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import pytest
from PIL import Image
from .helper import (
assert_image_equal,
assert_image_similar,
is_big_endian,
skip_unless_feature,
)
pytestmark = [
skip_unless_feature("webp"),
skip_unless_feature("webp_anim"),
]
def test_n_frames():
"""Ensure that WebP format sets n_frames and is_animated attributes correctly."""
with Image.open("Tests/images/hopper.webp") as im:
assert im.n_frames == 1
assert not im.is_animated
with Image.open("Tests/images/iss634.webp") as im:
assert im.n_frames == 42
assert im.is_animated
@pytest.mark.xfail(is_big_endian(), reason="Fails on big-endian")
def test_write_animation_L(tmp_path):
"""
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:
assert orig.n_frames > 1
temp_file = str(tmp_path / "temp.webp")
orig.save(temp_file, save_all=True)
with Image.open(temp_file) as im:
assert im.n_frames == orig.n_frames
# Compare first and last frames to the original animated GIF
orig.load()
im.load()
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()
assert_image_similar(im, orig.convert("RGBA"), 25.0)
@pytest.mark.xfail(is_big_endian(), reason="Fails on big-endian")
def test_write_animation_RGB(tmp_path):
"""
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:
assert im.n_frames == 2
# Compare first frame to original
im.load()
assert_image_equal(im, frame1.convert("RGBA"))
# Compare second frame to original
im.seek(1)
im.load()
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 = str(tmp_path / "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 = str(tmp_path / "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(tmp_path):
"""
Try passing a list of durations, and make sure the encoded
timestamps and durations are correct.
"""
durations = [0, 10, 20, 30, 40]
temp_file = str(tmp_path / "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:
assert im.n_frames == 5
assert 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()
assert im.info["duration"] == durations[frame]
assert im.info["timestamp"] == ts
ts += durations[frame]
def test_seeking(tmp_path):
"""
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 = str(tmp_path / "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:
assert im.n_frames == 5
assert 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()
assert im.info["duration"] == dur
assert im.info["timestamp"] == ts
ts -= dur
def test_seek_errors():
with Image.open("Tests/images/iss634.webp") as im:
with pytest.raises(EOFError):
im.seek(-1)
with pytest.raises(EOFError):
im.seek(42)
|
