Video local preview cannot be started during an active video call on Android

[nanang]

This is due to failure in setting output window visibility, note that Android renderer doesn't support PJMEDIA_VID_DEV_CAP_OUTPUT_HIDE capability, so pjsua_vid_preview_start() will return PJMEDIA_EVID_INVCAP and video doesn't not show up. Also, the function misses applying window output handle setting.

Thanks Giorgio Alfarano for the report and the patch.

[nanang]

In 5088:

Close #1850: Updated pjsua_vid_preview_start() to ignore any errors upon starting an already existed preview, just print a log, also apply the specified window handle.

[riza]

In 5098:

Re #1850(misc) : Mistype param when calling pjmedia_vid_dev_stream_set_cap. The param passed is suppose to be pjmedia_vid_dev_hwnd.