[Interest] Qt 5.13: how to properly enable gstreamer for Windows?

[Alexander Ivash]

I followed the instructions for Qt blog post and compiled gstreamer
plugin but now can't make Qt to use gstreamer backend.

I put

    putenv("QT_DEBUG_PLUGINS=1");
    putenv("QT_MULTIMEDIA_PREFERRED_PLUGINS=gst");

at the beginning of main.cpp but seems like Qt still using directshow.

What is wrong?

Regards, Alexander