Fix error and download avcodec-57.dll

ERROR: The application could not start because avcodec-57.dll was not found.

ERROR: The entry point to the procedure avcodec-57.dll was not found.

ERROR: dllregisterserver entry point not found - how to fix avcodec-57.dll

How to register avcodec-57.dll in Windows

How to unregister a DLL?

Causes of errors in the file avcodec-57.dll