The following example shows how you can maintain a loaded video’s original aspect ratio on a Flex VideoDisplay control by setting the maintainAspectRatio property.
Full code after the jump.
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/12/30/maintaining-an-videos-aspect-ratio-on-a-videodisplay-control-in-flex/ -->
<mx:Application name="VideoDisplay_maintainAspectRatio_test"
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="middle"
backgroundColor="white">
<mx:ApplicationControlBar dock="true">
<mx:Form styleName="plain">
<mx:FormItem label="maintainAspectRatio:">
<mx:CheckBox id="checkBox" />
</mx:FormItem>
</mx:Form>
</mx:ApplicationControlBar>
<mx:VideoDisplay id="videoDisplay"
maintainAspectRatio="{checkBox.selected}"
source="http://helpexamples.com/flash/video/cuepoints.flv"
autoPlay="false"
width="200"
height="200"
click="videoDisplay.play();" />
</mx:Application>
You can also set the maintainAspectRatio property using ActionScript, as seen in the following example:
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/12/30/maintaining-an-videos-aspect-ratio-on-a-videodisplay-control-in-flex/ -->
<mx:Application name="VideoDisplay_maintainAspectRatio_test"
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="middle"
backgroundColor="white">
<mx:Script>
<![CDATA[
private function checkBox_change(evt:Event):void {
videoDisplay.maintainAspectRatio = checkBox.selected;
}
]]>
</mx:Script>
<mx:ApplicationControlBar dock="true">
<mx:Form styleName="plain">
<mx:FormItem label="maintainAspectRatio:">
<mx:CheckBox id="checkBox"
selected="true"
change="checkBox_change(event);" />
</mx:FormItem>
</mx:Form>
</mx:ApplicationControlBar>
<mx:VideoDisplay id="videoDisplay"
source="http://helpexamples.com/flash/video/cuepoints.flv"
autoPlay="false"
width="200"
height="200"
click="videoDisplay.play();" />
</mx:Application>



I like having the ability to change my video aspect ratio on the fly like in VLC media player.