Converting a Video from 1600 * 1200 to 1200 * 900 I have a video in the format of 1600 * 1200.
I want to convert this video into 1200 * 900.

I have done this with handbrake, but the first 10 seconds of the video is black and scrambled.
Is there a way to convert the video correctly with handbrake or can I do this differently ?

UPDATE
When I play the converted video the first time with "Windows Media Player" the first 10 seconds are not visible correct. If I replay the same video in the same "Windows Media Player" session it shows up correctly also the first 10 seconds.
Use ffmpeg with -vf scale=1200:900 option. For example

ffmpeg -i input.mp4 -vf scale=1200:900 -c:a copy output.mp4