[FFmpeg-user] Reduce latency in ffmpeg snapshot

[Pedro Torres]

I have a latency problem with FFMPEG.
I have a streaming server running and I occasionally need to take multiple snapshots over a period of time (in the example below, 5s), and then examine the snapshots taken. Time is critical.
With this command I take 25 frames per second over 5 seconds, meaning I will have 125 snapshots in my folder.
ffmpeg.exe -ss 0.05 -re -i "server" -ss o -vf fps=25 -to 5 -y "destination folder"

The -vf fps is forcing the 25 frames per second even if the server can't provide them.
The problem is that -ss 0.05 is not doing its job. It is supposed to delay the initial snapshot for 50 milliseconds but FFMPEG takes around 200ms to "start" the service on itself :/. This means the first snapshot is taken after around 200ms after I called the service. (200ms is way too big of a latency for my purpose... I can survive with 100ms)
How can I force FFMPEG to start taking snapshots earlier? Or is there a way to get snapshots, let's say, from the buffer (e.g. start taking snapshots 150ms in the past)?
PS: Changing the -ss from 0.05 to 0.00 is not doing anything, I can only see the -ss doing something if the value is bigger than 0.2/0.25.

Thanks in advance.

Regards/Cumprimentos,


Pedro Torres

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