Pillow/Tests/test_file_webp_animated.py
2019-11-26 07:03:23 +11:00

164 lines
5.5 KiB
Python

from PIL import Image
from .helper import PillowTestCase
try:
from PIL import _webp
HAVE_WEBP = True
except ImportError:
HAVE_WEBP = False
class TestFileWebpAnimation(PillowTestCase):
def setUp(self):
if not HAVE_WEBP:
self.skipTest("WebP support not installed")
return
if not _webp.HAVE_WEBPANIM:
self.skipTest(
"WebP library does not contain animation support, "
"not testing animation"
)
def test_n_frames(self):
"""
Ensure that WebP format sets n_frames and is_animated
attributes correctly.
"""
with Image.open("Tests/images/hopper.webp") as im:
self.assertEqual(im.n_frames, 1)
self.assertFalse(im.is_animated)
with Image.open("Tests/images/iss634.webp") as im:
self.assertEqual(im.n_frames, 42)
self.assertTrue(im.is_animated)
def test_write_animation_L(self):
"""
Convert an animated GIF to animated WebP, then compare the
frame count, and first and last frames to ensure they're
visually similar.
"""
with Image.open("Tests/images/iss634.gif") as orig:
self.assertGreater(orig.n_frames, 1)
temp_file = self.tempfile("temp.webp")
orig.save(temp_file, save_all=True)
with Image.open(temp_file) as im:
self.assertEqual(im.n_frames, orig.n_frames)
# Compare first and last frames to the original animated GIF
orig.load()
im.load()
self.assert_image_similar(im, orig.convert("RGBA"), 25.0)
orig.seek(orig.n_frames - 1)
im.seek(im.n_frames - 1)
orig.load()
im.load()
self.assert_image_similar(im, orig.convert("RGBA"), 25.0)
def test_write_animation_RGB(self):
"""
Write an animated WebP from RGB frames, and ensure the frames
are visually similar to the originals.
"""
def check(temp_file):
with Image.open(temp_file) as im:
self.assertEqual(im.n_frames, 2)
# Compare first frame to original
im.load()
self.assert_image_equal(im, frame1.convert("RGBA"))
# Compare second frame to original
im.seek(1)
im.load()
self.assert_image_equal(im, frame2.convert("RGBA"))
with Image.open("Tests/images/anim_frame1.webp") as frame1:
with Image.open("Tests/images/anim_frame2.webp") as frame2:
temp_file1 = self.tempfile("temp.webp")
frame1.copy().save(
temp_file1, save_all=True, append_images=[frame2], lossless=True
)
check(temp_file1)
# Tests appending using a generator
def imGenerator(ims):
yield from ims
temp_file2 = self.tempfile("temp_generator.webp")
frame1.copy().save(
temp_file2,
save_all=True,
append_images=imGenerator([frame2]),
lossless=True,
)
check(temp_file2)
def test_timestamp_and_duration(self):
"""
Try passing a list of durations, and make sure the encoded
timestamps and durations are correct.
"""
durations = [0, 10, 20, 30, 40]
temp_file = self.tempfile("temp.webp")
with Image.open("Tests/images/anim_frame1.webp") as frame1:
with Image.open("Tests/images/anim_frame2.webp") as frame2:
frame1.save(
temp_file,
save_all=True,
append_images=[frame2, frame1, frame2, frame1],
duration=durations,
)
with Image.open(temp_file) as im:
self.assertEqual(im.n_frames, 5)
self.assertTrue(im.is_animated)
# Check that timestamps and durations match original values specified
ts = 0
for frame in range(im.n_frames):
im.seek(frame)
im.load()
self.assertEqual(im.info["duration"], durations[frame])
self.assertEqual(im.info["timestamp"], ts)
ts += durations[frame]
def test_seeking(self):
"""
Create an animated WebP file, and then try seeking through
frames in reverse-order, verifying the timestamps and durations
are correct.
"""
dur = 33
temp_file = self.tempfile("temp.webp")
with Image.open("Tests/images/anim_frame1.webp") as frame1:
with Image.open("Tests/images/anim_frame2.webp") as frame2:
frame1.save(
temp_file,
save_all=True,
append_images=[frame2, frame1, frame2, frame1],
duration=dur,
)
with Image.open(temp_file) as im:
self.assertEqual(im.n_frames, 5)
self.assertTrue(im.is_animated)
# Traverse frames in reverse, checking timestamps and durations
ts = dur * (im.n_frames - 1)
for frame in reversed(range(im.n_frames)):
im.seek(frame)
im.load()
self.assertEqual(im.info["duration"], dur)
self.assertEqual(im.info["timestamp"], ts)
ts -= dur