Re: QTMovie grabing while playback
Re: QTMovie grabing while playback
- Subject: Re: QTMovie grabing while playback
- From: "douglas a. welton" <email@hidden>
- Date: Fri, 25 Apr 2008 12:17:02 -0400
Nikolai,
Perhaps you might try creating an "empty" NSBitmapImageRep with the
size and pixel attributes you need. Then, use the resultant object as
a graphic context and draw your CIImage into that. The Reducer sample
code does something similar to this. I can imagine that this process
might be slow, but I don't know what your performance requirements are.
regards,
douglas
On Apr 25, 2008, at 11:58 AM, Nikolai Hellwig wrote:
Hi,
the image comes from:
- (CIImage*) view: (QTMovieView *)view willDisplayImage: (CIImage
*)image
{
...
// this is the conversion code
NSBitmapImageRep* bitmap = [[NSBitmapImageRep alloc]
initWithCIImage: image];
...
}
regards,
nikolai
Am 25.04.2008 um 16:43 schrieb douglas a. welton:
Nikolai,
Can you post a snippet of the code you are using for the conversion?
regards,
douglas
On Apr 25, 2008, at 9:04 AM, Nikolai Hellwig wrote:
Hey,
thank you very much. it helped a lot. but i still got one problem.
The image I derive from
NSBitmapImageRep initWithCIImage
is much smaller than the original pixel size of the video. Because
of that i can't use this method for production use. Is there
another way to do this?
regards,
nikolai
Nikolai,
QTMovieView has a delegate method
- (CIImage*) view: (QTMovieView *)Target_View willDisplayImage:
(CIImage *)New_Image
This method gives you a CIImage to play with before it is
displayed in the Target_View. Check the header file for
QTMovieView.h (near the bottom). I think the the MyMovieFilter
sample code uses this method.
Note: Depending on what type of analysis you are doing you may
need to convert the CIImage into a pixel-based format. If that
is too slow you may want to get friendly with
QTVisualContextIsNewImageAvailable() and the Display Link...
check out the CIVideoDemoGL sample code.
regards,
douglas
On Apr 23, 2008, at 12:19 PM, Nikolai Hellwig wrote:
Hi,
I've done some image analysing software for QTKit Capture. It
works fine. Now i need to use this for a quicktime movie.
I can playback the quicktime movie, but i can't find any
delegate which tells my application, that a new frame is
rendered. If i can get this information i could grab this frame
in order to analyse it.
can anyone tell me how to do it? I don't want the user to click
"grabFrame" or something like that.
regards
Nikolai Hellwig
Mit freundlichen Grüßen
Nikolai Hellwig
email@hidden
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Mit freundlichen Grüßen
Nikolai Hellwig
email@hidden
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