// webcam.h - webcam image capture

use image;

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typedef wstring(64) WEBCAM_NAME;

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// get list of all webcams;
// returns number of webcams available.

int get_webcam_list (out WEBCAM_NAME[] list);

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struct WEBCAM_CAPTURE;   // opaque type

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// returns 0 if OK, -1 if error.
int start_webcam (ref WEBCAM_CAPTURE info,
                      WEBCAM_NAME    source_name,
                      int            width  = 320,
                      int            height = 240);

void stop_webcam (ref WEBCAM_CAPTURE info);

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// to be called if webcam is no longer used
void deallocate_webcam (ref WEBCAM_CAPTURE info);

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// display dialog box with capture settings.
// (works only for old DirectShow cams)
void display_webcam_dialog (ref WEBCAM_CAPTURE info, long ParentWhwnd, int x, int y);

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// returns the most recent webcam image.
// returns -1 if there is no image available (especially just after starting webcam),
//   or returns an image number >= 0 that can be the same as for the previous call if no new image is available.
// The function manages 'image', don't ever allocate or deallocate it.
// You can use 'image' after the call until calling unlock_webcam_image().
// several threads can call this function.

int lock_and_get_webcam_image (ref WEBCAM_CAPTURE info,
                               out IMAGE_INFO     image,
                               out int            lock_number);

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// releases intern buffer
// You must always call unlock_webcam_image() after each lock_and_get_lock_webcam_image() call !

void unlock_webcam_image (ref WEBCAM_CAPTURE info, int lock_number);

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