extern int pwc_mbufs;
/** functions in pwc-if.c */
-int pwc_try_video_mode(struct pwc_device *pdev, int width, int height, int new_fps, int new_compression, int new_snapshot);
int pwc_handle_frame(struct pwc_device *pdev);
void pwc_next_image(struct pwc_device *pdev);
int pwc_isoc_init(struct pwc_device *pdev);