test_fps.py

import subprocess
import pytest
import re

@pytest.mark.d457
@pytest.mark.parametrize("frames", {20})
@pytest.mark.parametrize("device", {'0', '2'})
def test_fps(device, frames):
	try:
		print(f"\nDevice: {device}")
		formats = get_formats(device)
		for w, h in formats:
			print(f"format: {w}x{h}")
			for FPS in formats[(w, h)]:
				cmd = [ "v4l2-ctl",
					  f"-d{device}",
					  f"--set-fmt-video=width={w},height={h}",
					  ]
				subprocess.check_call(cmd)
				cmd = [ "v4l2-ctl",
					  f"-d{device}",
					  "-p",
					  f"{FPS}",
					  ]
				subprocess.check_call(cmd)
				cmd = [ "v4l2-ctl",
					  f"-d{device}",
					  "--stream-mmap",
					  "--stream-count",
					  f"{frames}",
					  "--verbose",
					  ]
				timeout = 5.0 * frames / FPS
				output = subprocess.run(cmd,
								  check=True,
								  text=True,
								  capture_output=True,
								  timeout=timeout).stderr.splitlines()
				last = None
				kpi = 5 # [%]
				for line in output:
					m = re.search(r"cap dqbuf:.*seq:\s*(\d*)\s*bytesused:.*", line)
					if m:
						frame = int(m.group(1))
						print(f"\t{frame}", end="")
						if last:
							assert frame > last, f"Repeated frame: {frame}"
							assert (frame - last) < 3 , f"Frames dropped between: {last} and {frame}"
						m = re.search(r"cap dqbuf:.*bytesused:.*fps:\s*(\d+\.\d+)\s*.*", line)
						if m:
							fps = float(m.group(1))
							if last:
								print(f"/{fps}", end="")
								assert fps > FPS * (1 - kpi/100), f"FPS too low: {fps}/{FPS}"
								assert fps < FPS * (1 + kpi/100), f"FPS too high: {fps}/{FPS}"
						last = frame
						print()
				assert last, "No frames received"

	except Exception as e:
		assert False, "Exception caught during test: {}".format(e)

def get_formats(device):
	try:
		cmd = [ "v4l2-ctl",
		 "-d" + device,
		 "--list-formats-ext",
		 ]
		output = subprocess.run(cmd,
						  check=True,
						  text=True,
						  capture_output=True
						  ).stdout.splitlines()
		formats = {}
		last = None
		for line in output:
			m = re.search(r"\s*Size: Discrete\s*(\d+)x(\d+)", line)
			if m:
				w = int(m.group(1))
				h = int(m.group(2))
				last = (w ,h)
				if not last in formats:
					formats[last] = set()
				continue
			m = re.search(r"\s*Interval: Discrete.*\((\d+\.\d+)\s+fps\)", line)
			if m:
				fps = float(m.group(1))
				if last:
					formats[last].add(fps)
		return formats

	except Exception as e:
		assert False, "Exception caught @get_formats: {}".format(e)