shhh, keep it quite or AT&T will block this ability. 
Looks like I'm going to have to research this DVR and set one up in a different room.
kryptonite wrote:
1) Why use the 2nd STB? Why not just connect your HD-DVR to the U-Verse DVR?
With that said:
2) Why not connect the AT&T DVR, or even the STB directly into the computer and use some sort of a video capture card?
1) Because I don't have a computer next to the DVR in the living room. 
2) Please point out any available capture card that captures Y-Pb-Pr component inputs and optical digital audio for less than $189.
I did some further research today on the 5.1 capture/sync problem. I think I may have a viable work-around.
I captured the same movie twice, using the 2.0 Stereo setting on one capture, and the 5.1 Surround setting on the other. (I'm talking about the setting in the U-Verse STB menu ... Menu -> Options -> Audio/Language Options -> Digital Audio Output). Then I extracted the audio from both captures, and placed them both onto the multi-track mixer in Adobe Audition.
From there, I was able to line up the soundtracks in sync at the beginning of the film, then compare them at the end of the film and see how far off the 5.1 audio had drifted.
The calculations show that the 5.1 audio is running exactly 0.04 % slower than it's supposed to, which is 1.44 seconds per hour.
Since Dolby Digital frames are 32 msec long, 1.44 seconds is exactly 45 frames. This means that the AC3 stream goes out of sync by one frame every 1 minute and 20 seconds, which corresponds with excellent agreement to how often you get audio dropouts on most AV receivers when listening to 5.1 audio.
Furthermore, I believe I can actually correct the 5.1 audio stream to re-sync it with the video. There are several commercial programs that have time stretch/compress capability (including Audition), but I was looking for a freeware solution and found SoX which looks like it will work. Tomorrow I'll try this out and see if I can get a finished product with 5.1 audio in sync.
More to come ...
SomeJoe7777 wrote:
I did some further research today on the 5.1 capture/sync problem. I think I may have a viable work-around.
I captured the same movie twice, using the 2.0 Stereo setting on one capture, and the 5.1 Surround setting on the other. (I'm talking about the setting in the U-Verse STB menu ... Menu -> Options -> Audio/Language Options -> Digital Audio Output). Then I extracted the audio from both captures, and placed them both onto the multi-track mixer in Adobe Audition.
From there, I was able to line up the soundtracks in sync at the beginning of the film, then compare them at the end of the film and see how far off the 5.1 audio had drifted.
The calculations show that the 5.1 audio is running exactly 0.04 % slower than it's supposed to, which is 1.44 seconds per hour.
Since Dolby Digital frames are 32 msec long, 1.44 seconds is exactly 45 frames. This means that the AC3 stream goes out of sync by one frame every 1 minute and 20 seconds, which corresponds with excellent agreement to how often you get audio dropouts on most AV receivers when listening to 5.1 audio.
Furthermore, I believe I can actually correct the 5.1 audio stream to re-sync it with the video. There are several commercial programs that have time stretch/compress capability (including Audition), but I was looking for a freeware solution and found SoX which looks like it will work. Tomorrow I'll try this out and see if I can get a finished product with 5.1 audio in sync.
More to come ...
Joe, I am looking forward to what you find out. I used Audition years ago for audio editing and file conversion. It is not surprising to hear about all of the features it has. I understand what you are giving in this post, and I plan to take advantage of it when I get an hdtv. I have a surround system, but I don't have Uv running into it. I am going to check out Sox though.
Well, after much trying, it's a "no-go" on the 5.1 audio sync.
The problem is that the 5.1 audio drift isn't constant. Overall, it's exactly 0.04 % slow as I stated (confirmed with multiple measurements). However, I attempted to correct this in several different ways with SoX, and what ends up happening is that the overall audio track comes out to the right length, and certian parts of the audio (beginning, parts in the middle, and parts at the end) are perfectly in sync. But in between them are also parts that are still out of sync, by up to 100-150 msec in some cases, which is very noticeable.
Essentially what is going on is that the 5.1 audio slows down, then speeds up, then slows down again repeatedly during playback. Overall the slowdown is 0.04 %, but there's spots where it's running 0.1 % slow and spots where its running 0.05 % fast. There's no real way to compensate for this.
When in stereo mode, the STB can compensate for the problem because it has timecodes within the transport stream that that associate each audio frame with the proper video frame. Thus, the STB is never off in it's conversion by more than a ½ Dolby Digital frame, which limits it's error to ± 32 msec.
But once the Dolby Digital is separated from the video during playback and outside the transport stream, all the timecodes are lost, and there's no way to match up audio and video frames anymore. So unless both streams are running at the required playback speed, there's no way to sync them when this type of error is in the system.
This error is consistent with buffering problems (underrun/overrun) and/or dropped/lost Dolby Digital packets. This is happening somewhere in AT&T's system, either in the STB, the audio encoder, or the handoff from the broadcaster.
Oh well, until AT&T fixes the 5.1 problems, 2.0 audio will have to do. Just have to keep hitting that Dolby Pro Logic II button on the AVR. 
On a more positive note, I was able to accomplish something else while I'm at it that's very useful for me.
I like closed captions, and frequently turn them on when watching a movie because I sometimes have difficulty with proper names & places. It's very useful to have the text on the screen.
HD video does not have closed captioning, unlike SD NTSC video. Usually, when watching HD video on U-Verse, you can turn the CC on via the STB menu, or when watching a Blu-Ray, you can turn on subtitles. But once HD video is captured with the Hauppauge HD-PVR, the closed captions are gone.
I picked up another capture device, a Hauppauge WinTV-HVR-850 USB device for $49. This is a very simple USB stick that can capture SD NTSC and HD ATSC from coax. It's drivers support closed captioning, and the included software can show the captions on the screen, but it can't otherwise export them.
But, I worked out a very complicated method using GraphEdit (a DirectShow driver debugger from Microsoft) that can actually capture the closed captions and send them to a file.
So what I've actually got hooked up is the component outs and optical audio out of the STB connected to the HD-DVR, and the coax out of the STB connected to the WinTV. Then I'm playing back a recording via THDVR, and running the HD capture utility and the GraphEdit capture utility simultaneously. The HD capture gets the video & audio into a .ts file, and the GraphEdit capture gets the closed captions into an .srt file.
I then combine all of them together, and the captions are available on playback. They're actually no longer closed captions at this point, they're subtitles, but they're still switchable on/off through the playback software.
If the subtitles aren't properly in sync with the video (almost never are), that can be easily corrected with Subtitle Workshop.
After all is said and done, not too shabby: 1080i video, 2.0 digital audio, and subtitles, all captured from U-Verse.
SomeJoe7777 wrote:Well, after much trying, it's a "no-go" on the 5.1 audio sync.
The problem is that the 5.1 audio drift isn't constant. Overall, it's exactly 0.04 % slow as I stated (confirmed with multiple measurements). However, I attempted to correct this in several different ways with SoX, and what ends up happening is that the overall audio track comes out to the right length, and certian parts of the audio (beginning, parts in the middle, and parts at the end) are perfectly in sync. But in between them are also parts that are still out of sync, by up to 100-150 msec in some cases, which is very noticeable.
Essentially what is going on is that the 5.1 audio slows down, then speeds up, then slows down again repeatedly during playback. Overall the slowdown is 0.04 %, but there's spots where it's running 0.1 % slow and spots where its running 0.05 % fast. There's no real way to compensate for this.
When in stereo mode, the STB can compensate for the problem because it has timecodes within the transport stream that that associate each audio frame with the proper video frame. Thus, the STB is never off in it's conversion by more than a ½ Dolby Digital frame, which limits it's error to ± 32 msec.
But once the Dolby Digital is separated from the video during playback and outside the transport stream, all the timecodes are lost, and there's no way to match up audio and video frames anymore. So unless both streams are running at the required playback speed, there's no way to sync them when this type of error is in the system.
This error is consistent with buffering problems (underrun/overrun) and/or dropped/lost Dolby Digital packets. This is happening somewhere in AT&T's system, either in the STB, the audio encoder, or the handoff from the broadcaster.
Oh well, until AT&T fixes the 5.1 problems, 2.0 audio will have to do. Just have to keep hitting that Dolby Pro Logic II button on the AVR.
Do you really think this problem will ever be fixed?? I'm doubtful it is even being worked on any more (any possibly never was). Or, it's quite possible they figured this out a long time ago, and it was a HW problem, and made a calculated business decision that any fix was just too expensive.
SomeJoe7777 wrote:I believe it's still being worked on, the problem is twofold:
1. The problem is deep within the Windows CE OS ... it's the audio driver and how it's interacting with the hardware. Thus, AT&T actually can't fix this, it's Microsoft that has to engineer the fix via the Mediaroom platform. Mediaroom is generic, once the fix is in that version, then that has to go over to the people who customize it for AT&T, then AT&T has to figure out how to roll that out alongside their existing systems.
2. The problem is intermittent and shows up under certain conditions and not others. Thus, the regression testing is a nightmare. Every different type of encoder at tthe head end has to be re-tested, and many end-user audio receivers have to be tested as well.
You can infer that the amount of time it's going to take to fix the problem is going to be long because of the amount of time it took to discover the problem. Notwithstanding that users knew of the problem for a long period, once AT&T became aware of it it took months just for them to test enough audio receivers to actually narrow down where the problem was.
Yes, I believe it will eventually be fixed, but because it's probably bundled into a new version of Mediaroom, I doubt we'll see it in the field until the next major update from AT&T (THDVR phase 3?).
Hmmm... Did your answer proved my point? Too expensive to fix...
kryptonite wrote:
1) Why use the 2nd STB? Why not just connect your HD-DVR to the U-Verse DVR?
With that said:
2) Why not connect the AT&T DVR, or even the STB directly into the computer and use some sort of a video capture card?
1) Because I don't have a computer next to the DVR in the living room.
2) Please point out any available capture card that captures Y-Pb-Pr component inputs and optical digital audio for less than $189.
AverMedia AVerTV HD DVR $89
Not compatable with Media Center
Will not capture from HDMI, but YPbPr is great.
No optical audio options...
You get what you pay for.
Can't wait.
Audio sync is now perfect with 5.1 digital captures. I captured "Escape From Alcatraz" from Turner Classic Movies (TCM) on Wednesday night, post-processed it last night. Resulting MKV file is perfectly in sync throughout the movie.
This indicates to me that the buffering issue upstream in the VHO is fixed, and this should result in no more audio drops from this issue. (You can still get audio drops from other causes, but this systemic one appears to be solved).
texasguy37
