[FFmpeg-user] Average N frames of RTSP video for better snapshot quality?

[Steven Kan]

After 7.5 years of waiting, my banana plant is finally flowering! I want to do a time-lapse capture of the flowering and fruiting process. Due to its location, the easiest way for me to get a camera out there is to use a little WyzeCam v3 with the RTSP firmware and the Wyze lamp socket. Unfortunately the WyzeCam doesn’t (yet) have a externally accessible JPG snapshot feature, so I have a cron job set up to:

./ffmpeg -rtsp_transport tcp -i rtsp://anonymous:password@$IPAddress/live -frames:v 1 $outfile

every hour. The results are OK, but not fantastic:

https://www.kan.org/pictures/BananaTimeLapseFirstImage.jpg <https://www.kan.org/pictures/BananaTimeLapseFirstImage.jpg>

Is there a way to tell ffmpeg to collect N frames of video and output one single averaged image to improve the SNR? Even if there’s some wind, the flower stalk shouldn’t be moving much. 

I tried:

./ffmpeg -rtsp_transport tcp -i rtsp://anonymous:password@192.168.1.39/live -frames:v 10 ~/BananaLapse/MultiFrame%03d.jpg

and that results in N JPGs. I suppose I could have a second ffmpeg command that averages those 10 JPGs, but can this all be done in one pass? Thanks!