from tscut.h264.bitstream import (
    read_bit,
    read_byte,
    read_word
)

def test_read_bit_1():
    buf = bytes(10)
    for p in range(80):
        pos, b = read_bit(buf, p)
        assert pos == p+1 and b == 0

def test_read_bit_2():
    buf = b'\xFF'*10
    for p in range(80):
        pos, b = read_bit(buf, p)
        assert pos == p+1 and b == 1

def test_read_byte_1():
    buf = bytes(10)
    for p in range(10):
        pos, b = read_byte(buf, p*8)
        assert pos == (p+1)*8 and b == 0

def test_read_byte_2():
    buf = bytes(10)
    buf = b'\xFF'*10
    for p in range(10):
        pos, b = read_byte(buf, p*8)
        assert pos == (p+1)*8 and b == 0xFF

def test_read_word_1():
    buf = bytes(20)
    for p in range(10):
        pos, b = read_word(buf, p*16)
        assert pos == (p+1)*16 and b == 0