How to use the sigal.video.video_size function in sigal

def test_generate_video_fit_height(tmpdir, fmt):
    """largest fitting dimension is height"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(50, 100), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings[fmt + '_options'])

    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_dst[0] == 50
    # less than 2% error on ratio
    assert abs(size_dst[0]/size_dst[1] - size_src[0]/size_src[1]) < 2e-2

def test_generate_video_fit_width(tmpdir, fmt):
    """largest fitting dimension is width"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(100, 50), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings[fmt + '_options'])

    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_dst[1] == 50
    # less than 2% error on ratio
    assert abs(size_dst[0]/size_dst[1] - size_src[0]/size_src[1]) < 2e-2

def test_generate_video_fit_width(tmpdir, fmt):
    """largest fitting dimension is width"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(100, 50), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings[fmt + '_options'])

    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_dst[1] == 50
    # less than 2% error on ratio
    assert abs(size_dst[0]/size_dst[1] - size_src[0]/size_src[1]) < 2e-2

def test_generate_video_dont_enlarge(tmpdir, fmt):
    """video dimensions should not be enlarged"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(1000, 1000), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings.get(fmt + '_options'))
    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_src == size_dst

def test_video_size():
    size_src = video_size(SRCFILE)
    assert size_src == (480, 270)
    size_src = video_size('missing/file.mp4')
    assert size_src == (0, 0)

def test_generate_video_dont_enlarge(tmpdir, fmt):
    """video dimensions should not be enlarged"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(1000, 1000), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings.get(fmt + '_options'))
    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_src == size_dst

def test_video_size():
    size_src = video_size(SRCFILE)
    assert size_src == (480, 270)
    size_src = video_size('missing/file.mp4')
    assert size_src == (0, 0)

def test_generate_video_fit_height(tmpdir, fmt):
    """largest fitting dimension is height"""

    base, ext = os.path.splitext(TEST_VIDEO)
    dstfile = str(tmpdir.join(base + '.' + fmt))
    settings = create_settings(video_size=(50, 100), video_format=fmt)
    generate_video(SRCFILE, dstfile, settings,
                   options=settings[fmt + '_options'])

    size_src = video_size(SRCFILE)
    size_dst = video_size(dstfile)

    assert size_dst[0] == 50
    # less than 2% error on ratio
    assert abs(size_dst[0]/size_dst[1] - size_src[0]/size_src[1]) < 2e-2