Lip Sync issues - Sky Stream

[Skull+Treaty]

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@TechMaster wrote:

@Skull+Treaty No I haven't but I just just flicked over to it for 5 mins and it was fine, no issues. Maybe I need to leave it a bit longer to test

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@TechMaster 
I think it's happened after returning from an ad break. 
Similar to you, TV & Stream are set to pass through and not had any issues on any other channel. 

[TechMaster]

@Skull+Treaty ok I will try it for a bit longer. 

for my setup on my TV I also set the HDMI Audio format to bitstream, and I have an option called match screen and sound which which I set to bypass. 

I also duplicated those settings to my hdmi 2 eArc port even though that just has the soundbar on it, as I was getting a weird issue with Disney plus not outputting Atmos via the steam box, matching the setting onto hdmi 2 fixed that issue (but that's another story)

[Littletaffia]

@Chris4Stream You are correct about PCM that there is no decoding but it still has to be converted from a digital signal to analogue. Sky want you to use PCM because their default is stereo and not multi channel. Other streaming service use multi channel PCM like the basic 5.1 channels on Paramount. Dolby Digital Plus is used when there is Atmos metadata attached.

With PCM multi channel I also engage DTS Neural:X to bring in my Atmos speakers so the whole packet of data is being processed so taking your theory to it's extent then I should be experiencing delay even with an initial delivery of PCM. This doesn't happen with my Denon AVR. Perhaps it's better processor. With a base Dolby Digital 5.1 I still engage Dolby Surround. Yet I still get perfect lip sync when using the Apple TV. Sky were more than happy to blame my Denon for the lip sync problems. 

I know that Apple did have, may still do on some pucks, but I believe this has been resolved with the newer 4th generation puck that I have. I did hold back on getting a puck because of these issues prior to the 4th gen being released. The older generations being updated by firmware.

Now your talking about HDMI communication, the infamous handshake. I do agree that HDMI is a complete balls up but it's what we have and software and hardware has to work within those constraints. Enhanced ARC was supposed to have solved audio issues, amongst other gremlins, but a lot seem to still exist. I'm not using ARC because all of my connections are direct to the Denon. 

There are obviously problems with Sky transmitting Dolby over bitstream hence their request for subscribers to use stereo PCM which requres less bandwidth. So the clock is out most likely on the puck and is not communicating properly with either the soundbar or AVR. Bitstream have clock embedded into the audio stream and it's obviously running behind the video so when it gets picked up by the soundbar or AVR it gets acknowedged but at the wrong time. That's before the processing can begin. The AVR can only acknowledge the timing from the sending device and sync to that signal. If the clock is slightly in front of the video then that's easily taken care of by delaying that audio. If it's behind, which it is, then that cannot be defeated.

Sky Stream and Glass must have more bugs that a David Attenborough programme.

[Zoltron]

The issue is Glass is also affected, I see just as many issues on my Glass TV downstairs as I see on my puck upstairs which is connected to a 70" Philips TV and Sonos Arc.

The issue is there is a relatively easy fix which has been used by PC's for a long time which could be used to fix this, regardless of whether it's the audio or video first, the fix is to have a buffer, by having a buffer the audio can then be shifted in either direction by the user. Whether this kind of implementation is possible on existing hardware is a question for the development teams to answer. Glass and stream must have some limited storage capacity, but whether there is enough storage capacity to buffer 5-10 seconds of UHD video will need to be looked into.

But I don't think this is necessary, because this lip sync issue is a new problem which has only recently come about.

The question is, what has changed? Is it firmware or the broadcast stream?

I'll stick my money on firmware, as I've only noticed the issue on my Glass and Puck since the AirPlay update.

[koopie]

The lip sync issue is not recent. It is at least 10 years old and the puck has just inherited poor software/hardware. It started when ARC came out and affected Sky Q. The only solution I could fine that was consistent was to plug an optical cable into Sky Q and my soundbar. The issue still persists on Sky Q as I still need to use an optical connection.

[Zoltron]

In respect of Glass and the Pucks, it is quite a new problem.

While there might have been certain setups which would have naturally been affected, A recent update seems to have created issues for a lot more subscribers.

I've never had an issue with Glass or Stream until now and I'm 2.5 years in on the service. It's only been the last 8 weeks or so for myself.

[Ian+McK]

The puck has within settings the ability to manually delay or advance  up the delivery of sound. It's is a pain to use and in this day and age it should be done automatically.

They pitch The Sky Stream as a premium service at a price they are very proud of.

I have asked Which? Consumer Service to look into the matter from trading standards print of view. It is appalling the lack of information from Sky. 

[BobbiElman]

All these replies about sound bars 

not everyone uses them. I have two pucks, livingroom has a sound bar with very little issues and incidences of lip sync issues ..but it happens  

my bedroom tv is a completely different story with no sound bar, a 2 year old Sony TV and it's a daily thing with lip sync issues with absolutely no pattern . 

I turned on the tv today with lip sync issues literally as soon as I turned it on. 

I also came from Virginmedia and I'm shocked at how bad the issue is with Sky.. 

and yeah, I've tried every single thing offered by Sky and in this thread and yet it continues ...

I feel like we've all been had and Sky knows it's an issue but doesn't care .
 

[Markp777]

Where is the setting to "advance" sound?

[Paul+Dray]

The problem with all these different experiences is that different issues and reasons for issues often get conflated in forums like this.  It's not accurate to blanket say 'Sky stream is broken' if your experiencing problems, as for some others they wouldn't have any major problems or perhaps technical enough to be able to work out conflicting issues in their setup themselves. That of course isn't excusing Sky Tech team for not being able to help certain customers adequately enough. I do certainly think there needs to be far better training in that department. 

[Fothergill1]

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@Markp777 wrote:

Where is the setting to "advance" sound?

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@Markp777 If you go to Settings > Picture & Sound > Sount and then select Digital audio delay HDMI you can adjust the sound delay.  There is no specific advance function but I suppose you could argue that you can advance the sound if you had previously delayed it.

[Paul+Dray]

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@Fothergill1 wrote:

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@Markp777 wrote:

Where is the setting to "advance" sound?

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@Markp777 If you go to Settings > Picture & Sound > Sount and then select Digital audio delay HDMI you can adjust the sound delay.  There is no specific advance function but I suppose you could argue that you can advance the sound if you had previously delayed it.

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Ooo that's stretching it a bit there @Fothergill1 i know what you mean though

[LesleySh]

We have a Sky puck streaming box. Recently the picture is out of sync with volume on sky sports cjanel

[richcawley74]

I have to keep resetting the puck as the picture looses sync with the audio of the programme I'm watching. Happens daily on all channels. Constantly resetting is driving me spare.