Potential double-free issue with Metadata

[Maizer]

Hi,
I'm sorry to bother you again, but I've discovered another issue.
When I assign the Metadata from an InputFormatContext to an OutputFormatContext, a severe double-free problem occurs. To work around this, I have to perform an extra step when processing the OutputFormatContext.Free by explicitly calling OutputFormatContext.SetMetadata(nil).
Do you have a solution for this? Or perhaps this behavior could be mentioned in the comments or documentation as a warning? This issue was very difficult to track down, and I spent two or three days on it.😊

[asticode]

Sharing the same dictionary between InputFormatContext and OutputFormatContext seems like a bad idea to me. You should clone the dictionary before providing it to the OutputFormatContext. However this was not an option to you since you didn't have the proper method to do that. The good news is that I've just added the Dictionary.Copy() method in master which allows you to do just that.

Let me know whether that fixes your issue and whether you need a tag 👍

[Maizer]

Thank you very much for your work, this is a perfect solution.🥰
Regarding the label: I don't see the need to add one for this.