Yannick and fellow forum readers,

I've been doing extensive testing and experimentation to see if I can get my HTPC to sync with the D-Box controller. Here are the results:

1) HDTV .ts files captured from cable box: only a very small number (maybe 5%) of these are recognized by the D-Box, presumably because their AC3 soundtracks have been compressed or modified. I am convinced that in order for D-Box to work with cable boxes and cable box recordings (which would open a MAJOR consumer market to D-Box), the engineers will need to develop new recognition code.

2) Blu-Ray played on a HTPC gives mixed results. DTS-HD is very easily converted to DTS-es since the DTS-HD specification is to have a "core" DTS soundtrack. As a result, ALL DTS-HD Blu-Ray disks played from my HTPC sync perfectly.

Likewise, Dolby 5.1 from Blu-Ray also syncs perfectly. Unfortunately, most Blu-Ray discs do not have English 5.1 soundtracks (instead they have Dolby True-HD), and instead use 5.1 only for foreign languages. (However, all foreign soundtracks I've tried work perfectly! If only I were fluent in these other languages... :))

However, Dolby True-HD is a MAJOR problem. My understanding is that the True-HD specification does not contain a perfectly well-defined 5.1 AC3 "core" (unlike DTS-HD which contains the DTS core). As a result, it is up to the Blu Ray player to convert True-HD to AC3 5.1 audio for transmission over S/PDIF. From what I have learned, each type of Blu-Ray player or HTPC software player or HDMI 1.3-compatible receiver might do this conversion slightly differently when outputting S/PDIF.

3) Therefore, the key question is... for Dolby True HD English soundtracks, exactly what type of AC3 S/PDIF conversion does the D-Box recognize? 5.1 converted from a PS3 (or other Sony Blu Ray player)? Do you or your engineers have any answers?

I know that PowerDVD 8 Ultra (the latest build), which is probably the most popular Blu Ray HTPC player, does NOT convert Dolby True-HD soundtracks to AC3 or DTS soundtracks that D-Box can recognize. This is very unfortunate! I have also tried using vlc, WinDVD, and Arcsoft TMT (all latest versions) without luck-- those that convert Dolby True-HD to AC3 or DTS did not allow D-Box to recognize the Blue Ray disc. TMT crashed repeatedly, so I can't say much about TMT other than it's reputation as buggy is very well deserved :)

Perhaps it's a pipe dream to want to use my HTPC with D-Box, but for me it's really the make-or-break factor since my HTPC is much more capable and flexible in general than any Blu Ray player.

Yannick-- it would be great if you could provide answers to #3 above. To all the experts reading this-- I would really appreciate your insights as well!

Thanks,
David

[note: I'm posting out of the 61-page D-Box enthusiasts' thread since some who don't read that thread are likely to be interested in the issues raised above.]

Do you still have big troubles with your HTPC and D-BOX 2P decoder? I m thinking about purchasing the 2P decoder with the SRP130 or 230 unit but I ve got over 300 HD movies on my HTPC that are all single .wmv or .mkv files.

It would be a big disappointment (to say at least) when my stuff arrives and I find out that none of this .wmv and .mkv material is compatible with my HTPC.

thanks!

Hi drliu,

I have a D-BOX SRP-120 with the MCI 2P decoder and when I saw your thread on avsforum, I felt the urge to register and post because I obtain different results than you with my HTPC. :) Furthermore, I will clarify one point about how players typically handle TrueHD/DTS-HD MA vs. AC3/DTS.

First of all, I use PowerDVD 9 Ultra (dunno if that makes a difference compared to 8 but 9 is latest now). ...oops, I just noticed your thread is a few months old. Meh, I will finish the post now that it's been started in case it helps others. :)

It is true that Dolby TrueHD doesn't use a differencing architecture unlike DTS-HD Master Audio does with the DTS core but the end result is the exact same because every single Blu-ray disc that contains a TrueHD track is _required_ to have the equivalent in AC3 for compatibility purpose. Most of the time, that track is not selectable from the menu but your player, if working as it should, will playback directly that AC3 track whenever TrueHD can't be played. It's the same behaviour with DTS-HD MA / DTS.

This is my case with PowerDVD 9 Ultra and my setup. When I play Blu-ray movies from that software, since the audio goes through S/PDIF, the AC3 or DTS track is automatically selected and it DOES sync with the D-BOX controller. Players should not have to do any conversions from the lossless format to the lossy one whatsoever because both are physically present on the disc.

Make sure that in the Audio tab of the Settings menu in PowerDVD, you have "Primary Audio" selected and not "DTS Mix" or "DD Mix". Also remember that this is by going through S/PDIF. If you pass through HDMI from your HTPC, PowerDVD will, by default, decode the lossless bitstream into 8-channel LPCM if your receiver can handle it. Maybe there's a way to force playback of the lossy format when going through HDMI. If I ever test that out, I will report back. :)

To answer sanderdvd, the way it was explained to me, D-BOX controllers do a 1:1 match with the audio track. Therefore, if the track is altered (i.e. compression), it will not sync. On the other hand, if it is intact, it should work whatever your video format (mkv, mp4, etc.)

Cheers!

After extensive testing, here are my conclusions:

1) Nearly all .ts files captured from HD-DVRs over firewire do NOT have the native DD or DTS soundtracks; thus they cannot be synced with D-Box.

2) Some, but not all, PowerDVD versions will output the DD 5.1 core of a TrueHD soundtrack over SPDIF. Unfortunately Ultra 8.2217, which is the most stable and best of all the blu-ray playing PowerDVD versions IMO, does not.

3) HOWEVER, you can copy the audio files from .2217a and replace the .2217 audio files, with the result that everything works (just don't sneeze!). I call this the "FrankenPowerDVD Solution". Ultra 9 will do the TrueHD to DD conversion, but Ultra 9 is so filled with bugs and other problems (including occasional glitches during playback on my GTX285-based system, and the inability to play many BD discs such as Donnie Darko, Firefly series, etc.) that it's not usable in my hands.

Hope these tips are helpful.

-David