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Domain: leitch.com

Stories and comments across the archive that link to leitch.com.

Comments · 7

  1. Re:A simple answer by ibennetch · · Score: 1 · on US House Kills Proposed Delay For Digital TV Transition

    Where do you get that BLACK is full power in an NTSC signal? Any time I look at a scope for analog signals I see black as 7.5 IRE and white as 100 IRE.

    Actually, the GP is correct -- the US 525 (and most other modern systems, with the exception of France) use negative modulation. 100%+ white can even cause the RF transmitter to completely cut out, I'm told. (actually I just looked in to it a bit further, apparently anything over 130 IRE causes the zero carrier, which leads to the buzz we've all heard [leitch PDF]).

    Anyway, IRE isn't the same as the percentage of full modulation -- IRE is a (somewhat invented) scale for referencing the luma information; to continue your scope comment you also see -40 IRE as part of the sync pulse; this of course doesn't correspond to the video signal being at -40% modulation, so it doesn't necessarily follow that 100 IRE == 100% modulation.

    Anyway, this old wikipedia article[1] is the best explanation I can find online right now and also has some information on why negative modulation is preferable to positive modulation.

    By the way, I'm not 100% certain but believe this negative modulation is only the AM RF over the air transmission and not the vanilla component/composite video in a facility. If that's true (and again, I'm not sure); that certainly would lead to further confusion in measuring and testing.

    Hope this helps rather than confuses :-)

    1: The section above about "IRE Interpretation" completely confuses me, though. I think the writer wrote "100% white" in a few places they meant "black"

  2. this is rather expensive stuff by sxpert · · Score: 1 · on Video Multiplexing on Large Screens?

    you're in for a wallet shock...

    what you are looking for is manufactured by pro-video hardware companies.
    the 2 items that come to mind right away are :

    the Leitch Neo SuiteView

    and

    the Miranda Kaleido K2

    both are over the 30K USD mark...

  3. Re:New FS by Lifewolf · · Score: 2, Informative · on The Linux Filesystem Challenge
    We've considered archiving our video in some kind of compressed streaming format like AVI, Quicktime, or MPEG-2, but none of these offer lossless codecs that are appropriate for us, and we're unwilling to accept using a lossy compressor.

    It doesn't sound as though "compressed streaming format[s]" are what you're really looking for, and AVI isn't a streaming format in any case. However, there are archival-type video codecs that may suit your needs:

    • BitJazz SheerVideo is an excellent, relatively quick, lossless, 4:4:4 video codec. The encoder is fairly inexpensive, the decoder is free, and they're working on a 10-bit version.
    • Digital Anarchy Microcosm is a lossless, 64-bit, RGBA codec. It's excellent if you're not working in YUV. The encoder is even less expensive than SheerVideo, and the decoder is free.
    • Apple Pixlet is quite nice, though not completely lossless.
    • Motion JPEG might be considered if you need pretty-much-visually-lossless but not mathematically lossless.

    In a perfect world, you'd have one of these working behind the scenes in some sort of network storage device in a manner similar to the dpsVelocity VTFS. If you haven't worked with an editing system that uses VTFS, I recommend getting a demo.

  4. Why not use what broadcasters use? by fieldmouse · · Score: 1 · on Feeding GPS Time to a Private NTP Server?

    Something like this

  5. Your own dedicated GPS driven Time Server by mamahuhu · · Score: 1 · on Do You Have The Time?

    Leitch supply equipment to the broadcast industry. It is vital for accurate timecodes to be used throughout a TV studio - for everything from editing to telling the audience the right time. Most broadcasters will use their own dedicated GPS driven Time Server that resides in their central equipment room. Leitch make a one of these. Check it out here .... I use the Leitch timeserver at leitch.com for my ntpdate on my linux box - as well as Mac OS X.

  6. Your own dedicated GPS driven Time Server by mamahuhu · · Score: 1 · on Do You Have The Time?

    Leitch supply equipment to the broadcast industry. It is vital for accurate timecodes to be used throughout a TV studio - for everything from editing to telling the audience the right time. Most broadcasters will use their own dedicated GPS driven Time Server that resides in their central equipment room. Leitch make a one of these. Check it out here .... I use the Leitch timeserver at leitch.com for my ntpdate on my linux box - as well as Mac OS X.

  7. Your own dedicated GPS driven Time Server by mamahuhu · · Score: 1 · on Do You Have The Time?

    Leitch supply equipment to the broadcast industry. It is vital for accurate timecodes to be used throughout a TV studio - for everything from editing to telling the audience the right time. Most broadcasters will use their own dedicated GPS driven Time Server that resides in their central equipment room. Leitch make a one of these. Check it out here .... I use the Leitch timeserver at leitch.com for my ntpdate on my linux box - as well as Mac OS X.