from .helper import PillowTestCase from PIL import Image 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. """ im = Image.open("Tests/images/hopper.webp") self.assertEqual(im.n_frames, 1) self.assertFalse(im.is_animated) im = Image.open("Tests/images/iss634.webp") 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. """ orig = Image.open("Tests/images/iss634.gif") self.assertGreater(orig.n_frames, 1) temp_file = self.tempfile("temp.webp") orig.save(temp_file, save_all=True) im = Image.open(temp_file) 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): im = Image.open(temp_file) 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")) frame1 = Image.open("Tests/images/anim_frame1.webp") frame2 = Image.open("Tests/images/anim_frame2.webp") 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): for im in ims: yield im 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") frame1 = Image.open("Tests/images/anim_frame1.webp") frame2 = Image.open("Tests/images/anim_frame2.webp") frame1.save( temp_file, save_all=True, append_images=[frame2, frame1, frame2, frame1], duration=durations, ) im = Image.open(temp_file) 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") frame1 = Image.open("Tests/images/anim_frame1.webp") frame2 = Image.open("Tests/images/anim_frame2.webp") frame1.save( temp_file, save_all=True, append_images=[frame2, frame1, frame2, frame1], duration=dur, ) im = Image.open(temp_file) 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