user6711: I have imported the smartphone screen record in Premiere using the option set to frame size to mantain video aspect ratio, with this option the video is centered with its aspect ratio, after that I have moved the video on V2 track and have added a background image in V1 track
The problem is that: unused area of scaled video results black. 
How to crop the V2 track to show the previous level V1 track in the unused space?


user6711: With autoscaled video to center using set to frame size, adding a Crop Effect to crop the black area is enough to solve the problem.


user3295: You imported the footage with the resolution set in your timeline by choosing set to frame size. Thats not what you want in this case, it adds black bars wherever your footage doesn't fill the frame size set in for the timeline.
Premiere would have kept the correct aspect ratio either way, it doesn't automatically stretch footage thats not the same resolution as the timeline, you would only see distortion if the pixel aspect ratio would differ between timeline and source. Re-import the footage without the set to frame size option and you should be fine.

6711: <p>I have imported the smartphone screen record in Premiere using the option <code>set to frame size</code> to mantain video aspect ratio, with this option the video is centered with its aspect ratio, after that I have moved the video on <strong>V2 track</strong> and have added a background image in <strong>V1 track</strong></p>

<p>The problem is that: unused area of scaled video results black. 
How to crop the V2 track to show the previous level V1 track in the unused space?</p>

<p><img src="https://i.stack.imgur.com/SFucq.jpg" alt="enter image description here"></p>
 6711: <p>With autoscaled video to center using <code>set to frame size</code>, adding a <code>Crop</code> Effect to crop the black area is enough to solve the problem.</p>

<p><img src="https://i.stack.imgur.com/TgKXN.jpg" alt="enter image description here"></p>
 3295: <p>You imported the footage with the resolution set in your timeline by choosing <code>set to frame size</code>. Thats not what you want in this case, it adds black bars wherever your footage doesn't fill the frame size set in for the timeline.</p>

<p>Premiere would have kept the correct aspect ratio either way, it doesn't automatically stretch footage thats not the same resolution as the timeline, you would only see distortion if the <a href="http://en.wikipedia.org/wiki/Pixel_aspect_ratio" rel="nofollow"><strong>pixel</strong> aspect ratio</a> would differ between timeline and source. Re-import the footage without the <code>set to frame size</code> option and you should be fine.</p>
