Dweep Gold data file dumper

dweep_dump.py

# Dweep Gold data file dumper
# run this from program folder. it'll look for './Dweep.DAT'
#  and dump what it can in ./out/

import os, sys
import struct
import PIL
from PIL import Image

destination = "./out/"
os.makedirs(destination, exist_ok=True)

framedata_reg = {}

with open("Dweep.DAT", 'rb') as f:
    filecount = struct.unpack('i', f.read(4))[0]
    positions = []
    for i in range(filecount):
        item = f.read(17)
        sz = struct.unpack('i', item[:4])[0]
        name = item[4:].decode('ascii').rstrip(' \t\r\n\0')
        positions.append((name, sz, ))
    for i, pos in enumerate(positions[:-1]):
        currname = pos[0]
        currpos = pos[1]
        nextpos = positions[i+1][1]
        sz = nextpos - pos[1]
        print(f'#{i}: {currname} at {currpos}: {sz} bytes long')
        f.seek(currpos)
        contents = f.read(sz)
        destfname = destination+currname
        with open(destfname, 'wb') as fout:
            fout.write(contents)
        # HACK: initial attempt at decoding the bitmaps
        if destfname.endswith(".DAT"):
            # must be a simple image definition
            num_strips = struct.unpack('i', contents[:4])[0]
            strip_base = 4
            strips = []
            for istrip in range(num_strips):
                print("\tStrip {istrip}")
                numframes = struct.unpack('i', contents[strip_base:strip_base+4])[0]
                strip_frames = []
                framesz = 5*4
                for fi in range(numframes):
                    print("\tFrame {fi}")
                    data_start, w, h, cx, cy = struct.unpack('iiiii', contents[
                        strip_base+4+fi*framesz:
                        strip_base+4+(fi+1)*framesz])
                    framedata = {
                        'data_start': data_start,
                        'w': w,
                        'h': h,
                        'cx': cx,
                        'cy': cy
                    }
                    print("\t", fi, framedata)
                    strip_frames.append(framedata)
                strips.append(strip_frames)
                strip_base = strip_base+4+numframes*framesz
            framedata_reg[currname.replace(".DAT", "")] = strips
        elif destfname.endswith('.RIP'):
            basename = currname.replace('.RIP', '')
            if basename in framedata_reg:
                frames = {}
                for istrip, strip in enumerate(framedata_reg[basename]):
                    for iframe, frame in enumerate(strip):
                        frames[f'_{istrip}_{iframe}'] = frame
                for suffix, framedata in frames.items():
                    print(framedata)
                    imgw = framedata['w']
                    imgh = framedata['h']
                    imgsz = imgw*imgh*2
                    datastart = framedata['data_start']
                    imgcontents = contents[datastart:datastart+imgsz]
                    #with open(f'{destination}{basename}{suffix}.RAW', 'wb') as imgfile:
                    #    imgfile.write(imgcontents)
                    # build rgb
                    rgb = b''
                    for pi in range(imgw*imgh): # TODO can we identify palleted? maybe hardcode
                        paddr = datastart+2*pi
                        lower = contents[paddr] if len(contents) > paddr else 0
                        higher = contents[paddr+1] if len(contents)-1 > paddr else 0
                        val = lower + higher*256
                        b = int(((val >> 0) & 0x1f)*255/31)
                        g = int(((val >> 5) & 0x3f)*255/63)
                        r = int(((val >> 11) & 0x1f)*255/31)
                        rgb += struct.pack('ccc', r.to_bytes(1, 'little'), g.to_bytes(1, 'little'), b.to_bytes(1, 'little'))
                    proper = Image.frombytes('RGB', (imgw, imgh,), rgb)
                    proper.save(f'{destination}{basename}{suffix}.png')
            else:
                print("Framedata not found, is dat really before? Did it parse?")
                #sys.exit(1)