Have a look at /Developer/Examples/QC/PlugIns
1) You can't specify what input you want, you'll get what's optimal
for QC / GPU / etc...
2) Keep directly the input images in your plug-in and use:
- (BOOL) didValueForInputKeyChange:(NSString*)key;
3/4) If you want the best performances for data that you must generate
on the fly (it's not already around in a buffer), use a
QCPlugInOutputImageProvider, not the -[QCPlugInContext
outputImageProviderFromBufferWithPixelFormat]
On Oct 28, 2007, at 9:41 PM, Sam Kass wrote:
I wrote a couple plug-ins for QC 3.0 (detailed on my QC blog: http://www.samkass.com/blog)
. They're not very efficient, and I was wondering if anyone had
started hacking around with the official plug-in interface yet. I
included the source to my plug-ins for reference.
Performance Issues:
1. The KLT feature tracking library I have assumes a black and
white, 8-bits-per-pixel input image with rowBytes = pixelsWide. Is
there any way to, instead of copying bytes around to ensure the
correct input, simply specify that that's what I need and use the
input buffer directly?
2. Is it less expensive, if I need two subsequent "frames" from the
input stream, to use an accumulator latch in patches, or to snag-and-
buffer two shots within the plug-in? Probably the latter-- if so,
how do I know the input image has changed?
3. In my other plug-in, I try to plot the output from the first plug-
in. I basically turn the image into bytes, malloc a new image of
the same size, copy the old image over, change a few pixels, then
output the new image. This is probably extremely sub-optimal. Ideas?
4. Related to 3, Is valloc better even when I'm changing the data?
--Sam
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Quartzcomposer-dev mailing list ([email protected]
)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/quartzcomposer-dev/pol%40apple.com
This email sent to [EMAIL PROTECTED]
________________________________
Pierre-Olivier Latour - [EMAIL PROTECTED]
Technologist - Apple, Inc.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Quartzcomposer-dev mailing list ([email protected])
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com
This email sent to [EMAIL PROTECTED]
