Recorded video frame rate is not the same as set value

[nhuythuy]

Hi all,

Could you please help me to explain this problem of frame rate setting for recording video using VLC? When I set frame rate = 10 (fps) then the output video frame rate is not the same as set value. It becomes for example 13.424066 or 11.382321. The output recorded frame rate is not fixed to 10 as set, but it varies every time I record video. If I set frame rate = 5 (fps) then output video frame rate even becomes 30.065703, very far from set value.

Thanks,

Thuy

[Lotesdelere]

I guess you're recording to H.264 into MP4 because in this case VLC is using variable frame rate, for some reason. I don't know if there is a way to force the use of a fixed frame rate.

You should create a new ticket on the VLC Trac with the links to this thread and to a sample file.

[nhuythuy]

Thank you Lotesdelere,

If VLC uses variable frame rate and set --sout-x264-preset=ultrafast (venc=x264{preset=ultrafast,tune=zerolatency}), will VLC select for me the best frame rate? If that is correct, should I remove frame rate option?

I have just created a ticket on VLC Trac here https://trac.videolan.org/vlc/ticket/7376

Thuy