FFmpeg Video Writter with Python

Introduction

As title, this is a video writter used to write video with friendly ffmpeg.

I'm angry with the fucking OpenCV because the video writter always saves only 6KB video header instead of saving videos.

I found the reason is that the video writter in OpenCV dose NOT check the shape of frame when writting into a file and it does NOT give any errors and warnings. In short, if the size is different from the original setting of video writter, it will NOT write any frames.

Requirements

• ffmpeg-python
• opencv-python
• numpy

OpenCV is optional and it's only used in the demo.

Usage

Quick Start

import cv2
from FFmpegVideoWritter import FFmpegVideoWritter

ffvw = FFmpegVideoWritter('./data/test.mp4', './result/result.mp4')

while True:
    frame = ffvw.get_frame()
    if frame is not None:
        out_frame = cv2.resize(frame, None, fx=0.5, fy=0.5)
        cv2.imshow('frame', cv2.cvtColor(out_frame, cv2.COLOR_BGR2RGB))
        cv2.waitKey(1)
        ffvw.write(out_frame)
    else:
        break

ffvw.close()
# You can get gif output!
ffvw.output_to_gif('./result/test.gif')

Demo

You can run the DEMO with the following command.

python main.py

Results

Drawing ramdomly rectangles from original video in main.py.