Synchronisation and SMPTE timecode (time code)

(philrees.co.uk)

35 points | by sublinear 2 days ago

7 comments

  • linsomniac 1 hour ago
    I wish more cameras with GPSes supported SMTPE or something to mark the video with a time code. I get the sense that GPS time is accurate to within 1/30th of a second, if not way way more, but even if it just got me in the neighborhood so I could nudge it a frame or two one way or another.

    I like recording things like my kids performances with a GoPro or two, and sometimes my wife or I get some shots on our phones. Multi-cam can be fantastic when you have people walking around in front of cameras, for example.

    I used to have a majorly hard time syncing the multiple cameras shots, though the last time I did it (a couple months ago) I had much better luck with the "sync using audio" feature, in the past I've had problems. But why can't we have a timecode with the video stream, in the cases of GPS cameras (I think everyt camera I have now has a GPS)?

    • pezezin 22 minutes ago
      > I get the sense that GPS time is accurate to within 1/30th of a second, if not way way more

      You are off by 6 orders of magnitude, GPS time is accurate to within 30 ns: https://www.gps.gov/gps-accuracy

  • monster_truck 2 hours ago
    A perfect resource, still as relevant as ever.

    Genlock, Clock Gen and their friends are at the top of the "check all of the responsible hardware, the ports, and the cables" list when someone is having a flaky problem that doesn't make sense to anybody. Shortly followed by 44.1 vs 48khz and 59.94 vs 60fps being wrong somewhere

  • windowliker 3 hours ago
    Phil Rees products were an absolute godsend in the 90s when most hobby and budget studios were still mainly all hardware being recorded to tape of some description. You would often find multiple little red and black boxes doing various conversion and routing jobs. And they all powered straight off the mains without a big heavy internal linear supply, or external wall wart, which was a great help during late nights where the right PSU may have gone walkies.
  • fleventynine 2 hours ago
    Ugh, the accidental complexity of drop-frame encoding, BCD, etc... This mess will likely be with us for a long time.
  • danbmil99 3 hours ago
    I built this, anyone interested? It was a wild ride

    https://amiga.resource.cx/exp/phantom

  • butterknife 6 hours ago
    We once had an AKAI MPC1000 running as a master for a "big studio" ProTools rig using LTC. Good times.
    • windowliker 3 hours ago
      Were you using a MIDI to SMPTE converter of some kind? The MPC 1000 only has MIDI I/O, no SMPTE tape sync. And the stock firmware only offered regular MIDI clock, not even MTC[1], though it is possible to get MTC in and out of an MPC 1000 using the unofficial JJOS OS[2].

      [1] https://en.wikipedia.org/wiki/MIDI_timecode

      [2] http://www7a.biglobe.ne.jp/~mpc1000/

      • monster_truck 2 hours ago
        You're holding it wrong. You can just record a real one and play it back. I use the same cursed approach with my 2500XL to intake/chop/modify/output cv/note signals to a modular setup (which has a handful of outs that don't need to be modified to do this)

        JJOS is legendary though. Crazy how much it adds

  • brcmthrowaway 4 hours ago
    Shout out to Chataigne, which supports SMPTE timecode via a 3.5mm jack for personal projects.