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Hi8 50p easy cap USB vs 25p Firewire
  • mikeymikey

    So when I'm capturing Hi8 tapes using easy cap viewer software through composite or S-video out of the cam, I can get 50p. However, when I capture via Adobe premiere using firewire I can only get 25p. Can someone explain this to me?

    Thanks a lot for anything on this I'm completely confused :)

    Mike

  • 9 Replies sorted by
  • kurthkurth

    No hi8 cameras shot progressive video. And I highly doubt that little toy would convert interlaced on the fly, so your software is not recognizing correctly, would be my guess. If it's pal, it's 50i. If adobe is converting after capture, it might be 25p. Look for the scan lines. Nowhere will you get 50p from 50i w/o loosing half the resolution.

  • flashflash

    You can transform an interlaced video into progressive video. To do this you have to shift the half frame (the odd frame) of the second image to the half frame frame (odd) of the first image. It's complicated to explain but very easy to perform. Search in your Editing software if there is a function to shift odd or even interlaced frame.

    It is a method used in the 90s by the special effects studios to transform interlaced images into progressive images. The shift function is available in compositing software such as Nuke for example. Not to be confused with the interpolation method (proposed by all software today) which makes the image lose its sharpness

  • mikeymikey

    I see. Thanks for the replies :)

    The file I have is 768 x 576 50p. When I scrub through in Premiere there are 50 individual frames. So what you're saying is that to get the extra frames it's halved the res and then upscaled again to give me the res back?!

  • kurthkurth

    There's no upscaling involved. Premiere might be doubling your frames, if it de-interlaced it already. Take your original 50i hi8 footage and de-interlace it to 25p. That'll be your best quality. Although the new topaz software might be your best option, it's not free (yet) , but there's probably a free trial with watermark...to test if it fits your needs.

  • Vitaliy_KiselevVitaliy_Kiselev

    @kurth

    Usually best is to deinterlace to 50p, not 25p.

  • kurthkurth

    @Vitaliy ...why ? it would just double every frame. And 50i can be deinterlaced to 25p , then slowed down 4% to 24p, if that's the look. ps...I guess it could interpolate each frame which would take a long time. But it still wouldn't have anymore resolution data.

  • Vitaliy_KiselevVitaliy_Kiselev

    @kurth

    Because each second line changes in 50fps :-).

    So, no it is not doubling. And proper deinterlacer will always make much better 50fps, and worse 25p (as here it needs to add blending).

    And you should never ever slow down 4%, until you really need to fit stuff into the film that is distributed with such framerate. Even in such case, most good guys just keep original frames and change sound part, not video.

  • kurthkurth

    @Vitaliy....ok yeah it's a complicated topic...ie. which field dominance etc. Only by testing and judging results...and that's what I meant by slowing down...playing 25p as 24p then slowing sound 4%. Regardless per the OP, do u think because it's hi8 and he's using composite to capture at 50p, it'll make a visible difference over firewire capture at 25p? Only he knows which is best. @mikey...how are you firewire capturing ? To a windows firewire card or to an older mac? If it's a mac...try converting using compressor. The new topaz ai still might produce the best quality. Does it input interlaced material ? ....answered my question....no, you gotta deinterlace it first. I'd download the trial and then input the 25p and 50p versions and see what comes out best. Just guessing....firewire 25p will be better than composite 50p. But only a test will tell.

  • mikeymikey

    Sorry for taking a while to respond to this. My easy cap stuff broke and I left my firewire back in the UK. I'm just ordering another one now and thought I would check this page again so thanks for your comments.

    Quality isn't actually a concern for me it was more the frames that I thought I was gaining. I film skating so having the old style of the Hi8 with the slow-motion has always been something cool to me.

    I'll make a screen capture of what I'm seeing with my easy cap/premiere process and also try the software you've mentioned so we can narrow down what exactly is happening!

    Thanks again for your help everyone. Mike

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