Quantcast Optimal TBC comb filter setup for Laserdisc, CED, VHD? - digitalFAQ Forum
Go Back    Forum > Digital Video > Video Project Help > Restore, Filter, Improve Quality

Reply
 
LinkBack Thread Tools
  #1  
04-23-2018, 01:41 AM
WestRGB WestRGB is online now
Free Member
 
Join Date: May 2017
Posts: 9
Thanked 1 Time in 1 Post
Hello DigitalFaq! Long time listener, first time caller.

For a long while I've been reading through these forums and quietly planning to do some video archivism of my own. My first projects will be VHS. And there is an abundance of information available on that subject (thank you lordsmurf).

However, I am trying to future-proof myself, because I know that down the road I will want to capture video from Laserdisc, CED, and VHD -- maybe other formats, too. But these formats all have certain things in common: they are all encoded composite video, therefore each of them will need (or benefit from) a TBC and a comb filter. (Please correct me if I'm wrong).

Where a TBC is concerned, I think I will wait patiently for a DataVideo model to make itself available on Ebay at the right price.

However, an ideal comb filter eludes me. In a perfect world, I'd like to have a dedicated external comb filter box that I can plug multiple composite video sources into.

I've read that several folks on these forums use their JVC S-VHS VCR for this purpose. But I've also read that comb filter technology has evolved and improved since then.

I've read that some folks plug composite video directly into their capture card, and use either its onboard comb filter or a software equivalent once brought into post.

What do the folks on this forum recommend for my purposes? Is there a solution with broad consensus?

And am I worrying too much about something that doesn't really matter that much?
Reply With Quote
The following users thank WestRGB for this useful post: lordsmurf (01-28-2020)
Someday, 12:01 PM
admin's Avatar
Ads / Sponsors
 
Join Date: ∞
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
07-08-2020, 07:51 AM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 9,658
Thanked 1,647 Times in 1,429 Posts
I've read several times where certain JVC S-VHS VCRs are used as comb filter for Laserdisc.

Composite isn't terrible, contrary to popular misconception. Quality of composite is highly dependent on the device itself, providing the in/out composite. Some can be blurry, have excess rainbow, chroma delays, etc. But it's the device that does it, not the carrier wires. Composite is lesser than s-video, but it's not a night-and-day sort of difference.

I've seen some interesting results with early production BVTBC10 units, but those will be some of the rarer TBCs to locate. However, mostly rainbow, nothing that isn't easily fixed post-capture with CCD in VirtualDub.

Comb filters haven't really evolved, no.

No capture card ever embedded this feature, though it surely could have. How sad.

Sometimes the best LD output is due to the LD player itself. Several models are known to look better than average.

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
  #3  
07-08-2020, 10:41 PM
lingyi lingyi is offline
Premium Member
 
Join Date: May 2011
Posts: 187
Thanked 66 Times in 52 Posts
For analog disc players, moreso than VCRs, getting a good high quality machine is priority #1. I highly recommend spending the money on a good machine rather a TBC.

For Laserdiscs, any of the Elite series players are highly regarded, as well as the stratospherically priced and HLD-X9 and HLD-X0 which are reportedly able to play troublesome chroma speckled discs far better than anything else.

Don't have any recommendations for VHD and CED, but do know that the players aren't all the same. Especially CED where RCA brought out some low end models to try and keep the format alive.

digitalfaq and videohelp.com are great for the majority of video topics, but there's few on either forum that know or talk about analog discs at all. Visit lddb.com for LD and think some VHD and CED talk and avsforum.com which used to have a LD forum.

Finally, unless there's something ultra rate that's absolutely not available in any form other than VHD or CED, forget about preserving them. To a much greater extent than VHS, like any analog disc (e.g. vinyl records) each play degrades the quality of the pressing. Also, since the caddies of VHD and CEDs aren't airtight, dust, air and humidity has been slowly degrading them over the decades. I remember an image of a dust particle that would drop to the bottom of a vinyl record, spanning across several grooves on a CED!

Edit: Here's a great FAQ about CED. I'm one of the couple of handfuls of members here and at videohelp that talk about Laserdisc, and probably one a handful that owned a couple of CED players. They were truly awful, even at their best. The only reason I got the players and the discs was because they were super cheap at a store I frequented after CED officially died. I know I got the players for ~$50 and I think the discs were $2-5, which was an amazing buy since LDs never went below $20.

I always wanted a VHD player, but never came across one.
Reply With Quote
  #4  
07-08-2020, 10:58 PM
lingyi lingyi is offline
Premium Member
 
Join Date: May 2011
Posts: 187
Thanked 66 Times in 52 Posts
A key thing about analog disc players is that each frame is an individual image on the disc. AFAIK, there's no field blending at least on Laserdisc. So TBC errors should be rare or non-existent. Again, a high quality player or players will give a higher quality image.

If you really want to bypass the composite output of Laserdisc, check out the Domesday86 project which captures the raw RF signal from LD. I thought the project was dead, but it was last updated late 2019. There's even a hardware kit for the decoder. But I don't know which players and discs it works with.

Oh...forgot, it's the comb filter on the better players that's credited for in large part of the higher quality picture. Also, as I recall, the HLD-X9 and HLD-X0 used a different type of laser also.
Reply With Quote
  #5  
07-08-2020, 11:48 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
You may want to consider the BrightEye family from Ensemble Designs, BE25, BE26 or BE75, They are analog capture devices built in professional TBC/Frame sync and comb filter for the composite input, The BE75 is the only one with S-Video (aka Y/C). Those are SDI capture devices you would need a SDI/PCIe interface on your computer.

It depends how you want to capture digital sound on some of the laser titles, so an additional AC3 box and AC-3 audio capture card may be required. If analog audio only those BE boxes have easy made breakouts for analog audio input, USB is just for changing settings and firmware update.

Last edited by latreche34; 07-09-2020 at 12:47 AM.
Reply With Quote
The following users thank latreche34 for this useful post: WestRGB (08-22-2020)
  #6  
08-22-2020, 08:49 PM
WestRGB WestRGB is online now
Free Member
 
Join Date: May 2017
Posts: 9
Thanked 1 Time in 1 Post
Two years later, and I'm still trying to plan an optimal workflow for CED, VHD, and Laserdisc

Quote:
You may want to consider the BrightEye family from Ensemble Designs, BE25, BE26 or BE75, They are analog capture devices built in professional TBC/Frame sync and comb filter for the composite input
This looks very promising for my needs. A couple questions:

1. I am not very familiar with SDI. Am I correct in understanding that SDI is a digital interface? In other words, these devices output a digital signal and not an analogue one -- correct?

2. I do most of my video work in Windows 10 and MacOS Sierra 10.12.6. Does BrightEye software behave well in (at least one of) these environments?

3. What are some recommended hardware/software solutions for transferring SDI video onto a computer?
Reply With Quote
  #7  
08-22-2020, 11:55 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
1- Have a read, The standard you will be using for your capturing job is going to be the SMPTE 259M-C. You don't have to know this if you don't want to.

2- BrightEye has nothing to do with your computer, It just makes sure it delivers a clean SMPTE 259M signal to the SDI/PCIe or SDI/USB3 adapter and the capture software associated with the SDI adapter takes that signal and saves it as a digital file in lossless 4:2:2 8/10bit AVI 720x486 (NTSC) or 720x576 (PAL-SECAM) and 48Khz/24bit PCM audio.

3- Look for Black Magic, Aja and Majwell, Although I haven't had success with the Majwell devices on my Wind 10 machine.

For Dolby digital and DTS titles you will have to get an AC-3 RF converter and a separate multi channel audio capture card/device.
Reply With Quote
The following users thank latreche34 for this useful post: WestRGB (08-25-2020)
  #8  
09-03-2020, 01:47 PM
WestRGB WestRGB is online now
Free Member
 
Join Date: May 2017
Posts: 9
Thanked 1 Time in 1 Post
Quote:
Originally Posted by lordsmurf View Post
I've read several times where certain JVC S-VHS VCRs are used as comb filter for Laserdisc.
Would this kind of setup enable the use of the internal Line TBC of a JVC S-VHS VCR?

I understand that VHD, CED, Laserdisc, and Betamax don't have Line TBCs. Would they all benefit from one? And would passing through a JVC S-VHS VCR accomplish that?
Reply With Quote
  #9  
09-04-2020, 01:17 AM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
No, VCR's apply line TBC on tapes only not on the input, I don't think LaserDiscs need line TBC, they don't have the mechanical problem that is inherit to tape based video systems. They might benefit from a full frame TBC if the laserdisc start to have problems.
Reply With Quote
  #10  
09-08-2020, 05:42 PM
ifb12 ifb12 is offline
Free Member
 
Join Date: May 2020
Posts: 4
Thanked 0 Times in 0 Posts
IMHO, the best comb filter is anything with an ADV78xx chip. There's an ADV7842 development board you can still get. Lumagen Radiance 2144 has the same chip. The Evertz 7837CDM uses the ADV7802. The BrightEye 75 is supposed to be good too, but I can't vouch for it (ADV7403).

I have some NTSC sample stills here, where the source was 1" Type C.

If you have LD that are rare/important, you really should capture the RF directly (Domesday Duplicator) and software decode with ld-decode. This is especially true if you have PAL discs. The PAL transform decoder is really good, and while the NTSC decoder isn't great now,once you've preserved the RF you are futureproof and can always decode the saved RF capture again with the latest software.

Oh, and LD players certainly have a TBC internally. Spinning plastic discs are imperfect just like helical scan magnetic tapes. This is a raw RF capture without TBC:

Reply With Quote
  #11  
09-08-2020, 11:16 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
You seem to be confused between line TBC and full frame TBC. Laser discs record fields as complete chunks so lines are not scanned individually like tape based video formats. There is no head A and head B that introduce line jitter due to imperfect timing between the two heads.
Reply With Quote
  #12  
09-09-2020, 11:10 AM
ifb12 ifb12 is offline
Free Member
 
Join Date: May 2020
Posts: 4
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by latreche34 View Post
You seem to be confused between line TBC and full frame TBC. Laser discs record fields as complete chunks so lines are not scanned individually like tape based video formats. There is no head A and head B that introduce line jitter due to imperfect timing between the two heads.
I am not confused. Instead of head switching you have a giant plastic disc with its own error modes. The rotational speed is not perfectly controlled (wow/flutter). The geometry is not perfect (warping). The laser is not perfect and can have poor tracking, which leads to fields being skipped or repeated. There are dropouts, sometimes pressed from the master. The disc may have degraded (rotted) or been scratched.

I said nothing about a line or full frame TBC. At a minimum, a player would need a line TBC which is obvious by visualizing the raw RF stream (attached this time). FYI, ld-decode implements both in software, and does other crazy things like disc-mapping and stacking.


Attached Images
File Type: jpg Screenshot_from_2020-08-31_21-34-12.jpg (101.7 KB, 3 downloads)
Reply With Quote
  #13  
09-09-2020, 12:34 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
I've never heard a TBC being an issue even in the lowest end stripped down laserdisc models, frame/field buffer is part of the laser disc design, it is not affected by the disc motor speed fluctuation, The problem is always having a good comb filter to go along with the player, PWM signal is close to digital, unless you have a problem with a disc the playback should be stable. Unlike tape based systems, line TBC is a must for a close to original signal recorded on tape even if the tape is freshly recorded, and as a tape starts to age a full frame TBC is a must.
Reply With Quote
  #14  
09-09-2020, 01:06 PM
ifb12 ifb12 is offline
Free Member
 
Join Date: May 2020
Posts: 4
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by latreche34 View Post
I don't think LaserDiscs need line TBC, they don't have the mechanical problem that is inherit to tape based video systems.
Quote:
Originally Posted by latreche34 View Post
frame/field buffer is part of the laser disc design, it is not affected by the disc motor speed fluctuation
I only ever said LD players must have an internal TBC ("frame/field buffer") and gave examples of the various mechanical/physical imperfections they exhibit in reality ("motor speed fluctuation"). VHS has another set of mechanical/physical imperfections. It just so happens that those imperfections don't strictly require an internal TBC for playback.

I haven't recommended or said anything about an external TBC, only my experience with various NTSC comb filters.
Reply With Quote
  #15  
09-09-2020, 04:08 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
Both quotes are correct, Line TBC is not a frame buffer, it's a line buffer.
Reply With Quote
  #16  
09-09-2020, 08:51 PM
ifb12 ifb12 is offline
Free Member
 
Join Date: May 2020
Posts: 4
Thanked 0 Times in 0 Posts
Who claimed otherwise? I'm done. I don't even know what you're arguing.
Reply With Quote
  #17  
09-10-2020, 12:50 AM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
Me neither !
Reply With Quote
  #18  
09-10-2020, 09:24 AM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 9,658
Thanked 1,647 Times in 1,429 Posts
Quote:
Originally Posted by WestRGB View Post
Would this kind of setup enable the use of the internal Line TBC of a JVC S-VHS VCR?
No, no passthrough.

Quote:
Originally Posted by latreche34 View Post
I don't think LaserDiscs need line TBC, they don't have the mechanical problem that is inherit to tape based video systems. They might benefit from a full frame TBC if the laserdisc start to have problems.
That's my understanding as well.

Quote:
Originally Posted by ifb12 View Post
IMHO, the best comb filter is anything with an ADV78xx chip.
I strongly disagree.

The cult following behind that chip is undeserved. Some aspects of it are inferior to non-existent. It's Canopus ADVC all over again. Credit given, where credit is undue.

Quote:
If you have LD that are rare/important, you really should capture the RF directly (Domesday Duplicator) and software decode with ld-decode.
Investigating this would be my suggestion as well. However, I'd suggest first grabbing an immediate capture, using available quality capture cards (and frame TBC as needed).

Quote:
Oh, and LD players certainly have a TBC internally. Spinning plastic discs are imperfect just like helical scan magnetic tapes.
I have never heard that.

Quote:
This is a raw RF capture without TBC:
I want to see that. Please attach to the forum post.

Quote:
Originally Posted by latreche34 View Post
You seem to be confused
Quote:
Originally Posted by ifb12 View Post
I am not confused.
I am.

Quote:
Originally Posted by latreche34 View Post
I've never heard a TBC being an issue even in the lowest end stripped down laserdisc models, frame/field buffer is part of the laser disc design,
Do LD players even have basic frame syncs? Not TBCs, but weak frame syncs like almost all consumer DVD recorders.

Quote:
line TBC is a must for a close to original signal recorded on tape even if the tape is freshly recorded, and as a tape starts to age a full frame TBC is a must.
Correct. Quoted because this can never be stated enough.

Quote:
Originally Posted by ifb12 View Post
I only ever said LD players must have an internal TBC ("frame/field buffer")
A buffer isn't a TBC. Do you have more information on LD players having TBCs? I'm curious if they even have frame syncs, much less TBCs.

Quote:
Originally Posted by ifb12 View Post
I don't even know what you're arguing.
Quote:
Originally Posted by latreche34 View Post
Me neither !

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
  #19  
09-10-2020, 03:43 PM
latreche34 latreche34 is offline
Free Member
 
Join Date: Dec 2015
Posts: 938
Thanked 123 Times in 116 Posts
Quote:
Do LD players even have basic frame syncs? Not TBCs, but weak frame syncs like almost all consumer DVD recorders.
I'd like to believe so but not a full fledged TBC that converts the signal to digital and back to analog, it's more of just timing the PWM data. Some of the latest models do have digital frame store for non CAV discs for the purpose of frame pause and interactive contents.
Reply With Quote
  #20  
09-15-2020, 08:14 PM
WestRGB WestRGB is online now
Free Member
 
Join Date: May 2017
Posts: 9
Thanked 1 Time in 1 Post
Quote:
Originally Posted by ifb12 View Post
I'm done. I don't even know what you're arguing.
Quote:
Originally Posted by latreche34 View Post
Me neither !
Y'all are both providing useful information

Quote:
Originally Posted by lingyi View Post
If you really want to bypass the composite output of Laserdisc, check out the Domesday86 project which captures the raw RF signal from LD.
I've spent a few days reading up on this. It looks really, really cool! Some folks are even adapting it to capture raw RF from VHS tapes. Real neat stuff

Unfortunately for my purposes, however, it is still very much a work in progress. From what I understand, it only supports analogue audio at the moment. And I believe the only way to view the content of the disc is by using their own open source software, LD-Decode, which presently does not have the ability to output to (for example) MPEG-2 or anything. It sounds like that's the next step in the project. It's a great option right now for LD preservation. But until it supports AC-3 and DTS (and until I can encode that content into a digital video file container) I will continue looking to set up a composite capture workflow.

So my goal is to put together a workflow that is capable of incorporating Composite Video with Analogue, AC-3, or DTS audio as the case may be. With those digital audio sources, I understand that getting a bit-accurate capture can be a real PITA. Here is what I've brainstormed for my workflow:

For Video (When capturing with Analogue Audio):
Laserdisc Player --->
Composite out --->
BrightEye75 --->
SDI out --->
Blackmagic DeckLink Mini Recorder --->
PC

For Analogue Audio:
Laserdisc Player --->
RCA Audio Out to 6-pin Phoenix Adapter Cable --->
BrightEye75 --->
SDI out --->
Blackmagic DeckLink Mini Recorder --->
PC

For Video (When capturing with AC-3 or DTS Audio):
Laserdisc Player --->
Composite out --->
BrightEye75 --->
SDI out --->
Blackmagic SDI to HDMI Micro Converter--->
HDMI out --->
Monoprice Blackbird 4K Series HDMI Audio Inserter --->
HDMI out --->
Blackmagic DeckLink Mini Recorder --->
PC

For AC-3 Audio:
Laserdisc Player --->
AC-3 RF out --->
Pioneer RFD-1--->
Optical Audio out --->
Monoprice Blackbird 4K Series HDMI Audio Inserter --->
HDMI out --->
Blackmagic DeckLink Mini Recorder --->
PC

For DTS Audio:
Laserdisc Player --->
Optical Audio out --->
Monoprice Blackbird 4K Series HDMI Audio Inserter --->
HDMI out --->
Blackmagic DeckLink Mini Recorder --->
PC

Now I understand that I will have to test this out myself to really know if it will work the way I want it to. But is anyone on here able to point out any glaring problems with this setup?
Reply With Quote
Reply




Tags
ced, comb filter, tbc, time base corrector, vhd

Similar Threads
Thread Thread Starter Forum Replies Last Post
Is my VHS-to-PC video setup optimal? displays Project Planning, Workflows 6 04-22-2020 12:05 PM
Standard VHS deck + external TBC & comb filter? traal Restore, Filter, Improve Quality 5 07-11-2019 01:48 PM
Extron YCS 100 comb filter ... and TBC?! jbd5010 Restore, Filter, Improve Quality 20 05-28-2018 07:06 PM
TBC recommended for laserdisc capture? comb filters? bilbofett Capture, Record, Transfer 55 04-17-2017 08:47 PM
Optimal resolution for DV and still photo cameras ? yendrek Capture, Record, Transfer 1 03-22-2005 06:26 AM

Thread Tools



 
All times are GMT -5. The time now is 07:28 PM