# PyTest has weird syntax for parameterizing fixtures:
# https://docs.pytest.org/en/latest/fixture.html#parametrizing-fixtures
import pytest
from hypothesis import given
import hypothesis.strategies as st
from assertions.seq import assert_ordered, assert_elems_gte, assert_elems_lt
from torchvideo.samplers import (
FullVideoSampler,
TemporalSegmentSampler,
ClipSampler,
frame_idx_to_list,
)
def full_video_sampler():
return FullVideoSampler()
def temporal_segment_sampler():
segment_count = st.integers(1, 100).example()
snippet_length = st.integers(1, 1000).example()
return TemporalSegmentSampler(segment_count, snippet_length)
def clip_sampler():
clip_length = st.integers(1, 1000).example()
return ClipSampler(clip_length)
@pytest.fixture(params=[clip_sampler, full_video_sampler, temporal_segment_sampler])
def frame_sampler(request):
return request.param()
class TestFrameSampler:
"""
These tests test general properties that all samplers should abide by.
"""
@given(st.integers(max_value=0))
def test_frame_sampler_raises_error_0_or_negative_frame_count(
self, frame_sampler, frame_count
):
with pytest.raises(ValueError, match=r"{} frames".format(frame_count)):
frame_sampler.sample(frame_count)
@given(st.integers(min_value=1, max_value=1000))
def test_frame_sampler_generates_sequential_idx(self, frame_sampler, frame_count):
frames_idx = frame_sampler.sample(frame_count)
frames_idx = frame_idx_to_list(frames_idx)
assert_ordered(frames_idx)
assert_elems_lt(frames_idx, frame_count)
assert_elems_gte(frames_idx, 0)
