script for converting neighbours from hell targa textures

nfh_tga_convert.py

#!/usr/bin/env python
import struct
from PIL import Image

class TGAHeader:
    def __init__(self):
        self.idlength = 0
        self.colourmaptype = 0
        self.datatypecode = 0
        self.colourmaporigin = 0
        self.colourmaplength = 0
        self.colourmapdepth = 0
        self.x_origin = 0
        self.y_origin = 0
        self.width = 0
        self.height = 0
        self.bitsperpixel = 0
        self.imagedescriptor = 0

class TGAFooter:
    def __init__(self):
        self.extensionoffset = 0
        self.developeroffset = 0
        self.signature = b''
        self.p = 0
        self.n = 0

def convert(input_path, output_path):
    with open(input_path, 'rb') as fd:
        header = TGAHeader()
        header.idlength = struct.unpack('B', fd.read(1))[0]
        header.colourmaptype = struct.unpack('B', fd.read(1))[0]
        header.datatypecode = struct.unpack('B', fd.read(1))[0]
        header.colourmaporigin = struct.unpack('<h', fd.read(2))[0]
        header.colourmaplength = struct.unpack('<h', fd.read(2))[0]
        header.colourmapdepth = struct.unpack('B', fd.read(1))[0]
        header.x_origin = struct.unpack('<h', fd.read(2))[0]
        header.y_origin = struct.unpack('<h', fd.read(2))[0]
        header.width = struct.unpack('<h', fd.read(2))[0]
        header.height = struct.unpack('<h', fd.read(2))[0]
        header.bitsperpixel = struct.unpack('B', fd.read(1))[0]
        header.imagedescriptor = struct.unpack('B', fd.read(1))[0]

        tga_pixel_size = header.bitsperpixel // 8
        tga_data_size = header.width * header.height * tga_pixel_size
        tga_data = fd.read(tga_data_size)

        fd.seek(-26, 2)
        footer = TGAFooter()
        footer.extensionoffset = struct.unpack('<i', fd.read(4))[0]
        footer.developeroffset = struct.unpack('<i', fd.read(4))[0]
        footer.signature = fd.read(16)
        footer.p = struct.unpack('B', fd.read(1))[0]
        footer.n = struct.unpack('B', fd.read(1))[0]

    # RGBA4444
    if header.imagedescriptor == 36:
        buffer = bytearray(header.width * header.height * 4)
        j = 0
        for i in range(0, len(tga_data), tga_pixel_size):
            buffer[j + 0] = (tga_data[i + 1] & 0x0F) << 4
            buffer[j + 1] = (tga_data[i] & 0xF0)
            buffer[j + 2] = (tga_data[i] & 0x0F) << 4
            buffer[j + 3] = (tga_data[i + 1] & 0xF0)
            j += 4
        img = Image.frombytes('RGBA', (header.width, header.height), bytes(buffer))
        img.save(output_path)

    # RGBA5650
    elif header.imagedescriptor == 32:
        buffer = bytearray(header.width * header.height * 3)
        j = 0
        for i in range(0, len(tga_data), tga_pixel_size):
            buffer[j + 0] = tga_data[i + 1] & 0xf8
            buffer[j + 1] = ((tga_data[i + 1] & 7) << 5) | ((tga_data[i] >> 3) & 0x1c)
            buffer[j + 2] = (tga_data[i] & 0x1f) << 3
            j += 3
        img = Image.frombytes('RGB', (header.width, header.height), bytes(buffer))
        img.save(output_path)

if __name__ == '__main__':
    import sys
    if len(sys.argv) != 3:
        print(f"Usage:\n\t {sys.argv[0]} <input> <output>")
        sys.exit(1)
    
    input_file = sys.argv[1]
    output_file = sys.argv[2]
    convert(input_file, output_file)