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-   -   Benefits of using TBC on Panasonic NV-FS200? (https://www.digitalfaq.com/forum/video-capture/7568-benefits-tbc-panasonic.html)

Maris 55 09-28-2016 02:04 PM

Benefits of using TBC on Panasonic NV-FS200?
 
Hello everyone.

I recently purchased Blaupunkt RTV-950 which is a clone of Panasonic NV-FS200. The VCR is in a good condition, little used. I have already done some VHS capturing tests routing the VCR through a Sony miniDV camcoder. Everything works OK ans seems clear to me except one thing- I can't see the advantages of switching on the TBC. I don't see any changes in picture quality, stability neither when watching directly to my TV, or capturing through a Sony miniDV.

I guess there are members here in forum who own this VCR and have captured tens and hundreds of VHS with it. I would kindly ask you to tell me if you always use the TBC on this Pany or not, and what benefits you gain when use. What improvements does it give: improves picture quality or does not affect picture at all, but improves sync stability. Maybe someone can tell more about what type of TBC it is and how it compares to standalone full-field TBC.
I don't need advice on Noise Filter. It has it's own switch and it works fine. I know that the TBC works too because when I try to capture through Canopus ADVC55, it does not like me switching the TBC on- the picture starts to shake horizontally. It does not shake with TBC on when using miniDV or watcung to TV.

Thanks,
Maris

sanlyn 09-28-2016 04:22 PM

Quote:

Originally Posted by Maris 55 (Post 45771)
I recently purchased Blaupunkt RTV-950 which is a clone of Panasonic NV-FS200. The VCR is in a good condition, little used. I have already done some VHS capturing tests routing the VCR through a Sony miniDV camcoder.

Hm , that made me cringe a bit. VHS to DV? PAL or not, most advanced users here and pro restoration shops don't encode VHS to DV. You'll have to re-encode to another lossy stage if you expect to improve or go to a format that isn't PC-only. That will be a quality cost. DV was designed as a shoot and watch format. It was never designed for post-processing or re-encoding to final delivery formats.

Quote:

Originally Posted by Maris 55 (Post 45771)
I would kindly ask you to tell me if you always use the TBC on this Pany or not, and what benefits you gain when use. What improvements does it give: improves picture quality or does not affect picture at all, but improves sync stability. Maybe someone can tell more about what type of TBC it is and how it compares to standalone full-field TBC.

It's true that the built-in line TBC in some players can adversely affect the image or frame sync. Depends, of course, on the player's condition. In that case there are workarounds. Line tbc's work on scanline timing. If you would care to submit a short, unaltered clip of several seconds of movements with your DV capture (Most NLE's that accept DV can make a smart-rendered brief cut without re-encoding DV), I think it would be fairly easy to show how VHS-to-DV affects interlace and edge integrity, creates compression artifacts, and how it cooks colors, or whether the TBC is helping or not. Choose a short clip with motion of some kind that was made with the TBC off.

Quote:

Originally Posted by Maris 55 (Post 45771)
I know that the TBC works too because when I try to capture through Canopus ADVC55......

Another capture device we wouldn't recommend. But they're your videos.

lordsmurf 09-28-2016 06:06 PM

PAL DV is fine.

The capture workflow, or the source tapes, or both, can sometimes hide the effects of the TBC.

S-VHS VCR line TBCs should definitely affect image quality positively. But depending on the source tapes, can be minor. This isn't common. And there's always a chance that you're simply not noticing the changes.

Post some samples.

sanlyn 09-28-2016 06:29 PM

Generally agreed. I think it's probably known that many really don't care for sending VHS through multiple lossy encodes, especially from DV. The more important point, as you alluded to, is that the member is asking for evaluative opinions, both subjective and objective, about video we've never seen.

lordsmurf 09-28-2016 06:32 PM

Quote:

Originally Posted by sanlyn (Post 45774)
I think it's probably known that many really don't care for sending VHS through multiple lossy encodes, especially from DV.

Yep. It's always about workflow (mostly hardware) and source. :cool:

Maris 55 09-29-2016 02:55 AM

Thanks for the replies. I know your thoughts about capturing to DV and then rendering to other lossy format. :)
But what I want to know from expierenced members is for what improvents shall I look in the picture when switching the TBC On and Off on this particular Blaupunkt RTV-950 (Panasonic NV-FS200).
As you told I understand that the improvements for some tapes can be minor and not noticable. But if they are noticable, what tipically they are? What shall I look for? Shall I leave the TBC ON even if I see no difference?
I guess that the Sony mini-DV, through which I capture, has a LTBC as well. Can't they disturb each other?

lordsmurf 09-29-2016 03:07 AM

Most notable will always be removal of visible timing issues ("wiggles"), as well as reduction of removal of chroma noise. And those are the two worst issues you find on VHS, aside from tracking.

Just today, for example, a project needed linear/mono audio, as the HiFi was full of static. That's another advantage of the S-VHS decks. You can select your audio track. Most HiFi tapes have linear tracks in the background. It resolve most timing wiggles, and several reduced the chroma noise. A little software cleanup is needed, and you'll never know the source VHS had issues. Some may not even recognize the source was VHS!

The Sony MiniDV camera may have a line TBC, too, and is what I referred to about workflow.

I'd still like to see off/on sample clips.

Maris 55 09-29-2016 03:19 AM

Quote:

Originally Posted by lordsmurf (Post 45777)
Most notable will always be removal of visible timing issues ("wiggles"), as well as reduction of removal of chroma noise.

Thanks! But then what does the Noise Filter do? I thought it was his job to remove the croma noise. I see the Noise Filter working when switched ON (although slightly), but of coarse I don't have knowledge what exactly it does. But this bothers me less than for what the TBC is in this machine and what you allready answered.
I will try to make some sample takes some day.

sanlyn 09-29-2016 06:48 AM

Yes, I understand the problem and appreciate your concern. The only way to make a judgment, even if you do it yourself, is to have one video sample made without the tbc and filters turned on, and the same video captured with the tbc and filters off. One has to compare between two versions of the same scenes, one can't compare just one scene to itself. The comparisons don't have to be long videos, just a few 8 or 10 seconds, preferably daylight scenes because daylight has a greater range of variables. You can post them directly into the forum using the reply window in Advanced mode and click the lower icon labeled "manage attachments". Please don't mount on sites like YouTube because they re-process everything and damage the results.

The more you watch these kinds of videos the more you see. You might notice little difference offhand but you will notice more problems later. If your tapes are gone by then, it's too late to make better captures.
:)

Maris 55 10-03-2016 01:57 PM

3 Attachment(s)
Hello,
I managed to do the test files. The workflow was:
Blaupunkt RTV-950 S-Video Out > Sony mini DV passthrough> WinDV
And of coarse I got a DV- avi video file. :) I choose an old daylight shooting with a VHS camera at my countryside and made 3 versions changing the settings of Blaupunkt.
Noise Filter On, TBC Off
NF Off, TBC ON
NF Off, TBC Off
Well now I kindly ask you to point me at what differences you can see in these captures. And then I will train my sight to see them as well.

Best,
Maris

sanlyn 10-03-2016 09:47 PM

Thanks very much for taking the trouble to create the samples. Very revealing, IMO.

All samples have DV compression noise, most visible with motion (bristling edges and detail "buzz", often called mosquito noise), which accentuates tape noise. This is a drawback with DV reversal of fields in YV12 color, On all images with the NF on, the noise is lessened but detail suffers. With NF ON detail is lost in the foreground grass and other objects. It's at its softest and looks smeared in "NF ON TBC OFF". There's a visible improvement in the borders and in overall clarity of fine and textural details with the TBC ON. Despite the noise, all samples have the distilled look that comes with this method of VHS capture. All have a broken top border. The top black pixels on the top border extend only halfway across the frame (not a problem -- it's rather common and can be cleanly fixed in post processing, bit it would require a lossy re-encode). "NF OFF TBC ON" is visibly brighter than the others, with some highlights in the sky being washed out.

As this is analog to DV it would take an effort to subdue DV compression noise, but more detail will be lost. What you have is PC-only playback, so there's no way to re-encode to more universally playable formats without further quality problems. You'll have to do some denoising and use fairly high bitrates for your final encodes to maintain clean detail and motion.

Overall luma and chroma levels look OK and color looks about right if not somewhat "scrubbed" (I'm guessing it's the tape more than anything else), although green and blue in RGB display are clipped beyond RGB 255. There's no such animal as a capture that couldn't use more work later. It comes with the territory.
:wink2:

msgohan 10-03-2016 10:59 PM

1 Attachment(s)
Blaupunkt_NF- Off_TBC- Off has incorrect field placement for PAL DV content: field 2 has been shifted up. This is a little-known issue with Sony's analog-to-DV conversion (both MiniDV and Digital8). Sometimes their camcorder conversion will put out correct streams, other times it screws up. This is unrelated to the other settings you switched on & off (or at least it should be). Proper PAL DV should have 1 line of blanking at the top, followed by 1 half-line.

But the AG-1980's TBC actually produces this same field error, too. I wonder whether the NV-FS200 shares the same issue. This would only apply when the TBC is turned on, but your +TBC sample looks okay here. Let's set that aside...

The +TBC sample has higher contrast throughout most of the clip. The level of difference appears to vary based on picture content -- AGC adjustments being made by the VCR's digitizer?

The +TBC sample is shifted 1 pixel to the right.

All have oversharpening halos; the -NF samples have more. Tough to tell how much of the smeary look of the +NF is due to the filter and how much is due to the lower sharpening.

Modified screenshots of one field attached. I adjusted the luma gain of all three and shifted the +TBC sample left. I used one of the fields that was not shifted up.

In terms of actual TBC performance (horizontal jitter reduction) you're not likely to see a difference with a relatively good tape like this when both TBCs are good.

Quote:

Originally Posted by sanlyn (Post 45809)
All have a broken top border. The top black pixels on the top border extend only halfway across the frame

Not an error; just the structure of interlaced video. NTSC hides this due to cropping.

lordsmurf 10-04-2016 12:06 AM

Quote:

Originally Posted by Maris 55 (Post 45800)
I managed to do the test files.

Unfortunately, that scene isn't helpful at illustrating timing errors (or lack of them). The panning shot makes it to where only the timer can be used, and the timer may not be useful if the source tape was good.

Maris 55 10-04-2016 02:43 AM

Thank you everyone for taking time to examine my questions!

Quote:

Originally Posted by sanlyn (Post 45809)
Thanks very much for taking the trouble to create the samples. Very revealing, IMO.

All samples have DV compression noise, most visible with motion (bristling edges and detail "buzz", often called mosquito noise), which accentuates tape noise. This is a drawback with DV reversal of fields in YV12 color, On all images with the NF on, the noise is lessened but detail suffers. With NF ON detail is lost in the foreground grass and other objects. It's at its softest and looks smeared in "NF ON TBC OFF". There's a visible improvement in the borders and in overall clarity of fine and textural details with the TBC ON. Despite the noise, all samples have the distilled look that comes with this method of VHS capture. All have a broken top border. The top black pixels on the top border extend only halfway across the frame (not a problem -- it's rather common and can be cleanly fixed in post processing, bit it would require a lossy re-encode). "NF OFF TBC ON" is visibly brighter than the others, with some highlights in the sky being washed out.
:wink2:

What is the method you use to examine the capture and to get into details you describe? Do you just use a media player like VLC and advance the video in a Pause mode? Does the VLC player or some other player has an option to advance the picture frame by frame in Pause mode? Or maybe you do it in a completely different way? :)
Anyway what settings would you suggest based on my samples- NF- ON / TBC- On for capture? As I understand the TBC of my VCR does a good job, but it indeed increase the Brightness of image.

Best,
Maris

sanlyn 10-04-2016 04:12 AM

Quote:

Originally Posted by Maris 55 (Post 45816)
What is the method you use to examine the capture and to get into details you describe? Do you just use a media player like VLC and advance the video in a Pause mode? Does the VLC player or some other player has an option to advance the picture frame by frame in Pause mode? Or maybe you do it in a completely different way?

I use three media players, as each has its own way of handling various playback issues and each of the three players is a specoific release version and setup: VLC, Media Player Classic, and MPC-BE. This playback method generally reveals more obvious points. The other method was opening one video in each of 3 instances of VirtualDub and observing frame by frame to look for distortion and other factors. Method 3 was to find exact frame matches of several frames in each video and mount each frame as separate layers in Photoshop Pro, then turn the visibility of each layer on and off for comparison.

The latter method led me to the sharpness issue, as one of the sets of frames showed the image while the pan had stopped and before it reversed direction. Layers also revealed the field offsets mentioned by msgohan, who gave more detail and information on that point than I did. I've seen those glitches in many posts over the years from a variety of players, both VCR and webcam, but never kept track of which models did what. Working with borders in Avisynth usually resolves the issues.

Quote:

Originally Posted by Maris 55 (Post 45816)
Anyway what settings would you suggest based on my samples- NF- ON / TBC- On for capture? As I understand the TBC of my VCR does a good job, but it indeed increase the Brightness of image.

I have no idea how to control brightness or contrast levels using any of your components. I've used lossless capture but did make attempts with DV some years back. With bad VHS tapes (and most of my tapes were rather awful), DV capture is a disaster. I agree with msgohan, as in my own experience I see differences in contrast and/or gamma with different tbc's, players, and capture devices. A tbc such as the AVT-8710 or a proc amp or capture card image controls can be used with VirtualDub to adjust levels using a capture histogram and eyeballing to monitor effects. I don't know how one would do that with a Canopus device other than using a metered proc amp such as a SignVideo PA-100 (however, the PA-100 measures brightness/contrast before it enters the capture device. not at the capture point). In this case the contrast issue didn't seem severe and can be corrected later in Avisynth, but another tape might be more problematic.

Maris 55 10-04-2016 05:22 AM

Thanks again!
I am audio recording engineer and it seems to me that video processing is a more complex task. :) You know one can never stop learning in his speciality and so must I continue to stay in touch with advancements in audio recording. This leads me to think that I should rather stay at the present level of hobbyist in video processing. :)

sanlyn 10-04-2016 07:19 AM

Having tried to repair some bad audio myself, of which I don't really know very much, I'd say they're both complicated. Maybe the fact that many hobbyists here are more familiar with video doesn't mean that we weren't all newbies when we first began these efforts. My first captures were disasters. I'll always remember the very first DVD I made, 15 minutes capped with a TV tuner from a TV show. I was so proud of myself at burning my first DVD, took 2 days to accomplish. I inserted the disk into my DVD player and waited. After about 10 seconds the player spit the disc back out again, without a single message on screen, LOL! That little fiasco led me eventually to this forum. It's a learning process, like any other endeavor.

msgohan 10-04-2016 09:40 AM

^ My first TV captures were 320x240 MJPEG. I removed the commercials and then recorded to VHS. Didn't notice how horrible the mosquito noise was, and it would be years before I would learn the concept of "fields". Little did I know that VHS was actually higher-quality than my captures (well, except chroma). The bad old days.

Quote:

Originally Posted by sanlyn (Post 45820)
The other method was opening one video in each of 3 instances of VirtualDub and observing frame by frame to look for distortion and other factors. Method 3 was to find exact frame matches of several frames in each video and mount each frame as separate layers in Photoshop Pro, then turn the visibility of each layer on and off for comparison.

This is where AvsPmod comes in handy. I realize you're not a fan, but its tabbed interface makes comparisons like these much easier. I had 3 scripts open in one window and as I scrubbed along the timeline I could switch between any of them instantly by hitting 1/2/3 on the keyboard at any time. No manually going to frame 25 then frame 40 in each VDub instance; the timeline can be shared in AvsPmod so going to frame 40 brings every version of the video to frame 40. The zoom function only supports Nearest Neighbor AFAIK, but you can just add other resizers into your scripts if smoother zoom is desired.


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