Lip sync on Q90R with 5.1 input

[d00p]

I -- and judging from posts in various fora on the web, a lot of other customers -- experience lip sync issues with 5.1 surround sound input on the Q90R (firmware v1066).

Specifically, I experience this on TV channels that are broadcast with 5.1 sound, but not on TV channels that are broadcast with only stereo sound.

This means that I can watch a show on one TV channel with the (stereo) sound and picture in perfect sync, and then simply change channel to another TV channel to experience a mismatch between the (surround) sound and picture. Switching back to the first TV channel, the (stereo) sound and picture is again in perfect sync. So lame 😕

The lip sync issues are present using the Q90R built-in speakers as well as with a Sonos Amp -- however, again, only with 5.1 TV channels, which also means that I cannot use the options for adding a general delay on the sound/picture as that, while perhaps fixing the 5.1 TV channels, will simply shift the issue to the stereo TV channels.

@Samsung: Needless to say, having such issues on a flagship model is really bad.. What are the plans for fixing this (expectedly, through a firmware update to get the TV to process 5.1 sound input properly)?

[paul1277]

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@bcab17 wrote:

There are many people that feel the lip-sync proplem is caused by the TV, not the soundbar. I'm just trying to figure out if it's only a Samsung problem (in my case, with 2019 QLED line).

Locally, I have opnly seen the LG C8 and C9, and there's no built in soundbar...so a separate soundbar would be needed. Whether it's an LG OLED or perhaps a Sony LED, connected to any number of soundbars, I need to find out if the DD audio from an external source, like a cable box, connected with HDMI to ANY tv, will have the lip-sync issue.

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Sometimes but it's fixable. I have a shield and use either Kodi or VLC connected to me Denon via HDMI. Denon connected via arc. EARC is supposed to reduce the problem, and it will send through full bandwidth atmos, and DTS X.  That means any sound bar or system needs to have EARC, and enough HDMI inputs. 

[m-oc]

The lip sync issue is caused by the TV (Q90R). However, please keep in mind this is a "negative" delay. What I mean by that is that the video is ahead of the sound. So the usual delay settings don't work, they make it worse. 

Normal lip sync issues where the video is behind the sound can be solved with the delay settings either input device or the TV.

To be honest this is why I bought the LG OLED65W9PLA because the unit is combined with a soundbar. 

[Walternate]

Hey there

I have the exact issue discussed in this 10 page (so far) thread with my recently purchased 55" Q90R which is connected to my SONOS via HDMI3 (ARC). My Setup is;

Sky-Q to TV via HDMI1 port

TV to SONOS Beam via HDMI3 (ARC) port

sound set on both TV and within Sky to "DD"

TV Software version is 1315 with no OTA update, but I saw a response a number of replies back that you can download 1335 direct from Samsung.

Now, before I updated to 1335 I found that connecting my Sky-Q directly to my SONOS Beam (utilising the SONOS supplied HDMI to optical dongle) there was ZERO sound sync issues - so if this option suits you, then I recommend that option, but clearly we all have very different setups, so....

I found a perculiar option within the TV settings which vastly reduced sound sync to near impercievable negative delay (but not 100%) when connecting via HDMI ARC to my SONOS sound bar, so I though i would try the same setting after manually updating to version 1335...

 ... I would say this is now pretty much 99.9% lip-sync'd (for me), please give this a try to see if it helps.. YMMV!!!

Settings > Support > Self Diagnosis > Signal Information > Signal History > HDMI Delay Level > (adjust and test as required) Options are "Basic" "Slow1" "Slow2" I am currently using Slow 2 with Sound delay in TV and Sky set to "0" and this is nigh on perfect for me.

[MrTest]

Wanted to add further to this having also struggled with lag following recent purchase of 55" Q80R TV + the Q80 Soundbar both connected on ARC.

2 scenarios and thoughts as to what I think is happening for me:

1) Virgin TIVO box to HDMI1 on TV | sound down ARC to Soundbar

===================================================

From what I have gathered ARC will push (L)PCM which is stereo in the case of the source or Dolby (compressed).

PCM works fine as there is no 'decoding', but is stereo only. When set to use Dolby (5.1) there is lag (picture then followed by audio [around 40ms at rough guess]) It's not possible to change the sync slider as this works when audio is heard ahead of picture. Workaround by Walternate above (thanks) that does help is to change the HDMI Delay level to Slow2. Not perfect but much better 🙂

2) PS4 to HDMI2 on TV (forcing GAME mode) | sound down ARC to Soundbar

===========================================================

Exactly the same as the TIVO box above when using Dolby which sounds great (with lag). LPCM is fine.

Things tried out:

- On the PS4, forcing the audio down optical directly to the soundbar (avoiding the TV) has EXACTLY the same lag issue

- PS4 connected to Soundbar first results is synced audio but bigger input latency (difference between controller movement and seeing effect on screen)

- In built apps (Amazon Prime / Youtube) setup to use Dolby / Dolby plus experience no lag

All this has me conclude that the lag / delay experienced with Dolby is down to the 'decoding' of the format and the TV is not applying 'HDMI lip sync' (or something similar named). PCM is not decoded from what I can gather and hence not an issue. Because the input latency to the picture is excellent (much better input lag playing FPS than I'm used to) it simply highlights the problem more.

When connected to the soundbar first the audio is fine BUT it is applying HDMI audio sync so the picture shows at the right time but results in worse input lag in a game.

In built apps work from the TV as I would assume the TV is applying 'HDMI sync' so it's all good.

So the crux of it is input devices wanting to use Dolby.

One solution for Samsung could be to apply 'HDMI sync' from the TV however I'm not sure this is great as the consequence would result in bigger input lag, but I wouldn't want this as one of the main reasons for the purchase was the excellent input latency. I take my hat off to Samsung on the excellent input latency for the TV, however it appears that having this and Dolby decode is perhaps beyond the realms of technology today (just my 2 pence...)

In my situation Cable / Films etc I'm good to have the increased input lag (as you are simply watching and makes no difference) so can plug straight into the soundbar (perhaps).

The PS4 leaves things confused as I want to keep the excellent input latency and have Dolby surround. Only option I can think of that someone earlier suggested is to split HDMI so I send audio to Soundbar and picture to TV. The difference compared with the optical out is that optical transports compressed Dolby that needs decoding by the Soundbar (same as the support for ARC) however HDMI (I think) transports bitstream which means it is direct and won't need decoding, so in theory should work.

If there is anyone that can shed any other info on the situation or can offer any alternative solutions I'm all ears... 🙂

Cheers

[userjYtfoTda0t]

Hi MrTest, I can add a few things.

1) Due to that the video processing in the TV takes time, the audio has to be delayed the same amount, somewhere in the audio chain. This is true also for PCM.

2) This delay can be done in the TV, which is clever because the TV (designer) knows how much delay should be added. A variant of this is that the TV pass the information about the delay on the HDMI (ARC) connection back to the AVR/Soundbar. I believe that this is what is called HDMI Lip-sync feature. The third variant is that the user figure out the delay and set it fixed in the AVR/soundbar (or in the source device).

My conclusion from my TV (Q90R) and AVR connected via S/PDIF (both directly from sources and Opto from TV)  is that the Q90R adds the correct audio delay in two cases; PCM via HDMI to OCB and both PCM and DD 5.1 from internal apps (at least all the ones I use). From my experience the correct delay (Movie mode and AutoMotionPlus active) is about 45ms. In those two cases I set the delay in my AVR to zero and it works fine.

The problem is (as every body here reports) when routing DD 5.1 (or DD 2.0) via HDMI to OCB. I have tried to measure the excessive delay i this case (see  my post https://eu.community.samsung.com/bgros26334/board/message?board.id=uk-tv&message.id=28720#M28720)

The meaurement is a delta measurement between a sound "blipp" using PCM and using DD 2.0. 

I come to the conclusion (might not be correct down to the ms) is that in this case the TV adds about 160ms too much delay. I could propose that Samsung engineers should investigate if the root cause is that the delay in the TV in this case is erroneously set to max = 200ms (which also can not be reduced by the Q90R manual delay setting).

[m-oc]

I had a senior product engineer/expert remotely connect to my Q90R and change settings deep i the engineer menus. It did improve the situation a bit but the lip sync seemed to vary and they couldn't get it any better. They alluded to the fact that they may eventually fix it but didn't know when. I don't think they know what is wrong. 

[bcab17]

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@m-oc wrote:

I had a senior product engineer/expert remotely connect to my Q90R and change settings deep i the engineer menus. It did improve the situation a bit but the lip sync seemed to vary and they couldn't get it any better. They alluded to the fact that they may eventually fix it but didn't know when. I don't think they know what is wrong. 

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If you don't mind my asking, how did you get a tech to "remote into your TV"? If you could provide the process, that would be great. THANKS.

[bcab17]

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@paul1277 wrote:

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@bcab17 wrote:

There are many people that feel the lip-sync proplem is caused by the TV, not the soundbar. I'm just trying to figure out if it's only a Samsung problem (in my case, with 2019 QLED line).

Locally, I have opnly seen the LG C8 and C9, and there's no built in soundbar...so a separate soundbar would be needed. Whether it's an LG OLED or perhaps a Sony LED, connected to any number of soundbars, I need to find out if the DD audio from an external source, like a cable box, connected with HDMI to ANY tv, will have the lip-sync issue.

---

Sometimes but it's fixable. I have a shield and use either Kodi or VLC connected to me Denon via HDMI. Denon connected via arc. EARC is supposed to reduce the problem, and it will send through full bandwidth atmos, and DTS X.  That means any sound bar or system needs to have EARC, and enough HDMI inputs. 

---

The Q90R tv has an ARC connection, not eARC. My Q80R soundbar is supposedly getting an update adding eARC. My understanding is that you need BOTH your tv and external audio (soundbar, av receiver, etc.) to have eARC to enjoy the benefits.

[NickJ2]

I am an engineer with Felston LipFix Technology and have been involved with lip sync correction for almost 20 years.  It continues to amaze me that this area is still misunderstood by both consumers AND most manufacturers. In the PAST our products could almost always solve lip-sync problems by allowiing viewers to DELAY the audio to match the video which was was almost always delayed.

But today - as this forum documents so well- AUDIO can arrive already delayed.  That is unfortunate since it can't be corrected by ANY product since it would require a video delay and today's HDMI 4K and 8K streams are so fast that would be impossible with today's fastest and most expensive FPGA's so it is not going to happen.

TV manufacturers and broadcsaters SHOULD insure that audio is NEVER delayed because delaying audio IS feasible but delaying video is NOT. Samsung includes an audio delaying feature in the s/pdif menu of most of their TV's for example but that feature (like our products) will only make things worse if audio arrives already delayed.

Some of the misunderstandings I'd like to try to correct:

1. The HDMI lip-sync feature introduced with HDMI 1.3 is a MISNOMER if there ever was one. Most consumers don't understand what it does so here goes: It simply allows (it's optional) a TV to tell the AV source what FIXED delays the TV will cause. It DOES NOT sync audio with video! If the audio arrives delayed it doesn't know that and it would still add the fixed audio delay the EDID requested making it WORSE!

2. Over 20 years ago a study at Stanford found that lip-sync error caused the viewer to have the same feelings about the characters as we have about people who don't make eye contact with us when speaking. Why?The evidence shows that our brains react to the contradiction of reality by making us look askanse (in the real world sound can't come before the action that created it) so it is the viewer who is not making eye contact. Although subliminal the impact is similar.

3. As in 2 above, we are all looking away from the lips and faces when lip sync is off. Most of us don't notice a 40 ms error. Some don't notice 100 ms error. It varies tremendously between individuals but when it is noticed and we focus intently on the lip movement we can usually detect a few ms error. This is why many don't feel Samsung's audio delay feature which adjusts in 10 ms steps will give them perfect sync (because they can detect an error below 10 ms).

The main problem with AV sync is that audio and video are not locked together initially and kept locked throughout the broadcast chain. They have alwys depended on an open loop system to measure video delay and add an offsetting audio delay which is prome to error which once made can't be automatically corrected.

The best solution is to insure video is delayed so the user can add whatever audio delay he needs to correct it. Samsung has that ability but I'd suggest they adjust delay in 1 ms increments instead of 10 ms. Our products can delay in 1/3 ms steps but my guess is that less than 1% want to adjust below 1 ms. 

For manufacturers like Samsung you can actually use their screen's video delay to offset some arriving audio delay.  For example if the screen delay is 50 ms turning the audio delay to zero may give you enough video delay to offse some arriving audio delay.

But some other major manufacturers actually aggravate the problem of delayed audio! Amazingly those manufacturers add an audio delay to offset their screen delay and don't give users the ability to turn the delay OFF. In those cases it's best to never let the TV touch the audio.

Hopefully if you get the broadcasters to NEVER transmit delayed audio and TV manufacturers to never delay audio without giving the consumer control over the delay (at LEAST the ability to turn it OFF) it willbe possible to correct once more.

[Rizel23]

I have my 75Q90 connected direct to my Q90 now     Using the HDMI inputs on the sound bar for Sky HD and Nvidia Shield.

Utilising the in built delay from settings from support\selfdiagnosis\signal information\search history;

 

I now have perfect audio sync from PCM upto Dolby Vision. 

Inbuilt apps have always had perfect sync via ARC to the sound bar. 

Overall an excellent set up now 👍