Ender519's profile

Mentor

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51 Messages

Wednesday, December 7th, 2011 3:07 AM

Confirmed: vip2250 fixes surround sound audio dropouts!

I had a vip1225 hooked up via HDMI to an Onkyo receiver (HT-S8400 to be specific) and I had problems with audio dropouts on surround.  Every few seconds, for a fraction of a second, the audio would drop.  It drove me nuts and I tried everything to fix it.. I tried different (new) HDMI cables, and even a different home theater system!   In the end, I had to keep it on stereo.

 

I went over and over this with UVerse support.  They kept wanting to send me to the paid support line for help configuring my home theater system and out of four techs I spoke to, none ackowledged hearing anything about audio dropouts over HDMI with surround.  In fact, they kept insisting that I plug the HDMI straight to the TV and I kept having to explain my TV is a stereo device, not a surround device so it's not a good test.  They also immediately started jumping on the bandwagen saying surround sound is out of scope.  I saw a couple of posts about the vip2250 fixing this issue but none of the techs would entertain that idea.

 

Finally I pled my case to a very nice agent in billing who had to go WAY out of her way to get me a vip2250.  Hooked it up and sure enough all audio dropout problems are resolved!

ACE - Expert

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34.7K Messages

12 years ago

Glad to hear it's working for you and thanks for posting.

Voyager

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2 Messages

12 years ago

I did switch my two boxes last eve and, lo and behold, with the vip2250 connected to my Onkyo receiver the sound dropping issue has been resolved. Thanks for the advice, all!

ACE - Expert

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34.7K Messages

12 years ago


@snoopy4331 wrote:

I did switch my two boxes last eve and, lo and behold, with the vip2250 connected to my Onkyo receiver the sound dropping issue has been resolved. Thanks for the advice, all!


That's great.  Thanks for letting everyone know!

 

Tutor

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10 Messages

12 years ago

We also have the surround sound audio drop out problem.  We have to switch to "stereo" unless we're watching a DVD.  We recently had the surround sound installed and the group that did it for us said they have many problems with AT&T customers and that we should ask for an upgraded receiver.

 

We have the old silver Cisco 4320 receiver.  I called AT&T to ask for the better receiver, but they wanted to send me to a technician for my audio problem.  What do I ask for to get this upgraded receiver without the runaround?  I'm not using the right words...

 

 

 

ACE - Expert

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34.7K Messages

12 years ago

Sending a technician may be your best shot to get a new box, though... if he has the newer type on his truck.

Mentor

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40 Messages

11 years ago

I wanted to share some more experiences with the VIP2250.

 

It has some major video bugs.  They are doing something really funky with the lower gradients.  If you display a 16-50 gray scale map on the VT2250 it shows tints of red as well it's completely clipping 17-18!    (you can display pictures via image share)

 

Not to mention the grayscale is dynamically modified!  If I leave the a black clipping image up 16-30, the grayscale actually jumps around!  I see it remapping some of the gradients!  It does this with the video information that's still playing in the background.

 

 

IMO the VIP2250 is a huge mess video wise.  It may improve audio but the video is not good.  When I bring my normal non DVR box to this same TV none of these issues are present.

 

You can see the flaw im talking about simply in the U-verse screen where it says "press OK to watch TV".  Watch the background on a 2250, notice how it transaitions the blobs around and watch it on another box.  

 

1.   it shouldn't be clipping gradients 17,18,19

2.  It shoiuld not be remapping the grayscale! 

3.  There should be NO color in values 20-25.  They are red tinged.  This is bad!

 

All of these issues go away when I use my non DVR on the same TV.  This is also why people see more compression artifacts on the VIP2250, the gamma is lower with the video driver it's using.  And when that dynamic change happens the gamma gets even lower.

 

Also if you find yourself thinking there is a bit of black crush (lack of detail in dark areas) with uverse and you have a 2250, it's more than likely the DVR.  You can't calibrate the DVR correctly, it is clipping some dark details and doing bizzare stuff with the gamma.

 

p.s.

 

TV is calibrated with a photospectrometer (i1 pro), I dialed it in which is when I started to notice this stuff.

 

So in it's current status... if you switch to a VIP2250 to get fixed audio , but you'll end up with poorer quality video.  I verified this on multiple TVs swapping the boxes around.  So frustrating...   

 

So now I want my old DVR back unless someone can tell me there is a fix coming for the video driver in the VT2250. 

 

Do they not have Q&A testing?  these boxes should meet some very basic guidelines displaying basic test patterns before the software is pushed out and released.  I'm sure most people don't know to check for these things, but I bet people do notice these problems.

Expert

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9.4K Messages

11 years ago

A few questions:

1. Have you compared a VIP1225 or VIP1216 next to it to see side-by-side differences?
2. Are you sure your TV is not doing dynamic contrast or some other setting?
3. Have you compared HDMI vs. Component outputs to see if the problems are isolated to only one particular connection?
4. Are you aware that nearly all modern TVs retain image settings (contrast, brightness, gamma, color management, etc.) on a per-input basis? e.g. If you've calibrated your TV using your Blu-Ray player on HDMI 1 but the U-Verse receiver is connected to HDMI 2, you have to copy the settings from HDMI 1 to HDMI 2 to get the calibration correct on that input?

Mentor

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40 Messages

11 years ago


@SomeJoe7777 wrote:
A few questions:

1. Have you compared a VIP1225 or VIP1216 next to it to see side-by-side differences?
2. Are you sure your TV is not doing dynamic contrast or some other setting?
3. Have you compared HDMI vs. Component outputs to see if the problems are isolated to only one particular connection?
4. Are you aware that nearly all modern TVs retain image settings (contrast, brightness, gamma, color management, etc.) on a per-input basis? e.g. If you've calibrated your TV using your Blu-Ray player on HDMI 1 but the U-Verse receiver is connected to HDMI 2, you have to copy the settings from HDMI 1 to HDMI 2 to get the calibration correct on that input?


1.  Yes, difference is substantial.    They don't need to be side by side to see some of the quirks.  Easily seen with same TVs and settings.  In fact anyone who's very famaliar with the blue stand by screen (press "OK" to watch tv) and how smooth the transitions should be in the blue areas that move around will see the difference right away in the 2250.  It's not smooth transitioning it's jerky and messy (gradients), you can see the gradients popping around.

 

2.  No, it's off.  It would be the AGC control on my VT50, and it's at 0.  The dynamic issue I bring up is I assume in the HDMI video driver in the STB or possibly the H.264 decoder?.  If you leave a HD program going on something like HBO, then bring up media sharing and display a photo (in this case a black clipping photo).  you can actually see the STB remap the gradients based on the video stream it's processing in the background.    So in this case I have a static picture up and the grayscale dynamically changes.  Are you famaliar with a black clipping slide use to set brightness?   If I tune to a channel that doesn't have video before I bring up the "media share" the image will never change, it's stable.  This is when I realized there's some connection to the STB processing the video and the grayscale popping around.

 

3.  I have tried 2 brand new 2250 boxes and only HDMI, both have done it.   I'll try component when I get some time, just to debug...

 

4.  sure, i've been calibrating TVs for many years now.  In this case I'm calibrating the ISF modes for the input in question via remote app called controlcal.   My experience level here is probably way above average.

 

 

The redish tinge in the dark grays (near black) and the clipped blacks are really annoying, that just shouldn't be.   The 2250 has a low gamme AND black crush.  Terrible combination.  The low gamma make sthe compression artifacts pop out even more and the clipped black make things look crushed in dark scenes.

 

And yes, I fully calibrated the grayscale using 10pt controls using a photospectrometer  😉  My other STB box shows NO color in the bars unlike the 2250 (on the same TV and input/settings).

 

thanks for the reply 🙂

 

Expert

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9.4K Messages

11 years ago

Interesting. It would seem that the VIP2250 has a fairly serious flaw in the video processing if it's doing what you're saying.

There are some unanswered questions, though. Since we can primarily only test the STBs using images from Media Share like you're doing, is this a bug in all video processing or just in the Media Share portion? There's not a good way to test, unless you might happen to catch the HDNet test patterns that they occasionally broadcast.

The VIP2250 does use a different CPU/H.264 decoder (Broadcom vs. Sigma Designs) and a different HDMI chip than the 1st generation STB units (VIP 1200, 1216, 1225). It would be interesting to determine whether these faults you've observed reside in hardware or in software, and in what stage of the video processing.

Mentor

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40 Messages

11 years ago


@SomeJoe7777 wrote:
Interesting. It would seem that the VIP2250 has a fairly serious flaw in the video processing if it's doing what you're saying.

There are some unanswered questions, though. Since we can primarily only test the STBs using images from Media Share like you're doing, is this a bug in all video processing or just in the Media Share portion? There's not a good way to test, unless you might happen to catch the HDNet test patterns that they occasionally broadcast.

The VIP2250 does use a different CPU/H.264 decoder (Broadcom vs. Sigma Designs) and a different HDMI chip than the 1st generation STB units (VIP 1200, 1216, 1225). It would be interesting to determine whether these faults you've observed reside in hardware or in software, and in what stage of the video processing.

Good questions.

 

Unfortunately the issue resides outside of media share.  I started investigating it because I was noticing brightness shifts in near black (easy to do on a TV like the VT50 which has a black level of .002fl).  I know with the u-verse transcoding we  do get some minor pops here and there but this was something new when I changed boxes.  What I started seeing was quirks in shades near black which would be brighter than it should be (show up as a brighter band) in the video information near black.  I thought I had a faulty box, so I had it swapped.  Issue continued.  I also noticed when I 1st ot the 2250  the standby screen didn't look smooth in it's gradients as my other box or previous DVR.    So I re-did the calibration (full calibration) on the HDMI input using a RGB 4:4:4 source.  That's when I started to notice the redish tint in the near blacks when I used media share in any grayscale slides.  I had also noticed it a bit in program material, but it's not huge deal just annoying.  I also noticed the image looked too dark after the tech swapped the box from the 1225 I originally had.  Now I'm using my non-dvr box and the image is much more linear and shadow detail is as it should be, actually quite good!  As well I don't see the compression artificats like I did with the 2250.  And it there's not the occasional blocking glitches.

 

My issue now is I have choppy audio... again.  The entire reason I got a 2250 was for the audio fix.  

 

This is frustrating, I upgraded receiver from a Pioneer VSX-33 (which has no issues with audio) to an Onkyo which does have issues.  The 2250 fixed the audio, but the video isn't up to par.

 

The 2250 does seem to have some pretty serious video flaws.  Anyone who has dynamic contrast turned on probably doesn't care about shadow detail and near blacks, since theirs are being dropped off anway with features like that turned on.   But some of us do!   The red tint in the grayscale is bad!  But the big one is the clipped blacks and the dynamic grayscale.  And the resulting higher gamma isn't a good thing.  None of my other U-verse STB boxes have ever exhibited this behavior.  

 

I wish I could try a cisco box.  I doubt their available in my arear though.

 

Do you know if anyone has anyone tried a optical -> SPDIF converter on a STB?  I'm hoping a converter with a new clock might help fix the issue.

 

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