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| rjisinspired |
| Posted: Feb 24 2012, 07:32 PM |
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I haven't had this crop up on me before. I captured an old tape for a friend and he played the DVD I gave him and he told me that something was "off". From what he described to me and after looking into it the problem seems to be that of overscan.
He has an old as dirt Zenith TV along with another TV that is about 45 years old. I'm still waiting on him to give me the model number of his set so I can see if there are any notes for correcting for this overscan.
Do you add black borders all around the image to correct for this? At first I had thought that maybe it was because I used cropping in avisynth because the 4 sides of the video had black borders, not the same size though. For example on one of the tapes I use the following for cropping: Crop(6, 2, -14, -4) and then I used a resize to go back to 720X480. Each tape has different sized borders but the example for cropping that I had shown is probably the worst so far, for the right border. Rest of the tapes seem to show 6-8 pixel of black for the right border. |
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| IanB |
| Posted: Feb 24 2012, 08:49 PM |
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You should not have resized the image. At most you could have just re-blacked the border (Crop+AddBorders with same numbers).
Analogue TV's have significant overscan, so your friend has always been missing a fair amount of edge. You have now increased the amount of edge they are missing and they have noticed.
You could possibly increase the amount of border to suit your friends TV, but when they finally get a modern TV they will see the borders and complain again.
If you leave the image the original size with the original borders (possibly reblacked), you can always just say that is how the original was, and demonstrate such. |
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| rjisinspired |
| Posted: Feb 24 2012, 11:00 PM |
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Looks like I'm going to try to add the borders, when I find out what the percentage amount is that it is off by but then again the borders were not consistent in size on all sides so...... I actually have no idea how to go about this now.
Doing the above I will need to re-encode an all ready created Xvid, degrading quality further. I could use the original captured mpegs but the black frame corrections I did aren't showing up as correcting the black frames I had typed for yet the times match up for both the mpeg2 and Xvid version files.
One of the videos I was up all night and well into late morning just searching through avidemux's BF correction file and manually inputting frame tweaker values into a script file. I really don't want to do this again. If there was an auto way to correct black frames I would rethink of working on the existing mpegs or recapturing them.
Update: my friend doesn't know of the correction, just that the image is zoomed in, doesn't help me. Looks like I screwed up these projects royally.
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| rjisinspired |
| Posted: Feb 24 2012, 11:56 PM |
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If anyone would know why a black frames script will not work on mpeg2 files or through avisynth but they work on Xvids let me know. Both format versions are frame exact and yet the script won't work on the mpeg2 captures or with the mpeg2 through avisynth. Makes absolutely no sense to me.
I would like to rework these files since I am able to comment out the crop and resize lines in avisynth. |
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| rjisinspired |
| Posted: Feb 25 2012, 10:15 AM |
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An old post but this took care of the black frames problem. Frame tweaker in avisynth:
Neuron2:
http://forum.doom9.org/archive/index.php/t-52880.html
Now only if I could use MPEGSource for the d2v version of the file I wouldn't have to doubly process the same video, would be able to do the processing with the black frames corrections in one shot but errors are thrown when using MPEGSource in that function code. Getting closer though.
I had the d2v file through avisynth to Vdub but did the trimming in Vdub. I have the VCF2AVS app to get the trims information to use in avisynth. Just need to get the MPEGSource part working. |
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| malky |
| Posted: Feb 26 2012, 01:45 AM |
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Something similar to what you did, only instead of recoding, a forced subtitle (really a frame) is displayed on the video.
http://forum.videohelp.com/threads/343940-...out-Re-encoding |
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| rjisinspired |
| Posted: Feb 26 2012, 04:10 PM |
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Thanks Malky
I'll look into giving that a go.
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