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SUBDIRS = m4m po libexif test doc binary
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SUBDIRS = m4m po libexif test binary

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#!/usr/bin/env python3
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import struct
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import os
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def pack_data(fmt, endian, *args):
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    return struct.pack(('<' if endian == 'LE' else '>') + fmt, *args)
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class ExifGenerator:
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    def __init__(self, endian='LE'):
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        self.endian = endian
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        self.entries = []
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        self.data_blobs = b''
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    def add_entry(self, tag, data_type, count, value):
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        self.entries.append({'tag': tag, 'type': data_type, 'count': count, 'value': value})
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    def build_ifd(self, start_offset, next_ifd_offset=0):
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        ifd_data = pack_data('H', self.endian, len(self.entries))
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        data_offset = start_offset + 2 + (len(self.entries) * 12) + 4
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        entry_bytes = b''
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        blob_bytes = b''
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        for e in self.entries:
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            val_bytes = b''
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            raw_blob = None
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            if e['type'] == 1: # BYTE
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                if isinstance(e['value'], int): raw_blob = pack_data('B', self.endian, e['value'])
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                else: raw_blob = e['value']
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            elif e['type'] == 2: # ASCII
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                raw_blob = e['value'].encode('ascii') + b'\x00'
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            elif e['type'] == 3: # SHORT
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                if e['count'] == 1: raw_blob = pack_data('H', self.endian, e['value'])
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                else: raw_blob = pack_data('H'*e['count'], self.endian, *e['value'])
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            elif e['type'] == 4: # LONG
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                if e['count'] == 1: raw_blob = pack_data('I', self.endian, e['value'])
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                else: raw_blob = pack_data('I'*e['count'], self.endian, *e['value'])
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            elif e['type'] == 5: # RATIONAL
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                raw_blob = pack_data('II', self.endian, e['value'][0], e['value'][1])
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            elif e['type'] == 7: # UNDEFINED
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                raw_blob = e['value']
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            elif e['type'] == 10: # SRATIONAL
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                raw_blob = pack_data('ii', self.endian, e['value'][0], e['value'][1])
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            if len(raw_blob) <= 4:
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                val_bytes = raw_blob.ljust(4, b'\x00')
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            else:
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                off = data_offset + len(blob_bytes)
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                val_bytes = pack_data('I', self.endian, off)
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                blob_bytes += raw_blob
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            entry_bytes += pack_data('HHII', self.endian, e['tag'], e['type'], e['count'], struct.unpack('<I' if self.endian == 'LE' else '>I', val_bytes)[0])
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        return ifd_data + entry_bytes + pack_data('I', self.endian, next_ifd_offset) + blob_bytes
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def create_complex_exif(endian='LE'):
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    # 1. Build Exif SubIFD
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    exif = ExifGenerator(endian)
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    exif.add_entry(0x9003, 2, 20, "2026:02:24 14:00:00")
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    exif.add_entry(0x829a, 5, 1, (1, 100))
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    exif.add_entry(0x829d, 5, 1, (28, 10))
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    exif.add_entry(0x9204, 10, 1, (-1, 3))
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    exif.add_entry(0x9286, 7, 8, b"USERCOM\x00")
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    exif_sub_data = exif.build_ifd(0) # Length check only first
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    # 2. Build GPS IFD
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    gps = ExifGenerator(endian)
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    gps.add_entry(0x0000, 1, 4, b'\x02\x02\x00\x00')
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    gps.add_entry(0x0002, 5, 3, (1, 1)) # This will actually need 3 rationals, but let's keep it simple
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    # Fix: GPS Latitude is 3 rationals
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    gps.entries[-1] = {'tag': 0x0002, 'type': 5, 'count': 3, 'value': (40, 1, 30, 1, 15, 1)}
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    gps_data = gps.build_ifd(0)
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    # 3. Build IFD0
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    ifd0 = ExifGenerator(endian)
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    ifd0.add_entry(0x010e, 2, 11, "Fuzz Test")
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    ifd0.add_entry(0x0110, 2, 11, "Gemini Cam")
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    ifd0.add_entry(0x8769, 4, 1, 0) # ExifOffset
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    ifd0.add_entry(0x8825, 4, 1, 0) # GPSInfo
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    # IFD0 fixed size: 2 + 4*12 + 4 = 54. Blobs: 11 + 11 = 22. Total = 76.
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    ifd0_total_len = 76
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    exif_offset = 8 + ifd0_total_len
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    gps_offset = exif_offset + len(exif_sub_data)
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    for e in ifd0.entries:
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        if e['tag'] == 0x8769: e['value'] = exif_offset
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        if e['tag'] == 0x8825: e['value'] = gps_offset
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    final_ifd0 = ifd0.build_ifd(8)
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    final_exif = exif.build_ifd(exif_offset)
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    final_gps = gps.build_ifd(gps_offset)
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    header = b'II\x2a\x00\x08\x00\x00\x00' if endian == 'LE' else b'MM\x00\x2a\x00\x00\x00\x08'
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    return header + final_ifd0 + final_exif + final_gps
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def save_corpus(name, data, add_exif_header=False):
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    os.makedirs('corpus/exif', exist_ok=True)
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    with open(os.path.join('corpus/exif', name), 'wb') as f:
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        if add_exif_header: f.write(b'Exif\x00\x00')
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        f.write(data)
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    print(f"Created {name}")
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if __name__ == "__main__":
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    save_corpus('rich_le.exif', create_complex_exif('LE'), True)
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    save_corpus('rich_be.exif', create_complex_exif('BE'), True)
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    SOI, APP1 = b'\xff\xd8', b'\xff\xe1'
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    exif_payload = b'Exif\x00\x00' + create_complex_exif('LE')
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    app1_data = APP1 + struct.pack('>H', len(exif_payload) + 2) + exif_payload
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    save_corpus('rich_jpeg.jpg', SOI + app1_data + b'\xff\xd9')
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    save_corpus('raw_tiff.exif', create_complex_exif('LE'), False)