Don’t want to lose this:

You can disable ldb … at runtime …:

(funcall (sb-alien:define-alien-routine
(“disable_lossage_handler” cl-user::disable-sbcl-ldb)
sb-alien:void))

About once a year I dabble with trying to setup a video streaming server so I can watch movies on my Mac which doesn’t have a DVD reader on it.  Usually this all falls apart because the debug loop is the scale of a DVD, the free tools are all full of personality, and the world of video encoding is quite confusing.  This time I think I got it.  So here some tricks I picked up along the way.

Darwin Streaming Server isn’t hard to set up.  I have it serving up files who’s extension is m4v, which I assume stands for mp4 video.

I use HandBrake on the Mac to rip the DVDs.  In fact I use HandBrakeCLI to rip them.  A command like: HandBrakeCLI --preset Universal --input /dev/disk3 --output foo.m4v  rip and convert DVD into a single file that is 1 to 2.5 Gig in size.

While that foo.m4v file can be served by  Darwin Streaming Server your better off if you add so called hints to the file.  These are apparently nonstandard mark up that Apple invented to make it possible to seek to arbitrary points in your movie.  While there are signs that “QT Sync” can do hinting I ended up using mp4creator to do it.  In addition to hinting you can optimize, so while I have no idea what that does, I do that as well.  Hinting is a pain because you need to do one pass to hint the video track and another pass to hint the audio track.  So you end up doing something like this: mp4creator --hint=1 "foo.m4v" ;  mp4creator --hint=2 "foo.m4v" ;  mp4creator -optimize "foo.m4v"

In that example the numbers 1 and 2 are denote the track number to hint.  Those are reasonably dependable; but to be save you can use  mp4creator -list foo.mp4v to be sure.  I wrote a bit of perl to glean out the right numbers and gin up the commands to do the hinting.

Usually when you stick a DVD into a mac the operating system launches the DVD player, but you can change that behavior in the CDs and DVDs Preference Panel.  Using that I launch an apple script.  Since I’m more fluent in shell scripting I have that turn around an launch a shell script.  That script devolved from other examples I found around the net.  The essoteric bit-o-clever in it are useful; so it appears below.  It has an unfortunate flaw that the heuristic for guessing which disks are DVDs sometimes gets the wrong answer; but it’s good enough for now.

My shell script then: 1) runs HandBrakeCLI, 2) ejects the DVD, 3) hints, optimizes, and 4) moves the result into  appropriate  directory for the Darwin Streaming Server.  A little cgi script then enumerates what’s available to machines on my household’s local network.

global dvdPath

try

    tell application “System Events” to set DVDs to name of disks whose capacity is less than 8.589934592E+9

    set dvdPath to quoted form of (POSIX path of item 1 of DVDs)

      do shell script “/Users/bhyde/bin/snarf_dvd.sh “ & dvdPath

end try

“The Barter Theater first opened its doors in June 10, 1933, providing relief and diversions for Depression-era audiences.  It was founded by Robert Porterfield, a young actor who suggested that audiences barter homegrown produce for admission.  Its motto was “With vegetables you cannot sell, you can buy a good laugh.”  Crowds were receptive to the idea of ‘ham or Hamlet,” and an estimated 80 percent of the audiences paid with fruits, vegetables, and livestock, or dairy products.”  [1]

I’m surprised I’d not recognized that bubbles of the business cycle has numerious analogies to a mast year [1,2].  Which has got me to wondering if there are cases where an industry might strive to synchronize the equivalent of a mast year so as to disrupt the populations adjacent to them in the supply chain.  No doubt it happens by mistake, but intentionally?

Here’s an interesting cognitive science puzzle.

Seth is seeking a cognitive task which he can use to test how his brain is working.  He want’s something quick, something he can self administer.  But this is the part I find particularly thought provoking, he want’s something that the brain won’t learn how to get better at.

This is like one of those cryptographic puzzles.  He needs a puzzle generating black box.  The class of puzzles mustn’t be too hard and they need to have difficulty metric delivered with htem.  But, no matter how many of these puzzles the brain solves, it should never manage to learn anything about the class of puzzles the black box spits out.

I wonder if there is something deep there?

They can only sell fruits and vegetables at Boston’s Haymarket and there is a guy who wanders around and fines the occasional vendor who tries to put on something else.  I’ve seen people try to sell batteries, olive oil, cleaning products.  Around the corner from
Haymarket are the remains of the old fish market and one maybe two vendors occasionally show up there; selling only fish.  The stores the line the sidewalk adjacent to Haymarket are mostly meat markets.  They aren’t as tightly regulated and they put on a larger variety of goods.  No doubt you could write a whole book about history of the negotiation between all these vendors and their landlords, e.g. the market owners.

The homogeneity of the vegetable market is an interesting contrast to the shopping mall where the landlord, it seems, strives to maximize the heterogeneous diversity of the tenants.  No doubt the tenants prefer the absence of competition and I assume their leases spell that out explicitly.

I don’t doubt that the vegetable vendors prefer that Haymarket’s regulator stamps out the occasional attempt to change the rules of the game.  The homogeneity creates externalities that the can be observed at larger scale in other geographic concentrations.
Which is why the stifling nature of zoning laws tends to be pretty uncontroversial.  No doubt the folks who live in NYC’s fabric district are peeved when some innovator decides to open a clothing store.

It is a mystery to me why there are so few commercial malls with a homogenous rather than a heterogeneous collection of stores.  Of course there are examples.  Tourist trap malls that sell nothing but trashy collectibles.  Antique furniture malls, that seem take over failed malls.  And of course mall landlords to work to achieve some kind of homogeneity; filling their space with vendors whom will all appeal to the same demographic.  So maybe some of the mystery can be resolved by saying that the homogeneity is on either the buyer side, or the seller side.  Maybe you can’t get high producer homogeneity until you achieve a sufficient population density.

Nice example of how tit-for-tat is often exactly the wrong approach.

It’s a curious saying, “Render unto Caesar.”  Advice to the oppressed, give it up, accept what you can not change.  Don’t organize a resistance.  Don’t fight back.  Cave.  No matter that he’s evil, illegitimate, foreign, and couldn’t careless about your culture.  Of course in context the entire quote is about surrender “…and unto God the things that are God’s” so it is really pretty consistently in the give it up and submit school of philosophy.

But there are times when it’s probably good advise: fighting city hall, gravity, death and taxes, etc.

I’ve spent a lot of calories over the years declining to submit to Microsoft’s monopoly.  Even had some success in doing so.  But rolling the clock back I’m comfortable that I didn’t expend too much effort evangelizing that other people decline to submit to that Caesar.

That’s all water under the bridge, more or less, but this issue arises again and again.  A dominate commercial monopoly exercises their power in offensive evil ways and the choice arises, submit or sign-up for the extremely abrasive alternative of fighting or shunning the network?

What brings this all to mind?  Today’s example – Facebook v.s. Google