#1  
02-18-2023, 09:29 PM
cwig cwig is offline
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I’m trying to debug an issue with my premium workflow I got at the end of December. The workflow is JVC SR-VS30 - TBC-1000 - ATI 600 - vdub 1.9 on Windows 7 (TBC/VCR connected to a UPS).

For context, I captured ~30 tapes and they largely turned out great except for a few inserted frames on some videos. After some debugging, I figured out that for whatever reason when using the overlay display mode on my machine, this occasionally caused some small blips in the video/audio sync, and then very rarely the sync blip was bad enough to cause some inserted frames with the slow motion voice issue. When I started capturing without any preview, the sync was rock solid, so I started to recapture the videos that had inserted frames.

Now onto the actual issue. While recapturing, at some point I started having issues where the videos seemed darker. See “sample_1st_capture.png” vs “sample_2nd_capture.png”. The first image is from my first round of captures and then the second is a week later when I was recapturing some of the tapes. I don’t believe I had adjusted any of the brightness/contrast settings after I dialed it on my first couple tapes. At this point, I wasn’t documenting everything super carefully so I could be wrong and I only ever slightly tweaked the settings from the defaults. These were captured about one week apart back in January, but I didn’t notice these differences until I started some of the post-processing of the videos this week.

While recapturing some of the tapes, I had a related issue pop up on a few captures. I actually didn’t notice right away because I was capturing without the preview. Most of the capture is very dark, but occasionally it would brighten up. See the attached videos “video_goes_dark_to_light.mp4” and “video_goes_light_to_dark.mp4”. When it is lighter, that is pretty close to the original capture. After noticing this was happening, I shut everything down and when I brought everything back, the workflow seemed to then be working fine (although still experiencing the slight darkening from the previous paragraph which I hadn’t noticed at this point). This issue happened a couple times and I didn’t think to debug it and just restarted everything again. These issues were occurring about a week after completing my first round of good captures.

After finishing my captures at the end of January, I didn’t have a chance to start post-processing them until this week when I started to notice the brightness differences between the earlier and later captures. I thought this might be tied to the random dark issues I had randomly experienced, so today I started debugging the issue. I tried capturing the “JVC blue screen” with and without the TBC, testing a few s-video cables, etc. It seemed that when I bypassed the TBC, it consistently worked better. First I recorded a capture with the TBC, in “with_tbc_1.mp4” you can see it change the darkness throughout (easier to see if you scrub through the video). Then after letting it sit for a while, it went really dark (see “with_tbc_2.mp4”) which is similar to the other samples I provided. Finally, when I plugged the VCR directly into the capture card, it looked better and a lot like some of the earlier captures I had taken (“without_tbc.mp4”). I shut everything down and let it sit for about 30 minutes. Then the TBC was only slightly darker than just the VCR and looked reasonable (with_tbc_after_restart.mp4).

Most of this is not easily reproducible on demand, so forgive the somewhat incomplete experimentation. Based on what I've tested, it appears to be related to the TBC. I believe I’ve taken pretty good care of the equipment and I shut it down when not in use. I can upload the larger lossless videos if needed, but I think the mp4s demonstrate the idea.

Any help on this would be greatly appreciated.


Attached Images
File Type: png sample_1st_capture.png (528.4 KB, 8 downloads)
File Type: png sample_2nd_capture.png (469.4 KB, 7 downloads)
Attached Files
File Type: mp4 video_goes_dark_to_light.mp4 (563.8 KB, 4 downloads)
File Type: mp4 video_goes_light_to_dark.mp4 (963.1 KB, 4 downloads)
File Type: mp4 with_tbc_1.mp4 (2.53 MB, 3 downloads)
File Type: mp4 with_tbc_2.mp4 (192.1 KB, 1 downloads)
File Type: mp4 with_tbc_after_restart.mp4 (132.3 KB, 3 downloads)
File Type: mp4 without_tbc.mp4 (16.6 KB, 1 downloads)
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  #2  
02-19-2023, 12:21 AM
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lordsmurf lordsmurf is online now
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This could still be related to preview/overlay, this is a common failing as well. But given that I know the TBC-1000 was flawless, that may be more likely...

Open the TBC-1000, check internal cable connections from front panel to board. Jostle in shipment can sometimes loosen these, and this is a common fail point. Sometimes transit damage can affect the cables, even with proper seating. In that case, sometimes it's a simple matter of letting the cables have more room, not pushed down by the lid. DataVideo TBC-1000 design wasn't the best, though no TBC really was.

Also, s-video cables are a common fail point, especially connections at both ends.

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  #3  
02-19-2023, 02:34 AM
latreche34 latreche34 is offline
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Is it that capture card that has the darkening symptom, Not sure what model but I read about something like this before.

https://www.youtube.com/@Capturing-Memories/videos
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  #4  
02-19-2023, 10:44 AM
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Quote:
Originally Posted by latreche34 View Post
Is it that capture card that has the darkening symptom, Not sure what model but I read about something like this before.
Not the ATI 600 USB.
550, 600 PCI, 650, yes = Theatre 500
600 USB, no = TI

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  #5  
02-20-2023, 08:56 AM
cwig cwig is offline
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Thanks for the help. I opened it up and made sure the cable connections were secured in place. It was hard to tell if they were actually loose, but at the moment things are looking pretty good so that might have been the issue. The issue didn't always consistently happen, so if it crops up again, I'll try some new s-video cables or reach out again.
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  #6  
04-07-2023, 06:00 PM
cwig cwig is offline
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As a follow up for anyone who comes across this in the future. After adjusting the input connector and leaving the TBC open, I got more consistently good results, but still had the occasional darkening. Just like a random minute or two in the middle of a capture. Lightly touching or tapping on the internal input cable during capture would cause a lot of noise. After some additional reading about related topics I ultimately came across this link:

https://www.digitalfaq.com/forum/vid...8710-vs-2.html

I made myself a similar cable. No soldering required, just cut an s-video cable and crimped on the pins. I was able to bypass the front input board and internal input cable. See the attached images. I’ve had no issues since the upgrade and lightly touching or tapping the cable has basically no impact on the output. This all leads me to believe that there must be a solder joint or something else starting to fail on the input board or the internal input cable. I haven’t really investigated any further as this solution is working well.


Attached Images
File Type: jpg cable_ends.jpg (144.4 KB, 7 downloads)
File Type: jpg cable_in_tbc.jpg (164.2 KB, 8 downloads)
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  #7  
04-07-2023, 10:44 PM
latreche34 latreche34 is offline
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Good thing you bypassed the dist. amp. since it is not needed for capturing, You can even bypass the small power board if you have the right input amps at the front by just plugging the red/black power cable from the front directly into the TBC board as shown in the picture from the linked thread above, Though I'm not sure if the regulator needs to be moved to the TBC board if the wires are connected to the same power input on the TBC board shown as a beige connector next to the large chip.



Attached Images
File Type: jpg differentversion-1.jpg (91.1 KB, 11 downloads)

https://www.youtube.com/@Capturing-Memories/videos
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