In previous posts have mentioned a bug in the Media Center Extender MPEG decoder audio stream selection logic, specifically what it does (as of the time of this post) is only select audio streams with a type of 0x80.
Why is this a bug? well its probably one of those behaviors that's technically correct (I don't have the access to the mpeg specs at this time) but practically wrong, let me explain.
When you look at a VOBs structure its apparent (without looking at the specs) that it is a mpeg2 with special capabilities; one of the core differences you see in a VOB is that they commonly have multiple audio tracks. The first audio track is always 0x80, second 0x81, and so on.
Thing is that sometimes the 0x80 stream is not the one you want when your playing a movie, full on DVD clients solve this by having menus that allow you to control which stream is played; since the Extender isnt such a player and regular mpeg2's only contain a single audio track it doest deal with this case well.
Specifically if one re-masters a DVD into a MPEG and selects the AC3 soundtrack when the 1st sound track is DTS many re-mastering tools will retain the audio stream identification tag which means that since the AC3 track was the second track it will be be 0x81 when in the output (Why would I choose AC3 over DTS? Extenders don't pass-through DTS and don't down-mix it to 2ch either).
NOTE: There are several scenarios where one might run into this, for example if the 1st audio track was spanish and the second was english you could end up with the same situation (that is if you don't speak spanish).
Problem is that since the Media Center Extenders mpeg decoder always picks 0x80 you end up with no audio, previously I knew of only two ways to solve this problem:
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Manually edit the file's tags using hex editors - Time consuming at best, complicated at worst net of which making this not a real option.
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Purchase and use TMPEGEnc Express - This costs $99, is not scriptable, does not have a command line interface, is not as user friendly as other tools (some of which I already own), takes a more aggressive approach (full demux/remux) to cleaning up a VOB than I would like, I should say that despite what I just said it works very well and does more than many other tools.
Well now VideoReDo TVSuite (the upcoming replacement for VideoReDo Plus, only $49 BTW) has a advanced option that you can enable that forces it into a mode where if there is a 0x81 stream available and no 0x80 it will output the 0x81 as 0x80 making the mpeg playable on a Media Center Extender.
I hope that this bug along with several other MPEG related handling behaviors in the Media Center Extender get fixed in the next update but I would not hold out hope as these do represent edge cases and as such will probably get prioritized low by that team.
So what does this all mean? Well its simply if you:
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Open VideoReD TVSuite
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Press Ctrl+Shift and select "Tools\Options"
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Update 'Default AC3 Output stream" to 128 (decimal for 0x80)
All mpeg2 files create by VideoReDo that are potentially effected by this issue are "fixed" so they play with no problems.
The next problem I hope (Boy do I) the VideoReDo folks get to is DVD sub-titles, specifically It would be great if they had a mode of operation that allowed them to output DVR-MS, WMV, or MP4 files from a DVD source with hard-coded subtitles. This would address the last major issue for folks streaming mainstream video content.