progressive scan and lip-synch / video game delays

richard plumb

Distinguished Member
Hi

Looking in advance at options for linking into an AE100 projector, but I guess this question is relevant for any panel projector.

Does the use of an external scaler/deinterlacer, such as the ProV, add any significant delay to the signal before it is displayed? I'm thinking mainly of DVD lipsynch errors, but also videogame lag, where a couple of frames could be the difference between life and death.

Would using a PC and DScaler be worse in this respect?

Even if I go progressive component with my Gamecube and a philips 962SA, I'll still probably need a deinterlacer/scaler for PS2 and digital TV.
 
J

Jenz

Guest
Richard,

Not sure about the ProV but can give you my setup.

When I use my Arcam DV27 in Progressive Scan mode (PAL and NTSC) I see a slight lipsync issue which is corrected using the DV27's Progressive audio delay setting (obviously as recommended).

When I use my Rock+ and the Interlaced outputs of the DV27 I do not have any lipsync issues.

When I use Xbox, PS2 and Gamecube into my Rock+ I dont have any gaming issues.

When I use Xbox, PS2 and Gamecube into my HTPC and DScaler I dont have any gaming issues.

Hope that helps. Neil.
p.s. None of the Scaler solutions has significantly improved my games playing either... and a 10ft wide Resident Evil has not improved the colour of my pants :eek:
 

museumsteve

Distinguished Member
Richard, I use an Iscan with a Panny and do get some lip sync issues with DVDs and in some cases games problems. Worse game issue I have is with Guitar Freaks, the slightest delay does mean the difference between a Good and Cool..which is annoying. I havenm;t been able to find out how to sort this out via my Denon AVCA1SE..so if anyone has any odeas I'd appreciate it..:)
 
D

davejw

Guest
The lip synch can normally be fixed by adjusting the timing delay on your AV amp. dial in an extra couple of milliseconds on all channels and test until it comes right. I needed extra 5 milliseconds to get rid of the issue or at least where I do not notice it on any dvd or games

Dave
 
D

davejw

Guest
The AVCA1SE has adjustments for speaker distances as standard these can usually be used to correct lip synch. The KA upgrade allows greater flexibility plus the ability to put a audio delay in to correct lipsynch. I have used the speaker distances to correct the issue on my amp.

Dave
 

John Dawson

Active Member
For the record guys the video delay introduced by the I-Scan pro is 3 fields, i.e. in the order of 50 to 60 milliseconds. The Panasonic plasmas, using their internal deinterlacers and scaling engine, have a roughly similar internal delay according to private correspondence I have had with a broadcast engineer who uses them at work.

Now, according to my broadcast colleague, it is much easier to become aware of lip sync issues when the audio leads the video, as is the case here. The view was that an experienced viewer might be upset by as little as 20 milliseconds misalignment if the audio leads the video but would be much more tolerant the other way round.

So we really do need to introduce an audio delay of say 60 milliseconds in such cases, or perhaps even a bit longer to be on the safe side. The 5 to 10 milliseconds available by mucking around with the speaker delay settings on a receiver just can't do this - you need a special and deliberate delay circuit with lots of addressable memory, or you can build it into a progressive player, as we do with the DV27 and progressive DV88s, which use the SiI503. The AVC1SE, as a top of the line product, may well have such a delay circuit built in - I know it is supported on processors by Meridian, TAG and our new Arcam AV8, if you need it.

Hope this helps,

John Dawson (Arcam)
 

Mr.D

Distinguished Member
I use an HTPC running Dscaler to feed consoles to my AE100.
On something like Halo where reaction time is very important I did notice a slight lag (found myself always over correcting slightly). Initially I found it problematic and with Halo especially it actually contributed to giving me motion sickness (and I'm not particularly susceptable). After a bit of conditioning I found I got used to the delay (its about 1-2 frames I reckon) and now I don't even notice it.

Something more 2d and less precise like Balder's Gate was never a problem. Not tried GTA3 yet but I'm sure I'll notice it there a bit too.

lipsync wise running things through Dscaler is fine: if anything I notice a slight delay using Theatertek for dvd (spdif to amp).
 

museumsteve

Distinguished Member
well hopefully lip sync wont be an issue after Thursday bas I should have a shiny upgraded avca1se which of course has an audio delay option..:) very happy indeed..:)
 

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