Thank you for posting your own request. We shall see what comes of it. In looking for better extensibility, I spent a week playing with Reaper. However, I decided that I wasn't interested in porting a year's worth of projects to another DAW just yet. I considered copying MIDI data back and forth between Sonar and Repear, but that was a nightmare. Ultimately, I'm most interested in leveraging an interpolation library I wrote in c++ a number of years ago. I want to control phrasal rhythms in a way that I have yet to witness in any plugin or the pre-baked functionality. I was prepared to port my library to another language if need be, but I've now progressed to going down scary paths to get the functionality I'm after. Unless a 64-bit SDK magically appears before I get going, in a few months, I'll be building three things to word in tandem: 1. a Windows Forms app from which I can compute my interpolations 2. a CAL program to apply my interpolations 3. a macro (haven't chosen the tool yet) to envoke the Cal program and supply it with the interpolation coeficients. Fortunately, I've worked it out so that no values need to be shuffled from Sonar to my app. It's a one way data path. Most of the floating point math will be conducted in the forms app, thus getting around the lack of such functionality in CAL. All remaining "floating point" math will actually be done using oversized integers in CAL. The final computation in CAL will be a division by some sensibly chosen factor to acquire the final value. If the kluge works, you can bet that I'll be simultaneously ashamed and proud. Cheers

Oh, that's right... no line breaks allowed. Well, I supposed that's safer than unescaped text.

I just tried to submit a reply containing break tags, but was brought to a rather alarming page: "An exception has been thrown on the page you are trying to access. The error has been logged and the site admin will take the necessary action to prevent such error." I guess they don't want me to do that.

Colin,
I finally wrote to Frank (of http://www.midi-plugins.de/), who said that he didn't have to do anything special to get things compiled under 64-bit, and that the MFX SDK used is still the old one. His response is pasted below.
 
I will try to get this compiled again soon!
- m
 
 
"Providing a 64bit MFX-plugin is rather easy. You do not need a special SDK (and BTW, there is none).
All you need to do is to compile your plugin project as 64 bit. I guess you are using Visual Studio (2010/2012)?
From the "Configuration Manager" set up a new platform (x64) for you project and build the project. You will probably have to fix a couple of warnings and errors but that's not a big thing.
Finally with the resulting dll you have to do the same with the 32bit version, register it to make it available in the 64bit Sonar version.
This is all I am doing for the 64bit version of by plugins. 32 and 64 bit version compile from the same source code."
 

Hi Markleford,
Thank you for continuing to prod. Many months ago when I was trying to get this to work, I was unsuccessful at getting a clean compile under VS 2008. I was modifying the demo project from the SDK. We're running VS 2013 Ultimate at work now, so maybe I'll give it another go in my off hours next week.
This is exciting news that someone has it working. Being able to build an MFX plugin will save me a great deal of hassle. Fortunately, I've fallen miles behind on my music project, so I'm not yet champing at the bit to write the supporting code.

VS 2012 U, I mean - not 2013.

Markleford:
 
Thanks for your dogged determination in getting your MFX to 64-bit.  For a time there, no one appeared to be listening.  Your plugins (and Frank's) have been real problem-solvers for me ever since you released them.  I don't know of many working alternatives (outside of MIDI Solutions' hardware boxes).  I was even able to get some of them to 'print to track' using the virtual MIDI cable workaround.
 
If you're in the market for any ideas on the next one, I'd love to see an 'event processor' for converting one MIDI message to another.  CC Map on Steroids.  I realize the difficulties in converting the first data byte to the second (MIDI notes to CC messages, for example, or double-precision pitchbend to CC).  To my knowledge, no one has ever tried combining MIDI notes and a CC message (or channel AT) to produce polyphonic aftertouch, either.
 
Just wishful thinking there.  I'd be happy to see the existing TenCrazy MFX in 64-bit.  Thanks again.

I'm running into some DirectX challenges. Despite there being no true MFX SDK, Am I right in understanding that I need the DirectX SDK to get a clean compile? I can't remember where I heard it, but I seem to recall that there's some old version of the DirectX SDK that needs to be used since the latest and greatest has deprecated features utilized by MFX. MS doesn't seem too keep on giving download access to the old DirectX SDKs.

FWIW, I tried building the sample project using the MFX sdk under VS 2010, no problems. I've been avoiding VS 2012...

@SuperG I can get a clean build of the SDK MFX sample under Visual Studio 6 (32-bit), the dlls register, and the plugins are visible in sonar. Under Visual Studio 2008 (also 32-bit), I had to make modifications to get a clean build (largely related to commenting out code for the antiquated help file system), the dlls appeared to register, but the plugins never became visible. 64-bit under Visual Studio 2008 had the same issues. I'll try VS 2010.