Dear friends,

I haven't the DV card yet, but I have DV Cam, that's why I want to know if there is any differences compare with RCA / S-video connector.

I need to know if I capture my movie from digital cam via firewire to make VCD, will the quality be improved compare using the RCA / S-Video connector ?

Is it true S-video better than RCA ? I've tried myself but I didn't see the difference.

Any input will be much appreciated. Thanks in advance.

Regards, Sunar.

-- Sunar Karjadi (rekotomo@denpasar.wasantara.net.id), January 25, 2001

Answers

Dear Sunar, I'm exploring all of these issues right now as you are. I worked for The Sony Stores for a number of years and I can tell you what my technical trainers taught me. RCA connection, otherwise known as composite, processes the video with the chrominance (Color) and luminance (Light) as one combined signal which was a big improvement over coaxial cable which combined chrominance, luminance and the sound all munched together. If you notice, an S-video connector is actually a din plug with more than one pin connector. This is due to the fact that it has the capability of ripping apart the chrominance and luminance and processing them separately, thus higher resolution and a cleaner signal. You'll find that all high resolution units like DVD's, laserdisc players and many others use this type of output to connect to higher end televisions. More specifically in the case of your DV camcorder the S-video is used to connect to higher end video cards. I suspect the reason that your not noticing a big difference between the RCA and S-Video is because both of these signals are still analog. The problem is, analog signals are to huge to deal with in a transfer situation and therefore, the(analog capture card) compresses the signal. This is where the quality takes place, then your further compressing it yet again into VCD format. Now, A DV connection or firewire is a completely digital transfer with absolutely no loss or compression. This is provided you don't choose to compress it on the fly as you transfer, as some cards allow you to do, (this is called Mpeg 2 compression capturing). Well, after all of that rambling, I'm going to try to answer your original question. When you convert any signal to VCD format it is compressed in order to comply with the VCD format specifications. Roughly VHS resolution. So one would argue, if your compressing it anyways your going to lose substantial quality, so it shouldn't matter what the source is. The general rule of thumb is: A higher quality source, even compressed or transferred onto a lower resolution capable unit will always result in a higher quality output. If you record a DVD on to a VHS, naturally it will be better than VHS to VHS, even in light of the fact that the VHS unit is comforming the signal to it's lower quality resolution capability. It's still better. It's not just resolution that makes up video quality. It's color saturation, it's the amount of video noise, edge detail, ETC. Anyways, technically, using a firewire connection should make a fairly susbstantial difference in final production. Definitely more dramatic than between two analog sources like RCA and S-video. Everything I said here is theoretical and perhaps in practical application I may have missed some factors but I think it's pretty sound. Perhaps, someone smarter will correct me. Regardless, I understood this to be your question. Hope it helps. If I totally missed your point then I apologize..

Thanks, Daniel

-- Daniel Beer (dbeer@home.com), January 28, 2001.

I have a Sony DCRTRV120 D8 camcorder, and in my PC I have both a G200 Matrox Marvel AGP vidcap and an ADSPyroDV card. I captured both using the Matrox MJPEG codec (S-video in) at 704x480, 29.97fps with the PC- VCR app and DV-IN through the Pyro card using Ulead Video Capture with DirectShow plug-in. The resulting DV-type 1 I opened in MediaStudio and converted to type-2 using a MainConcept DV codec. Both DV-type2 and MJPEG clips I opened in Premiere5.1c and exported to a VCD MPEG file one after the other through the Panasonic2.5 plug- in on full-pel, no noise redux, and adaptive/medium settings. The DV- sourced clip was still sharp and smooth; the MJPEG-sourced clip had ever slightly more blockiness (but still passes my standards). I guess you can say FireWire capture is better here. It may be true, VCD resolution-wise and small TVs, that no differences can be noticed between composite and S-video inputs. However, on a big TV (>30in), with a DV tape or DVD player for source THERE are some very definite differences. S-video sourced pix have little or no dot-crawl (edges in the picture shinny up and down) and reds do not bleed compared with composite.

-- Mehmet Tekdemir (turk690@yahoo.com), January 29, 2001.