I'm using Windows 10, intel core i5, 8GB ram. and download ffmpeg from official site: https://www.gyan.dev/ffmpeg/builds/
I'm trying to capture 5fps video from webcam but the output fps is only 3.4 and speed is 0.668x. (I also tried with libx264 but the speed is same 0.5).
This is my command:
ffmpeg ^
-f dshow -r 5 -s 640x480 -i video="Sony Visual Communication Camera" ^
-f rawvideo output.raw
screenshot of console output:
The cpu usage for above ffmpeg command is about 0.1% and also ram/disk usage is relatively low.
If I change the fps to 30 (-r 30), the output is: fps 7.9, speed 0.261x and CPU usage is still very low 0.1%.
But I can easily record 30fps video with the same format yuyv422 in Directshow GraphEdit:
So my question is why does ffmpeg show such poor performance even with 5fps video capturing? If it can only produce 3.4 fps in the first case why it can output up to 7.9 fps in the latter case (when I set desired fps to 30)? Did I mis-config ffmpeg ?
Any help is appreciated.