How to concatenate two videos (byte arrays) into one video file c#?

Question

ASP.NET

How to merge two videos (byte arrays) into one video file. The problem is the following, when I connect after the bytes are added, but the length of the video does not change (that is, it will be equal to the length of the first video that connects to the first). Apparently this is due to the fact that the first bytes in the video correspond to the length of the video, etc. I tried to connect without the first, but then the file is damaged and does not open

Answer 1

I, not knowing the structure of the video files, can say with a 99.8% probability that somewhere at the beginning there are 2, or 4, or 8 bytes of the length of the video. Which, of course, you do not change, so you get the video in its original form.

Answer 2

You should look at the general structure of the file. As LiptonOlolo noted, at the beginning of the file there is a header describing the further contents, including the length of the file in bytes. Since you end up with a new file, you should also edit its header.