dsibanner.py - Creates a DS(i) banner file

dsibanner.py

#!/usr/bin/env python3

# Requirements:
# pip3 install libscrc pillow

# For example files, see Wordle DS:
# https://github.com/Epicpkmn11/WordleDS/tree/main/resources/icon
# python3 dsibanner.py -i icon.*.png -d icon.0.png -t Wordle DS;Pk11 -a icon.json -o banner.bin

"""
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to <http://unlicense.org/>
"""

import json

from argparse import ArgumentParser, FileType
from libscrc import modbus
from PIL import Image
from struct import pack


def convertIcon(icon: Image.Image) -> bytes:
	if icon.size != (32, 32):
		raise Exception("Icon not 32×32")
	elif icon.mode != "P":
		raise Exception("Icon not paletted")
	elif len(icon.palette.palette) > 16 * 3:  # * 3 for RGB
		raise Exception("Icon has too many colors")

	data = b""
	for ty in range(4):
		for tx in range(4):
			for y in range(8):
				for x in range(4):
					byte = icon.getpixel((tx * 8 + x * 2, ty * 8 + y))
					byte |= icon.getpixel((tx * 8 + x * 2 + 1, ty * 8 + y)) << 4
					data += pack("B", byte)

	return data


def convertPalette(icon: Image.Image) -> bytes:
	if icon.mode != "P":
		raise Exception("Icon not paletted")
	elif len(icon.palette.palette) > 16 * 3:  # * 3 for RGB
		raise Exception("Icon has too many colors")

	data = b""
	for i in range(len(icon.palette.palette) // 3):
		r, g, b = [round(x * 0x1f / 0xff) & 0x1f for x in icon.palette.palette[i * 3:i * 3 + 3]]
		data += pack("<H", b << 10 | g << 5 | r)

	return data


def dsibanner(icons, titles, animation, output, dsIcon=None):
	"""
	Creates a DS(i) banner file

	Parameters
	----------
	icons
		list of Pillow Images for the icon
	titles
		list of titles (ja, en, fr, de, it, es, cn, kr) (; = newline)
	animation
		animation sequence in a list of lists as follows:
		[duration (frames), icon index, palette index, flip vertically (bool), flip horizontally (bool)]
	output
		"wb+" file to output to
	dsIcon
		(optional) Pillow Image of icon to use for DS mode, else icons[0] will be used
	"""

	# A couple sanity checks
	if len(icons) > 8:
		raise Exception("Too many icon frames")
	elif len(titles) > 8:
		raise Exception("Too many titles")
	elif animation and len(animation) > 0x40:
		raise Exception("Animaition sequence is too long")

	if len(icons) > 1:
		version = 0x0103
		titleCount = 8
	elif len(titles) == 8:
		version = 0x0003
		titleCount = 8
	elif len(titles) == 7:
		version = 0x0002
		titleCount = 7
	else:
		version = 0x0001
		titleCount = 6

	# Write icon(s) and palette(s)
	output.seek(0x20)
	output.write(convertIcon(dsIcon if dsIcon else icons[0]))
	output.write(convertPalette(dsIcon if dsIcon else icons[0]))
	if version == 0x0103:  # DSi (animated icon)
		output.seek(0x1240)
		for icon in [convertIcon(icon) for icon in icons]:
			output.write(icon)

		output.seek(0x2240)
		palettes = []
		for palette in [convertPalette(icon) for icon in icons]:
			if palette not in palettes:
				palettes.append(palette)
		for palette in palettes:
			output.write(palette.ljust(0x20, b"\0"))

		# Write animation sequence
		sequence = b""
		if animation:
			for frame in animation:
				duration = frame[0] & 0xFF
				iconIndex = frame[1] & 7
				palIndex = frame[2] & 7
				hFlip = frame[3] & 1
				vFlip = frame[4] & 1
				sequence += pack("<H", duration | (iconIndex << 8) | (palIndex << 11) | (hFlip << 14) | (vFlip << 15))
		else:
			sequence = b"\1\0\0\1"  # 1 frame duration for first frame, then for some reason 0x0100 for second
		output.seek(0x2340)
		output.write(sequence.ljust(0x80, b"\0"))

	# Write titles
	for i in range(titleCount):
		title = (titles[i] if i < len(titles) else titles[0]).replace(";", "\n")
		invalidChars = [x for x in title if ord(x) > 0xFFFF]
		if len(invalidChars) > 0:
			raise Exception(f"Invalid character(s) in title {i}: {', '.join(invalidChars)}")

		output.seek(0x240 + (i * 0x100))
		output.write(title.encode("utf-16-le").ljust(0x100, b"\0"))

	# Calculate checksums
	output.seek(0x20)
	if version == 0x0001:
		data = output.read(0x820)
		checksums = (modbus(data), 0, 0, 0)
	elif version == 0x0002:
		data = output.read(0x920)
		checksums = (modbus(data[:0x820]), modbus(data), 0, 0)
	elif version == 0x0003:
		data = output.read(0xA20)
		checksums = (modbus(data[:0x820]), modbus(data[:0x920]), modbus(data), 0)
	else:
		data = output.read(0x23A0)
		checksums = (modbus(data[:0x820]), modbus(data[:0x920]), modbus(data[:0xA20]), modbus(data[0x1220:]))

	output.seek(0)
	output.write(pack("<HHHHH", version, *checksums))


if __name__ == "__main__":
	parser = ArgumentParser(description="Creates a DS(i) banner file")
	parser.add_argument("-i", "--icons", metavar="icon.0.png", nargs="+", required=True, type=Image.open, help="icon image(s)")
	parser.add_argument("-d", "--dsicon", metavar="icon.png", type=Image.open, help="DS mode icon (optional)")
	parser.add_argument("-t", "--titles", required=True, type=str, nargs="+", help="application title (ja, en, fr, de, it, es, cn, kr) (; = newline)")
	parser.add_argument("-a", "--animation", metavar="icon.json", type=FileType("r"), help="animation sequence JSON")
	parser.add_argument("-o", "--output", metavar="banner.bin", default="banner.bin", type=FileType("wb+"), help="output banner.bin")

	args = parser.parse_args()

	dsibanner(args.icons, args.titles, json.load(args.animation) if args.animation else None, args.output, args.dsicon)

Do you think exporting to APNG/WebP/JPEG XL could be possible to preserve the correct framerates of the animated DSi icons?

@TheLavrov did you mean to comment on bannergif.py?

If Pillow supports any of those it should be as simple as changing the output format, I never looked into that at all as GIF was just convenient enough for me to deal with it

See line 158

@TheLavrov did you mean to comment on bannergif.py?

If Pillow supports any of those it should be as simple as changing the output format, I never looked into that at all as GIF was just convenient enough for me to deal with it

See line 158

Whoops, yes. My mistake. Thanks for the reply though, I'll stare at it a bit.

I took a look and it seems the output parameters should be the same so I think the only change needed should be making it not set a minimum of 20ms if the extension isn't .gif

Just changing the output extension when calling it should work besides that, probably