#21  
01-18-2022, 11:47 AM
RobustReviews RobustReviews is offline
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Quote:
Originally Posted by dpalomaki View Post
Does the sound play OK through the bad video segment, or is it garbled?

The following is pure speculation:

The youtube upload reminds me a bit of fast forward scanning a tape where in the video is not blanked. A lossless capture upload of a few seconds only on either side of the transitions from good to bad and bad to good may allow us to see if there are remnants of sync pulses hidden in it.

The video has a somewhat steady repeat of about 18 bands every frame. Allowing for vertical retrace and over scan this implies an issue with a frequency of perhaps 540 to 600 per second. That is about 10x the frame rate, and might correlate with the REW/FF speed of a typical full size VHS camcorder, as if the capstan did not grip the tape during this shoot and it went over the heads at fast forward speed. However, if that is the case I would expect linear track audio to be garbled. (As a reference, the Panasonic AG-455 S-VHS camcorder has a rated FF/REW speed spec of 12 minutes for a T120 cassette, or about 10x.)
That's some proper thought process there bud!

I do need to finish my VHS-Decode guide on here, I've got it working relatively well in the end (without special hardware) and will hopefully get a few more people dipping their toes into the project.
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  #22  
01-18-2022, 11:50 AM
Denicio Denicio is offline
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Quote:
Originally Posted by dpalomaki View Post
Does the sound play OK through the bad video segment, or is it garbled?

The following is pure speculation:

The youtube upload reminds me a bit of fast forward scanning a tape where in the video is not blanked. A lossless capture upload of a few seconds only on either side of the transitions from good to bad and bad to good may allow us to see if there are remnants of sync pulses hidden in it.

The video has a somewhat steady repeat of about 18 bands every frame. Allowing for vertical retrace and over scan this implies an issue with a frequency of perhaps 540 to 600 per second. That is about 10x the frame rate, and might correlate with the REW/FF speed of a typical full size VHS camcorder, as if the capstan did not grip the tape during this shoot and it went over the heads at fast forward speed. However, if that is the case I would expect linear track audio to be garbled. (As a reference, the Panasonic AG-455 S-VHS camcorder has a rated FF/REW speed spec of 12 minutes for a T120 cassette, or about 10x.)

And there is the twist. The audio plays fine & normal.

I will post more of this tomorrow to let you guys see and hear what is happening.
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  #23  
01-18-2022, 01:05 PM
timtape timtape is offline
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Originally Posted by Denicio View Post
And there is the twist. The audio plays fine & normal...
. Exactly.
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  #24  
01-19-2022, 08:23 AM
Denicio Denicio is offline
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Originally Posted by timtape View Post
. That would be fine. The effect on the poor footage is not subtle so a little more or less compression shouldn't be an issue. Just the transition from good to bad and if there, from bad back to good again , to give some context and maybe hints as to what went wrong.
Here is a much longer video of what i am trying to save. What i do find strange is that the jacked up video is also in what appears to be black and white, which seems odd.

I will be curious to see what you and others think is going on AND if it can be salvaged in any way.

https://youtu.be/X1HGyW3KnDY
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  #25  
01-19-2022, 09:46 AM
timtape timtape is offline
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Thanks for the longer clip. Apologies if already asked but are you sure the wanted section is an NTSC recording? The Sony manual of your player says it only plays NTSC. May be worth playing the tape on a deck which can play multiple TV systems?
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  #26  
01-19-2022, 09:56 AM
Denicio Denicio is offline
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Originally Posted by timtape View Post
Thanks for the longer clip. Apologies if already asked but are you sure the wanted section is an NTSC recording? The Sony manual of your player says it only plays NTSC. May be worth playing the tape on a deck which can play multiple TV systems?

Yes its NTSC. I 'know' this side of the family and there is no way they would have had a PAL system.

Also, the short clip before and the scrambled clip were both recorded with the same camera.

I personally dont own a VCR that can play multiple formats. No idea how to find one. There is a local place that does bulk transfers of VHS tapes as a business. I suppose i could reach out to them to see if they have a PAL system.
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  #27  
01-19-2022, 10:19 AM
timtape timtape is offline
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OK it seemed a long shot but I thought it was worth checking.
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  #28  
01-20-2022, 07:28 AM
timtape timtape is offline
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A couple of other observations about the extended clip.

1. The band of noise at the bottom of the screen may be due to a playback mistracking of the signal on the tape. (Exit guide?) If so that at least might be rectified with a guide custom adjustment.

2. In the later video the on screen tracking indicator locks onto a different position than to the good earlier shot.

Perhaps 1 and 2 are related. Interested to see what others might have to say about this.
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  #29  
01-20-2022, 08:31 AM
Denicio Denicio is offline
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Quote:
Originally Posted by timtape View Post
A couple of other observations about the extended clip.

1. The band of noise at the bottom of the screen may be due to a playback mistracking of the signal on the tape. (Exit guide?) If so that at least might be rectified with a guide custom adjustment.

2. In the later video the on screen tracking indicator locks onto a different position than to the good earlier shot.

Perhaps 1 and 2 are related. Interested to see what others might have to say about this.
At this point i dont know what to do. I am hoping someone here has a magical answer.
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