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The grid is superimposed on the video player to help to set or determine the exact text position on the screen. You can turn it off using View > Toggle Video Grid.
Tool Panel
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 | Captions style | Allows to set CC styles, such as pop-on, roll-up or paint-on. |
 | Split block | Splits current caption into two parts to allow individual positioning for each part. |
 | Merge block | Merges current split caption into one. |
A ‘split block’ feature will create two sub-captions, each of them can be individually positioned using hotkeys or by dragging the text over the video grid.
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