Confirmed: vip2250 fixes surround sound audio dropouts!

Mentor

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!

Message 1 of 129 (8,026 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

[ Edited ]

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.

 

Message 91 of 129 (4,781 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

With regard to your last question on previous post I have used a Theta Digital TLC optical to SPDIF converter which did do re-clocking of the digital audio from the optical output of a VIP1200 and it worked great. The TLC is not cheap but it does smooth out the digital audio. I would not recommend using the cheap Chinese converters available on Amazon. They do not provide re-clocking of digital audio.

 

Sorry to hear about your video issues with the VIP2250.

Message 92 of 129 (4,773 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!


Agent 305 wrote:

With regard to your last question on previous post I have used a Theta Digital TLC optical to SPDIF converter which did do re-clocking of the digital audio from the optical output of a VIP1200 and it worked great. The TLC is not cheap but it does smooth out the digital audio. I would not recommend using the cheap Chinese converters available on Amazon. They do not provide re-clocking of digital audio.

 

Sorry to hear about your video issues with the VIP2250.


Thank you!  Where can I read about one of these?  I must not be good at google I couldn't find it!

Message 93 of 129 (4,746 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

Hope this helps

 

Narrative from Theta Digital website...
 
Timebase Linque Conditioner

 

Originally, there was only one method available to connect a CD player / transport to an outboard D to A converter, that being coaxial. The mass-market manufacturers then produced players with the inferior TosLink plastic fiber optic output. AT&T glass fiber optics also became available as a means to interconnect digital equipment. All of these termination methods posed a problem for people trying to buy components that would interface with each other. The Timebase Linque Conditioner was designed to solve these problems. It accepted TosLink and coaxial inputs and output coaxial and optionally AT&T or Theta's Laserlinque. It also contained extensive re-clocking circuitry to combat the deleterious effects of jitter. Poor quality transports still pervaded the market, reducing the effective quality level Theta's D to As could offer. The Timebase Linque Conditioner ameliorated some of the problems. It was even found to improve the sound of our then best combination, the Data III / Generation V.

 

All of the digital-to-analog converters up until that time used integrated circuits (ICs) called op-amps, for the critical current-to-voltage conversion that occurs following the DAC, and for the output buffers. At that time, integrated circuit chips generally were used as cost-efficient compromises, which lowered the quality of components that depended on them, in comparison with equivalent circuits made up of discrete elements on a circuit board. After about a year of research, a new analog section was developed for the Generation III, based entirely on discrete class-A bipolar transistor. This circuitry offered greater processing speed, which produced more detail and a smoother sound.

 

Theta TLC Reviews...

http://www.audioreview.com/cat/digital-sources/dacs/theta-digital/tlc/prd_123794_2738crx.aspx#review...

 

 

Theta TLC Images...

http://www.google.com/search?q=Theta+Digital+TLC&hl=en&rls=com.microsoft:en-us:IE-SearchBox&prmd=imv...

 

On ebay....current
 

 

 

Audiogon Ad Expired...

http://app.audiogon.com/listings/theta-digital-timebase-linque-conditioner-cleans-any-di

 

 

ebay ad sold...

http://www.ebay.com/itm/Super-Rare-TLC-Timebase-Linque-Conditioner-by-Theta-Digital-ORG-BOX-CHARGER-...

 

Message 94 of 129 (4,730 Views)
Expert

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

My TV is a Sony KDS-55A3000, a 2007 model LCoS which was a great TV for its time. I still think it produces a superior picture to most LCD TVs, but your VT50 would probably outperform it.

However, on my TV, there is an HDMI settings option that controls how the TV negotiates with an HDMI source to control the color space. My TV has this setting as "Auto", "RGB", or "YCbCr", meaning that it can ask the HDMI source to send the picture data as the preferred output of the source, force the selection of RGB (making the source perform the YCbCr->RGB conversion), or force the selection of YCbCr (allowing the TV to do the YCbCr->RGB conversion).

See if your TV has a similar setting. Because the problems you're seeing are primarily grayscale issues as well as off-colors, I wonder if the YCbCr 4:2:0 -> RGB 4:4:4 chroma upsampling algorithm is part of the problem. Forcing your TV to negotiate YCbCr over HDMI transfers the chroma upsampling responsibility to your TV rather than the STB.

Furthermore, different chroma upsampling algorithms are supposed to be used for HD (Rec.709) and SD (Rec.601). You might repeat your testing with the STB output set to 480i vice 1080i and see if the chroma anomalies disappear.
Message 95 of 129 (4,723 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!


Agent 305 wrote:

Hope this helps

 

Narrative from Theta Digital website...
 ...


Thank you for taking the time to do this!   I must have been fat fingering something in my searches.

 

 

Message 96 of 129 (4,674 Views)
Highlighted
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

[ Edited ]

SomeJoe7777 wrote:
My TV is a Sony KDS-55A3000, a 2007 model LCoS which was a great TV for its time. I still think it produces a superior picture to most LCD TVs, but your VT50 would probably outperform it.

However, on my TV, there is an HDMI settings option that controls how the TV negotiates with an HDMI source to control the color space. My TV has this setting as "Auto", "RGB", or "YCbCr", meaning that it can ask the HDMI source to send the picture data as the preferred output of the source, force the selection of RGB (making the source perform the YCbCr->RGB conversion), or force the selection of YCbCr (allowing the TV to do the YCbCr->RGB conversion).

See if your TV has a similar setting. Because the problems you're seeing are primarily grayscale issues as well as off-colors, I wonder if the YCbCr 4:2:0 -> RGB 4:4:4 chroma upsampling algorithm is part of the problem. Forcing your TV to negotiate YCbCr over HDMI transfers the chroma upsampling responsibility to your TV rather than the STB.

Furthermore, different chroma upsampling algorithms are supposed to be used for HD (Rec.709) and SD (Rec.601). You might repeat your testing with the STB output set to 480i vice 1080i and see if the chroma anomalies disappear.

Interesting, I didn't think the Uvere STB's were even capable of outputting YCbCr (at any level) I thought it was only RGB 4:4:4.  Too bad there isn't a way to force the STB to use YCbCr by default, I believe that's what it should be doing by default.

 

My receiver shows RGB in and it's sending RGB back out.  (no conversion, it's on bypass for these tests as well... I tried a cable direct to the TV)

 

I don't believe I have a way to force the negotiation.  Thus far whatever TV I have connected the 2250 has exhibited the same issues, clipping grayscale 16-18.   Red tint in the lower grays.  The gamma is for sure lower on the 2250 than the other STB I have.  The difference is easily seen (especilly as the compression artifcats rear their up on the 2250), I have my main input calibrated to BT.1886 gamma with a 2.22 power law in one ISF mode and a sRGB gamma on the other  mode (I was cross comparing).  It's very apparant the 2250 lowers the gamma when it's connected vs the other box.  The non -DVR looks really good, the 2250 just looks like it has white crush, missing shadow detail and the overall gamma is too low.  To my eyes it appears to be around 1.8 - 1.9 which is kind scary to me since my BT.1886 gamma starts at around 2.2 at a 10% stimulous  and goes to 2.3 at 90%.

 

I really appreciate the suggestions!  I hope someone from AT&T reads this and gets on it.  I'm thinking this does explain why most people think the 2250 seems to show more compression artifcats, the lower gamma will do that for sure.  The image is very good on my other non DVR box with the BT1886 gamma, outstanding at times to be honest especially when I add just a hair of noise reduction and edge enhancement in my receiver  (Onkyo NR818).

 

I'll let ya know how 480i goes.  I'll snap some photos of the black clipping and white clipping slides on both DVRs with same input/settings.  So you can see what I am.

 

 

Message 97 of 129 (4,676 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

[ Edited ]

Agent 305 wrote:

Hope this helps

 

Narrative from Theta Digital website...
 
Timebase Linque Conditioner

 

....


I forgot to ask you.  I wanted to clarify something.  Does this unit help when the STB digital output is in surround sound mode?   My issues (like most) are on HD channels with 2 channel DD audio.   Does it pass everything through as 5.1 and 2.0 but simply correct jitter?

 

thanks again!

 

Message 98 of 129 (4,664 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

The Theta Digital TLC does not change the audio format coming into it. If you send it Dolby Digital 5.1in it will output Dolby Digital 5.1. If you send it Dolby Digital Stereo in it will output Dolby Digital Stereo. (the digital audio output settings are made in the STB)

 

What it does do is allow you to use the Toslink output form your STB and then use a Coax SPDIF cord to your processor or receiver. It will take the digital audio coming into it and reduce the jitter and re-clock it. My results were smoother and much more detailed digital audio with the Theta in the loop and no audio dropouts.

 

I used the Theta TLC with the Toslink output on my VIP1225 as a work around for the audio dropout problem I was having using the HDMI audio out on the VIP1225. 

 

When I got the VIP2250 STB my HDMI audio dropout problem was corrected so I sold the Theta TLC to a friend as I no longer used the Toslink audio out on the new  STB box. 

Message 99 of 129 (4,622 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!


SomeJoe7777 wrote:
You might repeat your testing with the STB output set to 480i vice 1080i and see if the chroma anomalies disappear.


In regards to 480i  the chromra anomalies are better as well the grayscale clipping is gone.  I can now see down to 17  (16 should be black).

 

I do hope someone who has some degree of influcence reads thee issues and addresses them.  Getting the video right will help peoples impressions of the service.  I bet most people do notice the side effects of the gamma being lower and clipped blacks (most probably haven't a clue what gamma is though).  Since it's coming out of black so fast compression artifcats show up more.  They should want to fix this...   too bad wants and will's aren't always the same Smiley Happy

 

I hope the problem resides in software and not the hardware...

 

I wonder when the next update is due an I wonder if this can even be considered for it.  Hopefully it's already on the plate.

Message 100 of 129 (4,545 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

[ Edited ]

Just before anyone else tries, the Theta Timebase Linque didn't help the drop outs to my Onkyo NR818.  I just got mine today and it's still popping/dropping frequently.  Doesn't seem like there is much difference, perhaps some improvement but it's certainly not a fix.

 

I might have to switch back to the 2250 and suffer a bit with the gamma/red tinted dark grays.

 

Now I have an antique Theta audio device...  I guess I'll put it back up on ebay... sigh.  

Message 101 of 129 (4,497 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

Boy it sure seems like if you didn't have bad luck you would have no luck.

 

Both the VIP2250 and the Theta Digital piece worked for me without the issues you are experiencing. The Theta Digital worked great as a work around for the HDMI audio dropouts on my VIP1225 and the VIP2250 corrected the HDMI audio dropouts completely negating my need for a work around at all and no video problem for me with the VIP2250.

 

How much do you want for the Theta Digital TLC? I will try and find a buyer for you.

 

I am sorry you are going through all these hoops to get your audio and video to respond properly. This is a great forum and I am sure someone here will get you back to enjoying your home theater again. 

Message 102 of 129 (4,469 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!


Agent 305 wrote:

Boy it sure seems like if you didn't have bad luck you would have no luck.

 

Both the VIP2250 and the Theta Digital piece worked for me without the issues you are experiencing. The Theta Digital worked great as a work around for the HDMI audio dropouts on my VIP1225 and the VIP2250 corrected the HDMI audio dropouts completely negating my need for a work around at all and no video problem for me with the VIP2250.

 

How much do you want for the Theta Digital TLC? I will try and find a buyer for you.

 

I am sorry you are going through all these hoops to get your audio and video to respond properly. This is a great forum and I am sure someone here will get you back to enjoying your home theater again. 


Thanks, ya story of my life.  I just roll with the punches at this point Smiley Wink  I put the 2250 back down on the VT50 for now.  Audio distorting/dropping out was drivng me nuts.

 

I paid $86+$12 shipping on ebay  ($98 total).  Don't feel bad, I bet it did work on your AVR and TV.  It's not you're responsibility here, but I do appreciate the help!

 

If this is the worst thing I have going on in my life... life is cake Smiley Very Happy

Message 103 of 129 (4,439 Views)
Teacher

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

[ Edited ]

Ugh, I tried to watch the 2250 on my TV but I just can't get into it.  The blacks are clipped color isn't right then add in the dynamic palette/grayscale adjustements are just too much. 

 

AT&T needs to address this.  I can't be the only one who has noticed this about the 2250.  It does this on both of my TVs.

 

So I either have crap audio /w good video or good audio with crap video.  With the 2250  clipped blacks I have to keep brightness up higher, which then make everything look a bit washed out.  Missing shadow detail on the 2250, and that dynamic re-vamping of the grayscale is frustrating.  I hope this all gets addressed in a future update Smiley Happy

 

Be nice if some AT&T person who has some power can help me out by maybe sending me a better STB Smiley Very Happy  Not sure if the cisco boxes have alll of these bugs too.  I don't mind beta testing Smiley Very Happy

 

So for now I'll have to manually switch back and forth between stereo and 5.1 Smiley Sad  I do wonder if the other DVR VIP1220 would work with the Theta.

Message 104 of 129 (4,397 Views)
Scholar

Re: Confirmed: vip2250 fixes surround sound audio dropouts!

Yes, infinity1976 even with a budgie TV it happens, it may happen with a CRT TV. I think, You put forth the supposition that it may be the VIP2250's video chip driver (the mysterious Broadcom binary blob), and it could be.  I've used a computer that does this shifty blooming of gamma/color while applications load, and it's video driver is a non OEM release; however it's shifting stops.

 

Oh well. Cat LOL

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