def test_aspect_string_to_float(self):
"""Tests if string contains an aspect ratio"""
self.assertAlmostEqual(bibencode_utils.aspect_string_to_float("4:3"),
1.333,
places=2)
self.assertAlmostEqual(bibencode_utils.aspect_string_to_float("16:9"),
1.777,
places=2)
def determine_resolution_preserving_aspect(input_file, width=None,
height=None, aspect=None):
""" Determines the right resolution for a given width or height while
preserving the aspect ratio.
@param input_file: full path of the video
@type input_file: string
@param width: The proposed width for the new size.
@type width: int
@param height: The proposed height for the new size
@type height: int
@param aspect: Override aspect ratio determined from the input file
@type aspect: float or "4:3" like string
@return: An FFMPEG compatible size string '640x480'
@rtype: string
"""
def _make_even(number):
""" Resolutions need to be even numbers for some video encoders.
We simply increase the resulution by one pixel if it is not even.
"""
if number % 2 != 0:
return number+1
else:
return number
if aspect:
if type(aspect) == type(str()):
aspect_ratio = aspect_string_to_float(aspect)
elif type(aspect) == type(float()):
aspect_ratio = aspect
else:
raise ValueError
else:
aspect_ratio_tuple = determine_aspect(input_file)
if aspect_ratio_tuple[0] is None:
aspect_ratio = float(aspect_ratio_tuple[1]) / float(aspect_ratio_tuple[2])
else:
aspect_ratio = aspect_string_to_float(aspect_ratio_tuple[0])
nresolution = None
if width and not height:
## The resolution hast to fit exactly the width
nheight = int(width / aspect_ratio)
nheight = _make_even(nheight)
nresolution = "%dx%d" % (width, nheight)
elif height and not width:
## The resolution hast to fit exactly the height
nwidth = int(height * aspect_ratio)
nwidth = _make_even(nwidth)
nresolution = "%dx%d" % (nwidth, height)
elif width and height:
## The resolution hast to be within both parameters, seen as a maximum
nwidth = width
nheight = height
new_aspect_ratio = float(width) / float(height)
if aspect_ratio > new_aspect_ratio:
nheight = int(width / aspect_ratio)
else:
nwidth = int(height * aspect_ratio)
nheight = _make_even(nheight)
nwidth = _make_even(nwidth)
nresolution = "%dx%d" % (nwidth, nheight)
else:
## Return the original size in square pixels
## original height * aspect_ratio
nwidth = aspect_ratio_tuple[2] * aspect_ratio
nwidth = _make_even(nwidth)
nresolution = "%dx%d" % (nwidth, aspect_ratio_tuple[2])
return nresolution
def test_aspect_string_to_float(self):
"""Tests if string contains an aspect ratio"""
self.assertAlmostEqual(bibencode_utils.aspect_string_to_float("4:3"), 1.333, places=2)
self.assertAlmostEqual(bibencode_utils.aspect_string_to_float("16:9"), 1.777, places=2)