[FFmpeg-user] Recording Mp4 - I cannot see frame size in registered file properties

[Magda Gontarz]

Dear Sir/Madam,

I would like to ask you about conversion using ffmpeg.
I have recorded screen with mkv file with a command:

ffmpeg -r 25 -rtbufsize 2100M -f dshow  -i
video="screen-capture-recorder":audio="virtual-audio-capturer" -b:a 224k
-s:v 1680x1050 name.mkv

Now I want to convert it to mp4:

ffmpeg -i name.mkv -s 1680x1050 name.mp4
ffmpeg -i input.mkv -c copy output.mp4

but I cannot get video frame size in file properties in details. How can I
obtain mp4 file with filled fields width and height of frame?

At first,I have not recorded mp4 file, because if I have overloaded laptop,
recorded movie does not run.

I am looking forward to hearing from you.

Kind regards,
Magdalena Gontarz