Unofficially Official LD-Decode thread

[Danfun64]

Taken wholesale from the ot.com thread.

https://github.com/happycube/ld-decode

Perhaps I should set up a FAQ?

1. How does it work?

2. Which would look better, a standard X0 analog to digital transfer or ld-decode using a lower end laserdisc player?

3. Which would look better, a standard X0 analog to digital transfer or ld-decode using an X0?

4. I noticed that there is a vhs-decode option in the works. How complete is it?

[lipscgr]

Can you give a quick explanation of what this actually is? I looked at the github site, and rest the read me, but it is all over my head. Do you know of a LD decode for big dummies site that can help? I have searched, but the web seems lacking.

[Danfun64]

Can you give a quick explanation of what this actually is? I looked at the github site, and rest the read me, but it is all over my head. Do you know of a LD decode for big dummies site that can help? I have searched, but the web seems lacking.

Unfortunately, that's one of the reasons I made this thread, I don't fully know myself.

From what I know, using a modified laserdisc player, you connect the rf output directly to a computer and "scan" a laserdisc. You then run the result through ld_decode, and in the process get a high quality image.

[lipscgr]

I do have a degree in electrical engineering. Maybe I could be of help. I just have no knowledge of laser discs, as I have never owned one. I need to get up to speed on how they work a little. It is my understanding that what is encoded on the disc is actually an analog signal. How are they typically "ripped"? Is it as simple as play the Disc and output either S-video or RCA to the input of a high quality video capture card? Is there any external amplifiers or filters that it runs through to help polish the signal?

Help me know what an X0 analog to digital transfer is.

[PDB]

Check the lddb.com forums. I believe the guy who came up with this system has a thread there.

[Danfun64]

This is the truly official thread: http://forum.lddb.com/viewtopic.php?f=32&t=2671

It doesn't explain much about it though. Think I should sign up there and fire my questions at him?

[spoRv]

Happycube is a member here, too... if you need some help, you could send him a PM from here!

[jerryshadoe]

Of course, he'd be a member here too

Andrea, your "baby" is growing. You did an awesome thing by starting this forum and it's great to see all of these people that love preservation/restoration projects come together.

@ Danfun64 - thanx for posting the link to the thread on lddb. I see the guy has already answered the questions that you posted in your OP. I think it would be helpful to re-post his answers here

[lipscgr]

I read the entire thread at lddb. It seems that basically any cheap laser disc is capable of producing a frequency modulated (FM) signal that can be accessible through a RF test pin. He then connects it to a TV tuner card that is capable of analyzing analog signals. The only catch is he is using Python on a Linux system, and has to run each program through a command line.

He decodes the signal, then runs it through a software based TBC filter, and then a Comb filter. From the results of the video I saw, his initial attempts were not that promising, but the latest youtube videos that he published are quite nice.

Basically a top of the line laser disc player has advanced circuitry that is enable to encode, as well as filter in real time. The cheap ones do not seem to do it as efficiently.

I think he can get extremely good results with software filtering from any cheap working laser disc.

[spoRv]

lipscgr, basically you wrote in few words the exact process, well done!
The only think you have missed is the fact the laserdisc player should be modified to get the RF out - it's the only downside of the process to me... I'm not able to do it by myself, and I trust no one when we are talking about modding one of my beloved laserdisc players!