Mark slow tests

[scotts]

Both test_video_encoder_round_trip() and test_video_encoder_against_ffmpeg_cli() are taking around 30 seconds or more on my dev machine for webm. If we could just say that the webm option is slow, that would be better, but I think this is okay for now.

This is relevant for when we just say pytest test, it will default to not running the slow tests. See our pyproject.toml:

torchcodec/pyproject.toml

Lines 43 to 51 in b9cf8d1

	[tool.pytest.ini_options]
	markers = [
	# defines a 'slow' mark to mark slow tests with `@pytest.mark.slow`
	"slow: mark test as slow"
	]
	# We don't want to run the slow tests by default. These options are ignored in
	# the CI, where we definitely want the 'slow' tests to run.
	addopts = "-v -m 'not slow'"

[Dan-Flores]

Thanks for adding this!

[NicolasHug]

LGTM but let's mark the webm tests only, as you originally suggested. I shared an example below on how to do that

[NicolasHug]

We can "mark" individual entries with arbitrary marks:

Suggested change

	@pytest.mark.slow
	@pytest.mark.parametrize("format", ("mov", "mp4", "mkv", "webm"))
	@pytest.mark.parametrize(
	"format", ("mov", "mp4", "mkv", pytest.param("webm", marks=pytest.mark.slow))
	)

This is also how we handle our automatic "needs_cuda" mark:

torchcodec/test/utils.py

Lines 29 to 34 in b9cf8d1

	def all_supported_devices():
	return (
	"cpu",
	pytest.param("cuda", marks=pytest.mark.needs_cuda),
	pytest.param("cuda:0:beta", marks=pytest.mark.needs_cuda),
	)

[NicolasHug]

Same here