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Video capture from LaserDisc - realistic?

Discussion in 'Computers' started by Rob Gillespie, May 2, 2003.

  1. Rob Gillespie

    Rob Gillespie Well-Known Member

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    I'm sure some of you have been here before. I have several LaserDiscs which will probably never be released on DVD. Since my LD player needs attention and paying several hundred £££ to get it repaired is not an option, I've been thinking about transferring them to DVD (before anyone gets upset) for my own personal use.

    I've been reading a bit on a couple of sites from people who've successfully done this by connecting the LD player directly to a video capture capture card then doing the necessary work from there. My point is - how realistic an option is doing this? I realise I'll have to get a decent card but this is something I've never tried before. Will my 7200rpm Seagate HDs be fast enough? What kind of capacity is needed to capture this kind of material? I know other people have transferred the material to digital video first, but that is not something I can do.

    Basically, any advice would be welcome. I'm only concerned about capturing at the moment (I figure that's enough to worry about for the time being). If it's not going to yield good results then I wont bother.
     
  2. JeremyFr

    JeremyFr Well-Known Member

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    I would forsee it as being possible and 7200rpm drives will work just fine. the only real concern I would have is if the disc's have macrovision and whether or not the capture card will allow you to capture. but other than that I would say it work fine.
     
  3. Rob Gillespie

    Rob Gillespie Well-Known Member

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    LDs didn't have Macrovision. Those were more civilized times [​IMG]
     
  4. Wayne Bundrick

    Wayne Bundrick Well-Known Member

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    I've done it (for my own personal use) and it worked just fine. The only thing I could wish for is a way to record the AC-3 soundtrack bitstream and preserve it exactly for the DVD. I think it's possible given the right equipment, but I don't have that. Instead I record the stereo digital soundtrack, and I am satisfied with that.

    If you capture to DV format, which is a pretty good choice, be aware that it requires 12-13 GB per hour.
     
  5. Rob Gillespie

    Rob Gillespie Well-Known Member

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    Right, the disc space wont be an issue then and since these discs are PCM only, neither will be the 5.1 issue.

    Can someone give me the signal chain needed for this? I've heard of people using a conversion card such as the Canopus ADVC50 but I'm not sure of the reasons why.

    Basically, I'm a dumb newbie with this [​IMG]
     
  6. Rob Gillespie

    Rob Gillespie Well-Known Member

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    The player is a Japanse CLD-HF9G, which is basically an Elite CLD-99 with a silver facia and LD+G capability (whatever).

    For the moment I'm just concerned with the capture. Obviously I want get the best possible with no dropped frames (is that even possible?) and the best image without[/i buying expensive hardware. I'm quite happy buy a conversion card and/or capture card, but that's about it.
     
  7. Ken Chan

    Ken Chan Well-Known Member

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    The ADVC-50 converts analog video and audio directly into DV, which you can then just dump on the drive, like any true DV source. DV is convenient because lots of program support it directly, although there is some issue about particular DV codecs (I believe Jeff Kleist has a poor opinion of the Microsoft one).

    I have an ADVC-100, which is an external box that does the same thing. It uses a FireWire connection. You plug the analog source into the box and hit play. You open the capture module of your app (e.g. Premiere, Vegas), select the OHCI-1394/FireWire/whatever-they-call-it input, and see the "live" picture as it is converted on the fly. You hit record in the app, and the DV datastream is stored as an AVI file. The DV bitrate (25Mb/s for the video alone, about 29Mb/s or 3.6MB/s for the entire stream) shouldn't be a problem for a modern ATA drive, and the CPU isn't busy compressing, so no dropped frames. With the card instead of the box, there's no FireWire connection/cable, but it should work the same.

    Unfortunately, neither has a digital audio input. Although the LD's 44.1KHz PCM would have to be resampled to DV's (and DVD's) 48KHz, at least it would stay digital.

    If you get a non-DV capture card, the signal chain isn't any different. You still connect the (hopefully S-)video and audio to the card. The card might have hardware encoding, either some flavor of MJPEG (basically JPEGs for each frame) or MPEG. I don't recommend MPEG for captures because it's lossy and not a good editing format. As with DV, since there is dedicated encoding hardware, all you need to do is make sure the bitrate can be handled by the drive; the amount of compression is usually selectable.

    The other alternative is to use a software codec, if that is allowed by the card. For example, Huffyuv is a lossless codec. To avoid dropped frames, you have to balance the CPU time to compress a frame, with the resulting size so that the drive can handle it. With current systems, it should actually be fairly easy.

    One thing to remember is that you'll need the codec to decompress the file in the future. So if you're using hardware MJPEG, you will need that card (or something compatibile), since most MJPEGs are proprietary. That's a strike against MJPEG. You can of course transcode the captured MJPEG into something like Huffyuv, and then there's no worry about dropping frames at that point.

    You might want to shave off any letterbox bars, especially if you're transcoding anyway -- they're just taking up space. Any decent program should be able to letterbox the image later. Note that if you are encoding to DVD, you will want to make the image (ideally both the top and bottom, but at least one of them) aligned with MPEG's 16-pixel blocks. MPEG doesn't compress the hard line between the "black bar" and the image that well.

    As for specific cards, some MJPEG cards use more color sampling than DV, but frankly you might not be able to tell the difference. DV is convenient and widely supported; the ADVC-50 is $200, so you might as well go with that. (Of course, DV is not without its issues; lots of info here.)

    One more thing: broadcast luminance is limited between 16 and 235 instead of 0-255. Some codecs do conversions and some don't. After you go through various stages, if the end product has flat contrast, you need to apply a filter to stretch the "Levels" to their full range. You can also detect that by looking at the image data with a histogram.

    //Ken
     
  8. Rob Gillespie

    Rob Gillespie Well-Known Member

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    Thanks, that's really useful. Do any similar cards have a digital audio input?

    I'm thinking of going for the ADVC-50 but since I don't have firewire the ADVC-1394 might be a better option.

    It's expensive over here - around £270 and that doesn't include the 5.25" front bay.
     
  9. Rob Gillespie

    Rob Gillespie Well-Known Member

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  10. Wayne Bundrick

    Wayne Bundrick Well-Known Member

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    It looks like the ADVC-50 needs a 1394 board. The ADVC-50 just converts analog to DV firewire output. Ken mentioned quality differences in DV codecs and Microsoft's being especially bad, but the Canopus codec is one of the best.

    DTS tracks probably won't transfer directly to DVD because of the sample rate difference, 44.1k vs. 48k.

    If you ever plan to get a DV camcorder and edit the video you shoot, the ADVC-1394 would help futureproof yourself.

    There is just one thing I don't like about the capture boards at this price point: they don't have realtime analog output so you can see your work on a TV screen instead of the computer screen. That feature tends to cost a few hundred dollars more.
     
  11. Rob Gillespie

    Rob Gillespie Well-Known Member

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    So would the 1394 negate the need for a separate firewire card?

    Sorry if I sound a bit dense on this, but Canopus' own website barely gives any information. I can't quite get my head around why a PCI card would then need to send it's signal out and back into another card. Weird design.
     
  12. Rob Gillespie

    Rob Gillespie Well-Known Member

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    Buzz, as is usually the case, the price over here is more or less a £ for $. The online price for the DV500 DVD is about £440.
     
  13. Wayne Bundrick

    Wayne Bundrick Well-Known Member

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    Rob, it looks like the Canopus ADVC-50 isn't really a PCI card, as you can mount it in a drive bay. They made it so that it can occupy a PCI slot, but the PCI card edge has no "teeth".

    The ADVC-1394 is its own firewire card. It does analog capture, plus it has a 1394 connector so you can capture digital or connect to other firewire devices.
     
  14. Ken Chan

    Ken Chan Well-Known Member

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    Yeah, sorry I didn't read the ADVC-50 description carefully enough. Looks like it might draw power from the PCI bus (when installed as a card instead of the drive bay; there it uses a standard 4-pin power connection) but nothing else. The ADVC-1394 is $50 more, which is in the same ballpark as a separate FireWire card.

    One nice thing about the ADVC-100 (which again requires a FireWire card/connection) is that it is bidirectional. So if your NLE previews to FireWire, you can hook up a TV to the analog output. So like the ADVC-50, it's only a converter, but it's external, so you can move it to other computers, bidirectional, and even generates color bars; $100 more.

    Buzz, here's a good book on color correction. Also, if you get the extras DVD for Se7en, there's like a twenty-minute deal where the colorist describes how he fixes up the final sequence -- make sure you've seen the movie first [​IMG] -- that's quite interesting. To do it right, you need good tools, and the handful of sliders you get on the low-end just don't cut it.

    //Ken
     
  15. Matt DeVillier

    Matt DeVillier Well-Known Member

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    I have an ADC-100 and have used it to backup my Original Trilogy THX Star Wars LDs. Converting to DV via one of the canopus products is probably the best you can do without going into the prosumer rhelm.
     
  16. Rob Gillespie

    Rob Gillespie Well-Known Member

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    Ahh now it makes more sense. Thanks fellas.
     
  17. Rob Gillespie

    Rob Gillespie Well-Known Member

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    Buzz - the DV500 DVD: Will that unit provide better quality than the Canopus? I'm not too worried about hardware encoding. I'm quite happy to let TMPGENC sit there for a few days and perform the MPEG2 conversion.

    Also, Harmony do not ship outside the US (shame really coz the $415 price tag is pretty nice). Anyone know of any dealers who ship over here? I'm not familiar with any of the US computer retailers.
     
  18. Jeff Kleist

    Jeff Kleist Well-Known Member

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    Rob, not only will onboard hardware encoding (local to the card) make your DV capture more stable, but you will thank Jeebus for that MPEG-2 acceleration [​IMG]

    Pinnacle and Canopus are neck and neck as far as quality goesl, Canopus has a bit better support from what i hear, but both codecs and hardware are great stuff
     
  19. Rob Gillespie

    Rob Gillespie Well-Known Member

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    So (if I understand this right), you're saying hardware conversion 'on the fly' can do a better job than TMPGENC?
     
  20. Jeff Kleist

    Jeff Kleist Well-Known Member

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    Rob no. The last thing you want is on-the-fly MPEG-2 encoding on anything that doesn't have a multiple 4-figure price tag.

    What I'm saying is that the DV500 has onboard MPEG-2 encoding acceleration. Now I don't have one (yet) myself, but from the way Buzz has been talking it makes what takes TMPEG days to do down to mere hours.
     

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