Check for correct frame rate and aspect ratio of each video lesson, and determine total length of the course

lesson-checker.py

# Requires installation of `ffmpeg` and `ffmpeg-python`:
# - https://www.ffmpeg.org
# - https://pypi.org/project/ffmpeg-python/

import fractions
from pathlib import Path

import ffmpeg


recordings_folder = Path("/Users/martin/Documents/real_python/my-tutorials/ggplotting/recordings")
# Or, run in the current folder:
# recordings_folder = Path.cwd()

probes = {}

for mfile in recordings_folder.iterdir():
    if mfile.suffix == ".mov":
        probe = ffmpeg.probe(mfile)
        video_streams = [stream for stream in probe["streams"] if stream["codec_type"] == "video"]
        if len(video_streams) > 1:
            raise Exception(f"{mfile.name}: More than one video stream.")
        probes[mfile.name] = video_streams[0]  # Usually there is only 1

data = {}
for filename, info in probes.items():
    data[filename] = {
        "duration_min": float(info["duration"]) / 60,  # In minutes
        "r_frame_rate": fractions.Fraction(info["r_frame_rate"]),
        "resolution": fractions.Fraction(info["width"], info["height"])
    }

total_course_length = 0

for filename, info in data.items():
    if info["r_frame_rate"].numerator < 30:
        print(f"{filename}: Low frame rate ({info['r_frame_rate']})")
    if info["resolution"] != fractions.Fraction(16, 9):
        print(f"{filename}: Wrong resolution ({info['resolution']})")
    total_course_length += info["duration_min"]

print(f"{len(data)} lessons")
print(f"{total_course_length:.2f} minutes total")