AXIS Media Control - FAQ

GOV length - saving bandwidth

Question:

What is the value recommended for GOV length in the MPEG-4 settings for your cameras/video servers?

Answer:

The GOV length determines how many frames of the one type (I or P) are sent before the next type is sent. When using the I-structure this simply describes the number of I-VOP’s from one header (identifier) to the next.

For the IP-structure, this setting determines the sum total of P-frames and I-frames in a GOV. Setting the GOV-length to a high value saves considerably on bandwidth, but there may be noticeable image decay.

The default value for ARTPEC-2 based Axis products is 8, which gives one I-VOP and 7 P-VOP’s. To avoid image quality reduction because of excessive GOV length, using values greater than 100 for these products is not recommended. A maximum of 20 is recommended.

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