Restoring Old Movies and Videos
By John M. Clement
This is the beginning of an evaluation of how to go about preserving old videotapes. More will be written as the project progresses.
To start off doing this requires good input so if you are restoring old videos invest in the best possible VCR. For VHS this means a super VHS machine with time base correction. The best place to buy one at a modest price is on Ebay. Then use a capture card which accepts svideo input. Converting film to video requires some specialized equipment, so that is better done by a commercial firm which has invested in the necessary hardware.
There are a number of software packages which are available, but they all seem to have some problems. The major popular software is produced by Magix, Adobe, Ulead, and Pinnacle. I have experience with 3 of their products and have found them all to have some problems. It is also possible to assemble a do-it-yourself package of software at a modest cost for fixing problems in old videos. Good advice on doing this is at: http://www.micahworld.com/doramatraders/dvdtools/ . This includes filters to reduce ghosting in videos, something that is not done in many commercial packages.
The first difficulty is in compatability between hardware, software, and standard file formats. Various programs can produce video formats that other programs can not read. I have a Hauppauge WinTV PVR 250 card with software that produces a jpeg compressed file. But Adobe Premier could not read the file, while both Ulead and Magix could. Both Ulead and Magix could burn a DVD on my Pioneer burner, but Adobe Premier claimed it was incompatible. I produced an uncompressed avi file using Ulead. Adobe Premier could read it, but Magix Movie edit pro gave a completely black screen after loading it. As a result Adobe Premier is not a good choice with the Hauppauge card.
I bought, the ATI TV Wonder Elite, but it had a number of problems. First, it had an audio input, but I could not find any way of monitoring or adjusting the level of the sound so I must conclude that it uses nondefeatable ALC, which is not acceptable for quality music reproduction. Then after running for a short time the audio would shut off. Perhaps this is because my processor is too slow, but I can not say for sure. It is also possible that it was a defective returned card as someone had already entered the serial number into the manual, and the CD sleve had a large cut in it. So it was returned. The sales people at ATI claimed the audio was adjustable on the Wonder Elite!
The Hauppage 250 comes with a bundled version of Ulead Movie Factory Suite 3.0. This includes a light version of several other products. This seemed to work very well and was capable of enough correction to restore the color in a 1 hour video of a currently unavailable opera. The sound had a bit of noise, but it was possible to extract the sound track, denoise it in a separate program, and put it back. The original sound track had to be split from the video and then deleted. Unfortunately the removal of the original sound track does not store, so it had to be redone every time the program was started. Then Ulead burned a CD. The video was very good, but I then discovered it had grossly compressed the sound. In quiet parts the low background noise was raised enough to be painfully loud, and there was a burst of distortion whenever the sound became louder. Basically the music which had some dynamic range was reduced to mush. The Hauppage card was the culprit as it apparently uses Automatic Level Control. Since there are no controls on the audio, it was difficult to fix this problem.
Two possible fixes presented themselves. The audio could be recorded separately, but this caused it to get slightly out of sync with the video. By looking at the Hauppauge chat board www.hauppauge.co.uk/board it was possible to find some registry changes that might help*. It was possible to reduce the volume so that the limiter was never used. This did produce a better audio track, but it still had higher noise than desirable. In particular it had some loud hum. But by using a hum filter and some noise reduction the sound was improved to be tolerable. The original video had a nasty 240 Hz buzz that had to also be filtered. Unfortunately there is no way to monitor and change the level as each registry change requires a reboot and there is no audio monitor built into the Hauppauge software.
If you want good sound on your videos, the choices are limited. Most consumer oriented video editing programs have limited audio facilities. Generally it is possible to extract the sound and process it in a separate program. Magix Audio Cleaning lab is my choice for one of the easiest to use economical programs with a large number of usable features. Then it is possible to put it back and suppress the original sound track. The Magix Movie Edit pro 11 does have some capability for adequately suppressing noise. Basically it has a light version of Audio Cleaning Lab included. It does not have any pop and tick suppression, but does have a good noise suppression section that uses a noise print.
Unfortunately it does not have any fine adjustments for the audio level so it is extremely difficult to match two audio clips exactly. I copied a video from two tapes and in the better copy there was a dropout in the sound for several seconds. The second copy did not have the dropout, so I tried to splice the short segment from the second video into the first one. Since the audio could only be adjusted in 3dB increments, it could only be matched by putting all of the sliders on the equalizer about 1.5 dB upward. When the audio clip is displayed as a wave file, it does not change in height as you adjust the volume in the 3dB steps. In addition when 2 audio clips overlap there was a popping noise introduced. This was solved by deleting the unwanted clip (which had no sound). It was also not possible to make a smooth pop free transition between the inserted audio and the main video file. The moral is that the only way to make a good audio splice is to do it externally with an audio only editor, and hope you can get them back in sync. An added complication is that sometimes the audio clip would stop playing, or after saving the project, Movie Edit would give an error message upon reload, and delete the clip. Audio editing that may take a couple of minutes on an audio only editor may take hours on Magix Movie Edit.
For restoring color balance, most of the products have some good features. But the Magix Movie Edit lacks precise adjustment of HLS hue/lightness/saturation. Specifically hue adjustment is only available on an obscure window with a small unlabeled slider. This is a gross oversight because the NTSC system is notorious for shifting the hue. Adjusting the RGB red/green/blue levels is not the same as adjusting the hue, and can not compensate for a phase shift in the color signal. Automatic color control is often unusable in long videos because it can misadjust during motion and create off the wall colors.
So far it is quite evident that the programs are geared more towards creation of new videos than the restoration of older material.
*Registry changes for Hauppauge 250
The keys are in [HKEY_LOCAL_MACHINE\CurrentControlSet\Services\Globespan\Parameters\ivac15\Driver]
Change the HcwAudioScart1Volume. It defaults to 7701 but by changing the 77 to a lower value it is possible to lower the audio. The HcwAudioScart1Prescale can also be lowered and this might also fix the problem. The Hauppauge 150 has keys that allow completely disabling the ACL, but they have not been discovered for the 250.