed), but at least something...
Only I wonder that there is written "Update"... It means I need something before?

[Guest]

If you don't want to go through the hassle of getting and installing the platform SDK just to get the aligned malloc/free, then you can use the code for those functions to be found in the file alloc.cpp contained in the DGDecode source zip (part of DGMPGDec).