File size: 2,874 Bytes
24c19d8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | #!/usr/bin/env python3
"""Test the enumerative entropy coding implementation."""
from enumerative_coding import EnumerativeEncoder, ExpGolombCoder
def test_exp_golomb():
"""Test exp-Golomb coding."""
print("Testing Exp-Golomb coding:")
test_values = [0, 1, 2, 3, 4, 5, 10, 15, 31, 32, 100]
for n in test_values:
encoded = ExpGolombCoder.encode(n)
decoded, _ = ExpGolombCoder.decode(encoded, 0)
print(f" {n:3d} -> {encoded:>10s} -> {decoded:3d} ({'✓' if n == decoded else '✗'})")
def test_combinatorics():
"""Test combinatorial functions."""
print("\nTesting combinatorial functions:")
# Test binomial coefficients using the encoder's table
encoder = EnumerativeEncoder()
test_cases = [(5, 2), (10, 3), (7, 0), (7, 7), (6, 4)]
for n, k in test_cases:
result = encoder.binom_table.get(n, k)
expected = math.comb(n, k) if hasattr(math, 'comb') else None
print(f" C({n},{k}) = {result}" + (f" (expected {expected})" if expected else ""))
def test_simple_sequence():
"""Test encoding/decoding of simple sequences."""
print("\nTesting simple sequences:")
encoder = EnumerativeEncoder()
test_sequences = [
[0, 1, 0],
[0, 1, 1, 2],
[1, 2, 3, 1, 2, 3],
[0, 0, 1, 1, 2],
]
for seq in test_sequences:
print(f"\n Testing sequence: {seq}")
try:
encoded = encoder.encode(seq)
decoded = encoder.decode(encoded)
print(f" Original: {seq}")
print(f" Decoded: {decoded}")
print(f" Correct: {'✓' if seq == decoded else '✗'}")
print(f" Size: {len(seq)} symbols -> {len(encoded)} bytes")
except Exception as e:
print(f" Error: {e}")
def test_paper_example():
"""Test with an example that should match the paper's approach."""
print("\nTesting paper-style example:")
# Create a sequence with known symbol frequencies
# This tests the 3-step encoding process
sequence = [0, 0, 1, 2, 1, 0, 2, 1, 1, 2] # 3 zeros, 4 ones, 3 twos
print(f" Sequence: {sequence}")
print(f" Symbols: {sorted(set(sequence))}")
print(f" Counts: {[sequence.count(s) for s in sorted(set(sequence))]}")
encoder = EnumerativeEncoder()
encoded = encoder.encode(sequence)
decoded = encoder.decode(encoded)
print(f" Encoded size: {len(encoded)} bytes")
print(f" Correctly decoded: {'✓' if sequence == decoded else '✗'}")
if sequence != decoded:
print(f" Expected: {sequence}")
print(f" Got: {decoded}")
if __name__ == "__main__":
import math
test_exp_golomb()
test_combinatorics()
test_simple_sequence()
test_paper_example() |