11-May-2021 (Tue) Wherein there has been a lapse of time

I made a time-lapse video of the dance floor installation!

This is the first two days of the floor installation. They also came back for a third full day of sanding, but that wasn't very interesting to watch; and now we're going to paint it, which will take another day or two.

(We do have an older video where you can watch paint dry, if you're in to that sort of thing.)

We set up a laptop recording 24/7 all weekend with OBS, and that generated a 98 GB TS file. Fun fact: guess what Quicktime Player, VLC and ffmpeg really don't like to deal with? That's right, 98 GB TS files. So my plan to just scrub through it and find the timestamps to extract didn't work because no player would let me scrub. I ended up splitting it into 10 minute segments with:

    -map 0 -f segment -segment_time 10 -reset_timestamps 1 $encode_options

With "-codec copy" it wouldn't split at all, so I had to re-encode it. Then I was able to manually page through and delete the segments that were in the middle of the night. Next, I time-lapsed like this:

    -f concat -i file_list.txt -vf 'tblend=average, setpts=PTS*0.01, tmix=frames=30' -r 30 $encode_options

The "tblend" filter is what gives the ghostly motion-blur effect on the people walking around. Without that, time lapses have a much more flickery, stuttery quality to them.

That final encode took twenty hours to convert 22 hours of source video into a 13 minute time lapse on a 3.2 GHz iMac Pro. So this is maybe not the ideal procedure.

17 Responses:

  1. I had to speed it up to x2 to be sure it was Journey's Don't Stop Believing slowed down to 1/10th? So apropos. Pure Genius.

    • jwz says:

      Thanks to its omnipresence in Bootie's mashups, that song became probably the most annoyingly overplayed song in DNA Lounge history, so one time I used the slowed-down version on some video as a gag, and then I just kept doing that, so I guess it's our theme song now?

  2. Dude says:

    Glad the other commenter suggested playing it a double speed, 'cause I initially thought it was Julee Cruise's "Falling" at half-speed to distort her voice. Nope, just Steve Perry.

    And even without all the construction stuff, it's trippy to see that room fully lit up.

  3. David Konerding says:

    Huh, they used a jigsaw to cut out the ply that abuts the pillars after drawing a template. I have the same table saw. Everything is square, although I can't see how they lined the boards up so well (laser?). At some point, a person dressed like a boy scout is chatting.

    • jwz says:

      There was a lot of other fiddly jigsawing that you can't really see on the video, like around the main stairs, the stage stairs, and the transitions at doorways. No lasers were used.

  4. stega says:

    Next time you're considering doing TL work and want to make it easy on yourself grab a relatively inexpensive cam that will handle it for you. A Brio is probably your best and cheapest bet: not a huge viewing angle but decent enough for indoor stuff, can be run off mains power and not-god-awful to setup. (I run a ton of TL, streaming, and motion trigger cams here at the ranch -- even a big Tikee Pro -- and have experimented/tested lots of the options out there.)

    • jwz says:

      I've tried several dedicated time-lapse cameras (including a Brinno, which I'm guessing is what you meant by Brio), and also a couple of iOS packages, and they were all garbage, which is what led me to using a "real" camera this time. And this is the first time I've had any time-lapse video come out halfway decent, so I think I made the right call.

  5. MattyJ says:

    In the grand tradition of offering advice when none was asked, have you tried DaVinci Resolve for video editing? Learning curve for simple stuff isn't too terrible and I've had it chew through 30-40 GB source H265 files like they're nothing (2.6 GHz MacBook Pro). Worth a shot if you haven't tried it already and hate it.

  6. Smylers says:

    Love the bit from 6:51 where the stack of not-yet-used sheets of wood is moved, dealing them like playing cards.

  7. Carlos says:

    It's funny - even in the time-lapse and from a distance, you can see that these guys care about doing a good job. There's no half-assedery, fuck-it-good-enough, who's-gonna-see-it bullshit going on.

    You must have put a fair bit of work into finding a company that takes this much pride in their work.


    • jwz says:

      These guys did fantastic work, we were very impressed.

      But to be honest, we went with the first company (fourth quote) who didn't sound like they were just trying to gouge us on the price... So we really lucked out!

      • Carlos says:

        Maybe give the company a shout-out here, so people searching their name find this and your comments?


      • Thomas Lord says:

        Tough times and glimmers of hope often bring out the best in people because people are people and that's where we come from, according to scholars.

  8. Thomas Lord says:


    I'm glad I thought to do this before comment period on this post expired.

    Thank you anonymous donors for this act. It's a kind act to the whole community that cares about culture around these parts and beyond.

  9. Pete Twentythree says:

    I must confess to staring at that poor uncovered mixer. Very glad it was covered at 11:40ish so at least it won't get the dust from the sanding. Oh my pots and faders I do declare!

    • Chris P says:

      I like to think the music is actually diegetic and the mixer was in active use the entire itme.

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