Using MAST/VAST with position conditional triggers

Question

Hi folks! I'm trying to use a MAST file that loads in VAST files to do preroll, midroll, and postroll all from the same XML. Each of these is triggered by a timecode using a property condition looking at position. Essentially, when the currentTime is greater than or equal to a time code, it triggers the ads. Currently the events are firing at the right time, and the VAST files are being loaded and translated correctly, but all three videos are playing after the main content finishes. Can anyone tell me how to remedy this?
Here are some more clues. The conditions for triggering look something like this:
<startConditions>
                                        <condition value="20" type="property" operator="GEQ" name="position" />
</startConditions>
<endConditions>
                                        <condition type="event" name="OnItemEnd" />
</endConditions>
Another clue is that I delved into the MASTPlugin and found in the getInsertionIndex method of MASTProxyElement a comment:
"if our current child is in the midst of playback, we don't want to interrupt it, so we insert immediately after the current child."
The playing status is determined by the presence of a time trait with a currentTime or by the presence of a play trait with a play state of PLAYING. Since the position property will only be triggered after the main content is playing, it would seem that content added with a position trigger would always be added to the end of the main content. Is there some easy way to do this using position triggers or something that might be wrong with the XML?
I am aware of Advertising Plugin which does a great job of this very task, but unfortunately the client wants to use MAST/VAST and uses tracking implemented in the VAST data. Anybody have a solution, or should I start sweet talking the client?

Answer 1

Wow, I missed this question a long time ago.
The basics of what I did were to remove any use of SerialElements or ParallelElements from the MASTProxyElement class. I passed in references to the main MediaContainer and MediaPlayer through metadata on the plugin resource and passed those to the MASTProxyElement from the MASTPluginInfo class. Then I gutted the onDocumentProcessed method of MASTProxyElement. That is what executes when it detects an ad needs to play. There I made the most changes making it just create standard media elements rather than messing with Parallel and Serials. I then created a separate MediaContainer and Player solely for the ads. Using a stage reference off of the main MediaContainer, I add my container to the stage, pause and hide the main player, and then listen for the completion of the ad from my separate player. When that is complete, I clean up my ad and tell the main player to show and resume.
This was a major reworking of the plugin and required a lot of deep diving into the OSMF plugin, along with a few monkey patches to OSMF. The original plugin's support for different versions of VAST and VPAID are incomplete and I had to fix a lot to get a lot of the expanded functionality to work. The plugin codebase is proprietary now, so I cannot share it with the community. However, I am happy to share the general approach I took and to provide a warning about the complexity of the task to anyone attempting to do the same.