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  1. Is it possible to pass interlaced video (DV format in .dv file) from a PC (Windows 7) hard drive to an external native interlaced (CRT) display?

    I want to transition from storing DV video on Digital 8 tapes to .dv files on hard drive. Currently I playback tape directly on a CRT TV using composite cables (RCA jacks) between tape deck and TV. When I compare to viewing the .dv files from PC hard drive on a CRT TV (using S-video to connect) the quality is degraded relative to our current setup (Digital 8 tape to TV).

    I assume the PC is de-interlacing or somehow altering the signal before sending to the TV through the S-video. Assuming this is correct, is there a way to avoid this - either a software or hardware (video card) solution?

    Thank you for any suggestions.
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  2. Member Skiller's Avatar
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    Originally Posted by pdowty View Post
    Is it possible to pass interlaced video (DV format in .dv file) from a PC (Windows 7) hard drive to an external native interlaced (CRT) display?
    Yes, the easiest way to do this is with a MiniDV or Digital8 camcorder that has DV-in capabilities. It enables you to send the DV format video via Firewire to the camcorder (no quality loss) and the camcorder will output it live as Composite or S-Video. Interlacing will be intact, there's no scaling and the levels are correct – it's pure and simple.



    Originally Posted by pdowty View Post
    I assume the PC is de-interlacing or somehow altering the signal before sending to the TV through the S-video.
    Yes, the TV-Outs of GPUs are crap. Do not waste your time with them.
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  3. Thanks Skiller. How important is the PC software in ensuring there is no quality loss through the Firewire to the camcorder? That is, will standard PC media player software make the video available via export through the Firewire port?
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  4. Interlace video also component i.e. highest quality (RGB or YPbPr) may be produced directly by PC also - on analog (VGA) or digital (HDMI) domain.
    Just select proper video mode in graphics card configuration.

    Originally Posted by pdowty View Post
    Yes, the TV-Outs of GPUs are crap. Do not waste your time with them.
    Usually this is same or very similar type of output as on many digital devices - perhaps it need to be configured correctly?
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  5. Member Skiller's Avatar
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    Originally Posted by pdowty View Post
    How important is the PC software in ensuring there is no quality loss through the Firewire to the camcorder? That is, will standard PC media player software make the video available via export through the Firewire port?
    Standard PC media players do not send out the DV video through the computer's Firewire port, they just play it back on your computer screen. WinDV does. There's no quality loss, it transfers all the bits of the DV video (since it's standard DV video, just like what the camcorder produces) unaltered to the camcorder. Of course this requires the video to be standard DV video. It does not work with any other formats.


    Originally Posted by pandy View Post
    Interlace video also component i.e. highest quality (RGB or YPbPr) may be produced directly by PC also - on analog (VGA) or digital (HDMI) domain.
    Just select proper video mode in graphics card configuration.
    Yes, but you cannot connect VGA or HDMI to a standard 15 Khz CRT (although it may work reasonably well with an external converter box – never tried that).

    Originally Posted by pandy View Post
    Usually this is same or very similar type of output as on many digital devices - perhaps it need to be configured correctly?
    The actual D/A-conversion is not the problem, it's what happens before. With TV-Outs of GPUs (talking about analog SD outputs here, not HDMI or VGA) two worlds are colliding and interfering. I've tried for years to get a perfect output from my GPU's S-Video out and gave up when I realized my MiniDV camcorder with DV-in does a way better job and it's easier. Problems you will encounter: PAR (square vs. non-square), levels, field order, wrong chroma upsampling, undesireable scaling instead of 1:1 mapping. Yes, you can define the TV-Out as a secondary desktop at 720x576i @ 50Hz or 720x480i @ 59.94 hz but that hardly helps. Really, S-Video and composite TV-Outs are a mess.
    Last edited by Skiller; 23rd Jan 2015 at 08:08.
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  6. Originally Posted by Skiller View Post
    Yes, but you cannot connect VGA or HDMI to a standard 15 Khz CRT (although it may work reasonably well with an external converter box – never tried that).
    Well - select 576i or 480i video mode - SCART popular in Europe allow almost directly to connect PC as a source with such video mode on.

    Originally Posted by Skiller View Post
    The actual D/A-conversion is not the problem, it's what happens before. With TV-Outs of GPUs (talking about analog SD outputs here, not HDMI or VGA) two worlds are colliding and interfering. I've tried for years to get a perfect output from my GPU's S-Video out and gave up when I realized my MiniDV camcorder with DV-in does a way better job and it's easier. Problems you will encounter: PAR (square vs. non-square), levels, field order, wrong chroma upsampling, undesireable scaling instead of 1:1 mapping. Yes, you can define the TV-Out as a secondary desktop at 720x576i @ 50Hz or 720x480i @ 59.94 hz but that hardly helps. Really, S-Video and composite TV-Outs are a mess.
    Use correct configuration and component interface. Ia assume some US CRT (professional) supports also RGB with external Sync then connection is simple, alternatively RGB to YPbPr conversion may be necessary (analog converters are available due large group of customers wiling to connect old game console to modern TV's).
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  7. Member Skiller's Avatar
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    Originally Posted by pandy View Post
    Well - select 576i or 480i video mode - SCART popular in Europe allow almost directly to connect PC as a source with such video mode on.
    Yes, but it's still not quite that easy. VGA standard outputs separate sync pulses for horizontal and vertical. For Scart RGB you need composite sync. So this would work only if you can make the GPU output composite sync (I think I've seen this option somewhere, so it's possible), but then there's still the problem that there is no standard of which VGA pin should carry composite sync (since it's not defined by VGA standard), so there is no standard way of wiring VGA to Scart. If you get an adapter cable it may work or it may not.
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    Originally Posted by pdowty View Post
    Is it possible to pass interlaced video (DV format in .dv file) from a PC (Windows 7) hard drive to an external native interlaced (CRT) display?
    Perhaps you would consider upgrading to more modern equipment?

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  9. Member Skiller's Avatar
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    I just knew you were going to suggest that.


    Watching interlaced videos on a native interlaced display is certainly not a bad idea to say the least, so I don't acknowledge that suggestion.
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    Originally Posted by Skiller View Post
    Watching interlaced videos on a native interlaced display is certainly not a bad idea to say the least, so I don't acknowledge that suggestion.
    There are certainly high quality CRT devices but some crappy old TV that only takes composite input is certainly not one of them.

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    I agree that old analog CRT TVs are flattering to composite video sources. I also agree that when using a PC as a playback device, standard PC connections and a flat screen TV work best.

    Unfortunately, CRT TVs don't last indefinitely, so it might be best to start preparing for the time when using one is no longer an option.
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  12. Originally Posted by Skiller View Post
    Originally Posted by pandy View Post
    Well - select 576i or 480i video mode - SCART popular in Europe allow almost directly to connect PC as a source with such video mode on.
    Yes, but it's still not quite that easy. VGA standard outputs separate sync pulses for horizontal and vertical. For Scart RGB you need composite sync. So this would work only if you can make the GPU output composite sync (I think I've seen this option somewhere, so it's possible), but then there's still the problem that there is no standard of which VGA pin should carry composite sync (since it's not defined by VGA standard), so there is no standard way of wiring VGA to Scart. If you get an adapter cable it may work or it may not.
    Once again, first all video cards support Sync On Green (composite sync with green video) and you can turn on this functionality and connect CVBS from SCART to green (so green video on two SCART pins) but some TV's support also SOG at the input (and as such no HW modifications are required - plain software configuration).

    Side to this converting common VGA separate sync is simple and nothing special is required...

    http://www.geocities.ws/podernixie/htpc/vga2euro.gif
    http://members.optusnet.com.au/eviltim/scartdd.png
    http://www.geocities.ws/podernixie/htpc/dvd2vga2.gif
    http://www.nexusuk.org/projects/vga2scart/circuit
    http://project.irone.org/simple-vga-to-tv-converter.html
    http://www.electroschematics.com/wp-content/uploads/2009/11/adapter-cga-scart.gif
    http://www.abload.de/img/scart_rgb_simpleqxmt.png
    http://www.mtuncel.com/AVGtoTV2/vga2tv.gif

    So - chasing highest quality is not so difficult...
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    @Skiller Once again pandy is apparently hijacking a thread to pursue an argument with someone (in this case you) that it finds interesting but is most likely unhelpful to the OP. That is its M.O. It comes here mainly to start arguments, so treat it like what it is, a troll. It is on my ignore list.
    Last edited by usually_quiet; 24th Jan 2015 at 09:17.
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  14. Thanks for this discussion. It is very helpful. We're a group of ecologists that have monitored aquatic vegetation for 14 years using underwater video. We are being forced to change our system due to increasing difficulty in acquiring 8mm tapes and maintaining the Digitial 8 tape decks. We like the idea of moving from our analog NTSC underwater video camera and leaving interlacing behind but similar digital cameras don't have the same light sensitivity for low-light conditions. We are exploring this route. But even if a new system is worked out we need to maintain access to our 14 year archive of interlaced video as we frequently review particular segments. We frequently use stop frame and frame-by-frame viewing and want to avoid degradation wherever possible to help us identify the vegetation.

    Given we are not video specialists we would pick less technical options first (e.g. avoiding working out wiring of sync signals). The suggestion to use tape decks for just passing the signal with WinDV on the PC is a great solution for us for now.
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  15. Originally Posted by usually_quiet View Post
    @Skiller Once again pandy is apparently hijacking a thread to pursue an argument with someone (in this case you) that it finds interesting but is most likely unhelpful to the OP. That is its M.O. It comes here mainly to start arguments, so treat it like what it is, a troll. It is on my ignore list.
    Well... you perfectly fit in trolling definition and remarks that i'm on your ignored list (but you always comments my "ignored" messages) sounds like you desperately need to find a good shrink (bipolar disorder?).

    Be practical not jealous - buy a few books and learn yourself something useful...

    Also i hope that my thread "hijacking" will not trig your practical country to any military actions (for example some drone attack) ...
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