Is there a correlation between Key frame Intervals and Frame Rate?
We are trying to find out how to maximize storage mainly on Avigilon Servers. Usually, we drop the frame rate around 10 FPS when space is an issue but should I also be changing the Key Frame Intervals? All the information I can dig up online is mostly for broadcasting. Any IPVM gurus have any helpful insight? Thanks.
Alex, good question!
In general, I would not recommend to manually change the key frame interval. It will reduce bandwidth (as key frames are much larger than partial frames). However, it can result in images breaking up if there is too much motion in between key frames.
Do the Avigilon cameras you are using support Smart Codecs? i.e., see Avigilon's announcement and IPVM's Smart Codec Guide. A key element of smart codecs is that they dynamically and intelligently manage adjusting key frames so that image quality loss / breakups do not occur.
Alex when I comes to Avigilon I would recommend matching your key frame to your FPS. When you are reviewing and scrubbing video you are shown the key frames. I find that when you set the key frame higher you can miss events if you have the set the double or triple your frame rate when you're scrubbing video. If you don't search video this way then it will not be as much of an issue but I find most customers really like the scrubbing video feature.
I also find Avigilon's smart codec and idle scene mode works best if you have your cameras recording 24/7. Avigilon has added a lot of flexibility on which stream you want to record and what compression, FPS, bit rate, key frame for each stream. Plus with the smart code, you can now encode none moving objects at a different compression compared to moving objects and drop the FPS, image rate, image quality, max bit and key frame if there is no motion.
We are finishing up a 100 camera project for stadium including 8 PRO cameras and we are seeing about 50% bandwidth reduction with smart codec enabled. Tonight they will have a packed house so I am interested to see if the smart codec will help with 10,000 people onsite.
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