THE FROGS — An Ode to Ardour

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Apr 022013

So, way back when I was in the college thing, my dear friend Steve Killen and a few other folks translated The Frogs. And then assembled a team of costumers and actors and put on a really great performance on a shoestring budget (I was there watching Steve navigate the club funds process!).

Steve made some OK tapes of the performances and… I happened to own a couple of speakers and nice amps and know my way around a mixing board so someone lent us a few floor mics and I ran the sound. I happened to be a GNU/Linux nerd and was familiar enough with Ardour to record sound that didn’t clip so… I grabbed the board recording with my laptop, with the idea that we’d throw together a DVD.

Fast forward six or seven years and somehow both of us moving, at different times, from Baltimore to the Raleigh area… Steve still had the tapes, I still had the audio.

A few days ago, Steve’s old PCI bttv card ended up in my 8-core monostrosity, and after a few harrowing days of screwing around with v4l, I was finally able tonight to rip the tape that I recorded audio for (good old ancient tech — the card just dumps the raw ntsc signal and I captured it as a raw yuv interlaced stream, using a sweet gigabyte per minute). And now comes the really fun part… syncing the audio and video. And then the really fun part: muxing and creating an mpeg2 for burning onto a playable dvd (good thing I have those dvd±rw discs that still seem to work!).

The last part will simply be an issue of the pain that is getting mencoder to stitch together a bunch of files and generate a file that is the proper size and doesn’t look crappy in too many parts (shouldn’t be too difficult, since the source video is an EP VHS tape so there’s not much data to encode… and this 8-core beast can do a parallel encode much faster than realtime).

But editing? Oh editing is going to be fun. I discovered a terrible truth: both kdenlive and openshot are based on mlt, and mlt only supports using JACK for transport timing and not output… and neither program exposes mlt’s support for even that 🙁

Luckily, xjadeo was resurrected last year, and at least installs… unfortunately, the interface is entirely command line based and oh is it a typical unix monostrosity with dozens of flags. Steve cut the video at intermission, making life a bit more difficult since we have to splice the audio and video in two more places… tonight and tomorrow will involve lots of command line magic to get the audio and video basically in sync.

Then! Reality! The audio and video were recorded on different devices, so that whole different clocks and sample rate thing comes in and they gradually desync from each other. The Internet comes to the rescue: it turns out Ardour has a rubber band tool so I just need to find a sync point at the start and end of the video, and then it’ll do the resampling and retiming with pitch correction and all that jazz for me. TECHNOLOGY.

So… I hate video software, and I really, really love Ardour for making the audio half of close to trivial.


Unfortunately, the video is an EP VHS tape. And we only managed to find two consumer grade vhs players… the tape is a bit messed up at the beginning with a tracking problem. And then it’s vhs and low bandwidth vhs so it’s a bit wavy… I played around with a few filters in mplayer, and I think we can do decent deinterlacing, improve the white balance, denoise it a bit, and maybe even eliminate the flutter. It’s acceptable at least after Steve zoomed into the stage.

The real gem is the audio. Whoever loaned Steve the floor mics deserves a hug… We have excellent stereo seperation, and it only took minor filtering to make it sound really, really good (gate -> highpass -> 2:1 compression -> hard limiter -> slight reverb -> isthis a bbc radio play or an amateur production of a Greek comedy?). The stereo separation makes it easy to tell who is who, dialogue is crisp and intelligent, and it makes the video watching experience pleasant (kind of sucks we did it so long ago on analog tape because the costumes were really great, but we were limited by the cheaply available techbology of teh day). The mics even picked up action in front of the stage, albeit barely… but without much noise so the only real task left with audio mastering after basic sync is done is to run through once and route the few low pickup sections through another set of filters (way more gating, tons of compression).

p.s. I also managed to get a garden built (thanks to bpt for making the compost appear!) and other people to volunteer for hcoop and brewed a beer and found a copy of Tempest 2000 for the Atari Jaguar at a used book store. Hooray for doing stuff.