Comments on: Don’t Forget The Kitchen Sync

By: rowan.depomerai | Testing The Test

rowan.depomerai | Testing The Test — Tue, 25 Aug 2009 15:19:00 +0000

[...] Last time I told you about the efforts we’ve been making at BBC HD to get an A/V sync test to your TV in order that you can measure the synchronisation between audio and video in your home TV setup. You’ll be very pleased to know that we’re done and the test has made it to air! Andy Quested has posted in his blog about how you can use the sync test – and its counterpart the test card – to line-up your equipment. I therefore won’t repeat that here, but I wanted to give you a bit more detail about what we’ve achieved and how. [...]

By: rowan.depomerai | That Syncing Feeling

rowan.depomerai | That Syncing Feeling — Tue, 25 Aug 2009 15:18:19 +0000

[...] you read the comments on this blog, you’ll recall that we’ve been having problems with the lipsync of stereo [...]

By: Martin Day

Martin Day — Mon, 09 Feb 2009 16:50:04 +0000

FWIW, we had terrible lip sync issues with the BAFTAs last night (on Sky SD, but I also had the same problem on Freesat) – picture first, as before, it seems. And not just a little bit out, either – probably the worst lip sync I’ve yet seen since that episode of Hustle in January. During one film clip, someone got slapped – the arm moved, and there must have been a second-long pause before the sound came.

Could of course be some oddity of my system, but I tried turning everything off and back on again (and, as mentioned, we switched from Sky to the Freesat-compatible tuner in the Pioneer), and it made no difference. As always, it seemed to be back in sync in time for the news…!

Looking forward to hearing the results of your test(s).

Cheers

Martin

By: Rowan

Rowan — Fri, 06 Feb 2009 13:40:58 +0000

Hi Jez. Simple answer is yes it’s out of my area of expertise, but my suspicion (and this is by no means an official line from the BBC) I wouldn’t get your hopes up any time soon. It would be a lot of HD kit in a lot of places, and I suspect the difficulty in getting half-decent small HD cameras could be a contributing factor too. If I hear anything though I’ll let you know. R

By: Jez

Jez — Thu, 05 Feb 2009 11:53:43 +0000

Nice one Rowan, thanks for the update.

I know this may be outside your area of expertise, but do you know if the BBC are considering ever broadcasting MotD in HD, or does that require too much equipment to too many football grounds on a Saturday?

By: Rowan

Rowan — Wed, 04 Feb 2009 18:31:52 +0000

No problem Martin! Thanks for the comment

Just realised I hadn’t updated you guys. Basically, the tests we had planned for Monday due to snow and people not being able to make it. I hope to get this stuff done tomorrow, so expect a full report either as a comment here or maybe even as a new blog post. (Since I haven’t written one for quite a while…)

Cheers

Rowan

By: Martin Day

Martin Day — Sat, 31 Jan 2009 09:10:01 +0000

Thanks for that, Rowan. I do appreciate you taking the time to get to the bottom of these issues.

Best wishes

Martin

By: Rowan

Rowan — Fri, 30 Jan 2009 17:39:00 +0000

Thanks Jez – I appreciate the appreciation…as it were!

Right, well the answer about Hustle is that it seems to be a compound error. The programme itself was delivered to us with a slight sync error it seems, but small enough to fall within our technical policies. Perfect sync simply isn’t a realistic requirement – remember for example that many programmes will have ADR/dubbed audio, so fractional errors will always exist. Additionally, there seems to have been another small error (less than a frame) within the stereo path of the broadcast chain. (i.e. affecting stereo programmes like Hustle but not surround sound programmes.) Applied to most programmes it was small enough to not be noticeable, however, applied in addition to the pre-existing error on Hustle, the combined effect was enough to be clearly visible. We apologise for that – we were certainly very unhappy with it.

What we’ve done is made a temporary fix which probably won’t get everything perfect, but should improve things to within tolerable levels for now. I’m then arranging the most comprehensive tests of sync we’ve ever done on the channel, which will take place next week, so we hope to get much closer to perfection then.

Have a good weekend everyone, and I hope you’re able to enjoy some great programming on BBC HD without major sync problems!

By: Jez

Jez — Fri, 30 Jan 2009 15:43:15 +0000

Hi Rowan,

Really good that you and Andy are prepared to keep in touch with us all via these pages. It must be a bit of a pain as presumably 90% of what you get is effectively “things aren’t right”, but thanks. It’s good when there are problems to see that you guys are working on things, rather than being kept in the dark.

By: Rowan

Rowan — Fri, 30 Jan 2009 12:22:00 +0000

Hi John, thanks for reading. However as I’ve already said, we’re aware of the problem on Hustle last night and are looking into it. Generally the HD channel sync has been good over the last few days, but I’ll let you know if we find out why that particular programme went wrong…

By: John

John — Fri, 30 Jan 2009 11:52:11 +0000

Hustle was appalling last night. It was so far out of sync to be almost unbearable (watching on HD via HDMI and sound through the TV speakers). BBC channels seem particularly badly affected. Box is a Pace and I just rebooted it last week and had seen what I thought was an improvement – until last night!

By: Rowan

Rowan — Fri, 30 Jan 2009 11:22:58 +0000

Hi Martin. Last night’s Hustle was indeed quite badly out of sync. Trying to work out why as we speak… it’s confusing us too right now!

By: Martin Day

Martin Day — Fri, 30 Jan 2009 11:01:50 +0000

Thanks again for getting back to me.

We were late watching Hustle last night (and only have SD Sky+ – we get BBC HD via the plasma), so watched in SD, and even on that the sound was clearly delayed. (And, again, my lip-reading wife noticed it, so it wasn’t just me going nuts!) So either there’s a problem with both my Sky+ box AND my month-old Freesat HD-equivalent Pioneer plasma, or there’s something wrong with the programme itself…!

I’m thoroughly confused now…

Cheers

Martin

By: Rowan

Rowan — Mon, 26 Jan 2009 15:16:42 +0000

Hi Martin

I watched the most recent Hustle myself here on our (carefully calibrated) equipment and I have to say it looked spot on to me. As for Jonathan Ross, I’ve just taken a look, and while my playback method involved a software decoder – meaning the sync isn’t 100% reliable – it looked good. Andy Quested says it looked fine for him at home too, as he saw it on Friday whereas I didn’t.

If you say the sync test was spot on, then I’m confused as to how other things could be so different. The same broadcast chain is used – and in fact the Barbara Cartland clip you mention is part of the same file being played from the same server! It is of course possible for an individual programme to be delivered to us out of sync, but our own quality checks should pick this up and I have no reason to believe that anything recently broadcast has slipped through the net.

Have you tried things like tuning to a different channel and back again, or turning the unit off and on again? Sad though this is, we know some receivers do drift sync over time (and my own SD receiver from a popular media company who shall remain nameless does this a fair bit), so I’m inclined to look to that as a possible cause.

Sorry I can’t be more help! Rowan

By: Martin Day

Martin Day — Sat, 24 Jan 2009 14:38:16 +0000

PS. Have now watched the audio sync test, and it was bang-on. However, by half an hour later, and for the Barbara Cartland clip, the sound was off; you could clearly see the actors forming the words before the audio arrived. Watched Jonathan Ross last night, and the sound was delayed (though nothing’s been quite as bad as Hustle a couple of weeks back!) – and I wasn’t the only one in the house to notice. We switched to SD because the delay was proving distracting; a shame, as the pictures were so crisp!

Any thoughts on the matter gratefully received!