Issue with sv.VideoInfo FPS Handling for Precise Video Metadata Retrieval

[joesu-angible]

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• I have searched the Supervision issues and found no similar feature requests.

Description

Hello,

I'm using sv.VideoInfo.from_video_path to retrieve video metadata and perform video manipulations. However, I've noticed an issue with how fps is calculated. Specifically, sv.VideoInfo.from_video_path uses the following method:
fps = int(video.get(cv2.CAP_PROP_FPS))

This approach can lead to inaccuracies in certain scenarios. For example, if the actual FPS of a video is 24.999, the method will round this down to 24. Over a long video, this discrepancy can cause significant shifts and synchronization problems.

Would it be possible to modify the implementation to return the FPS as a float rather than truncating it to an integer? This would improve accuracy for edge cases like this.

Thank you for your attention!

Use case

Change the method of fps from fps = int(video.get(cv2.CAP_PROP_FPS)) to fps = float(video.get(cv2.CAP_PROP_FPS))

Additional

No response

Are you willing to submit a PR?

• Yes I'd like to help by submitting a PR!

[LinasKo]

Hi @joesu-angible 👋

Thank you for reporting the issue! Indeed, half of our own asset videos don't have a round number for the fps.

Test code

import supervision as sv
from supervision.assets import VideoAssets, download_assets
import cv2

# int fps:   People walking, Market square, Skiing, Milk bottling plant, Vehicles
# float fps: Subway, Basketball, Grocery Store, Beach, Vehicles 2

asset = VideoAssets.VEHICLES_2
download_assets(asset)

video = cv2.VideoCapture(asset.value)

fps = video.get(cv2.CAP_PROP_FPS)
print(fps, type(fps))

video_info = sv.VideoInfo.from_video_path(asset.value)
print(video_info)

This would be a superb PR submission! However, since we've had the int(fps) code for a while, this issue requires looking at the wider impacts. There's multiple things to check, but I believe each of these is pretty simple:

• Can we still use VideoSink to store a video?
• Does ByteTrack still work if a non-int FPS is passed in? Does setting track_seconds * fps for the lost track buffer work?
• Does speed estimation in inference_example.py work?
• It's also used in coordinate calculation in {ultralytics,inference,yolo_nas}_example.py
• timers.py for time in zone calculation. Used in ultralytics{_naive}_stream_example.py
• Is FPS monitor anyhow affected? I don't think so, but it'd be worth checking.

Does that sound interesting, @joesu-angible?