Orinoco_Womble

Moth3r said:

Possibly the ideal would be to use a video scaler to convert the composite signal into component outputs (look on ebay, scalers are not as important in the digital age)

From what I can find on the net, the Faroudja 'video scalers' and video processors all seem to upsize the image and change it in some way and usually to a higher resolution.  The best I could find convert to 720P output as a minimum which I guess is not ideal considering LD is interlaced.  I thought the idea was to do the scaling and deinterlacing in s/w as this can have better results than scaling in real time.  The only devices that I could find that did not seem to scale the image were the two combfilter/chroma decoder devices that you mentioned in the X0 forum.

Has anybody used or owned any of these devices and can comment on all of this stuff please?

ahh, ok.  Thanks for the info Moth3r.  Presumably, those units would also include a better combfilter than what's inside the LD player.

Is this what the X0 team used for their captures?

vbangle  :p

LOL nicely done vbangle.  Point taken :)

Just been reading through the older posts again and came across this post from Laserman:

Laserman said:

Thanks for the PM Moth3r.
By that I meant the best way to fix the problem is to do it electronically rather than trying to filter it later.
Basically the problem with Laserdisc is that even the best players crap out at around 5 to 5.5MHz. This leaves laserdisc with a relatively slow rise time (the time taken for a signal on the video path to change from one colour to another) and can cause the 'ringing' or halos as well as awful transitions between colours.
To solve the problem somewhat you can map the Chroma signal to the Luma signal. The Luma signal is relatively quick, around 150nanoseconds, whereas the chroma signal lags with a rise time of around 800nanoseconds. By devising a circuit to lock the chroma signal rise time to the Luma's faster rise time the effect can be pretty much eliminated, resulting in a DVD like picture from laserdisc.

If you have a laserdisc with a set of colourbars on it you can see the problem between the Magenta and Green vertical bars quite clearly.
If you were smarter than me you could then work out a way to lower the rise time of the Luma signal with some sort of rise time acceleration and nail the halos forever.

Now, this sounds really interesting.  Can anyone shed any further light on this whole 'remapping' business and how it might be achieved please?

bkev said:

Perhaps my question was unneeded.  I was worried about a valued member of the community, is all.  You definitely have a point about it not being my business, Zombie; I just wished we knew more.  

 

Personally, I think it's a very valid question and there's nothing wrong with having concern for a mate.  Good on ya bKev.

Could someone on the X0 team please let us know if Laserman is ok?

g-force said:

That was Moth3r's quote, not mine! A mocomped-denoiser is one that motion compensates objects in previous and next frames to their positions in the current frame and does some sort of filtering (median, average, fft etc.) on those frames.

-G

 Oops, aploogies dude.  I got yours and Moth3r's quotes mixed up.  Thanks for answering the question though.

This place just gets more and more interesting every day :)

I've had a look and checked the D925 service manual to confirm what you are saying and from what I can tell it looks like Moth3r is correct (as usual).  According to the block diagram in the manual, the video for the Scart connector comes from exactly the same point in the circuit as the standard composite plug.  The composite video is then fed back from SCH4 to SCH3 and eventually back to the Audio board (SCH2).  This is probably to keep the wiring to the scart connector all neat and tidy inside the player.  It's most likely that you're looking at the audio board, which has all of the scart connections on it for Audio/video etc.  There is no additional processing done to the composite signal from when it leaves the point at the Composite plug, all the way across the 3 circuit boards listed and out through the SCART connector.  The composite output is exactly the same as that on the SCART connector.

Hope this helps.

Moth3r said:

Interesting. Did you use a TBC? Uncorrected VHS sources contain a fair bit of jitter or wobble from one capture to the next. Multi-capture averaging on this kind of source probably would end up blurring edges. Fortunately, laserdisc sources are much more stable.

Yeah, my video player has a built in TBC, which I think is only a line based unit and not a full frame jobbie as I'd like.
The tape I was trying to preserve is pretty fecked and the capture device was my DVD recorder, so probably not the best setup for testing the averaging method.  I found I got better results from capturing once and running a noise filter over the MPG2.  A better VRC/TBC/Capture setup and using a better CODEC would probably get better results than what I was geting.

g-force said:

something like this:

interleave(source1,source2,source3)
temporalsoften(1,255,255)
selectevery(3,1)

Yep, this was the script that I used.  Didn't know about the 25,2 bit though, will have to give that a try once I get a better capture device.

g-force said:

Also, there may be some benefit to throwing a mocomped-denoised source into the mix as well.

Sorry, didn't understand that bit at all. Umm, whats a mocomped-denoiser?

WXM: thanks for posting that 'before and after' pic.  Wow, that's imporessive stuff!  You not only removed noise but it looks like the colours are more vibrant and stable and even and the contrast is much better.  I am definitely going to have to play around with this a bit more.

Studio Laserdisc Recorder SONY LVR-4000P - Ebay Germany

Thought someone might be interested in such an unusual piece of kit.
No idea where you’d get the blank discs though 😕