A simple Android application to transfer large blocks of data via successive QR codes.

License: Public Domain

Existing work:
  tagdrop -- https://github.com/mofosyne/tagdrop
  "Watch it & Got it" -- https://code.google.com/p/watchitgotit/
  qrcodetransfer / "Jumping the Gap" -- https://github.com/VolumeLabs/qrcodetransfer
  file2qr-qr2file -- https://github.com/eandriol/file2qr-qr2file


== Using QRStream with the Linux terminal ==

Use zbarcam development sources to read from a webcam:

	$ zbarcam --raw | iconv -f UTF-8 -t ISO-8859-1 |
	while true; do
		dd bs=[blocksize+1] count=1 status=none | head -c -1
	done > outputfile

  where [blocksize+1] is one more than the block size QRStream is using, shown
  below the barcode.  The extra byte needs to be read because zbarcam places a
  linebreak after every code.  Ctrl-C to finish.

  zbarcam v0.10 will not handle binary data correctly -- it terminates each
  code when it hits a nul character.  This issue is resolved in the development
  sources.
  
  Some webcams will require LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so in the
  environment to work with zbarcam.

Use qrencode -8 to produce codes:

	$ split inputfile -b 367 'Code #' -a 4 --numeric-suffixes=1 --filter='
		clear
		echo $FILE
		qrencode -8 -m 2 -t utf8
		read </dev/tty'

  Increase the block size from 367 to enlarge the codes.  Optimal values are in
  android/app/src/main/java/com/github/xloem/qrstream/QRCodeMetric.java .
  Press enter to advance the code.  Ctrl-C to abort.

Use zint --binary with for example feh to show codes:

	$ split inputfile -b 367 'Code #' -a 4 --numeric-suffixes=1 --filter='
		zint --binary -b 58 --border=2 -o "$FILE".png -i -'
	$ feh -dZF --force-aliasing 'Code #'*.png
	$ rm 'Code #'*.png

  Increase the block size from 367 to enlarge the codes.  Space or mousebutton
  to advance.  Arrow keys to navigate.  'Q' to quit.

  Although zint supports aztec codes, there is some bug with binary data when
  using them.  The data becomes corrupt.