diff options
Diffstat (limited to 'tools/xor_compress.py')
-rw-r--r-- | tools/xor_compress.py | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/tools/xor_compress.py b/tools/xor_compress.py index 30418db..5b3e6a2 100644 --- a/tools/xor_compress.py +++ b/tools/xor_compress.py @@ -9,35 +9,35 @@ with (open(sys.argv[1], 'rb') if len(sys.argv) > 1 else sys.stdin) as f: n = len(data) output = [] -v = 0 +v = 0x00 i = 0 while i < n: - val = data[i] + byte = data[i] i += 1 - if data[i] == v: #>=0x80 + if data[i] == v: # Alternating (>= 0x80) # Run stops at 0x81 bytes or when the values stop alternating size = 1 - while i < n and size < 0x81 and data[i] == (v if size % 2 else val): + while i < n and size < 0x81 and data[i] == (v if size % 2 else byte): size += 1 i += 1 output.append(size + 0x7e) - output.append(v ^ val) + output.append(v ^ byte) if size % 2: - v = val + v = byte else: # Sequential (< 0x80) # Run stops at 0x80 bytes or when the value two ahead is equal to v - buffer = [v ^ val] + buffer = [v ^ byte] while i < n: - v = val + v = byte if len(buffer) > 0x7f or (i + 1 < n and data[i + 1] == v): break - val = data[i] - buffer.append(v ^ val) + byte = data[i] + buffer.append(v ^ byte) i += 1 output.append(len(buffer) - 1) output.extend(buffer) |