You will come across this window when you are creating a new screen capture project.
Here you can set the dimension of your project, not necessarily the same as the capture area. Note that when then project dimension is not the same as the capture area, Flash Demo Builder will automatically resize the captured image to fit the project dimension. This may cause the captured image to look a little bit blur due to the resize process.
However this feature is very useful when you are capturing the whole desktop area and you want to put it in a smaller area in your website.
To select a different project dimension than the capture area, click on Project dimension list box.
Choose the percentage size of 25%,50%,75%,100%,150%,200% or custom. When choosing Custom you can enter the width and height of the project manually.
Lock aspect ratio is only enabled when you choose Project dimension as Custom. When it is checked you will not be able to enter the height value. The height value will automatically calculated from the width value by preserving the capture area aspect ratio.
It is important to check Lock aspect ratio when choosing Project dimension as Custom otherwise the capture result may have a blank area either on the side or at the top/bottom depending on the aspect ratio of the new dimension.
Note
Defining the right project dimension early before you start capturing like this is a more recommended method compare to resizing the project later on using Changing Project Dimension feature as it produce a smaller published size with a much better quality.