From 0e0c16c46011c815a11898a49b30d3e219e0f465 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <srid@srid.ca>
Date: Wed, 20 May 2026 08:06:44 -0400
Subject: [PATCH] twitter-convert, restore minimally

---
 configurations/home/srid@zest.nix       |  1 +
 packages/twitter-convert/default.nix    | 18 ++++++++++++++++++
 packages/twitter-convert/ffmpeg_ar      | 12 ++++++++++++
 packages/twitter-convert/ffmpeg_twitter |  8 ++++++++
 4 files changed, 39 insertions(+)
 create mode 100644 packages/twitter-convert/default.nix
 create mode 100755 packages/twitter-convert/ffmpeg_ar
 create mode 100755 packages/twitter-convert/ffmpeg_twitter

diff --git a/configurations/home/srid@zest.nix b/configurations/home/srid@zest.nix
index 611a27f..e371c91 100644
--- a/configurations/home/srid@zest.nix
+++ b/configurations/home/srid@zest.nix
@@ -33,5 +33,6 @@ in
   home.packages = [
     inputs.disc-scrape.packages.${pkgs.stdenv.hostPlatform.system}.default
     pkgs.zellij-one
+    pkgs.twitter-convert
   ];
 }
diff --git a/packages/twitter-convert/default.nix b/packages/twitter-convert/default.nix
new file mode 100644
index 0000000..b760277
--- /dev/null
+++ b/packages/twitter-convert/default.nix
@@ -0,0 +1,18 @@
+{ writeShellApplication, ffmpeg, ... }:
+
+# Some useful resources for this undocumented shit:
+# - https://stackoverflow.com/q/59056863/55246
+# - https://gist.github.com/nikhan/26ddd9c4e99bbf209dd7
+writeShellApplication {
+  name = "twitter-convert";
+  runtimeInputs = [ ffmpeg ];
+  meta.description = ''
+    Convert a video for uploading to X / Twitter.
+
+    You may need a Basic or Premium tier to upload longer videos.
+  '';
+  text = ''
+    export ARSCRIPT="${./ffmpeg_ar}"
+    ${./ffmpeg_twitter} "$1"
+  '';
+}
diff --git a/packages/twitter-convert/ffmpeg_ar b/packages/twitter-convert/ffmpeg_ar
new file mode 100755
index 0000000..a40aa8d
--- /dev/null
+++ b/packages/twitter-convert/ffmpeg_ar
@@ -0,0 +1,12 @@
+#!/bin/bash
+eval $(ffprobe -v error -show_entries stream=width,height -of default=noprint_wrappers=1 "$1")
+#results in e.g.
+#width=300
+#height=1200
+echo "height=$height"$'\n'"width=$width"
+newenv=$(bc <<< "width=$width; height=$height;"$'\nscale=3; aspect=width / height;\nprint "aspect=", aspect;
+    print "''\n'$'";\n\nif (aspect>3) { r=(height) * (aspect/3); print "height=";}
+    if (aspect<(1/3)) {r=(width) / (aspect/(1/3)); print "width=";}\nscale=0
+    if (r) { print r/1 }')
+[ ! -z "$newenv" ] && echo "$newenv" && export $newenv
+echo "aspect=""$(bc <<< "scale=3; $width/$height")"
diff --git a/packages/twitter-convert/ffmpeg_twitter b/packages/twitter-convert/ffmpeg_twitter
new file mode 100755
index 0000000..6cd45fb
--- /dev/null
+++ b/packages/twitter-convert/ffmpeg_twitter
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+set -xe
+
+export $($ARSCRIPT "$1")
+ffmpeg -i "$1" \
+      -filter_complex 'fps=30,format=yuv420p,pad='"ceil($width/2)*2:ceil($height/2)*2"':(ow-iw)/2:(oh-ih)/2' -c:v h264_videotoolbox -c:a aac -ac 2 -ar 44100 -r 30 \
+      output.mp4
\ No newline at end of file