Gro-Tsen

Moov'in

	## FIRST, install Firefox Nightly on Android. Then run it once and let it start.
	## Then force stop it and clear its cache (but not further data).

	## Then understand the following commands, adapt them, and use them
	## (as root through adb).

	# Get the original profile name:
	cd /data/data/org.mozilla.firefox/files/mozilla
	srcsalt="$(echo *.default)"
	echo "$srcsalt"

	<?xml version="1.0" encoding="UTF-8"?>
	<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
	<!-- Created on 2019-05-15 to fix a reappearance of this bug: -->
	<!-- https://bugs.launchpad.net/ubuntu/+source/djvulibre/+bug/1778088 -->
	<!-- (DjVu seen as image/vnd.djvu instead of image/vnd.djvu+multipage) -->
	<!-- https://twitter.com/gro_tsen/status/1128645721614356480 -->
	<!-- Run "update-mime-database ~/.local/share/mime" after creating this. -->
	<!-- Use "xdg-mime query filetype some-file.djvu" to test. -->
	<!-- - David A. Madore -->
	<mime-type type="image/vnd.djvu+multipage">

	// This code is in the Public Domain.

	#include <stdint.h>
	#include <string.h>
	#include <assert.h>

	void
	serialize_be_16 (uint8_t b[2], uint16_t w)
	{
	for ( int i=0 ; i<2 ; i++ )

	## Initial attempt:
	ffmpeg -loop 1 -i /tmp/schumann-piano-concerto-III-97-to-104.png -i /tmp/schumann-piano-concerto-III-97-to-104.ogg -c:v libx264 -tune stillimage -c:a aac -b:a 192k -shortest /tmp/out.mp4

	## Phone doesn't like YUV444 format, so let's try this:
	ffmpeg -loop 1 -i /tmp/schumann-piano-concerto-III-97-to-104.png -i /tmp/schumann-piano-concerto-III-97-to-104.ogg -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest /tmp/out.mp4

	## Still not happy. Change framerate, audio bitrate and scale, perhaps?
	ffmpeg -r 25 -loop 1 -i /tmp/schumann-piano-concerto-III-97-to-104.png -i /tmp/schumann-piano-concerto-III-97-to-104.ogg -c:v libx264 -tune stillimage -ar 48000 -c:a aac -b:a 96k -vf scale=1280:260 -pix_fmt yuv420p -shortest /tmp/schumann-piano-concerto-III-97-to-104.mp4

	## Apparently, Twitter also worries about the aspect ratio:

	## The vector space in which everything will happen:
	V = QQ^8

	## The simple roots (and smallest root alpha0) of E_8 under the usual “even”
	## coordinate system:
	alpha1 = V((1,-1,-1,-1,-1,-1,-1,1))/2
	alpha2 = V((1,1,0,0,0,0,0,0))
	alpha3 = V((-1,1,0,0,0,0,0,0))
	alpha4 = V((0,-1,1,0,0,0,0,0))
	alpha5 = V((0,0,-1,1,0,0,0,0))

	## Find numbers n which have a good score sigma(n)/(n*log(log(n))):
	## see https://twitter.com/johncarlosbaez/status/1149700802371608576

	## Prime factorization of 2520:
	bootstrap = {2: 3, 3: 2, 5: 1, 7: 1}

	## Compute the score sigma(n)/(n*log(log(n))) from the prime factorization:
	def goodness(d):
	n = prod([p^(d[p]) for p in d.keys()])
	sig = prod([(p^(d[p]+1)-1)/(p-1) for p in d.keys()])

	double
	uniform (void)
	// Return a uniformly distributed random variable between 0 and 1.
	{
	#define ENTROPY_PER_RAND 31
	#if RAND_MAX != (1<<ENTROPY_PER_RAND)-1
	#error Please fix ENTROPY_PER_RAND
	#endif
	int entropy = 0;
	double val = 0.5;

	#### Start gap with enough memory (e.g., "gap -o 8g" for 8GB) to run this.

	## The MOG cells are labeled top to bottom and left to right:
	## so the leftmost column is 1,2,3,4 and the rightmost is 21,22,23,24,
	## whereas the top line is 1,5,9,13,17,21.

	## Generators of the Mathieu group M_24:
	rotate_blocks := (1,9,17)(2,10,18)(3,11,19)(4,12,20)(5,13,21)(6,14,22)(7,15,23)(8,16,24);
	flip_blocks12 := (1,5)(2,6)(3,7)(4,8)(9,13)(10,14)(11,15)(12,16);
	omega_cols := (2,3,4)(6,7,8)(10,11,12)(14,15,16)(18,19,20)(22,23,24);

	for i in $(seq 0 9) ; do convert -size 960x720 'xc:gray' -font 'FreeSans' -pointsize 200 -gravity Center -annotate 0 $i frame${i}.png ; done
	for i in $(seq 0 9) ; do echo "file frame${i}.png" ; echo "duration 6.000" ; done > video.script
	sox -n -r 48000 -c 2 -t flac silence.flac trim 0.0 60.0
	ffmpeg -f concat -i video.script -i silence.flac -c:v libvpx -crf 12 -pix_fmt yuv420p -c:a libopus -b:a 192k test.webm