I have a few lines to get you going from objc... I use OpenCL and OpenGL in the
captureOutput delegate so your on your own there but this would be a start.
- (void)awakeFromNib
{
NSError *error = nil;
if (!mCaptureSession)
{
// Set up a capture session that outputs raw frames
BOOL success;
mCaptureSession = [[QTCaptureSession alloc] init];
// Find a video device
QTCaptureDevice *device = [QTCaptureDevice
defaultInputDeviceWithMediaType: QTMediaTypeVideo];
success = [device open:&error];
if (!success)
{
[[NSAlert alertWithError:error] runModal];
return;
}
// Add a device input for that device to the capture session
mCaptureDeviceInput = [[QTCaptureDeviceInput alloc]
initWithDevice:device];
success = [mCaptureSession addInput:mCaptureDeviceInput error: &error];
if (!success)
{
[[NSAlert alertWithError:error] runModal];
return;
}
// Add a decompressed video output that returns raw frames to the
session
mCaptureDecompressedVideoOutput = [[QTCaptureDecompressedVideoOutput
alloc] init];
[mCaptureDecompressedVideoOutput setDelegate:self];
success = [mCaptureSession addOutput:mCaptureDecompressedVideoOutput
error: &error];
if (!success)
{
[[NSAlert alertWithError:error] runModal];
return;
}
// Start the session
[mCaptureSession startRunning];
}
}
- (void)dealloc
{
[mCaptureSession release];
[mCaptureDeviceInput release];
[mCaptureDecompressedVideoOutput release];
[super dealloc];
}
// This delegate method is called whenever the QTCaptureDecompressedVideoOutput
receives a frame
- (void)captureOutput:(QTCaptureOutput *)captureOutput
didOutputVideoFrame:(CVImageBufferRef)videoFrame
withSampleBuffer:(QTSampleBuffer *)sampleBuffer
fromConnection:(QTCaptureConnection *)connection
{
}
On Jan 11, 2011, at 6:58 AM, Ben Dean wrote:
> Hmm, thanks, I really appreciate the help. Obviously an oversight on my
> part, but I'm targeting OSX and the built-in apple "iSight" or whatever they
> iCall it. It looks like it's on the list for UVC. I'm pretty new to this
> game, and have very little experience with language interop and device
> drivers, so I'd really value an overall idea what the interface between a
> driver and Racket would look like. I think the target audience of the UVC
> site knows more about this sort of thing than I do, so any additional
> pointers would be great.
>
> On Tue, Jan 11, 2011 at 6:51 AM, Neil Van Dyke <[email protected]> wrote:
> Noel Welsh wrote at 01/11/2011 05:31 AM:
>
> Then depending on the platform and webcam different APIs are available.
>
>
> Yeah, webcam support has always been a mess, on all platforms.
>
> If you're on GNU/Linux, I'm not sure of the current best approach, but I
> guess would probably start with Linux UVC and some popular, high-quality USB
> camera that is supported by UVC. http://www.ideasonboard.org/uvc/
>
> I'd have the compatibility list on that page in one hand, and Newegg.com in
> the other hand. And before buying, I'd do a quick Google for the make&model
> and "linux" and "uvc" to see if anyone is reporting problems. It happens.
>
> You could also do eBay, where I recall there have been some sweet spots of
> premium cameras that are supported well by Linux but that are inexpensive
> now. (Sorry, I don't remember particular models anymore.) One of the nice
> things about slightly-older devices is that there's been time for Linux
> device support to be implemented and tested.
>
> If you're using a less-popular slightly-older camera, beware that some
> manufacturers have made engineering changes to their cameras without changing
> the model number, sometimes breaking drivers that have been
> reverse-engineered. Compatibility tables might not be aware of the multiple
> variants -- sometimes someone just reported that a particular model worked
> (perhaps with a small patch for the ID or something), so that model would
> marked as supported in the table, without any awareness that there are
> multiple variants.
>
> --
> http://www.neilvandyke.org/
>
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