satellite audio and video not in sync in chapel

We have a newer building (less than 2 years) and when I broadcast any satellite transmission in the chapel using a projector, the audio is ahead of the video. I've called Local Unit Support but they're not familiar with this issue.

It seems as though the RF out in some of the classrooms are closer to being synced than the Composite or RCA jacks.

Has anybody had this issue and if so, what did you do to fix it?

Sync is a digital issue. Maybe your rack is different, but in mine, the only digital device is the receiver and the DVD recorder. Is the feed for your projector running though a DVR/DVD device? I suspect that's the problem. It would have worked fine with a VCR, but when it got replaced with a DVD recorder ....

Also, depending on your projector, it might be adding a delay. Check the menu settings.

You can also try power cycling the receiver to clear it out, but if the RF outs are in sync, I doubt if it's a receiver issue.

More info.

My satellite cabinet is in the library, a good 120 feet from the chapel. It appears that the audio, which goes through the audio cabinet in the chapel, is accelerated. I have a DVD recorder in my cabinet which is also composite. When recording a broadcast, the video seems to be relatively synced. There is a slight delay, probably undetected by most, but when I turn the volume down on the TV, and turn up the volume on the chapel speaker (located in the library), the audio is accelerated substantially.

I currently don't have any device with an RF Input that has a composite output. So, is it possible to slow do the audio in the chapel?

Hope this makes sense.

Thanks for the advice and help in advance.

tpark23 wrote:I have a DVD recorder in my cabinet which is also composite. When recording a broadcast, the video seems to be relatively synced. There is a slight delay, probably undetected by most, but when I turn the volume down on the TV, and turn up the volume on the chapel speaker (located in the library), the audio is accelerated substantially.

I strongly suspect the TV in the rack is on the output of the DVD recorder. This is so you can use it to program the recorder. But the DVD is delaying the signal to the TV as it has to do a A/D and then a D/A conversation. On my unit I hear it as a delay, like a large auditorium. Your model may be different. If you've engaged the time-shift feature, the delay could several seconds, even hours.

The real question is what is it like in the chapel? Unless they are getting video from the DVD recorder (perhaps so it would be easy to do playback) they won't see any problems. Let's make sure there really is a problem.

I guess I'm not exactly sure what you're referring to. The video is going directly from the satellite receiver to the pulpit. It isn't' going through the recorder. However, the audio goes from the satellite to an audio cabinet in the chapel. What is the 'time/shift' feature?

There is a problem. I've had several complaints from the Priesthood broadcast last night that they couldn't even watch it because it was so pronounced. I'm going to talk to the FM group and get the original audio/video contractor back to fix it.

Thanks for your help.

If you pull up a menu on the DVD, does it show up in the chapel?

Are you able to playback a DVD to the chapel? If so, are there any switches you have to set?

tpark23 wrote:There is a problem. I've had several complaints from the Priesthood broadcast last night that they couldn't even watch it because it was so pronounced. I'm going to talk to the FM group and get the original audio/video contractor back to fix it.

Assuming that no one has modified the original setup, that's probably the best plan.

No, the DVD recorder is connected separately. It may be the projector, but I can't seem to adjust anything.

Thanks so much.

tpark23 wrote:It may be the projector, but I can't seem to adjust anything.

What make/model?

Sony VPL EX50

I don't see it there either. You've got me stumped. As I said, delay can only come from digital processing. Since some outputs are in sync, I don't think it's the receiver (unless it some strange new type that has multiple video outputs).

If the audio was behind the video, it could be the DSP in the audio rack.

The most likely thing is the chapel video is being fed from the DVD recorder, but you say that's not the case. Make sure no one has stuck a DVD or DVR in between the wall and the projector.

Beyond that, I'd have to be there in person to figure this out.

Do you have any languages channels or is your setup English only? And do you know if your rack has always had a DVD or was it originally installed with a VCR?

I also have Spanish.

My DVD Recorder is external. I hook it up to the RCA jacks inside the cabinet in order to record.

I was messing around with one of the projectors (this building has 3) and changed a setting called DDE (Dynamic Detail Enhancer). It has 'off' 'progressive' and 'film' setting. When I turned it off, it appears to work much better. It's not perfectly synced, but I don't think most people would notice.

tpark23 wrote:I was messing around with one of the projectors (this building has 3) and changed a setting called DDE (Dynamic Detail Enhancer). It has 'off' 'progressive' and 'film' setting. When I turned it off, it appears to work much better.

Interesting. No mention in the manual that I can see about it adding a delay. Oh well. As long as it's fixed. Good job.

On our satellite system, the audio has always been just slightly ahead of the video. One of the reasons is because the receiver is processing more than 60 languages, and the video is set to match the timing of the 3rd or 4th language. English comes 1st.

When we got the new projector, we had to route the video through a VCR to tune the raw signal. This has induced an additional delay in the video that has made the difference more noticeable by more members.

There is a way to sync the audio to the video, but the FM group needs to have a pretty sharp specialist to do it, and it happens in the chapel sound system somewhere.

We have never been able to run the chapel sound with the sound of a television receiving a composite signal. They just have not been able to get it together in our building since the new sound system was installed.

lajackson wrote:On our satellite system, the audio has always been just slightly ahead of the video. One of the reasons is because the receiver is processing more than 60 languages, and the video is set to match the timing of the 3rd or 4th language. English comes 1st.

lajackson wrote:When we got the new projector, we had to route the video through a VCR to tune the raw signal. This has induced an additional delay in the video that has made the difference more noticeable by more members.

I suspect the delay is in the new projector that was introduced at the same time. You'd need lab equipment to see the delay a VCR adds. (A DVR or DVD recorder is a different story.)

lajackson wrote:There is a way to sync the audio to the video, but the FM group needs to have a pretty sharp specialist to do it, and it happens in the chapel sound system somewhere.

I'm not sure if they can do it with with the stock setup. If they can, then they have to call Marshal Industries to come out and re-program it. Or they can get someone to add a delay box to the line.

lajackson wrote:We have never been able to run the chapel sound with the sound of a television receiving a composite signal. They just have not been able to get it together in our building since the new sound system was installed.

Sync problems? Or something else?

RussellHltn wrote:Sync problems? Or something else?

If we plug a television in, the video and sound of the television are synced, but the chapel sound precedes the television sound and video by a fraction of a second.

lajackson wrote:If we plug a television in, the video and sound of the television are synced, but the chapel sound precedes the television sound and video by a fraction of a second.

When you say a "we plug a television in" what kind of unit are we talking about?

FWIW, we have the same problem in our new building. The amount of delay changes from time to time, but it's always there. Usually it's not enough for anyone to notice, but it drives me nuts. Once or twice, it has been bad enough that people have complained.

I've honestly never dug into debugging this, since it hasn't been too distracting for others. I'll try to spend some time on this in the near future & let you know what I find. In our case, the video & audio path is Satellite Receiver>>Source Switch>>DA>>Chapel Projector/Sound system

Assuming the signals are in sync at the receiver, it's got to be either the switcher (it's an active genlock switcher), or the projector. I'm most suspicious of the projector. Not sure if the problem is worth throwing delay lines at, but it would be nice to know what's going on.

Anyway, I just wanted to let you know you're not alone...

RussellHltn wrote:When you say a "we plug a television in" what kind of unit are we talking about?

Coax from the wall into the back of a 25" Sony television. We use it on the side of the chapel and usual set it to closed caption. We have several hearing impaired who really appreciate it.

lajackson wrote:a 25" Sony television

Are we talking about a CRT or a flat screen? More to the point, is it a all analog set or does it have digital processing? If there's no digital processing in the set, then we have to look somewhere else for the delay.

RussellHltn wrote:Are we talking about a CRT or a flat screen? More to the point, is it a all analog set or does it have digital processing? If there's no digital processing in the set, then we have to look somewhere else for the delay.

CRT analog. Old enough that you could not use it to pick up a digital signal off the air anymore. You would need a digital converter box.

It does have an onscreen menu system for settings and CC, etc. I guess that part is digital.

lajackson wrote:CRT analog. Old enough that you could not use it to pick up a digital signal off the air anymore.

I think we can eliminate the TV set as the problem. Something else - something digital - is causing a delay in the TV's feed.

I don't think it's the receiver. Not unless someone decided to avoid buying a audio distribution box and instead programed a spare set of outputs in the receiver for the same (English) channel.

This is kind of an old thread, but I wanted to follow up on this since I just did some testing that I thought I'd share with you. As I mentioned in an earlier post, we have this problem in our building, and has continued to be an annoyance. It has been so bad on occasion that there have been several complaints from the audience, including the Stake President.

So, I finally had a chance to look into this a little more this weekend (conference weekend is usually my chance to clean up & fix equipment between sessions). Here's what I found.

As suspected, the culprit is clearly our projectors. I didn't have any test equipment available, but was able to get a pretty good idea of what was going on with a test recording on DVD. But I was surprised to find how much variation there was between our projectors. We have three different models of projectors, but they are all Sony, so I had expected they would have similar "engines", and have similar results.

One projector (the oldest model) had a delay of less than one frame (less than 33ms). The lip-sync delay is virtually undetectable with this model.

The "worst" one of the three had a delay of 3-4 frames (well over 100ms). This produces a very annoying amount of lip sync delay.

Anyway, this explains a lot, since we usually reach for the new projector first when doing a setup, which explains why the problem is usually there, but inconsistent. For a one-projector setup, our solution is easy- we'll just use the older projector.

But this doesn't solve our problem for multiple projector setups. I think what I'd like to try is add 50-60ms of delay to the audio line going from the satellite/production cabinet to the chapel. That way it will be closer to all three projectors and probably below most people's threshold of awareness.

This can be done by adding a delay unit. But I'm curious whether the main chapel mixer has the cabapility to do this. It is software based, and I believe it has some DSP capabilities, so maybe it's something that we can do within the current system without investing in new equipment? I'll be sure to ask our audio contractor (General Communications) next time I have a chance.

Anyway, I hope that's helpful,

-Shane

The first thing I'd do is disable as much processing on the projectors as I could. You may find that simply turning off a few menu items will fix the issue.

I actually considered that and tried different settings on the projector. I think it helped a little. But it was hard to tell since my measurement method was kind of crude, and I couldn't measure subtle changes. But, it seemed like I was able to get that 3-4 frame delay down to less than 3 frames by trying different settings.

There was nothing I could do to get it down to an unnoticeable level.

From the research I've done, this appears to be a very common issue with home theater and commercial installations using newer projectors.

Is it practical to run the audio through the projector that is causing the delay and daisy chain the projectors together? Not ideal, I know.

SBankhead wrote:From the research I've done, this appears to be a very common issue with home theater and commercial installations using newer projectors.

If it's a common issue in home theater, then I'd expect there to be a simple solution. Otherwise the projector manufacturers will get black marks and slow sales.

silid wrote:Is it practical to run the audio through the projector that is causing the delay and daisy chain the projectors together? Not ideal, I know.

At our location, we do not run audio through the projectors at all. Just video. Audio comes directly from the rack to the building sound system. It is possible that the combination of the VHS machine we are using for a tuner and the projector (that cannot cool itself and stay running for two hours, sigh) are inserting the video delay.

However, our very old televisions also have the delay, so it appears to be a difference between the audio processing and the video processing at the satellite rack.

And if we route the composite RF signal into a regular television, old or new, and the TV processes both the audio and video, the delay is still noticeable.

lajackson wrote:At our location, we do not run audio through the projectors at all. Just video. Audio comes directly from the rack to the building sound system. It is possible that the combination of the VHS machine we are using for a tuner and the projector (that cannot cool itself and stay running for two hours, sigh) are inserting the video delay.

However, our very old televisions also have the delay, so it appears to be a difference between the audio processing and the video processing at the satellite rack.

And if we route the composite RF signal into a regular television, old or new, and the TV processes both the audio and video, the delay is still noticeable.

We only use the RF signal in the chapel to pick up the ASL broadcast on a specific channel. We use a video output signal (No RF) for the projector and we've never noticed a delay. Is the delay on all audio channels (IE; other languages)? Do you have a video output w/o the RF?

techgy wrote:We only use the RF signal in the chapel to pick up the ASL broadcast on a specific channel. We use a video output signal (No RF) for the projector and we've never noticed a delay. Is the delay on all audio channels (IE; other languages)? Do you have a video output w/o the RF?

We do not have a separate video only output signal in the chapel, just the RF from the old coax.

It is hard to tell if other languages have a delay, since the lips do not match the words in other languages [grin].

When English is being fed on the Spanish channel (i.e., the BYU feed during non-broadcast times), there does not seem to be as much of a delay.

lajackson wrote:However, our very old televisions also have the delay, so it appears to be a difference between the audio processing and the video processing at the satellite rack.

That's odd. Have you tried rebooting the receiver?

lajackson wrote:It is hard to tell if other languages have a delay, since the lips do not match the words in other languages [grin].

It does when the choir sings.

lajackson wrote:We do not have a separate video only output signal in the chapel, just the RF from the old coax.

It is hard to tell if other languages have a delay, since the lips do not match the words in other languages [grin].

I figured that all buildings that had satellite had a video output, but I guess not. It actually provides a cleaner signal that the RF does.

RussellHltn wrote:If it's a common issue in home theater, then I'd expect there to be a simple solution. Otherwise the projector manufacturers will get black marks and slow sales.

I agree, I'm not sure how a common Sony projector can have such a large delay without a lot of complaints. But I assure you it's there. You can Google different combinations of "audio video delay lip sync" and see that there are a lot of people dealing with the issue.

I suspect most of the delay has to do with the scan conversion of our composite video input, which would require some processing. I don't think there is much delay at all if the projector is connected to a VGA source at its native resolution.

There is a simple solution, except that it requires investing in some equipment. Some home theater receivers have delay adjustments, and you can also buy delay boxes to fix the problem. For instance: http://www.felston.com/

I'm just exploring other options before adding more equipment to our setup. I'll report back if I have any success.

RussellHltn wrote:That's odd. Have you tried rebooting the receiver?

In thunderstorm country, almost every successful broadcast is preceded by a reboot, so yes.

I opined last conference that it is the feed itself, where the video is inserted a little later into the lengthy audio stream to accomodate the multitude of languages being provided over the Church satellite system (upwards of 70 or 80 now, I think). There were no takers for that theory last time, and I doubt there will be this time, either.

We are really quite happy to get any semblance of the broadcast around here, and have not worried too much about the nuances and technical details of the video portion of the feed. When I showed up Sunday morning, the choir director had turned on the chapel sound for Music and the Spoken Word (I taught her how several years ago), but the projector had not even been set up.

Perhaps the next specialist called will not be so casual in the performing of his calling.

Agency. I still vote we keep it.

lajackson wrote:I opined last conference that it is the feed itself, where the video is inserted a little later into the lengthy audio stream to accommodate the multitude of languages being provided over the Church satellite system (upwards of 70 or 80 now, I think). There were no takers for that theory last time, and I doubt there will be this time, either.

I wouldn't rule out a problem with the feed, but I'm not sure as I'm buying the reason.

In the analog days, sync wasn't an issue. Everything ran "real-time". With the introduction of digital processing, delay was a natural by-product. All it takes is for someone to add a new processing step in either the video or audio chain and things are out of sync.

What receiver do you have? I wonder if there's a delay feature that's mis-set in your case.

Something that would be interesting to check, look for sync in the "countdown" video, or the in-between session stuff.

RussellHltn wrote:I wouldn't rule out a problem with the feed, but I'm not sure as I'm buying the reason. . . .

What receiver do you have? I wonder if there's a delay feature that's mis-set in your case.

Something that would be interesting to check, look for sync in the "countdown" video, or the in-between session stuff.

This answer is as technical as I can get it from off the top of my head.

We have the standard Church digital receiver. Two audio channels are pulled and added with the video onto separate tunable broadcast frequencies, then the two frequency channels are combined into a single RF feed and distributed throughout the building. Plug in a TV and tune to the channel with the audio you want to hear.

I have not noticed the problem to be as great during broadcast material that does not originate from the Conference Center. On the other hand, I do not pay as much attention to the other material as I do to the conference speakers, which is why I happened to notice it again this past weekend.

I suppose I should quite fussing and go check it out for myself, if no one else cares enough to do it. [grin]

lajackson wrote:We have the standard Church digital receiver.

Which one? The models have changed over time. I've got both a "original" (tech support seemed surprised it was still working) and a "late" (for ASL). There might be more models in between.

Best I can say is the "original" is a cream colored with just two push buttons.

The late is gray with a LCD display and buttons arranged in a circle pattern for Up/down and sideways.

RussellHltn wrote:Which one? The models have changed over time. I've got both a "original" (tech support seemed surprised it was still working) and a "late" (for ASL). There might be more models in between.

Best I can say is the "original" is a cream colored with just two push buttons.

The late is gray with a LCD display and buttons arranged in a circle pattern for Up/down and sideways.

I think we still have an original. It was replaced about a year after we went digital with one just like it. I will check Sunday when I am there next.

Do the different models have differences in visible sync?

lajackson wrote:Do the different models have differences in visible sync?

I wouldn't think so, but then I've never explored all the options in them.

SBankhead wrote:This can be done by adding a delay unit. But I'm curious whether the main chapel mixer has the cabapility to do this. It is software based, and I believe it has some DSP capabilities, so maybe it's something that we can do within the current system without investing in new equipment? I'll be sure to ask our audio contractor (General Communications) next time I have a chance.

So the answer depends on what audio system you have in your building, as there are variations. All of the Rane, and BSS London based systems could have an a delay added on the input side of the DSP (in software). Most of the Ivie Units do not have Input delays as possibilities (the newer 1280 and 2400 Units could), but do have output delays, which would not work well, since that would delay the speech from the pulpit during regular meetings. And if your building is based around Mixer amplifiers you would need an altogether separate piece of gear.
As with all DSP gear in the Church you would need to have one of the Church approved contractors/consultants do the work.

RussellHltn wrote:Which one?

Wegener DVR-396
MPEG-2 IRD

Beige. Two buttons on the front panel.

lajackson wrote:.

However, our very old televisions also have the delay, so it appears to be a difference between the audio processing and the video processing at the satellite rack.

And if we route the composite RF signal into a regular television, old or new, and the TV processes both the audio and video, the delay is still noticeable.

If you have a delay on the analog systems, the first thing I would try is to reset the satellite receiver. Occasionally, the internal clock of the satellite receiver gets out of sync between the audio and the video. Rebooting the receiver will cause it to start off fresh.
Also, if your building has multiple receivers in it, make sure that the audio and video are routed from the same receiver. NOTE: Each of the receivers has its own internal clock that it syncs to, so if you have audio from 1 receiver, and video from another the chances that they will ever be in sync is virtually nil.

StevePoulsen wrote:If you have a delay on the analog systems, the first thing I would try is to reset the satellite receiver. . . .

Also, if your building has multiple receivers in it, make sure that the audio and video are routed from the same receiver.

As I mentioned, we need to reboot before almost every broadcast.

We have only one video receiver.

lajackson wrote:Do the different models have differences in visible sync?

No persay, Each and every receiver has its own internal clock, other than that their processing is the same.

lajackson wrote:As I mentioned, we need to reboot before almost every broadcast.

We have only one video receiver.

At this point I would call the help Desk in SLC, they have monitors and can check the feed up and down at the same time you check what in your building.