Seeking a Parallel Element

Question

Hi all,
I'm currently working on a multilingual AlR project with video playback that supports multiple audio tracks. Each flv video file is accompanied by a seperate mp3 audio track for each language that the app supports. I need to sync the playback of the video with the appropriate audio track for the selected language.
I have been able to get this to work by using a ParallelElement and adding the video/audio.
However when I try to seek the playback to a specific time i get a 'The specified capability is not currently supported' error.
If i add a listener for Media Player Capability Change:
mediaPlayer.addEventListener(MediaPlayerCapabilityChangeEvent.CAN_SEEK_CHANGE, doSeek);
In the event hander, when I call seek on the media player, I do not get an error. However the video/audio does not seek.
Does anyone have any advice on how I could get the seek behavior to work for a Parallel Element ? Do I need to manually add a trait the element? Or maybe to each media element individually?
Cheers,
M
My code.....
mediaContainer = new MediaContainer();
mediaPlayer = new MediaPlayer();
mediaPlayer.addEventListener(MediaPlayerCapabilityChangeEvent.CAN_SEEK_CHANGE, doSeek);
var mediaFactory:DefaultMediaFactory = new DefaultMediaFactory();
var videoElement:MediaElement = mediaFactory.createMediaElement(new URLResource('assets/video/part1.flv'));
var audioElement:MediaElement = mediaFactory.createMediaElement(new URLResource('assets/video/part1_aud_eng.mp3'));
var parallel:ParallelElement = new ParallelElement();
parallel.addChild(videoElement);
parallel.addChild(audioElement);
mediaContainer.addMediaElement(parallel);
mediaPlayer.media = parallel;
// mediaPlayer.seek(10); // Throws error

Answer 1

This is a use case we also ran across fairly recently.  Rather than approach it by trying to switch between elements that are passed to the MediaPlayerWrapper, I'd encourage you to try to model the switching behavior within a single MediaElement (i.e. so that you don't switch elements out of the MediaPlayerWrapper).  Switching elements at the MediaPlayer level is equivalent to saying "the previous video is done, here's the next one" -- that's why they restart upon each switch.
The MediaElement-based solution can be seen in our ExamplePlayer sample app here (search for "Switching Proxy") and here.  The idea is that you place your two VideoElements behind a single ProxyElement, where the ProxyElement is capable of switching between the two videos.  The ProxyElement models the same API as all other MediaElements, and automatically dispatches the appropriate events when you change what it proxies, so the transitions from one video to the next should be smooth.  The sample version switches back and forth between videos based on a timer, but you could change the switching logic based on your requirements.