Spaces:
Running
Running
File size: 15,556 Bytes
b72ab63 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 |
"""
Blizzard Mipmap Format (.blp)
Jerome Leclanche <[email protected]>
The contents of this file are hereby released in the public domain (CC0)
Full text of the CC0 license:
https://creativecommons.org/publicdomain/zero/1.0/
BLP1 files, used mostly in Warcraft III, are not fully supported.
All types of BLP2 files used in World of Warcraft are supported.
The BLP file structure consists of a header, up to 16 mipmaps of the
texture
Texture sizes must be powers of two, though the two dimensions do
not have to be equal; 512x256 is valid, but 512x200 is not.
The first mipmap (mipmap #0) is the full size image; each subsequent
mipmap halves both dimensions. The final mipmap should be 1x1.
BLP files come in many different flavours:
* JPEG-compressed (type == 0) - only supported for BLP1.
* RAW images (type == 1, encoding == 1). Each mipmap is stored as an
array of 8-bit values, one per pixel, left to right, top to bottom.
Each value is an index to the palette.
* DXT-compressed (type == 1, encoding == 2):
- DXT1 compression is used if alpha_encoding == 0.
- An additional alpha bit is used if alpha_depth == 1.
- DXT3 compression is used if alpha_encoding == 1.
- DXT5 compression is used if alpha_encoding == 7.
"""
from __future__ import annotations
import os
import struct
from enum import IntEnum
from io import BytesIO
from . import Image, ImageFile
class Format(IntEnum):
JPEG = 0
class Encoding(IntEnum):
UNCOMPRESSED = 1
DXT = 2
UNCOMPRESSED_RAW_BGRA = 3
class AlphaEncoding(IntEnum):
DXT1 = 0
DXT3 = 1
DXT5 = 7
def unpack_565(i):
return ((i >> 11) & 0x1F) << 3, ((i >> 5) & 0x3F) << 2, (i & 0x1F) << 3
def decode_dxt1(data, alpha=False):
"""
input: one "row" of data (i.e. will produce 4*width pixels)
"""
blocks = len(data) // 8 # number of blocks in row
ret = (bytearray(), bytearray(), bytearray(), bytearray())
for block in range(blocks):
# Decode next 8-byte block.
idx = block * 8
color0, color1, bits = struct.unpack_from("<HHI", data, idx)
r0, g0, b0 = unpack_565(color0)
r1, g1, b1 = unpack_565(color1)
# Decode this block into 4x4 pixels
# Accumulate the results onto our 4 row accumulators
for j in range(4):
for i in range(4):
# get next control op and generate a pixel
control = bits & 3
bits = bits >> 2
a = 0xFF
if control == 0:
r, g, b = r0, g0, b0
elif control == 1:
r, g, b = r1, g1, b1
elif control == 2:
if color0 > color1:
r = (2 * r0 + r1) // 3
g = (2 * g0 + g1) // 3
b = (2 * b0 + b1) // 3
else:
r = (r0 + r1) // 2
g = (g0 + g1) // 2
b = (b0 + b1) // 2
elif control == 3:
if color0 > color1:
r = (2 * r1 + r0) // 3
g = (2 * g1 + g0) // 3
b = (2 * b1 + b0) // 3
else:
r, g, b, a = 0, 0, 0, 0
if alpha:
ret[j].extend([r, g, b, a])
else:
ret[j].extend([r, g, b])
return ret
def decode_dxt3(data):
"""
input: one "row" of data (i.e. will produce 4*width pixels)
"""
blocks = len(data) // 16 # number of blocks in row
ret = (bytearray(), bytearray(), bytearray(), bytearray())
for block in range(blocks):
idx = block * 16
block = data[idx : idx + 16]
# Decode next 16-byte block.
bits = struct.unpack_from("<8B", block)
color0, color1 = struct.unpack_from("<HH", block, 8)
(code,) = struct.unpack_from("<I", block, 12)
r0, g0, b0 = unpack_565(color0)
r1, g1, b1 = unpack_565(color1)
for j in range(4):
high = False # Do we want the higher bits?
for i in range(4):
alphacode_index = (4 * j + i) // 2
a = bits[alphacode_index]
if high:
high = False
a >>= 4
else:
high = True
a &= 0xF
a *= 17 # We get a value between 0 and 15
color_code = (code >> 2 * (4 * j + i)) & 0x03
if color_code == 0:
r, g, b = r0, g0, b0
elif color_code == 1:
r, g, b = r1, g1, b1
elif color_code == 2:
r = (2 * r0 + r1) // 3
g = (2 * g0 + g1) // 3
b = (2 * b0 + b1) // 3
elif color_code == 3:
r = (2 * r1 + r0) // 3
g = (2 * g1 + g0) // 3
b = (2 * b1 + b0) // 3
ret[j].extend([r, g, b, a])
return ret
def decode_dxt5(data):
"""
input: one "row" of data (i.e. will produce 4 * width pixels)
"""
blocks = len(data) // 16 # number of blocks in row
ret = (bytearray(), bytearray(), bytearray(), bytearray())
for block in range(blocks):
idx = block * 16
block = data[idx : idx + 16]
# Decode next 16-byte block.
a0, a1 = struct.unpack_from("<BB", block)
bits = struct.unpack_from("<6B", block, 2)
alphacode1 = bits[2] | (bits[3] << 8) | (bits[4] << 16) | (bits[5] << 24)
alphacode2 = bits[0] | (bits[1] << 8)
color0, color1 = struct.unpack_from("<HH", block, 8)
(code,) = struct.unpack_from("<I", block, 12)
r0, g0, b0 = unpack_565(color0)
r1, g1, b1 = unpack_565(color1)
for j in range(4):
for i in range(4):
# get next control op and generate a pixel
alphacode_index = 3 * (4 * j + i)
if alphacode_index <= 12:
alphacode = (alphacode2 >> alphacode_index) & 0x07
elif alphacode_index == 15:
alphacode = (alphacode2 >> 15) | ((alphacode1 << 1) & 0x06)
else: # alphacode_index >= 18 and alphacode_index <= 45
alphacode = (alphacode1 >> (alphacode_index - 16)) & 0x07
if alphacode == 0:
a = a0
elif alphacode == 1:
a = a1
elif a0 > a1:
a = ((8 - alphacode) * a0 + (alphacode - 1) * a1) // 7
elif alphacode == 6:
a = 0
elif alphacode == 7:
a = 255
else:
a = ((6 - alphacode) * a0 + (alphacode - 1) * a1) // 5
color_code = (code >> 2 * (4 * j + i)) & 0x03
if color_code == 0:
r, g, b = r0, g0, b0
elif color_code == 1:
r, g, b = r1, g1, b1
elif color_code == 2:
r = (2 * r0 + r1) // 3
g = (2 * g0 + g1) // 3
b = (2 * b0 + b1) // 3
elif color_code == 3:
r = (2 * r1 + r0) // 3
g = (2 * g1 + g0) // 3
b = (2 * b1 + b0) // 3
ret[j].extend([r, g, b, a])
return ret
class BLPFormatError(NotImplementedError):
pass
def _accept(prefix):
return prefix[:4] in (b"BLP1", b"BLP2")
class BlpImageFile(ImageFile.ImageFile):
"""
Blizzard Mipmap Format
"""
format = "BLP"
format_description = "Blizzard Mipmap Format"
def _open(self):
self.magic = self.fp.read(4)
self.fp.seek(5, os.SEEK_CUR)
(self._blp_alpha_depth,) = struct.unpack("<b", self.fp.read(1))
self.fp.seek(2, os.SEEK_CUR)
self._size = struct.unpack("<II", self.fp.read(8))
if self.magic in (b"BLP1", b"BLP2"):
decoder = self.magic.decode()
else:
msg = f"Bad BLP magic {repr(self.magic)}"
raise BLPFormatError(msg)
self._mode = "RGBA" if self._blp_alpha_depth else "RGB"
self.tile = [(decoder, (0, 0) + self.size, 0, (self.mode, 0, 1))]
class _BLPBaseDecoder(ImageFile.PyDecoder):
_pulls_fd = True
def decode(self, buffer):
try:
self._read_blp_header()
self._load()
except struct.error as e:
msg = "Truncated BLP file"
raise OSError(msg) from e
return -1, 0
def _read_blp_header(self):
self.fd.seek(4)
(self._blp_compression,) = struct.unpack("<i", self._safe_read(4))
(self._blp_encoding,) = struct.unpack("<b", self._safe_read(1))
(self._blp_alpha_depth,) = struct.unpack("<b", self._safe_read(1))
(self._blp_alpha_encoding,) = struct.unpack("<b", self._safe_read(1))
self.fd.seek(1, os.SEEK_CUR) # mips
self.size = struct.unpack("<II", self._safe_read(8))
if isinstance(self, BLP1Decoder):
# Only present for BLP1
(self._blp_encoding,) = struct.unpack("<i", self._safe_read(4))
self.fd.seek(4, os.SEEK_CUR) # subtype
self._blp_offsets = struct.unpack("<16I", self._safe_read(16 * 4))
self._blp_lengths = struct.unpack("<16I", self._safe_read(16 * 4))
def _safe_read(self, length):
return ImageFile._safe_read(self.fd, length)
def _read_palette(self):
ret = []
for i in range(256):
try:
b, g, r, a = struct.unpack("<4B", self._safe_read(4))
except struct.error:
break
ret.append((b, g, r, a))
return ret
def _read_bgra(self, palette):
data = bytearray()
_data = BytesIO(self._safe_read(self._blp_lengths[0]))
while True:
try:
(offset,) = struct.unpack("<B", _data.read(1))
except struct.error:
break
b, g, r, a = palette[offset]
d = (r, g, b)
if self._blp_alpha_depth:
d += (a,)
data.extend(d)
return data
class BLP1Decoder(_BLPBaseDecoder):
def _load(self):
if self._blp_compression == Format.JPEG:
self._decode_jpeg_stream()
elif self._blp_compression == 1:
if self._blp_encoding in (4, 5):
palette = self._read_palette()
data = self._read_bgra(palette)
self.set_as_raw(data)
else:
msg = f"Unsupported BLP encoding {repr(self._blp_encoding)}"
raise BLPFormatError(msg)
else:
msg = f"Unsupported BLP compression {repr(self._blp_encoding)}"
raise BLPFormatError(msg)
def _decode_jpeg_stream(self):
from .JpegImagePlugin import JpegImageFile
(jpeg_header_size,) = struct.unpack("<I", self._safe_read(4))
jpeg_header = self._safe_read(jpeg_header_size)
self._safe_read(self._blp_offsets[0] - self.fd.tell()) # What IS this?
data = self._safe_read(self._blp_lengths[0])
data = jpeg_header + data
data = BytesIO(data)
image = JpegImageFile(data)
Image._decompression_bomb_check(image.size)
if image.mode == "CMYK":
decoder_name, extents, offset, args = image.tile[0]
image.tile = [(decoder_name, extents, offset, (args[0], "CMYK"))]
r, g, b = image.convert("RGB").split()
image = Image.merge("RGB", (b, g, r))
self.set_as_raw(image.tobytes())
class BLP2Decoder(_BLPBaseDecoder):
def _load(self):
palette = self._read_palette()
self.fd.seek(self._blp_offsets[0])
if self._blp_compression == 1:
# Uncompressed or DirectX compression
if self._blp_encoding == Encoding.UNCOMPRESSED:
data = self._read_bgra(palette)
elif self._blp_encoding == Encoding.DXT:
data = bytearray()
if self._blp_alpha_encoding == AlphaEncoding.DXT1:
linesize = (self.size[0] + 3) // 4 * 8
for yb in range((self.size[1] + 3) // 4):
for d in decode_dxt1(
self._safe_read(linesize), alpha=bool(self._blp_alpha_depth)
):
data += d
elif self._blp_alpha_encoding == AlphaEncoding.DXT3:
linesize = (self.size[0] + 3) // 4 * 16
for yb in range((self.size[1] + 3) // 4):
for d in decode_dxt3(self._safe_read(linesize)):
data += d
elif self._blp_alpha_encoding == AlphaEncoding.DXT5:
linesize = (self.size[0] + 3) // 4 * 16
for yb in range((self.size[1] + 3) // 4):
for d in decode_dxt5(self._safe_read(linesize)):
data += d
else:
msg = f"Unsupported alpha encoding {repr(self._blp_alpha_encoding)}"
raise BLPFormatError(msg)
else:
msg = f"Unknown BLP encoding {repr(self._blp_encoding)}"
raise BLPFormatError(msg)
else:
msg = f"Unknown BLP compression {repr(self._blp_compression)}"
raise BLPFormatError(msg)
self.set_as_raw(data)
class BLPEncoder(ImageFile.PyEncoder):
_pushes_fd = True
def _write_palette(self):
data = b""
palette = self.im.getpalette("RGBA", "RGBA")
for i in range(len(palette) // 4):
r, g, b, a = palette[i * 4 : (i + 1) * 4]
data += struct.pack("<4B", b, g, r, a)
while len(data) < 256 * 4:
data += b"\x00" * 4
return data
def encode(self, bufsize):
palette_data = self._write_palette()
offset = 20 + 16 * 4 * 2 + len(palette_data)
data = struct.pack("<16I", offset, *((0,) * 15))
w, h = self.im.size
data += struct.pack("<16I", w * h, *((0,) * 15))
data += palette_data
for y in range(h):
for x in range(w):
data += struct.pack("<B", self.im.getpixel((x, y)))
return len(data), 0, data
def _save(im, fp, filename):
if im.mode != "P":
msg = "Unsupported BLP image mode"
raise ValueError(msg)
magic = b"BLP1" if im.encoderinfo.get("blp_version") == "BLP1" else b"BLP2"
fp.write(magic)
fp.write(struct.pack("<i", 1)) # Uncompressed or DirectX compression
fp.write(struct.pack("<b", Encoding.UNCOMPRESSED))
fp.write(struct.pack("<b", 1 if im.palette.mode == "RGBA" else 0))
fp.write(struct.pack("<b", 0)) # alpha encoding
fp.write(struct.pack("<b", 0)) # mips
fp.write(struct.pack("<II", *im.size))
if magic == b"BLP1":
fp.write(struct.pack("<i", 5))
fp.write(struct.pack("<i", 0))
ImageFile._save(im, fp, [("BLP", (0, 0) + im.size, 0, im.mode)])
Image.register_open(BlpImageFile.format, BlpImageFile, _accept)
Image.register_extension(BlpImageFile.format, ".blp")
Image.register_decoder("BLP1", BLP1Decoder)
Image.register_decoder("BLP2", BLP2Decoder)
Image.register_save(BlpImageFile.format, _save)
Image.register_encoder("BLP", BLPEncoder)
|