Filming Okonomiyaki stand Noda, Osaka

Hello,
Last time I stayed around Noda in Osaka there was a okonomiyaki and takoyaki stand outside the north exit of JR Noda station. I was quite amazed about the way they made the food and was thinking of the possibility to videorecord it to show family at home.

How would be the best way to ask permission to do so?

Maybe "sumimasen, koko de bideo o totte mo ii desu ka?"

You need to get a permission that you want record for your personal use.

"sumimasen, koko de bideo o totte mo ii desu ka?" makes very well.

Alright. Thank you for your reply.

Will they understand that I want to record when they make the okonomiyaki? Of course I do not want to spoil or steal any company secrets, if there are any.

I think it's normally alright.
The secret ingredients already mixed as they start cooking in front of customers. You are not allowed to enter into the backside kitchen, due to secret ingredients hidden there.

Just a suggestion for improvement:

Your sentence says "excuse me, is it OK I take a video here?," with the "here" part meaning "me standing here?"

So if you want to clearly tell them that it is their cooking that you want to film, I might say:
- Sumimasen, chouri no yousu no bideo wo totte mo ii desu ka? (Excuse me, is it OK I videotape your cooking?)

and could add, if they look puzzled:
- Kazoku ni misetai no desu. (It is because I want to show it to my family.)