AXIS Media Control - FAQ

GOV structure – maintaining a high frame rate

Question:

I would like to get the highest possible fram rate when accessing MPEG-4 streams delivered from the camera/video servers. How should the Axis product be configured to achieve this?

Answer:

The MPEG-4 setting that should be changed in the product's web interface is GOV structure.
The GOV-structure can take 2 different forms; I or IP, which describe the type of frames included in the video stream, as well as their internal order.

An I-VOP is a complete frame, whereas a P-VOP is only the differences in the frame as compared with the previous one. As the IP-structure mostly sends the differences compared to the previous frame and far fewer complete frames, this uses much less bandwidth than the I-structure, which sends the whole frame every time. When using the resolutions 4CIF, 640x480 or 2CIF Expanded resolutions, the I-structure is the best way to maintain higher frame rate than the one achieved with the default settings. The drawback will be an increase in the amount of bandwidth required.

This FAQ applies to the 210/211/210A/211A/212 PTZ/213 PTZ/214 PTZ/216FD/221/225FD/231D/232D/240Q/241S(Blade)/Q(Blade)/241SA/QA.