在 Android 平板电脑上使用 StageVideo 闪烁？
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【中文标题】在 Android 平板电脑上使用 StageVideo 闪烁？【英文标题】：Flicker with StageVideo on Android tablet? 【发布时间】：2012-05-20 08:34:34 【问题描述】：我有一个 stageVideo 类，我用它在平板电脑上播放视频，但每次播放视频时，平板电脑屏幕都会闪烁几次（变黑然后又出现大约四次左右）我想知道是什么可能导致这种情况。当我切换到播放视频的视图时，它会执行此操作。视频的 url 被传递给视频 mxml 视图。我正在使用 flex 4.6 和 android 平板电脑（EEE 变压器素数）。
package ios
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageQuality;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.events.NetStatusEvent;
import flash.events.StageVideoAvailabilityEvent;
import flash.events.StageVideoEvent;
import flash.geom.Rectangle;
import flash.media.StageVideo;
import flash.media.StageVideoAvailability;
import flash.media.Video;
import flash.net.NetConnection;
import flash.net.NetStream;
[Bindable]
public class iOSStageVideo extends Sprite
private var videoPath:String;
private var videoWidth:Number;
private var videoHeight:Number;
private var _sv:StageVideo;
private var _vd:Video;
private var _obj:Object;
private var _ns:NetStream;
public function iOSStageVideo( path:String , w:Number , h:Number ):void
videoPath = path;
videoWidth = w;
videoHeight = h;
addEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
//stage is ready
private function onAddedToStage(e:Event):void
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
var nc:NetConnection = new NetConnection();
nc.connect(null);
_ns = new NetStream(nc);
_obj = new Object();
_ns.client = _obj; _ns.bufferTime = 2;
_ns.client = _obj;
_obj.onMetaData = MetaData;
_sv = stage.stageVideos[0];
_sv.viewPort = new Rectangle(0, 42, videoWidth , videoHeight );
_sv.attachNetStream(_ns);
playVideo();
//video is ready, play it
//public, can be called externally
public function playVideo():void
_ns.play( videoPath );
_ns.addEventListener(NetStatusEvent.NET_STATUS, videoStatus);
//required metadata for stagevideo, even if not used
private function MetaData(info:Object):void
//get video status
private function videoStatus(e:NetStatusEvent):void
switch(e.info.code)
case "NetStream.Play.StreamNotFound":
//do something
break;
case "NetStream.Play.Start":
//do something
break
case "NetStream.Play.Stop":
//do something
trace('the video has ended');
stopVideo();
break;
case "NetStream.Buffer.Empty":
//do something
break;
case "NetStream.Buffer.Full":
//do something
break;
case "NetStream.Buffer.Flush":
//do something
break;
case "NetStream.Play.Complete":
//do something
break;
//stop and clear the video
//public, can be called externally
public function stopVideo():void
trace("StopVideo is ran.");
_ns.close();
_ns.dispose();
dispatchEvent( new Event('videoDone', true ) );
public function stopVideoBack():void
_ns.close();
_ns.dispose();
这是我在视频播放完毕时播放视频的视图代码
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" title="" backgroundAlpha="0" creationComplete="init(event)" addedToStage="onAddedToStage(event)" >
<fx:Script>
<![CDATA[
import ios.iOSStageVideo;
import mx.core.UIComponent;
import mx.events.FlexEvent;
protected var path:String = new String("");
protected var backPage:String = new String("");
protected var vid:iOSStageVideo = new iOSStageVideo( path , 1280 , 720 );
private var arr:Array;
//protected var vid:iOSStageVideo;
protected var container:UIComponent = new UIComponent();
protected function init(event:FlexEvent):void
// Sets up the back button to back to the right slide
arr = data as Array;
trace(data);
path = String(arr[0]);
backPage = String(arr[1])
//creates the video
vid = new iOSStageVideo( path , 1280 , 720 );
loadVideo();
//takes out the trash when the back button is hit so the stage video is ready when the new view is loaded
stage.addEventListener("keyDown", handleButtons, false,1);
stage.addEventListener("keyUp", handleButtons, false, 1);
override public function createReturnObject():Object
var returnedObject:Object = new Object();
returnedObject.myValue = arr[2];
trace("arr[2] ->" + arr[2])
return returnedObject;
protected function loadVideo():void
//loades the video
vid.addEventListener('videoDone' , videoStop);
container.width = stage.stageWidth;
container.height = stage.stageHeight;
addElement( container );
container.addChild( vid );
protected function playVideo(event:MouseEvent):void
vid.playVideo();
private function videoStop(e:Event):void
//removes container
container.removeChild( vid );
removeElement( container );
navigator.popView();
private function removeEverything():void
vid.stopVideoBack();
try
container.removeChild( vid );
removeElement( container );
catch(error:Error)
trace("error with container");
protected function onAddedToStage(event:Event):void
if (stage.autoOrients)
stage.removeEventListener(StageOrientationEvent.ORIENTATION_CHANGING, orientationChanging);
stage.addEventListener(StageOrientationEvent.ORIENTATION_CHANGING, orientationChanging, false, 100, true);
private function orientationChanging(event:StageOrientationEvent):void
event.stopImmediatePropagation();
if (event.afterOrientation == StageOrientation.ROTATED_LEFT || event.afterOrientation == StageOrientation.ROTATED_RIGHT)
event.preventDefault();
protected function handleButtons(event:KeyboardEvent):void
if (event.keyCode == Keyboard.HOME)
// Handle Home button.
else if (event.keyCode == Keyboard.BACK)
// Hanlde back button.
removeEverything();
]]>
</fx:Script>
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
</s:View>
编译器参数
-locale en_US
-swf-version=13
-target-player=11.0
-define CONFIG::LOGGING false
-define CONFIG::FLASH_10_1 true
已添加已更新代码以具有 StageVideoEvent 侦听器并简化为一个视图（还知道 renderMode 设置为 direct）
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" title="video" backgroundAlpha="0" creationComplete="init(event)" >
<fx:Script>
<![CDATA[
import mx.core.UIComponent;
protected var videoPath:String = new String("video.mp4");
private var videoWidth:Number = 1280;
private var videoHeight:Number = 680;
private var stageVideoAvail:Boolean;
private var sv:StageVideo;
private function init(e:Event):void
trace("ran one");
onAddedToStage();
private function onAddedToStage():void
trace('test');
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
stage.addEventListener(StageVideoAvailabilityEvent.STAGE_VIDEO_AVAILABILITY, onStageVideoAvailability);
private function onStageVideoAvailability( e : StageVideoAvailabilityEvent ) : void
if (e.availability == StageVideoAvailability.AVAILABLE)
stageVideoAvail = true;
initVideo();
else
stageVideoAvail = false;
private function initVideo():void
var obj:Object = new Object();
var nc:NetConnection = new NetConnection();
nc.connect(null);
var ns:NetStream = new NetStream(nc);
ns.client = obj;
if(stageVideoAvail)
sv = stage.stageVideos[0];
sv.addEventListener(StageVideoEvent.RENDER_STATE, onRender);
sv.attachNetStream(ns);
trace('available');
else
var vid:Video = new Video(videoWidth, 768);
addChild(vid);
vid.attachNetStream(ns);
trace('not');
ns.play( videoPath );
private function onRender(e:StageVideoEvent):void
sv.viewPort = new Rectangle(0, 0, videoWidth, 768);
public function onMetaData(e:Object):void
public function onXMPData(e:Object):void
]]>
</fx:Script>
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
</s:View>
此应用程序中唯一的其他视图只有一个带有 navigator.pushView(Copyofvideo,null,null); 的按钮当点击按钮时，屏幕会闪烁，然后播放视频。
【问题讨论】：
你能解决闪烁和黑屏的问题吗？ 【参考方案1】：闪烁的一个可能原因是您在致电_ns.play() 之前没有收听StageVideo 的可用性。通过收听StageVideoAvailabilityEvent.STAGE_VIDEO_AVAILABILITY，您可以管理获得和失去StageVideo。
代替
private function onAddedToStage(e:Event):void
...
_sv = stage.stageVideos[0];
_sv.viewPort = new Rectangle(0, 42, videoWidth , videoHeight );
_sv.attachNetStream(_ns);
playVideo();
这样做
private function onAddedToStage(e:Event):void
stage.addEventListener( StageVideoAvailabilityEvent.STAGE_VIDEO_AVAILABILITY, onStageVideoAvailability );
private function onStageVideoAvailability( event : StageVideoAvailabilityEvent ) : void
var available : Boolean = (event.availability == StageVideoAvailability.AVAILABLE);
...
if ( available )
addStageVideo();
else
//implement an alternative e.g. addRegularVideo();
playVideo();
Adobe Developer Connection 在本教程中讨论了如何监听 StageVideo 的可用性：
Getting started with stage video
本教程提供了更多代码示例：
Creating a StageVideo Test in FDT with Flex 4.5 and FlashPlayer 10.2
【讨论】：
它似乎还在闪烁。我为 stageVideoAvailability 添加了一个事件侦听器，并尝试将其简化为一个视图。新代码位于添加的帖子底部。应该能够复制视图和编译器参数并将 renderMode 设置为直接添加视频并查看它。顺便谢谢你的帮助！【参考方案2】：您是否尝试更改渲染模式？当舞台视频处于直接模式时，我遇到了问题。将其更改为 CPU 似乎可以解决我遇到的 StageVideo 问题。
【讨论】：
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