Both lines on the video track can be changed (the same as the volume line on an audio track) but they don't seem to have any affect on the video.
They are visible if you right click (on an audio object or an empty section of a track) and tick 'Show track curves'. If then you move a video clip onto the track the track the curves will remain where they are.
See this from one of the Magix User Board members:
http://www.aaproductions.net/mep/tips/edit/audio/audio.htm
Regards,
Carl
@cpc000cpc; If you re-read the question you will see that it pertains to the VIDEO track and not the audio track.
To rephrase - what do those lines do when those lines are displayed on the VIDEO track? Adjusting them up and/or down does not seem to have any affect on the VIDEO in any way regardless of whether the lines are displayed before the video is on the timeline or after the video is on the time line.
Nothing -- they effect only audio objects on a track! Tracks themselves are not exclusively audio or video.
Sorry if I was not clear on that. I was trying to explain the circumstances where you could get audio lines (volume and balance) displayed over video objects, or images or text or whatever. You only get the option to 'Display track curves' if you right click on an audio object or an empty section of a track. If you use the [Alt+-] keyboard short cut the curves are placed only on track two which is typically (but not always) the audio linked with video in track one.
Regards,
Carl