Can't capture video from tvtuner on Linux

edit

When I try to capture frame from my avermedia volar hx tv tuner card (TV tuner card is connected with camera)...

VideoCapture cap; cap.open();

OpenCV shows the error as:

libv4l2: error getting pixformat: Invalid argument libv4l2: error getting pixformat: 
Invalid argument HIGHGUI ERROR: V4L: device /dev/video1: Unable to query number of channels

Output format from tv tuner card is - 720*576 uncompressed raw video. It uses video for linux library.

Please help me in resolving the issue.