If I run wmvcore tests for V2, no failure for the test. However, as I said before, during the tests, gstreamer will complain abount:
`ERROR audio-info audio-info.c:302:gst_audio_info_from_caps: no rate property given`
This error comes the wg_format_from_caps() call inside pad_added_cb().
Also, if I call wg_format_from_caps() in autoplug_continue_cb(), same error will happen.