Forcing component input passthrough with SD on the iScan HD?

[tongshadow]

Recently I have acquired a DVDO iScan HD to upscale and deinterlace my gaming consoles. Needless to say I'm impressed by the performance, it often makes 480i games look like 480p, it gets rid off all the flickering! However there's an issue with interlaced sources, the additional processing adds some input lag (around 2~3F/36~48ms). Upscaling from progressive sources dont add input lag at all, so it's fine for my Xbox games but since most PS2 games are in 480i/240p most of them become kinda uncomfortable to play, while some are unplayable.
My display is a BenQ RL2755HM, it has extremely low display lag (10ms/less than 1F) so it's definitely not the culprit here, since I feel no input lag at all when playing on my Xbox/PS2 using a progressive source. It only has VGA, HDMI and DVI inputs though, so plugging the consoles straight into the TV isnt an option.

However there's a trick to >technically< get rid off that processing time, and that is feeding an HD video source (I use the GSM on my PS2) to the iScan, this will make the iScan passthrough the HD (720p/1080i) signal to the Analog output (D-SUB 15) and straight into the display. This solved the input lag issue for me, and apparently my BenQ can deinterlace rather fast.
The problem is not all PS2 games support GSM, so this trick isnt always viable.

So my question is: Is there any way to force the iScan HD to passthrough 240p/480i/480p signals to get rid off that processing time? Or a way to at least minimize that? Will the VGA/Analog Output produce less lag since the A/D conversion wont technically happen?

Thanks in advance!

[telemetry]

The iScan series is always performing a conversion step. In the accompanying thread Downconversion to 240p with DVDO devices (EDIT: DVDO devices here include the iScan units), Fudoh states that even if you can configure the iScan to output 240p, the chain would still be converting 240p > 480p > 240p, so you can't avoid the lag without a native 480p source.

http://shmups.system11.org/viewtopic.ph ... 5#p1189535

oh, ok, but please consider that the iScan will upconvert your 240p to 480p first and then re-convert them to 240p adding quite a bit of lag.

In your case you'd usually use a Scart RGB to component transcoder instead.

EDIT: bad at quoting

[Fudoh]

The classic solution to your problem is a matrix switch, where you loop the iScan into using an output AND an input of the matrix. This way your signal gets routed PAST and THROUGH the processor and you decide - using a single button press - wether you want to get a processed or unprocessed signal to your display.

[tongshadow]

Thank you guys for the replies! So yea, I saw that 240p thing and for me it isnt quite beneficial just yet.

Fudoh, would the matrix switch add more delay to the chain? And which model should I get? My inputs are all component and my outputs are DVI/HDMI and VGA. And I should use the VGA output for the passthrough right?

[Fudoh]

technically you wouldn't use the passthrough of the iScan for 15khz source signals, but you would bypass the iScan for these. Since the iScan's HD15 output can be routed to an input of the matrix, you would still use the same output from the matrix for both, the unprocessed PS2 signal AND any HD signals possible passing through the iScan.

Do a little drawing to visualize the signal path and your requirements in terms of input/output connections. A matrix wouldn't add any more lag. Good analogue matrix switches are available from Kramer and Extron for very little money.

[Fusion916]

Good analogue matrix switches are available from Kramer and Extron for very little money.

Just want to plug my product here.

http://www.ebay.com/itm/191972124152