HDBaseT AVLC - is it really visually lossless?

5to1

Well-known Member
So continuing on from the problem I listed in my previous thread: 4k over Cat 6 or repair my HDMI cable? going with HDBaseT AVLC seems the easiest solution given I'd just have to swap over my HD extender. But I'm bit concerned about the basis of the visually lossless claims. And also what bottlenecks I'll face in the future.

I'm considering the WyreStorm EX-70-H2 which is a HDBaseT AVLC extender. My sources are Sky Q and Virgin (for BT Sport 4K). I'm very unlikely to get a 4K BD player as I'm not a movie collector, so can live with streaming.

As I understand it these extenders work by using low latency compression to overcome the HDBaseT 10Gbps limit. From initial reading the visually lossless (I realise its not actually lossless) claim is made on the basis of using a panel of people and seeing if they could spot when the signal was switched from AVLC to full bandwidth. In practice what have peoples impressions been? Especially if you have any experience of that Wyrestorm extender, as I've found it at quite a competitive price.

Also given my sources what roadblocks am I likely to encounter in the future. I can't see Sky/Virgin broadcasting >18 Gbps anytime soon. And if I do add a 4K BD player I can always locate it with the TV, rather then in the comms cupboard. But I'm wondering if there's something I've missed.

My other option is to run a new cable. I can get away with a 5m cable. And as I have an unused basement I can get it close to the TV without having to do any re-plastering/etc. But for now I'd have to leave it exposed between the AV cabinet beneath the TV and the TV (about 20cm). I guess I could spray it to match the white wall for now, but I know it would annoy me. However, I know I wont get around to taking the TV off the wall (have to dig out the box to store it while I work), channeling in the cable and patching it up, for a while. I've got two young kids and lots of stuff on at the moment.

If I do go the new cable route I'd probably use a hybrid optical cable. At 5m lengths they seem quite competitive now. I presume this would be best for future proofing? I could run trunking, but that means a much bigger channel and greater risk of cracking plaster/etc which will be harder to patch up myself.

Any advice greatly appreciated.
 

5to1

Well-known Member
Should have mentioned this is now gone up my list of priorities as Sky have finally activated QMS on my sub. I had to have a long argument and escalate, as whilst they admitted the call recordings confirmed it was supposed to be part of my package, they claimed they couldn't do it as it was a mistake. But they've finally come good. So i'm itching to make use of the 4K sport I'm paying for on both Sky and BT Sport :)
 

5to1

Well-known Member
Oh and I should have mentioned, being a glutton for punishment, I had a go at repairing the existing cable whilst I waited for Sky to pull their finger out.

I tried a screw down connector from Amazon, which didnt work at all. But I then had some success with this punch down connector:

CLB50-HDMI-T

The cable now carries 1080p without issue. It also appeared to carry 4k 8 Bit from Sky Q, but I then noticed some sparkles in the black bars when watching movies. One of the shield lines broke when I was connecting it, so I'd soldered that. Then I noticed it had a ground pin, so tried soldering that and things have gone backwards :( It now drops in and out at 4K. (It wouldn't carry 12 bit at all).

So I guess my third option is to have another crack at getting the cable working at 8 bit. Or trying a solder connector, but its very awkward so I didnt fancy putting my back through that :( hence I went for solder less options first.

My only concern is i'll waste a lot of time with the possibility of no success. So perhaps better to go with HDBaseT or Hybrid which should definitely work.
 

tcp/ip

Active Member
I am looking for a HDBaseT based solution as well as my problem is different HDMI is working fine but the cable does not seem to support Dolby Vision, 4k is fine but as soon as I enable Dolby Vision on my Apple TV 4k or Nvidia Shield all I get are black screens on my new Panasonic 1500 OLED which is a pain in the ass. I had a look at the CLB50-HDMI-T but can I see it does not support HDR or Dolby Vision so I feel this could be a bit of a cheap older tech solution but if you don't want HDR could be fine. My search and research continues but interested in this thread.
 
D

Deleted member 24354

Guest
I am lost as to the point of this thread. You are not asking any questions other than looking for validation on something that you have already decided upon.
You have linked to some decidedly dubious cables, which many would not touch with a barge pole, given their pseudo advertising babble and mediocre feedback.

Repairing HDMI cables is difficult (as you have found) and invalidates any sort of certification that they may have had.

There are a few professional HDBaseT 4K solutions available but they are not cheap.
Under 8m I would just run a a Premium Certified High Speed HDMI. Over 8m use a RuiPro hybrid fibre HDMI.
HDBaseT have a look at the new Kramer equipment which is full fat 4K over Cat6a
 

5to1

Well-known Member
I'm not sure why you think I'm looking for validation for a decision i've already made. I actually haven't made any decision, which is pretty clear from my posts.

I have come up with 3 possible options and listed what I see as the pro's and cons:

1) WyreStorm EX-70-H2 which uses AVLC. Easiest solution for me as it means just swapping out the existing HD extender. But i'm not sure if AVLC is as good as claimed. And also if there are any upcoming bottlenecks I would face for Sky/Virgin.

2) Replace the cable. At this stage I figure I may as well use a hybrid cable if i'm going to the trouble, I dont want to have to do it again if I can help it. I just pulled a couple of quick examples. I haven't looked into Hybrid cables, but will choose a suitable one if I go this route. And I clarified my main concern/annoyance would I can't chase/hide the cable fully for a while. Hence the comments/advice on (1) would help me decide wether to go this route.

3) Attempt a solder repair. Since solder less has worked at 8 bit with sparkles visible in black bars. There is a chance a soldered repair would work. Again based on advice on route (1) & (2) I may go down this route. For example if (1) involves compromises and issues in the near future with my sources and (2) cables priced sub £100 arent suitable I may give this a crack first. Or run a standard cable.

I dont want to spend hundreds of pounds on an extender. I may as well pay someone to come in and chase in a new cable. Or alternatively do it myself.


NB: Which specific Kramer extender do you mean? My understanding was HDBaseT based extenders max out at ~10 Gbps. Therefore any that do full fat 4k utilise either AVLC or DSC (lossless?).
 

5to1

Well-known Member
I had a look at the CLB50-HDMI-T but can I see it does not support HDR or Dolby Vision so I feel this could be a bit of a cheap older tech solution but if you don't want HDR could be fine. My search and research continues but interested in this thread.

The CLB50-HDMI-T is just a new connector. It may or may not support HDR/DV. Depends very much on your specific run. If your cable is short, of good quality and the conductors form a good connection it may well carry the required Bandwidth. It got very close for me, with only a few sparkles visible with Sky Q set to 4k/8 Bit.

If you have some time to waste, it doesnt hurt to give it a try for a few quid. Even if its a short term solution until your sources outgrow it. The cost of extenders will only come down. That's why I gave it a shot. Worst case I have a second cable that I can use upto 1080p should I want to connect anything else.
 

tcp/ip

Active Member
The CLB50-HDMI-T is just a new connector. It may or may not support HDR/DV. Depends very much on your specific run. If your cable is short, of good quality and the conductors form a good connection it may well carry the required Bandwidth. It got very close for me, with only a few sparkles visible with Sky Q set to 4k/8 Bit.

If you have some time to waste, it doesnt hurt to give it a try for a few quid. Even if its a short term solution until your sources outgrow it. The cost of extenders will only come down. That's why I gave it a shot. Worst case I have a second cable that I can use upto 1080p should I want to connect anything else.

The two HDMI existing cables are:
Inakustik Reference High Speed HDMI cable with Ethernet - 20.0m
Inakustik Excellence High Speed HDMI cable with Ethernet - 15.0m

Running new ones is not really an option as they are run through roofs and under floors to get back to my comms room.
 

5to1

Well-known Member
The two HDMI existing cables are:
Inakustik Reference High Speed HDMI cable with Ethernet - 20.0m
Inakustik Excellence High Speed HDMI cable with Ethernet - 15.0m

Running new ones is not really an option as they are run through roofs and under floors to get back to my comms room.

Sorry, I completely misread your previous post :)

I thought you were trying to repair a broken cable. Just realised you're existing cable is intact, but doesn't work with 4K HDR.

In this case the CLB50-HDMI-T is definitely not for you. It's a solution to broken cables. It wont make a working cable better, chopping a working cable and re-ending it will only make it worse :)

If you have Cat6 run then a HDBaseT AVLC 18 Gbps extender would work. But as per my post, my main concern is wether the claim of the compression being visually lossless is true in practice.

Or you'll have to bring your Xbox/Shield closer to the TV. Unfortunately there's no other way around it, if you haven't got Cat6 and can't run new cables :( There's very little likelihood your existing cables will carry full fat 4k, they are too long.
 

Joe Fernand

Distinguished Member
AVForums Sponsor
'visually lossless' - will have a few marketing Depts scratching their heads once they have to introduce designs based around the VS3000 16Gb HDBT chipset :)

Plenty folk say they can see no degradation using current HDBT 10Gb for 4K UHD!

Ideally you want to try and minimise/eliminate unnecessary breaks in your CAT cable run.

Joe
 

5to1

Well-known Member
'visually lossless' - will have a few marketing Depts scratching their heads once they have to introduce designs based around the VS3000 16Gb HDBT chipset :)

Plenty folk say they can see no degradation using current HDBT 10Gb for 4K UHD!

Ideally you want to try and minimise/eliminate unnecessary breaks in your CAT cable run.

Joe

The cynic in me is struggling to believe you can squeeze 18Gbps down a 10Gbps pipe, with on the fly low latency compression and not produce any noticeable difference :/

The Cat 6 run is max 10m and has no breaks in it. Just a straight cable. So i'm pretty sure it will work. I also have a spare Cat 6 run.

I'm dithering between throwing ~£100 (i've seen the Wyrestorm around that price) at a HDBaseT AVLC extender and saving myself some hassle. Particularly as I don't believe Sky will deliver full fat 4K/HDR when it finally arrives, although I'm not sure what Virgin BT is (probably 4K HLG, but dont know bit rate). Does anybody have an idea what the bandwidth of Virgin HDR is?

But on the other hand I think just run the cable and live with 20cm exposed until I get around to chasing it into the wall :/
 
D

Deleted member 24354

Guest
NB: Which specific Kramer extender do you mean? My understanding was HDBaseT based extenders max out at ~10 Gbps. Therefore any that do full fat 4k utilise either AVLC or DSC (lossless?).

TP-594Txr and TP-594Rxr but they are expensive!

Transmission of 4k, done properly, over Cat6 is expensive. Forget whatever you see on Amazon because 99% of that is Chinese Junk that will not deliver 4k 60Hz no matter what the marketing blurb says.

Wyrestorm only support 4:2:0 Chroma, so no full fat 4k there either.

If it were me (and I have been here numerous times on installs) take the time to either run a conduit if you want 'future proofing' or run a Premium Certified Cable. I guarantee that you will not re-solder and HDMI plug and get it to work at 4K, the manufacturing tolerances are extremely tight, especially on the shielding.

Good luck on whatever option you choose.
 

5to1

Well-known Member
TP-594Txr and TP-594Rxr but they are expensive!

I believe those are also HDBaseT AVLC extenders. Since HDBaseT caps out at 10Gbps, I believe all the extenders on the market use AVLC. Which whilst claimed to be visually lossless, is not lossless compression at a bit level.

Until VS3000 makes it to market, I dont think any Cat 6 extenders can do true lossless full fat 4K :/ And I suspect for a year or two they will be so expensive I may aswell get someone in to do the work and paint the room at the same time :D

Transmission of 4k, done properly, over Cat6 is expensive. Forget whatever you see on Amazon because 99% of that is Chinese Junk that will not deliver 4k 60Hz no matter what the marketing blurb says.

Wyrestorm only support 4:2:0 Chroma, so no full fat 4k there either.

The latest revision of the Wyrestorm extenders are also HDBaseT AVLC, same as the Kramer:

EX-70-H2

Like the Kramer they will do 4:4:4 Chroma using AVLC. I presume they all use off the shelf chipset for the compression, as its not trivial to do on the fly compression in software.

I'm not considering some cheap Chinese Rubbish :) I'd only go HDBaseT AVLC branded.

If it were me (and I have been here numerous times on installs) take the time to either run a conduit if you want 'future proofing' or run a Premium Certified Cable.

I made a mistake with the lounge, as it was feasible to run conduit. The bedroom runs would have been far trickier and probably questionable if I could have fished a cable through later given the bends/etc.

I have two young kids now and the lounge is used daily. So not really feasible for me to even chase the cable into the wall. I'd have to dig out the box, pack the TV away, chisel out the wall, install the conduit, patch it up plus any other cracks, sand it and stick the TV back on. Plus if there were any issues, given the lounge is used daily, I couldn't leave it till later to resolve. So if I run the cable I'll have to hide it as best as I can. Which means about 20cm between AV cabinet and base of TV exposed. Then when the room is next painted, I'd chase the cable in and install the conduit.

Good luck on whatever option you choose.

Thanks. I'm still dithering between living with the exposed cable or living with AVLC :/
 

5to1

Well-known Member
HDFury Maestro

Yes, I looked at all the reputable brands. That's HDBaseT based as well, so unless they have started shipping VS3000, it will also be using AVLC or some form of compression :(

It's only optical extenders that can do full fat uncompressed right now. But I dont have optical cable buried in the wall :( Plus again they are expensive, to the point I might aswell run a new cable.
 

tcp/ip

Active Member
Yes, I looked at all the reputable brands. That's HDBaseT based as well, so unless they have started shipping VS3000, it will also be using AVLC or some form of compression :(

It's only optical extenders that can do full fat uncompressed right now. But I dont have optical cable buried in the wall :( Plus again they are expensive, to the point I might aswell run a new cable.

If you concern is mainly cost you are correct just run a new cable and be done with it. My issues is a new cable run is basically impossible unless there is a high-quality HDMI cable that is waterproof and I can run that from the comms room outside the house and back into the media room. Does such a product exist?
 

5to1

Well-known Member
If you concern is mainly cost you are correct just run a new cable and be done with it. My issues is a new cable run is basically impossible unless there is a high-quality HDMI cable that is waterproof and I can run that from the comms room outside the house and back into the media room. Does such a product exist?

It's cost versus convenience :) I'll pay the £100 for the Wyrestorm for the convenience of simply dropping it in, it's the "visually lossless" compression that is making me think twice.

At your distances you'll have to go optical. Check out optical extenders and Hybrid optical HDMI cables. Neither will be cheap :( Running it outside shouldn't be a problem, even if you can't find an outdoor one you could just run it in trunking.
 

jfinnie

Distinguished Member
I use this "visually lossless" HDBT solution from Atlona:
Works well. There have been a few firmware updates in the time I've had it which I've applied but I couldn't say I've noticed any difference in performance.

I've never noticed a display artifact I would put down to the visually lossless coding, though it has been noted in studies elsewhere that while the observant might notice a difference in a "flicker" test, where the images are sequentially shown with and without compression for 2.5s each for 30s and then a choice has to be made as to which is the original and which is compressed; however a typical viewer on a typical display in a typical environment would not. The flicker test used by VESA is regarded as being aggressive, loading the dice in favour of noticing difference and yet DSC still performs very well under those conditions, and manages to be classified as visually lossless. Having said that, I'm interested to move to the lossless VS3000 based solutions when they become available. Most likely a waste of money!

Useful paper here:
 

jfinnie

Distinguished Member
Still at least £250 as a solution
It is, but for a lot of folk that might be good value. Direct and indirect costs from having to hang around / arrange a new cable going in can soon add up when there is an effective DIY at your leisure option on offer.

For what it is worth on a TV at any kind of normal seating distance and with content which is transmitted highly compressed I'd be really surprised if any difference were ever notable, I'm watching on a 92" projection in a dedicated room.

Images that have already been previously compressed for transmission, like Sky, should really be virtually lossless when passed through something like DSC, as there will already be areas with little detail that compress easily resulting from the image compression for broadcast. For Sky type transmissions I really, really wouldn't sweat over the potential impact of DSC.
 

tcp/ip

Active Member
It is, but for a lot of folk that might be good value. Direct and indirect costs from having to hang around / arrange a new cable going in can soon add up when there is an effective DIY at your leisure option on offer.

For what it is worth on a TV at any kind of normal seating distance and with content which is transmitted highly compressed I'd be really surprised if any difference were ever notable, I'm watching on a 92" projection in a dedicated room.

Images that have already been previously compressed for transmission, like Sky, should really be virtually lossless when passed through something like DSC, as there will already be areas with little detail that compress easily resulting from the image compression for broadcast. For Sky type transmissions I really, really wouldn't sweat over the potential impact of DSC.

Thanks a million for your information and also the whitepaper.
I spoke with the company you mentioned support team and it looks like nearly the perfect solution.
However, the only product in the world that support HDR 10+ 60hz and Dolby Vision 60 hz is another of their product range and that is the omni 512 encoder and omni 521 decoder.
They gave me the name and contact details for the UK&I sales manager so I have sent him and email looking for resellers in the UK&I, I am hoping this will be a simple self install.
 

jfinnie

Distinguished Member
Thanks a million for your information and also the whitepaper.
I spoke with the company you mentioned support team and it looks like nearly the perfect solution.
However, the only product in the world that support HDR 10+ 60hz and Dolby Vision 60 hz is another of their product range and that is the omni 512 encoder and omni 521 decoder.
They gave me the name and contact details for the UK&I sales manager so I have sent him and email looking for resellers in the UK&I, I am hoping this will be a simple self install.
Luckily I don't care about DV support as that is a spanner in the works for HDBT currently. DV is I guess perhaps the main reason for interest in the forthcoming VS3000 series.

The product you mention will be too expensive for most I'm sure. I'd also be a bit concerned about whether the encoders in that are going to be up to the job for critical viewing. It's going to be approx 18 to 1 compression I believe for a full fat 18G signal.
 
D

Deleted member 24354

Guest
4K 4:4:4 60Hz with DolbyVision is way beyond 18Gbps we are over 24Gbps which there is nothing that is HDBT can support. Currently there are no certified copper or hybrid fibre HDMI cables that can support that bandwidth.
 

jfinnie

Distinguished Member
4K 4:4:4 60Hz with DolbyVision is way beyond 18Gbps we are over 24Gbps which there is nothing that is HDBT can support. Currently there are no certified copper or hybrid fibre HDMI cables that can support that bandwidth.
As no-one is broadcasting or streaming or supplying discs in 4:4:4 DV @60Hz, the only folk who that is likely to affect is going to be gamers; and if you're gaming and able to concentrate enough to spot the difference between 4:4:4 and 4:2:2/4:2:0 at normal seating distances for 4K then I think you're probably not doing it right...! I don't believe there is any source that refuses to do DV at 60Hz because it can't get a 4:4:4 link?

I think HDBT is a good solution for many applications, but it is always trailing the capabilities of direct HDMI solutions. If you want to be right at that bleeding edge then don't go HDBT. For what it is worth I don't think it has much of a future as single links past 18G (they've not even got there fully yet).

Back to the OP; they don't have a conduit and seem to want to avoid the building works and / or exposed cables; if they can get the Wyrestorm solution for £100 from a trusted source, and it supports the formats they need, I'd have just bought it already as at that price I'm sure it could be punted onwards for no loss; it's almost not worth the thought energy. I paid more for my Atlona at trade cost, and I'm happy at that. If it works and does the job for them, great, if not, move it on and time to get busy with the tools. Job done.
 

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