To make the video height 100% and the width increase proportionally based on the video resolution in CE.SDK, you can make the rectangle containing the video fill the entire page using the "Percent" height and width mode. Then, set its content fill mode to "Contain".
This will scale the video to fit proportionally within the rectangle. You can use the following code to achieve this:
engine.block.setWidth(rect, 1);
engine.block.setWidthMode(rect, 'Percent');
engine.block.setHeight(rect, 1);
engine.block.setHeightMode(rect, 'Percent');
engine.block.setContentFillMode(rect, 'Contain');