VHS capture questions

[JohnnyRico]

Hi all,

I am trying to capture VHS video from my analog camcorder to my PC. My primary goal is to archive the video so it doesn't degrade as quickly as it will on VHS. I am using an AverMedia DVDEzMaker PCI with a BT878 chip and I want to capture MPEG2 video. In addition to archiving the MPEG2 video to CD, I want the ability to create SVCDs (short term) and DVDs (long term - once I get a DVD burner).

I've been playing around with InterVideo WinDVDCreator 2 and did some test captures on the DVD HQ setting (720x480) and created a SVCD from this that looked pretty good when played on a DVD player. The problem was that the MPEG2 files are huge (1MB per second) when captured at this setting. My friend told me that capturing from VHS at 720x480 is overkill and that I should capture at 1/2 DVD (352x480). On top of this I know that the required framesize for SVCD is 480x480 but WinDVDCreator 2 will automatically resize the video if I burn to SVCD format. One other thing to note is that someone has posted on these boards that there are issues when resizing video that was captured at less than 388x### on the BT878. Not sure if this is correct or not.

My main questions are:

- Will capturing from VHS to MPEG2 at less than 720x480 (e.g. 480x480) look as good as 720x480 when burned to a SVCD? How about to a DVD?
- Will SVCDs look better if I capture at 480x480 instead of another size and later resizing to 480x480 when I create the SVCD?
- If I capture at 480x480, will this cause me any quality problems down the road when I have a DVD burner and want to burn actual DVDs?

In addition to the answers to these questions, I would appreciate any advice on what I should do to get the best quality MPEG2 captures for my purposes (i.e. going to both SVCD and DVD) while minimizing the size of the archived video.

Thanks in advance

[indolikaa]

JohnnyRico,

I capture a lot of older VHS and Beta.

- Will capturing from VHS to MPEG2 at less than 720x480 (e.g. 480x480) look as good as 720x480 when burned to a SVCD? How about to a DVD?

A tricky question. 480x480 is not a DVD-legal resolution, so you cannot burn SVCD to a DVD and expect any player compatibility. And, if you do not increase your bitrate allocation, you might find that 720x480 looks worse than 480x480. This leads into your third question...

- If I capture at 480x480, will this cause me any quality problems down the road when I have a DVD burner and want to burn actual DVDs?

Because SVCD is not a legal DVD resolution, you will likely have to reencode to something else. I doubt there will be a flood of DVD players on the market that will handle DVD-SVCD discs. You can likely convert SVCD to Half-D1 (352x480) which IS DVD-legal and not lose any perceptable quality.

Will SVCDs look better if I capture at 480x480 instead of another size and later resizing to 480x480 when I create the SVCD?

It will look better if you capture straight to 480x480 rather than reencode from another resolution, IMHO.

For these reasons, I recommend Half-D1 for all VHS transfers. You can read more about the intricacies of such a process at lordsmurf.com, a highly recommended site.

.indolikaa.

[duhmez]

If you capture to 720x480 HUFYUV, then encode as 480,480 Mpeg 2, it WILL look better.

[indolikaa]

If you capture to 720x480 HUFYUV, then encode as 480,480 Mpeg 2, it WILL look better.

You are kidding, right?

[overloaded_ide]

VHS is less than 352x480 in the first place, so capturing above that is overkill!

Your bit rate determines your quality and the amount of time you can fit into a set amount of space. Lower resolutions require less bits for the same quality. For instance if your video size is 4 times as large, then you need 4 times as many bits for the same quality picture basically.

Half the size, half the bits, half the space, roughly.

What looks good at 352x480 with 4,000 bps may look like garbage at 720x480 with 4,000bps.

In short answer then, capture at the highest setting equal to your source and intended use.
Since I only do DVDs (not Vcd or SVCD) then for me 352x480 is the closest to VHS I can get and be DVD compliant. Anything above that is waisted and requires higher bitrate to maintain equal quality.
At 352x480 there is less information to store, so it requires less bps to store it, thus your file size can be smaller. You will not get better than VHS quality by capturing higher, just waste resources like space.

My sugestion would then be to capture to the setting compliant to your intended use that is closest to your source. If the closest is 480x480 for Svcd then capture to that, if you need to re-encode latter for DVD then go down to 352x480. That should give the best results compared to trying to capture 352x480 now and encodeing higher which would be bad, or capturing to 720x480 which is way over kill for either Svcd or DVD since your source is only 352x480 anyway.

[duhmez]

no I am not kidding. Huffyuv is lossless. So no loss there. Then, you can use a more time consuming(and better) resize filter such as lanczosresize in avisynth. This will be better than the capture card's on the fly resizer.
then you can use a 2 pass VBR encode, which is better than straight capture. So for a few reasons, it is better. Another reason it will be better, when a frame is dropped during avi capture, it will duplicate a frame. Mpeg won't necessarily do this. It can put a thing in there to tell it how to handle the missed frame.

the downside to straight mpg capture because of this, if you demux, and remux the video later, for whatever reason, A/V sync may be lost.
AVI huffyuv to mpeg via my method will result in perfect sync every timem even if you decide to edit it later.

[JohnnyRico]

Thanks for all the fast resonses! I knew I came to the right place. Based on what I have heard so far, I guess I will capture at 480x480 and a fairly high bitrate. I can then burn SVCD easily without having to resize and when the time comes for burning dvd, I will have to resize down to 352x480 which sounds like it is better than trying to resize UP. Also if what that other guy said about problems capturing below 388x### is true, I will avoid that problem by capping at 480x480. I'll try some tests and see how it goes.

duhmez, I am strictly going for MPEG2 real-time capture (with BT878 hardware on my capture card). I tried the AVI to MPEG2 thing a while back and it just required too much time (and too much disk) to be viable. I agree that the quality is clearly better doing what you recommend but I am willing to sacrifice a bit of quality for time. I was really waiting until the hardware realtime MPEG2 capture had sufficient quality for my needs and it is finally here. Not perfect but good enough.

[lordsmurf]

no I am not kidding. Huffyuv is lossless. So no loss there. Then, you can use a more time consuming(and better) resize filter such as lanczosresize in avisynth. This will be better than the capture card's on the fly resizer.
then you can use a 2 pass VBR encode, which is better than straight capture. So for a few reasons, it is better. Another reason it will be better, when a frame is dropped during avi capture, it will duplicate a frame. Mpeg won't necessarily do this. It can put a thing in there to tell it how to handle the missed frame.

the downside to straight mpg capture because of this, if you demux, and remux the video later, for whatever reason, A/V sync may be lost.
AVI huffyuv to mpeg via my method will result in perfect sync every timem even if you decide to edit it later.

This only applies to cheap run-of-the-mill cards that were under $50 using software-only solutions for MPEG capture. For a good MPEG all-hardware or hardware-assisted card (ATI, Matrox, Canopus, even Hauppauge), these are all untrue accusations.

HuffYUV is not lossless. Less lossy, least lossy, but not perfectly lossless.

Some card resizers are better than software resizers.

A/V sync is only lost on crappy MPEG capture software (like PowerVCR), and the dropped frames things you mention is false. If it drops, it drops. There is no magic reduplication algorithm. That frame was dropped, and there is now a hole in the data.

If you want excellent MPEG capture results, ditch the BT-based card and get something better.

[duhmez]

Didn't notice it was a vhs source. i agree 720 is overkill for it. VHS si roughly 352 ish kind of.

I would actually recommend capping @ 352,480 then, burn onto a cdrw, see if your player will play a nonstandard SVCD with 352,480. DVD drives are cheap now and it probably won't be too long until you get one, and reencoding SVCD is a major pain in the @ss. Cap 352,480 now, your quality will be as good as it is going to be, then your sources are all ready for DVD authoring in the future.

granted mpeg audio is not suported for dvd spec, but usually works. And if you use chrissyboy's l33t
svcd2dvd it can make the audio into ac3 for you if you wich, while not reencoding.

For each cap I suggest you demux and remux it imediately when done. See if A/V sync is OK. if it is, then it always will be if you have to de and remux for DVD authoring.

If the A?V sync goes out from a simple de/remux, then you will have to reencode the file, in it's entirety, in tmpgenc to maintain AV sync.

[duhmez]

1)Huffyuv is lossless.

2) ive got some mpeg files, I demux and remux, and it is now out of sync. Why is this?
Ive been using SVCD2DVD and this is one of the issues that crops up from time to time. there IS some magic info in the mpeg program that will keep things in sync.

I'm not exactly sure of the technical reason, but here's the sticky from the svcd2dvdmpg forum.

QUOTE: (Chrissyboy author of svcd2dvdmpeg "SVCD, VCD & DVDs contain mpeg program streams. In a mpeg program stream there exists presentation timestamps(PTS). These, as you may expect, are used to keep the audio & video in sync. In the MPEG encoding process (TV card or whatever), audio and video may start at a different PTS or some frames may be lost during the recording. You will not notice this when playing back the recording, as the PTS info present in the MPEG2 PS will mean that video and audio will be presented at the correct time, even with frames missing. Audio and video will still be "in sync", as the player knows exactly, when to present the A/V chunks.
"
Link is below.

I've witnessed this exact thing. I demux and remux an mpeg (that is,just using tmpgenc demux/remux) and it goes out of sync. It does NOT happen on all mpegs of course, just a couple that I have tried.

https://www.videohelp.com/forum/viewtopic.php?t=174728

Also, if the frames are dropped and there is holes in the data, how can it feed 29.97 FPS without going out of sync? Answer: It uses the PTS which gets lotst in any demux operation.

[SatStorm]

Okey, once again...

What I know from my short experience....

If you are NTSC, you wish to capture (s)VHS, in an analogue (avi) format and then encode to mpeg 2 using TMPGenc encoder, then:

1. Capture @ 704 x 480 using a good codec like Huffyuv or Mjpeg (like mjpeg)
2. Correct elements of the NTSC system (luminance, chroma correction, etc). You can do this realtime using hardware (TBC, etc) or by using software (like those filter-like plug-ins of Virtualdub)
3 Filter your source: Dynamic Noise reduction, Video DeNoise, even temporal smoother for live action, or Temporal cleaner for anime. Extreme filtering (very bad source) can also be done with 2D cleaner. Of course, there are plenty of filters to try, some may be better for your needs that the ones I point to you.
4. Sharp a bit and then Resize your source to 352 x 480. All filtering blures a bit the picture, so a slighty sharpening helps visually most of the time. But only slighty (like 6-8 on virtualdub). Resizing to 352 x 480 using Lazcos or Bilinear methods are an important step, for best results.
5. Encode with TMPGenc. Just load any 1/2 D1 DVD NTSC template and hit "start". TMPGenc has unofficial stop evolve "2 Pass VBR" mode, so unfortunatelly it is the upredictible CQ mode to use for the best possible results. A set like 1150 min 4000 max @ 65 is fair, @ 80 is about perfect


One alternative to all this you have, is to read and learn how to use avisynth. Faster and better results that way, but not a GUI solution
Also, you might prefer use another encoder, like CCE Basic for your projects.

IMHO, most cheap 50$ cards (bt8x8 based) can succeed great results using those 2 alternative methods. But it is the hard way. Using more advance and expencive hardware, the results are the same, but much easier and faster IMHO. So if you have the money for a Matrox card, or even ATI (since you are NTSC, for PAL users there are better alternatives..) better choose those than a cheap one.
Also, avoid external capture cards of any kind and Via Chipset on motherboard.