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About ginger_marianne

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  1. I guess what I would say to the OP is if your cable/wire is around 10 feet (or maybe a little higher), don't even factor impedance into the equation. Also, you probably don't have to worry about shielding unless you actually notice interference. Impedance mismatches generally subtract from the image (i.e. the full signal is not being realized because of losses). Interference adds to your image. If you need shielding for your cable (due to interference), you probably don't have to worry about the characteristic impedance of the cable. With shielded cables (e.g. coaxial), I'm not sure how much o
  2. True. But on the ground, going from receiver to monitor/recorder, you probably have no need for shielding. It depends on the application. And when shielding is used, it probably doesn't have to be in the form of a thick cable with 75 ohm characteristic impedance, as long as the run is short enough. My understanding of video cables (limited as it is) is that cables are generally shielded to maintain characteristic impedance within tight tolerances (and not to prevent interference from outside sources). Correct me if I'm wrong.
  3. I remember reading that it's irrelevant what type of wiring you use if you're under 1/10 the wavelength of the maximum frequency you're using. In other words, losses due to impedance mismatches are minimal when the wire length (regardless of the type) is under 1/10 the wavelength. Assuming a frequency of 10 MHz for composite video, the wavelength would be ~ 300/10 meters (or 30 meters), or a little under 100 feet. So, based on this, you would be able to use any wire up to 10 feet or 3 meters with virtually no loss. Is this correct? Something that has confused me in the past is why people
  4. I've thought about it. I just won't do it. Personally, if I produce something, I don't want to do it again. It's a lot of work. Deleting the source file gives me a sense of finality. Also, I store all my files in triplicate (3 hard drives) with an indexing system and MD5 hashes (of all files). If it's worth keeping, I do this. If it's not, I don't keep it at all. Doing this process on hundreds of hours of DV would be too much. I suppose I could alter my system and just keep one copy of the DV files. But it's not for me. If the video was already produced with transitions and titles
  5. That's a good strategy if you can do it. But how many people who would ask the type of questions in this thread would\could actually do that? And besides, that could get very expensive. Depending on how much video you produce, that could require a lot of tapes (or more likely hard drives). DV takes up 4 times more space than DVD compatible mpeg-2 (and maybe 8 times more space than h264 or VC-1). I just wouldn't be able to do that, although I wish I could. You're right that the newer codecs are very compressed, so frame accurate cutting is probably not possible. But it is possible with mpeg-
  6. I actually looked into this a little bit more, and there is actually a problem with some encoders, such as Cinema Craft Encoder, and the field order. First of all, all of my stand-alone DVD players can play both BFF (bottom field first) and TFF (top field first) just fine, so it's not necessarily an issue of which one you pick, although TFF is probably the more conventional choice. The problem arises when the flag set on your mpeg-2 file is mismatched with the way your mpeg-2 is actually encoded. For, instance, if it's flagged as TFF but actually encoded as BFF, then you'll have a problem w
  7. That's true. Virtualdub is not a proper editor. But I do a lot of video manipulation. The fact for me is that I won't encode a video into a format unless I know that I'll be able to cut out parts or rearrange it later without having to re-encode it. Let's say I choose divx/avi format now for a video that I make. I want to know that 10 or 20 years from now I'll be able to manipulate it, cut out parts, etc. while still maintaining the original quality. I can't tell you how often people will re-encode a video every time they want to perform even the most basic tasks. Most people can't seem to gra
  8. I wanted to add a couple other things. There are no short cuts when it comes to dealing with video encoding/editing. I've wanted to pull my hair out several times dealing with this stuff. Unless you actually have some understanding of the topic, you'll never get the results you want. What I would suggest is picking a process (possibly from one of those described in this thread) and work with it to see if you can get the results you want. Something else I would suggest is possibly downloading some video (preferably those without copyright violations) and work with those. Use GSpot to see what t
  9. I believe WMV is just a container for the codec. Actually, the VC-1 codec, which I mentioned earlier is part of the Blu Ray standard, is often placed in a WMV container. I've seen some samples, and it does provide excellent quality at a low bit rate. I used IgCutter (my lossless wmv/asf editor), and it worked perfectly with it. It's easy to check which codec specifically is being used with GSpot. If you encode VC-1 at 720x480 (or 720x576), there's a chance that it will be Blu Ray compatible without re-encoding, assuming you guess (or know) all the other settings needed for compatibility. WM
  10. I've personally never de-interlaced mpeg2. They've always played properly for me interlaced. I was wondering which (if any) of these de-interlacing methods allow the mpeg2 to retain DVD compatibility? I would argue that there is absolutely no reason to use mpeg2 unless it is DVD compatible. Each of the other codecs that I previously mentioned can equal the quality of mpeg2 at a lower bit rate. Thanks
  11. I don't think anyone will tell you exactly which settings you should use because it depends on the hardware you have to work with. I can only give you 3 things you should look out for. 1. Capture: If you plan to do any editing (other than basic, lossless cuts) after you capture your video, then use the lowest compression codec you have available to you. A low compression codec will take a lot more space on your hard drive than mpeg2 will, but it will yield a lot better quality. Two good codecs that I've used are DV and mjpeg (720x480). After your capture, then you can convert to mpeg2 or h2
  12. Okay, I'll take your word for it. They shouldn't take up that much space anyway. Thanks
  13. Thanks for your response. Every recommendation I've seen has been to use capacitors with the LM7805, but to be honest, I have yet to see a lick of difference (for my application) with or without them. The signal looks the same as the original to me. But it wouldn't be the first time I've missed the obvious (has happened multiple times in this thread already). I'll just keep playing with it to see what I notice. But so far, I see none of the noise that occurred with the resistor. I'm trying to keep everything as small as possible. So far, the LM7805 hasn't gotten any more than mildly warm (i
  14. Okay, I'm sorry if I'm posting too much. I tried the 5V regulator from Radio Shack. It's absolutely perfect. No capacitors are needed when used with the splitter. It provides a clean 5V. And there's no noise at all, even without a capacitor. And it's tiny. So, ignore everything I said previously about resistors. Thanks
  15. Update: In my quest to use this splitter with a 12V (+/-25%) source, I've made a couple modifications since my last post. I decided to lower the resistance from 440 ohm to 380 ohm (or 330 ohm) because the 440 ohm wasn't perfect around the 9V range. Also, I added a 100 uF capacitor from the ground to the +5V (pin 1 to pin 2 on the input side of the splitter). Again, I didn't modify the splitter and simply added the capacitor to the wiring. Apparently, adding the resistor introduces a small amount of noise (low frequency?). The thing about the noise is that it usually isn't visible. It wo
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