Getting Started - cv2

This is a walkthrough of getting started with vidformer OpenCV cv2 compatability layer.

⚠️ Adding cv2 functions is a work in progress. See the cv2 filters page for which functions have been implemented.

Installation

See Installation guide

Or you can .

⚠️ Due to how Colab networking works, vidformer can't stream/play results in Colab, only save them to disk. cv2.vidplay() will not work!

Hello, world!

Copy in your video, or use ours:

curl -O https://f.dominik.win/data/dve2/tos_720p.mp4

Then just replace import cv2 with import vidformer.cv2 as cv2. Here's our example script:

import vidformer.cv2 as cv2

cap = cv2.VideoCapture("tos_720p.mp4")
fps = cap.get(cv2.CAP_PROP_FPS)
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))

out = cv2.VideoWriter("output.mp4", cv2.VideoWriter_fourcc(*"mp4v"),
                        fps, (width, height))
while True:
    ret, frame = cap.read()
    if not ret:
      break

    cv2.putText(frame, "Hello, World!", (100, 100), cv2.FONT_HERSHEY_SIMPLEX,
                1, (255, 0, 0), 1)
    out.write(frame)

cap.release()
out.release()

Stream the Results

Saving videos to disk works, but we can also display them in the notebook. Since we stream the results and only render them on demand this can start practically instantly!

First, replace "output.mp4" with None to skip writing the video to disk. Then you can use cv2.vidplay() to play the video!

import vidformer.cv2 as cv2

cap = cv2.VideoCapture("tos_720p.mp4")
fps = cap.get(cv2.CAP_PROP_FPS)
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))

out = cv2.VideoWriter(None, cv2.VideoWriter_fourcc(*"mp4v"),
                        fps, (width, height))
while True:
    ret, frame = cap.read()
    if not ret:
      break

    cv2.putText(frame, "Hello, World!", (100, 100), cv2.FONT_HERSHEY_SIMPLEX,
                1, (255, 0, 0), 1)
    out.write(frame)

cap.release()
out.release()

cv2.vidplay(out)

⚠️ By default cv2.vidplay() will return a video which plays in a Jupyter Notebook. If running outside a jupyter notebook you can pass method="link" to return a link instead.