This is a description of what I have learned about how to get the best possible quality video from VHS tapes. If such a thing doesn't interest you, by all means skip this lengthy post!
Here goes.
1. Use the best VCR you can find.
2. Make sure you turn on the Edit switch (sometimes called "tape dub"). This defeats the "edge sharpening" circuit which makes some people think the picture looks sharper, but actually loses detail. Also, use the S-Video output.
3. Some people recommend using a Time Base Corrector between the VCR and your capture device. My understanding of what a TBC does is that it regenerates the sync signal which is extremely important if you are going to record the signal on another analog tape. I am less certain, however, of its importance if you immediately digitize the signal.
4. Capture your video. I use the pass-throuh on my camcorder. I find this works far better than my ATI Radeon 8500 DV capture card.
Now comes the fun.
5. For truly amazing results, repeat step 4. That's right, capture the video a second time. You then take this video and line it up on the Vegas timeline directly above (or below) your original capture. Line the two up so they are frame accurate. To do this alignment, set the opacity of the top video track to exactly 50%, and then move the event on one track left or right one frame at a time until you have perfect alignment. Use only the audio from one of the two tracks. Check along the entire timeline to make sure that the video hasn't gotten out of sync. If it has, split the video that isn't synced to the audio and re-sync the two video tracks (you should have to do this more than once or twice, even for a long capture).
You may find that your second capture is off by half a frame. This is due to the fact that the capture card just sees fields coming in and then combines them into frames. You therefore have a 50/50 chance of this happening. If it does, use this AVISynth script to fix either of the two captures:
AviSource("e:\my video\VHS.avi")
SeparateFields
Trim(1,0)
Weave
Once you have fixed the capture, put it on the Vegas timeline and proceed as described above.
[The following was added to the original post: Before rendering, set opacity back to 100%, set each track level to 50%, and set composite mode for both tracks to "Add." This will create an average of both tracks. If you need to average three tracks, set each track level to 33%.]
Render the results of the merging of these two captures back to another file.
6. You now have either a single capture, or if you are a qaulity freak and have nothing better to do with your life, and followed the procedure in step number 5, you now have an already vastly improved version of your tape. However, regardless of whether you did step 5 or not, you can improve things even further. Use the following three filters in VirtualDub, in this order, to "scrub" the video:
Video DeNoise 1.2 (6.4.8)
Chroma Noise Reduction (1.1)
NRS (TS 6-10-100)
Use the defaults for the first two. For NRS, enable only the Temporal Smoother, and set the Luminance Thresholds to 6 and 10. Leave everything else unchecked and in their default positions.
This filtering is very subtle, but will get rid of most flicker, most chroma fringing (including halos from bad edits on old non-flying erase head machines), and introduce almost no visible artifacting. If you want to be more aggressive, you can up the thresholds to 8 and 12, or even a little higher. However, while you may at first like the results (because these settings reduce the noise more), you will start to notice artifacts. Once you notice them, you will hate them, and wish you hadn't set the thresholds so high.
After VirtualDub has finished creating the cleaned video, bring this new video into Vegas and edit, edit, edit.
BTW, none of these VirtualDub plugins can be loaded from within Vegas using PluginPac because they are temporal in nature, and PluginPac doesn't handle temporal plugins (ones that operate on more than one frame at a time).
Hope this helps someone! I've been working on this off and on for months, and I just spent a complete day today testing all the various plugins and searching every video forum I could find. The only things that might improve on these results would be:
1. Do more than two captures. Some people have done as many as five (the noise reduction improves in a logarithmic fashion, so you get progressively less improvement with each subsequent capture). I have not explored this because it seemed too time consuming.
2. Use AVISynth noise reduction filters. There are apparently many more noise reduction filters available for AVISynth, but it is difficult to interactively test these, so I stayed away from them. (Actually, I did test them, and Peachsmoother and Dust are the two you might want to try).
3. Try the temporal cleaner in SpotRemover. Turn off the spot removing function (designed to remove transitory dust specks from film) and just us the cleaner. It is miraculous on some scenes, but introduces bad artifacts on others. I wanted somthing that worked really well on pretty much any VHS video.
Here goes.
1. Use the best VCR you can find.
2. Make sure you turn on the Edit switch (sometimes called "tape dub"). This defeats the "edge sharpening" circuit which makes some people think the picture looks sharper, but actually loses detail. Also, use the S-Video output.
3. Some people recommend using a Time Base Corrector between the VCR and your capture device. My understanding of what a TBC does is that it regenerates the sync signal which is extremely important if you are going to record the signal on another analog tape. I am less certain, however, of its importance if you immediately digitize the signal.
4. Capture your video. I use the pass-throuh on my camcorder. I find this works far better than my ATI Radeon 8500 DV capture card.
Now comes the fun.
5. For truly amazing results, repeat step 4. That's right, capture the video a second time. You then take this video and line it up on the Vegas timeline directly above (or below) your original capture. Line the two up so they are frame accurate. To do this alignment, set the opacity of the top video track to exactly 50%, and then move the event on one track left or right one frame at a time until you have perfect alignment. Use only the audio from one of the two tracks. Check along the entire timeline to make sure that the video hasn't gotten out of sync. If it has, split the video that isn't synced to the audio and re-sync the two video tracks (you should have to do this more than once or twice, even for a long capture).
You may find that your second capture is off by half a frame. This is due to the fact that the capture card just sees fields coming in and then combines them into frames. You therefore have a 50/50 chance of this happening. If it does, use this AVISynth script to fix either of the two captures:
AviSource("e:\my video\VHS.avi")
SeparateFields
Trim(1,0)
Weave
Once you have fixed the capture, put it on the Vegas timeline and proceed as described above.
[The following was added to the original post: Before rendering, set opacity back to 100%, set each track level to 50%, and set composite mode for both tracks to "Add." This will create an average of both tracks. If you need to average three tracks, set each track level to 33%.]
Render the results of the merging of these two captures back to another file.
6. You now have either a single capture, or if you are a qaulity freak and have nothing better to do with your life, and followed the procedure in step number 5, you now have an already vastly improved version of your tape. However, regardless of whether you did step 5 or not, you can improve things even further. Use the following three filters in VirtualDub, in this order, to "scrub" the video:
Video DeNoise 1.2 (6.4.8)
Chroma Noise Reduction (1.1)
NRS (TS 6-10-100)
Use the defaults for the first two. For NRS, enable only the Temporal Smoother, and set the Luminance Thresholds to 6 and 10. Leave everything else unchecked and in their default positions.
This filtering is very subtle, but will get rid of most flicker, most chroma fringing (including halos from bad edits on old non-flying erase head machines), and introduce almost no visible artifacting. If you want to be more aggressive, you can up the thresholds to 8 and 12, or even a little higher. However, while you may at first like the results (because these settings reduce the noise more), you will start to notice artifacts. Once you notice them, you will hate them, and wish you hadn't set the thresholds so high.
After VirtualDub has finished creating the cleaned video, bring this new video into Vegas and edit, edit, edit.
BTW, none of these VirtualDub plugins can be loaded from within Vegas using PluginPac because they are temporal in nature, and PluginPac doesn't handle temporal plugins (ones that operate on more than one frame at a time).
Hope this helps someone! I've been working on this off and on for months, and I just spent a complete day today testing all the various plugins and searching every video forum I could find. The only things that might improve on these results would be:
1. Do more than two captures. Some people have done as many as five (the noise reduction improves in a logarithmic fashion, so you get progressively less improvement with each subsequent capture). I have not explored this because it seemed too time consuming.
2. Use AVISynth noise reduction filters. There are apparently many more noise reduction filters available for AVISynth, but it is difficult to interactively test these, so I stayed away from them. (Actually, I did test them, and Peachsmoother and Dust are the two you might want to try).
3. Try the temporal cleaner in SpotRemover. Turn off the spot removing function (designed to remove transitory dust specks from film) and just us the cleaner. It is miraculous on some scenes, but introduces bad artifacts on others. I wanted somthing that worked really well on pretty much any VHS video.