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manolito · 21st July 2018, 02:13

I don't know about foxyshadis advice to use videoFred's script for this task. We are in the Newbies thread after all. And the main purpose of this elaborate script is 8mm film conversion which has far more and very different requirements compared to VHS capturing.

Being a person who has converted most of his old VHS cassettes many years ago (and anyone like johnmeyer who is an expert on such conversions knows this) I can only emphasize that this is a major undertaking for someone who never did this before. It takes a lot of experimenting, trial and error, and the end result often is not worth all the energy.

For someone who will only do such conversions once or twice, I would definitely recommend to use a professional service with good credentials for such a task. Only if you plan to do this regularly you should consider getting your feet wet on this.

I think it is a myth that anyone can get "almost DVD" quality from VHS. Just look at the specs. VHS decks have a typical horizontal resolution of about 240 lines. No way to invent details which are simply not present in the source.

And you have to understand that there is a conversion between the analog and digital domain involved here. No way to avoid a certain quality loss. It might not be too obvious if the conversion is done intelligently, but it will still be there.

lansing already gave some good advice. First of all the playback VHS deck needs to be of high quality, clean and with good alignment. S-VHS is desirable (if the capture device supports it), a premium JVC deck with built-in TBC is a bonus. But if the VHS deck you already own plays the tapes with good visual quality you may get away with it.

Next thing is the capture hardware. You won't find dedicated capture cards these days, everything you can buy now are USB capture boxes. You need to decide how many bucks you want to spend. The better devices can also digitize audio (the cheaper ones will use the soundcard for this which will introduce sync problems). Some even have built-in hardware video encoders so you can encode to a compressed video format like MPEG2 or AVC on the fly while capturing. Not really necessary...

Now the challenge is to capture the clip to your HDD without dropped frames and without audio sync problems. VirtualDub is by far the best capturing software IMO. Capture video using a lossless codec like Huffyuv, use uncompressed PCM for audio. At this capturing stage you should not be concerned about "beautifying" the clip, just capture it as it is and make sure you don't introduce any artifacts.

Advanced: If you are picky about capturing with the correct aspect ratio (circles need to be really round and not elliptical) you need to check this now. The hardware A/D converter in your capture device (mostly a Philips chip these days) has a so-called "capture window". Just setting the capture size to 720 x 480 or 720 x 576 will usually result in a slight aspect ratio error. A lot of people just live with it though...

The resulting captured file will be in an AVI container. It should have 4:2:2 color subsampling (YUY2), and it should have been captured with 2 fields per frame. In the video compressor settings you should specify a field threshold of 288 for PAL or 240 for NTSC to achieve this. This captured file is well suited for editing in your favorite video editing software because it only consists of I-Frames, and due to the low compression ratio editing will be fast.

So now is the time to "enhance the quality" if you feel that it is necessary. Most important advice: Do not overdo the filtering like denoising and sharpening. This is a typical trap for beginners. But there are some very useful AviSynth filters especially for VHS captures. CNR2 by tritical reduces the typical chroma noise. Another filter I like very much is FixVHSOversharp. Many VCRs use "edge enhancement" to overcome the limited resolution by sharpening all edges. Looks impressive first, but gets old quickly. This filter can remove this edge sharpening. Plus there are tons of other filters you could apply here, but as I said: Less can be More...

Alright, I hope I have not discouraged you too much.

Cheers
manolito

21st July 2018, 02:13	#4 \| Link
manolito Registered User Join Date: Sep 2003 Location: Berlin, Germany Posts: 3,079	I don't know about foxyshadis advice to use videoFred's script for this task. We are in the Newbies thread after all. And the main purpose of this elaborate script is 8mm film conversion which has far more and very different requirements compared to VHS capturing. Being a person who has converted most of his old VHS cassettes many years ago (and anyone like johnmeyer who is an expert on such conversions knows this) I can only emphasize that this is a major undertaking for someone who never did this before. It takes a lot of experimenting, trial and error, and the end result often is not worth all the energy. For someone who will only do such conversions once or twice, I would definitely recommend to use a professional service with good credentials for such a task. Only if you plan to do this regularly you should consider getting your feet wet on this. I think it is a myth that anyone can get "almost DVD" quality from VHS. Just look at the specs. VHS decks have a typical horizontal resolution of about 240 lines. No way to invent details which are simply not present in the source. And you have to understand that there is a conversion between the analog and digital domain involved here. No way to avoid a certain quality loss. It might not be too obvious if the conversion is done intelligently, but it will still be there. lansing already gave some good advice. First of all the playback VHS deck needs to be of high quality, clean and with good alignment. S-VHS is desirable (if the capture device supports it), a premium JVC deck with built-in TBC is a bonus. But if the VHS deck you already own plays the tapes with good visual quality you may get away with it. Next thing is the capture hardware. You won't find dedicated capture cards these days, everything you can buy now are USB capture boxes. You need to decide how many bucks you want to spend. The better devices can also digitize audio (the cheaper ones will use the soundcard for this which will introduce sync problems). Some even have built-in hardware video encoders so you can encode to a compressed video format like MPEG2 or AVC on the fly while capturing. Not really necessary... Now the challenge is to capture the clip to your HDD without dropped frames and without audio sync problems. VirtualDub is by far the best capturing software IMO. Capture video using a lossless codec like Huffyuv, use uncompressed PCM for audio. At this capturing stage you should not be concerned about "beautifying" the clip, just capture it as it is and make sure you don't introduce any artifacts. Advanced: If you are picky about capturing with the correct aspect ratio (circles need to be really round and not elliptical) you need to check this now. The hardware A/D converter in your capture device (mostly a Philips chip these days) has a so-called "capture window". Just setting the capture size to 720 x 480 or 720 x 576 will usually result in a slight aspect ratio error. A lot of people just live with it though... The resulting captured file will be in an AVI container. It should have 4:2:2 color subsampling (YUY2), and it should have been captured with 2 fields per frame. In the video compressor settings you should specify a field threshold of 288 for PAL or 240 for NTSC to achieve this. This captured file is well suited for editing in your favorite video editing software because it only consists of I-Frames, and due to the low compression ratio editing will be fast. So now is the time to "enhance the quality" if you feel that it is necessary. Most important advice: Do not overdo the filtering like denoising and sharpening. This is a typical trap for beginners. But there are some very useful AviSynth filters especially for VHS captures. CNR2 by tritical reduces the typical chroma noise. Another filter I like very much is FixVHSOversharp. Many VCRs use "edge enhancement" to overcome the limited resolution by sharpening all edges. Looks impressive first, but gets old quickly. This filter can remove this edge sharpening. Plus there are tons of other filters you could apply here, but as I said: Less can be More... Alright, I hope I have not discouraged you too much. Cheers manolito Last edited by manolito; 21st July 2018 at 15:30.