Python parser for the Star Wars: X-Wing (Collector's CD) .BRF mission briefing file format.

parseBrf.py

import json
import struct

ANIMATION_COMMANDS = {
    1: ('wait_for_click', []),
    10: ('clear_text', []),
    11: ('show_title', [('i', 'text_id')]),
    12: ('show_main', [('i', 'text_id')]),
    15: ('center_map', [('f', 'x'), ('f', 'y')]),
    16: ('zoom_map', [('f', 'x'), ('f', 'y')]),
    21: ('clear_boxes', []),
    22: ('box_1', [('i', 'ship_id')]),
    23: ('box_2', [('i', 'ship_id')]),
    24: ('box_3', [('i', 'ship_id')]),
    25: ('box_4', [('i', 'ship_id')]),
    26: ('clear_tags', []),
    27: ('tag_1', [('i', 'tag_id'), ('f', 'x'), ('f', 'y')]),
    28: ('tag_2', [('i', 'tag_id'), ('f', 'x'), ('f', 'y')]),
    29: ('tag_3', [('i', 'tag_id'), ('f', 'x'), ('f', 'y')]),
    30: ('tag_4', [('i', 'tag_id'), ('f', 'x'), ('f', 'y')])
}

class BrfParser:
    def __init__(self, f):
        self.f = f

        self._parseHeader()
        self.ships = []
        for i in range(self.numShips):
            self.ships.append({"coordinates": []})

        # Parse all of the coordinates
        #print(self.numCoordinates)
        for i in range(self.numCoordinates):
            for j in range(self.numShips):
                c = {}
                c["x"] = self._readFixed()
                c["y"] = self._readFixed()
                c["z"] = self._readFixed()
                self.ships[j]['coordinates'].append(c)
            pass

        # This is where we get the value for the text jump
        #print("f.tell = %s, have %d ships"%(self.f.tell(), self.numShips))
        #textJumpLength = int(self.f.tell()/2)*15 + 151 - 192 - 4
        #textJumpLength = int(self.numShips*6+3)*15 + 151 - 192 - 4
        textJumpLength = self.numShips*90

        # Parse ship data
        for i in range(self.numShips):
            self.ships[i]['stype'] = self._readShort()
            self.ships[i]['iff'] = self._readShort()
            self.ships[i]['wave_size'] = self._readShort()
            self.ships[i]['num_waves'] = self._readShort()
            self.ships[i]['designation'] = self._readFixedString(16)
            self.ships[i]['cargo'] = self._readFixedString(16)
            self.ships[i]['alt_cargo'] = self._readFixedString(16)
            self._readShort() # save counter?
            self._readShort() # Probably alternate cargo ship?
            self._readShort() # 4
            self._readShort()
        #print(json.dumps(self.ships, indent=3))
        """h = self._readShort()
        if h != 2:
            raise Exception("Section header %X is not 2!"%h)
        self.f.read(100)"""
        section_size = self._readShort()
        self.f.read(50*section_size)

        #print(json.dumps(self.ships, indent=3))

        # Parse the animation pages
        numPages = self._readShort()
        #print("Parsing %s pages"%numPages)
        pages = []
        footerType = 0
        #for i in range(numPages):
        while len(pages) < numPages:
            #print()
            #print("At 0x%X, starting page %s"%(self.f.tell(), len(pages)))
            page = {}
            page['clock_period'] = self._readShort()
            page['size'] = self._readShort()
            wordsRead = 0
            if footerType == 0x29:
                page['a'] = self._readShort()
                page['b'] = self._readShort()
                wordsRead += 2
            if page['clock_period'] == 0x270f and page['size'] == 0x29:
                #print("Hit footer 29")
                footerType = 0x29
                continue
            elif page['clock_period'] == 400 and page['size'] == 1:
                # Hack for t5m01wx.brf
                continue
            elif page['clock_period'] == 400 and page['size'] == 701:
                # Hack for t4m18ym.brf
                page['clock_period'] = 701
                page['size'] = self._readShort()
            else:
                footerType = 0
            #print("0x%X"%self.f.tell(), page)
            #self._readShort() # Unknown
            cmds = []
            #gotFooter = False
            while wordsRead < page['size']:
                c,cnt = self._readAnimationCommand()
                wordsRead += cnt
                #print(c)
                cmds.append(c)

            #print("Got %s animation commands"%len(cmds))
            page['commands'] = cmds
            pages.append(page)
            pass
        #print("Finished at 0x%X, %d"%(self.f.tell(), footerType))
        a = self._readShort()
        b = self._readShort()
        if a == 0x270f and b == 0x29:
            self._readShort()
            self._readShort()
        #self._readShort()
        #c = self._readShort()
        #print(json.dumps(pages, indent=3))
        #print(found_special_page)
        #print("0x%X"%self.f.tell())
        #print("Num coordinates: %s Section size: %s"%(self.numCoordinates, section_size))

        # Unknown
        #a = self._readShort()
        a = self._readShort()
        b = self._readShort()
        #print("%s %s at 0x%X"%(a,b, self.f.tell()))

        # Completion messages
        completionMessages = []
        for i in range(3):
            completionMessages.append(self._readFixedString(64))
        #print(json.dumps(completionMessages, indent=3))

        # Now jump to the texts
        #print("Jumping 0x%X bytes"%textJumpLength)
        self.f.read(textJumpLength)
        #print("At 0x%X"%self.f.tell())
        self._checkForHeader20()

        # Read the tags
        tags = []
        for i in range(32):
            taglen = self._readShort()
            if taglen > 0:
                tags.append(self.f.read(taglen).decode('utf-8'))
            pass

        # Read the briefing texts
        self._checkForHeader20()
        self._readShort() # Unknown, should be zero?

        texts = []
        while True:
            textlen = self._readShort()
            if textlen == None:
                break
            if textlen > 0:
                texts.append(self.f.read(textlen).decode('utf-8'))
                self.f.read(textlen) # Extra bytes
        #print(json.dumps(texts, indent=3))
        #print(json.dumps(tags, indent=3))

        res = {
            'text': texts,
            'tags': tags,
            'ships': self.ships,
            'pages': pages
        }
        #print(json.dumps(res, indent=3))
        self.result = res

    def _checkForHeader20(self):
        p = self.f.tell()
        h = self._readShort()
        if h != 0x20:
            self._raiseError("At 0x%X, wanted header 20, got %X"%(p,h))

    def _raiseError(self, etext):
        s = ""
        for i in range(16):
            s = "%s %02X"%(s,self._readByte())
        print(s)
        raise Exception(etext)

    def _readAnimationCommand(self):
        clock_ticks = self._readShort()
        #print("Clock ticks: %s"%clock_ticks)
        cmd = self._readShort()
        """if cmd == 0x29:
            # This is the footer
            return None, 2"""
        if cmd not in ANIMATION_COMMANDS:
            # Hack: These are tailered for specific mission files
            if cmd == 14:
                c = ('unknown', [('i', '?')])
            else:
                c = ('unknown', [('i', '?'), ('f', '?'), ('f', '?')])
        else:
            c = ANIMATION_COMMANDS[cmd]
        params = {}
        wordsRead = 2
        for p in c[1]:
            if p[0] == 'i':
                params[p[1]] = self._readShort()
            elif p[0] == 'f':
                params[p[1]] = self._readFixed()
            else:
                raise Exception('Unknown parameter type %s'%p[0])
            wordsRead += 1
        params['type'] = c[0]
        params['clock_ticks'] = clock_ticks
        return params, wordsRead

    def _readFixedString(self, l):
        s = self.f.read(l)
        return s.split(b"\x00")[0].decode('utf-8')

    def _readShort(self):
        v = self.f.read(2)
        if len(v) == 0:
            return None
        return struct.unpack("h", v)[0]

    def _readByte(self):
        v = self.f.read(1)
        return struct.unpack('B', v)[0]

    def _readFixed(self):
        return self._readShort()/100.0

    def _parseHeader(self):
        v = self.f.read(2)
        if v[0] != 2 or v[1] != 0:
            raise Exception("Unknown file version %X %X"%(v[0],v[1]))
        self.numShips = self._readShort()
        self.numCoordinates = self._readShort()

if __name__ == "__main__":
    import sys
    if len(sys.argv) > 1:
        p = BrfParser(open(sys.argv[1], "rb"))
        print(json.dumps(p.result, indent=3))
    else:
        import os

        fails = []
        successes = []
        for fname in os.listdir("classic_missions"):
            if fname.split(".")[-1] == 'brf':
                print(fname)
                try:
                    BrfParser(open("classic_missions/%s"%fname, "rb"))
                    successes.append(fname)
                except:
                    fails.append(fname)

        print("fails:")
        for fname in fails:
            print(fname)

        print("Failed %s/%s"%(len(fails),len(successes)+len(fails)))