TexturesUtils/pvr_ccz_decoder.py at master · SpaceLeaper/TexturesUtils · GitHub

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import zlib
import math
from PIL import Image
import texture2ddecoder


def pvr_ccz_decode(data, logging=False, exc=None):
	# extract PVR payload from CCZ (big endian)
	if data[0:4] != b"CCZ!":
		raise exc("not a valid CCZ container !")

	ccz_version = int.from_bytes(data[4:8], "big")
	ccz_compression_type = int.from_bytes(data[8:12], "big")
	ccz_decompressed_size = int.from_bytes(data[12:16], "big")
	ccz_payload = data[16:]

	if ccz_compression_type != 0:
		raise Exception(f"invalid compression type {ccz_compression_type} !")

	logging and print(f"version : {ccz_version} | compression type : {ccz_compression_type} | decompressed size : {ccz_decompressed_size} | compressed size : {len(ccz_payload)}")

	data = zlib.decompress(ccz_payload)

	if len(data) != ccz_decompressed_size:
		raise Exception("invalid decompressed size for PVR !")

	# parse PVR (little endian)
	if data[0:4] != b"PVR\x03":
		raise Exception("invalid PVR header / version !")

	# 4:8 uint32_t flags;
	pvr_pixel_format = int.from_bytes(data[8:16], "little") # 8:16 uint64_t pixelFormat; - note: sometimes seems to be uint32_t ?
	# 16:20 uint32_t colourSpace;
	# 20:24 uint32_t channelType;
	pvr_height = int.from_bytes(data[24:28], "little") # 24:28 uint32_t height;
	pvr_width = int.from_bytes(data[28:32], "little") # 28:32 uint32_t width;
	# 32:36 uint32_t depth;
	# 36:40 uint32_t numSurfaces;
	# 40:44 uint32_t numFaces;
	pvr_mipmap_count = int.from_bytes(data[44:48], "little") # 44:48 uint32_t mipMapCount;
	pvr_metadata_size = int.from_bytes(data[48:52], "little") # 48:52 uint32_t metaDataSize;

	if pvr_metadata_size > 0:
		raise Exception("non-null PVR metadata size !")

	pixel_formats = {
		6: "ETC1",
		23: "ETC2_RGBA",
		578721384203708274: "RGBA8888"
	}

	if pvr_pixel_format not in pixel_formats:
		raise Exception(f"pixel format {pvr_pixel_format} not implemented !")

	pvr_pixel_format = pixel_formats[pvr_pixel_format]

	logging and print(f"pixel format : {pvr_pixel_format} | size (wh) : {pvr_width}x{pvr_height}")

	if pvr_mipmap_count > 1:
		raise Exception(f"mipmap count {pvr_mipmap_count} not implemented !")

	data = data[52:]

	if pvr_pixel_format == "ETC1":
		# ETC1 spec specifies 4x4 block size of 8 bytes each
		bw, bh = math.ceil(pvr_width / 4), math.ceil(pvr_height / 4)
		data_size = bw * bh * 8

		if data_size != (ccz_decompressed_size - 52):
			raise Exception("PVR payload size mismatch !")

		raw = texture2ddecoder.decode_etc1(data, pvr_width, pvr_height)
		img = Image.frombytes("RGBA", (pvr_width, pvr_height), raw, "raw", ("BGRA")) # reload RGB888 as PNG
	elif pvr_pixel_format == "ETC2_RGBA":
		raw = texture2ddecoder.decode_etc2a8(data, pvr_width, pvr_height) # etc2 & full 8-bit alpha
		img = Image.frombytes("RGBA", (pvr_width, pvr_height), raw, "raw", ("BGRA")).convert("RGBA")
	elif pvr_pixel_format == "RGBA8888":
		img = Image.frombytes("RGBA", (pvr_width, pvr_height), data)

	return img