Comment 5 for bug 1463262

So, when a black thumbnail happens, I see this in the gallery-app log:

ThumbnailerImageResponse::dbus_call_finished(): D-Bus error: "Handler::create_finished(): unity::ResourceException: RequestBase::thumbnail(): key = /home/phablet/Videos/com.ubuntu.camera/video20150604_035125835.mp4\0556047\01433389892.339516360\01433389892.339516360:
    VideoScreenshotter::data(): Video extractor pipeline failed"

We certainly need to improve logging in the thumbnailer. I want to see messages such as this in the thumbnailer log, not the application log. I'll add relevant debug to our code.