bars.py

import cv2
from PIL import Image, ImageDraw
import sys

class Movie:
    def __init__(self, video_file):
        self.cap = cv2.VideoCapture(video_file)
        self.name = video_file
        self.base_name = '.'.join(video_file.split('.')[:-1])

        while not self.cap.isOpened():
            self.cap = cv2.VideoCapture(video_file)
            cv2.waitKey(1000)
            print ("Wait for the header")

        self.pos_frame = int(self.cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES))
        self.frames = int(self.cap.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT))

    def get_frames(self):
        while True:
            flag, frame = self.cap.read()
            if flag:
                # the frame is ready and already captured.
                #frame = cv2.resize(frame, (1,1), interpolation=cv2.INTER_LINEAR)
                average = cv2.mean(frame)
                yield tuple([int(x) for x in average[0:3]])
                cv2.imshow('video', frame)
                self.pos_frame = self.cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES)
            else:
                # the next frame is not ready, so we try to read it again.
                self.cap.set(cv2.cv.CV_CAP_PROP_POS_FRAMES)
                print ("frame is not ready")
                cv2.waitKey(1000)

            if cv2.waitKey(10) == 27:
                break
            if self.cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES) == self.cap.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT):
                # When we're at the end, we stop.
                break

def make_image(image_name, movie, height=50):
    image = Image.new('RGB', (mov.frames, height), "white")
    draw = ImageDraw.Draw(image)
    for frame in movie.get_frames():
        draw.line([(int(mov.pos_frame), 0), (int(mov.pos_frame), height)], frame, 2)
    outfile = open(image_name, 'wb')
    image.save(outfile, "PNG")
    outfile.close()


if __name__ == "__main__":
    mov = Movie(sys.argv[1])
    make_image(sys.argv[2], mov, height=100)