[FFmpeg-user] Adding Watermark to Video

[Al-Haseeb Jafar]

I'm completely unfamiliar with ffmpeg (I just know its name).
On my video site phpvibe CMS is using the following ffmpeg command.
CMD 1:
{ffmpeg-cmd} -i {input} -vcodec libx264 -s {ffmpeg-vsize} -threads 4
-movflags faststart {output}.mp4
I want to add a functionality to this code of adding watermark to the top
right corner, padding 10 pixels right and top, while converting the video.
I found this command for this purpose.
CMD 2:
{ffmpeg-cmd} -i {input} -i watermark.png -filter_complex
"overlay=main_w-overlay_w-10:10" {output}.mp4
Can you help me properly adding CMD 2 into CMD 1, plz?
And where should be watermark.png? I mean in which directory?
I'm ready to pay for this.