Go Back    Forum > Digital Video > Video Project Help > Restore, Filter, Improve Quality

Reply
 
LinkBack Thread Tools
  #1  
06-10-2021, 02:21 PM
mbassiouny mbassiouny is offline
Premium Member
 
Join Date: Jul 2020
Posts: 263
Thanked 32 Times in 31 Posts
Hi,

So I was just wondering, is the line tbc in high-end VCRs replaceable by software processing?

I know what it is and if we take the "definition" from http://www.digitalfaq.com/forum/vide...#ixzz6xPlE9kbe

Quote:
clean the visual quality, by:
- removing or reducing chroma noise (the red/blue colored mist found in all VHS tape formats)
- removing geometric distortions from the image, such as the wiggling appearance of older video, as if viewed through a rippling pond or bathtub (aka "horizontal" jitter)
Very often VCR TBCs are merged with embedded noise reduction circuits, which use the power of the TBC to further suppress or remove grain and prevent color bleeding. For example, the DNR/TBC unit found inside the higher end JVC S-VHS and D-VHS professional and prosumer VCRs

- Chroma bleeding and chroma issues can be handled with filters.
- Distortions and jitter are much trickier but still something can be done with filters too
- The noise reduction circuits in a lot of situations seems to cause a loss of details, specially when using violent NR in 2000s technology, what do we still trust these? aren't today's algorithms used in NR filter much more efficient? specially especially with spatio-temporal filtering that avoids applying the filter blindly and harming parts of the vide unnecessarily.

- " remove grain and prevent color bleeding" same here, degrain, edge masking,DeBlot filter, etc to fix these.

So I was wondering why are line TBC+NR still useful or recommended even though it seems like we have better software-side alternative

is there anything I am missing here or that I don't understand properly about line-tbc?
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Ads / Sponsors
 
Join Date: ∞
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
06-10-2021, 02:36 PM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 13,503
Thanked 2,448 Times in 2,080 Posts
No.

The main aspect of line TBC is the wiggle and movement distortion. Software cannot do anything for that. It requires non-visual pre-digitized signal. There's currently some R&D for post-capture line TBC, but understand that's been thecase for 20 years now.

The chroma noise is really more DNR, but baked into almost all line TBCs (mostly those in VCRs).

And line TBC isn't frame TBC.

- Did my advice help you? Then become a Premium Member and support this site.
- For sale in the marketplace: TBCs, workflows, capture cards, VCRs
Reply With Quote
The following users thank lordsmurf for this useful post: mbassiouny (06-10-2021)
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
Fix tape tracking and tearing? chillaustin Restore, Filter, Improve Quality 0 05-28-2021 04:20 PM
Line TBC with Avisynth script? jjdd Restore, Filter, Improve Quality 3 11-14-2019 01:43 AM
Coming Soon: lordsmurf's Avisynth processing guides! lordsmurf General Discussion 41 10-18-2018 04:41 AM
Panasonic AG-1980P Y/C board recap? (replaced capacitors) x77x Video Hardware Repair 14 10-21-2015 04:35 PM
Command line scanning application - helping picking software? Gustovac Computers 3 10-03-2012 12:13 PM

Thread Tools



 
All times are GMT -5. The time now is 12:22 PM