SSL is blocking the video. What to do?

Question

Digital certificates

There is a site1 where SSL is installed and it is planned to host video content. Videos are taken from site2, on which the HTTPS protocol is not installed (iframe code is torn out).
When you go to site1 with the player code, only a black screen is visible, because. SSL blocks its content. If you insert the video code from the site on which SSL is installed (for example, vk, youtube), then everything is ok.
What are the options for solving the problem? Is it possible to display video in this case, or is the only way out only code from secure sites?

Answer 1

Yes, indeed.
Just change (replace) in the HTTP: code to HTTPS:
The vk or youtube code will work correctly.