Videos usually are described by a set of parameters including:
width & height.
But I came to realize that there are more parameters including
I frames (or I guess they are the KEY-FRAMES).
Now I noticed that they exist when I was working on a custom video capturing technique in which I have the ability to control how often they appear in terms of seconds, so they are either 1 sec away from each other or 2 sec away or 3.....
But some weird things happened when I tried to change the appearance of these frames.
When I encoded a video with (2 sec or 1 between I Frames) I got a video that doesn't seek well.
Now If I try to merge the encoded video with an equal length audio file for some reason when I seek forward or backward I see black screen before I seek to the requested frame.
When I encoded a video with (0 sec between I frames) I got a video that seeks fine, but for some reason the size increased.
Now if I try to merge the encoded video with audio of equal length I get a video mixed with audio that works well and seeks well with no black screen on seeking.
What are I frames?
Why do they affect seek behavior?
Why do they affect the merging of video with audio?
Why do they affect the size of the video?