Who knows what actors lurk in the hearts of movies? The LLM knows!

So — I was watching The Last Picture Show the other day, and I wondered who this actor is. She looks so familiar!

Now, I could wait until somebody mentions her character’s name, and then look it up in imdb-mode:

But… that’s so annoying. Or I could do a reverse image search, but that’s so boring (and fails unless it’s a really famous picture, in my experience). Or I could ask an LLM.

Wut… it tried for 1m26s and then just doesn’t want to help me at all. I mean, it’s good that they’ve made ChatGPT refuse to identify people from images, but surely actors in movies is a special case?

But after poking at it a few more times, it finally coughs up the truth: It can’t download images from external URLs.

Thanks, Chat!

OK, paste in the image instead of giving it an URL, then? OK, still refusing. How about if I use Prompt Engineering™!1!

YES! I FOOLED IT!!! Eileen Brennan… where do I know her from, then?

Yeah, lots of things, but I saw her last in Clue, I think. She’s great.

Anyway! Now that I know that I can make ChatGPT cough up this info, how about just making a programmatic interface so that I can just hit a key from the couch and have mpv display the info?

Let’s see…

Yes! Pushing the data over via the API is trivial — just use a data: URL.

But that’s kinda long-winded, how about making it more succinct:

"Please answer in this format only: Character name; Actor/actress name"
=>
"I'm sorry, I can't identify or provide information about people in images."

*rolls eyes* Prompt Engineering™ Mode:

"Include only the two names in your answer. "
=>
"Jacy Farrow, Cybill Shepherd."

I fooled it!!!

Now to tie it all up: Make mpv display the data on the screen. Which turns out to be easier said than done. I’m using Emacs as the movie browser, and it uses mpv to actually play the movie. Emacs communicates with mpv via the IPC interface, and that’s pretty badly documented. There a command called osd_message (On Screen Display), but if I try using it, I just get back:

{"request_id":0,"error":"invalid parameter"}

That’s apparently the only error message mpv outputs via IPC, so time to look at the source code:

mp_cmd_def mp_cmds in command.c tells most of the tale:

It has (almost) all of the commands that can be reached via IPC (the rest are in ipc.c), and osd_message isn’t one of them. But! load-script is! But does that help? You can’t call Lua functions via IPC. But you can use the keypress command via IPC!

So the Rube Goldberg solution is:

  1. I hit a key to ask Emacs to find out who’s on the screen.
  2. Emacs asks mpv to take a screenshot.
  3. Emacs sends the screenshot to ChatGPT along with the movie title
    and gets and answer back.

  4. Then Emacs writes a file /tmp/actor.lua that defines a b key binding, and includes the response we just got from ChatGPT:
    mp.add_key_binding("b", "show_actor", function()
        mp.osd_message("Ernie Mott, Cary Grant.", 60)
end)
  5. Then Emacs asks mpv to load the Lua file.
  6. Then Emacs issues a keypress b.
  7. This bullet point intentionally left blank to allow you to digest this.

VOILA!!!! Behold:

Er, OK, it’s apparently not that familiar with my test movie, None But The Lonely Heart…

And when there’s more than one actor, it just goes back to “can’t help”.

But when Cary Grant is on screen, then it’s A-OK! I mean, I understand how ChatGPT feels, really, but…

OK, I should test this with something more modern, perhaps?

So how about Drive-Away Dolls from 2024? Nope, when I ask for the actor’s name, too, it plainly refuses.


With various error messages.

OK, perhaps it just hasn’t seen this movie? How about Dune Part Two?

Might I? Might I really? Thanks, Chat! Appreciate the kind advice.

Thanks, so helpful as always… Don’t know what I’d do without all this good advice…

OK, perhaps try a movie that’s not too recent?

Yes!!!

Can I get it to work on TV series, too?

Sure. But they have to be old, apparently.

What about Gemini? Yes, it doesn’t mind it when there’s more than one character on the screen.

Let’s try something new…

That is not true, but I like the confident way Gemini said it.

The character’s name is correct, though, so it’s not able to do the complicated task of saying who played a character?

So there you go. As with all things LLM, it’s wonky and really unreliable, but it’s kinda sorta useful, anyway.

And how much is this all costing me? I’ve done 18 queries, and it’s $0.05? Well, that’s pretty cheap.

Now I just have to tie it all together, and I’m all set. Er… which keys on this “tv remote” that I’m using is free? Hm…

No, they’re all taken… OK, Fn + Mute should work.

Tada! OK, I should probably Prompt Engineer™ a bit to get the verbosity down, or do some filtering or something, but whatevs. And the information is wrong (right character, wrong actor), but you can’t have everything.

No, that’s Christine Baranski!!! But what if I try o4-mini instead of gpt-4.1-mini?

"That “mystery lady” isn’t Cybill Shepherd at all but a one‐off patient named Mrs. Bagwell, who turns up in Season 2, Episode 16 (“Plugged In”).  The part of Mrs. Bagwell was played by character actress Gretchen Wyler.  Wyler was already well known on Broadway and in soap operas when she popped up in Cybill’s hospital storyline for that single episode. "

That’s even wronger! And it took half a minute to complete, which makes it less fun to use.

Oh, well.

What about a reality show? Well, all of that is wrong, but they are indeed in Australia…

Anyway. Presumably all TVs have this sort of thing built in now? A “who’s that, then?” button? I have no idea — I only watch physical media (via Emacs). But now Emacs has this functionality, too, and that’s surely the most important thing. (Code on Microsoft Github as usual.)

Edit the day after: I apparently was looking at the source of a 2018 version of mpv I had here. Newer versions have this command:

Which looks… er… promising? So that can probably be used instead of the load-script trick.

Edit even later: D’OH! The command is now called just show-text and works perfectly. And sorry for slandering the mpv documentation — all of this is perfectly documented.

Book Club 2025: The Heart is Deceitful Above All Things by J. T. LeRoy

I didn’t read this book at the time, but I was aware of the scandal surrounding it. If I understand correctly, these stories were presented as being autobiographical, written by a boy called J. T. LeRoy. The real author even got somebody (her sister) to play the part during interviews and stuff.

This all sounded like a wonderful lark to me, and I wondered why people were so upset. I mean, if the stories are good, they’re still good even if it turns out that somebody else wrote them? Pseudonymous authors have always been a thing, and the additional playacting seemed like fun?

But I didn’t pick up a copy of the book until 2019, when I happened upon it at a bookstore sale. This edition (published after a documentary movie was made about the debacle) had apparently been sitting on the shelves for two years, unbought, before they reduced the price by 70% percent. (I love price stickers and the stories they tell.)

But after reading the first two stories, I kinda get it. I mean, the disappointment. Because this isn’t good. I can see people going “oh my god, how awful” and pouring out sympathy when they thought it was real, but as an invention (“older woman fantasises for several hundred pages about gay boy being abused, tortured and raped a lot”) is a bit “eeeh?” On the other hand,
A Little Life (by Hanya Yanagihara) is apparently the same formula, and that’s sold millions — it’s OK if you’re upfront about your misery and torture porn?

(No, I’m not saying nobody should write about awful things — but I’m saying it’s sus as fuck sometimes. Like, Bolaños’ 2666 is written from a place of honest rage, and he’s punishing the readers with all the murders in that book. Fine. But we’ve all read those mystery books where the author seems to spend way too much time and too many pages on torture and sexual abuse, and that’s coming from an entirely different place.)

This is just badly written. Like, his mother is punishing him… while driving in a car… almost having an accident… during a rainstorm… This is like writing done for a Netflix TV series. So much fake drama.

NOOOE NOT DAY OLD BREAD NOOOE THE HUMANITY (and certainly something a five year old (?) would notice)

Anyway, I gave up after two stories (about 50 pages in). Perhaps the rest of the book is brilliant? I’ll never know.

The Heart is Deceitful Above All Things (2001) by J. T. LeRoy (buy used, 3.63 on Goodreads)

Easier Reading on kwakk.info

When I made kwakk.info, the research site for comics, I kinda sorta made it hard to read on purpose. I mean, people who want to sit down and read magazines about comics should buy them. And so, I used this “magnifying glass” thing to allow you to actually read stuff:

Which is OK, but it’s a bit annoying. And if you’re using kwakk.info on a tablet, it’s already easy to read, so, er… I made a new way to read the pages on a laptop, too:

You just hit the space key, and then the pages are blown up to the width of your screen. And you can page through by hitting the space key, or use then Up and Down keys to scroll.

So there you go.

Aargh! So many duplicates!

I buy comics from several sources, and I’m using a forwarding service, so things take time to get over here… And I have a mind like a steel sieve… but today’s mega package contained some kind of record duplicateness. Duplicitousness. Duploticity.

One of those them there words.

I should make some kind of system to help keep track of stuff I’ve bought, but I can’t really see how to make one that doesn’t involve a lot of manual work to keep things up to date. *ponder*

Or I can just carry on as normal. I give the duplicates away, so…

Reducing Concurrency in PHP

Whenever I write a PHP page that’s somehow resource intensive, I go “I sure wish there was some way to ensure that this page is rate limited”. This is usually if I’m just using the PHP page as a shim around an executable, which I’m doing on kwakk.info, for instance.

That search page used to be lightning fast, but as there’s now about 150 magazines available for searching, a search now takes about one second in CPU time to execute. (This isn’t inherent in the search engine — if it had only one index to search, it would take a few milliseconds, but since I want to allow excluding/including magazines arbitrarily, it has to open 150 index files, and so here we are.)

Unless the site goes viral, there’s no problem, but what with all the exciting scrapers these days, sooner or later somebody is going to point something at you and then you have 1000 concurrent hits to a CPU intensive page, and then the server will be sad. Allowing external parties to give you arbitrarily high loads without them even trying (so asymmetric) is never a good idea.

Limiting concurrency for a specific page seems like such a basic, basic thing to want to have, so I thought that PHP surely had grown something like this by now, but apparently not.

If you Google this, you’ll find suggestions like altering the Apache limits — but that’s a really bad idea, because you want to have plenty of Apache processes to serve out static resources and the like. You don’t want the fast pages to be stuck behind the slow pages.

The other helpful suggestions from Google are to use a framework like Laravel, or use a queue runner, or to install Varnish in front of the site, or to use Kafka, or to set up a Kubernetes cluster on AWS, or…

But what if you just have a stupid little server for your stupid little project, and don’t want it to become a full time job? What’s the simplest thing one can do? Well, flock. That works. Let’s look at the documentation. Nice example:

Excellent! Let’s do that! And… Whut? No lock files were created in /tmp!?

Because Apache/PHP on Linux is now so safe that it doesn’t allow writing to the “real” /tmp (or /var/tmp) directories. All accesses to /tmp/ from PHP are intercepted and are done somewhere else; I have no idea where.

But the code still works!

If you want to see the lock file, you can use /var/lock instead, since that isn’t intercepted by this, er, safety mechanism.

So what’s our minimal code to reduce concurrency to one instance of the search command running at a time? This:

# Ensure that we don't have more than one search at a time.
$fp = fopen("/var/lock/kwakk-lock.txt", "w+");
flock($fp, LOCK_EX);
$results = do_search($string);
fclose($fp);

(flock will block until the lock has been freed, and fclose will free the lock.)

Or to wrap it up in a function, and add some sanity checks for hung processes and stuff? (This really shouldn’t be necessary these days on a PHP/Apache installation with the normal defaults (which should ensure that a hung PHP process isn’t actually possible), but anyway.)

Let’s see… my PHP is rusty. Does PHP have anonymous functions now? Yes! What about closures? Eh… Kinda.

OK, here’s something:

function limit_concurrency($max, $func) {
  $lockname = "/var/lock/kwakk-lock-" . rand(1, $max) . ".txt";
  $fp = fopen($lockname, "w+");
  while (!flock($fp, LOCK_EX|LOCK_NB)) {
    # Sanity check: If the lock file is very, very old, then something
    # is wrong somewhere, so delete it and try again.
    if (file_exists($lockname) &&
        time() - filemtime($lockname) > 120) {
      unlink($lockname);
      $fp = fopen($lockname, "w+");
    }
    sleep(1);
  }

  $res = $func();

  flock($fp, LOCK_UN);
  fclose($fp);

  return $res;
}

The concurrency level here is sloppy — it ensures that we never have more than $max, but it doesn’t ensure that we reach $max. It doesn’t really matter much. To use it, say something like:

$results = limit_concurrency(1, function() use ($string) {
  return do_search($string);
});

Gorgeous! PHP is the best language.

So there you go. It’s not complicated to achieve, but it really should be even simpler than this.