InputLag video analysis using opencv

inputlag-analysis.py

import numpy as np
import cv2

video = 'D:\\InputLag\\RECentral\\SFV 3.060.mp4'
cap = cv2.VideoCapture(video)

def average_by_line(img):
    return img.sum(axis=1) / 1280

DEBUG = 0

i = 0

ret, frame = cap.read()
MIN_Y = 0
MAX_Y = 1280//2
MIN_X = 200
MAX_X = 600
hsv = np.zeros_like(frame[MIN_X:MAX_X, MIN_Y:MAX_Y])
hsv[...,1] = 255
hsv[...,0] = 255

while cap.isOpened():
    ret, green_frame = cap.read()
    if green_frame is None:
        break
    i += 1
    if i % 60 == 0 and DEBUG:
        print(i/60)

    # Useful when you've got a buggy detection to check the debug
    # if i < 2586:
    #     continue
    # else:
    #     DEBUG=1
    #
    # DEBUG frame by frame
    # cv2.imshow('frame', green_frame[MIN_X:MAX_X, MIN_Y:MAX_Y])
    # cv2.waitKey()

    # convert to hsl to ease the detection of green/magenta lines
    hsl_frame = cv2.cvtColor(green_frame, cv2.COLOR_BGR2HLS)

    hue = average_by_line(hsl_frame[..., 0])
    sat = average_by_line(hsl_frame[..., 2])
    lum = average_by_line(hsl_frame[..., 1])

    # green line selector
    selector = (50 <= hue) & (hue <= 65) & (sat > 200) & (lum < 180) & (lum > 50)

    # if we have magenta line, just ignore
    if np.any(selector) and not np.any((140 <= hue) & (hue <= 160) & (sat > 200) & (lum < 180) & (lum > 50)):
        # we have an input, get the first non-zero to have the timing
        green_lines = np.nonzero(selector)
        if DEBUG:
            print("[%.02f] Found one!" % (i / 60), 16.6666 * green_lines[0][0] / 720)
            cv2.imshow('frame', green_frame)

        # opticflow is computed on grayscale
        prvs = cv2.cvtColor(green_frame, cv2.COLOR_BGR2GRAY)
        # pure black & white :D
        #prvs = (prvs // 128) * 255
        lag = 0

        if DEBUG:
            cur_key = cv2.waitKey()
        previous_metric = None
        while lag < 15:
            ret, frame = cap.read()

            i += 1
            lag += 1

            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            # pure black & white :D
            # gray = (gray // 128) * 255

            # we target only the center left part of the game
            # and we compute the optical flow
            flow = cv2.calcOpticalFlowFarneback(prvs[MIN_X:MAX_X, MIN_Y:MAX_Y], gray[MIN_X:MAX_X, MIN_Y:MAX_Y], None, 0.5, 3, 15, 3, 5, 1.1, 0)

            # sum the magnitude values, if it's high: the character moved
            change_metric = np.abs(flow[..., 0]).sum()
            if DEBUG:
                print("\t",change_metric, end=" / ")
                if previous_metric is not None:
                    print(change_metric/previous_metric)
                else:
                    print(None)
                mag, ang = cv2.cartToPolar(flow[..., 0], flow[..., 1])
                # display the frame then the opticflow representation
                hsv[..., 0] = ang * 180 / np.pi / 2
                hsv[..., 2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_MINMAX)
                print("\t\t", (hsv[..., 2] > MIN_X).sum())
                rgb = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
                cv2.imshow('frame', frame)
                cv2.waitKey()
                cv2.imshow('frame', rgb)
                cv2.waitKey()

            # if lag == 1 and change_metric > 200000:
                # too much movement to do anything (tekken 7)
                # lag = None
                # break
            # adjust condition with the game
            if previous_metric is not None and change_metric > 150000:# and change_metric > (previous_metric*2):

                if DEBUG:
                    print("\t Found lag: ", lag)
                break

            prvs = gray
            previous_metric = change_metric
        if lag is None:
            continue
        if lag == 15:
            if DEBUG:
                print("\t ERROR COULDNT FIND LAG!")
            lag = None
            cv2.imshow('frame', green_frame)
            cv2.waitKey()
            continue
        print("%i,%f,%i" % (i, 16.6666 * green_lines[0][0] / 720, lag))

cap.release()
cv2.destroyAllWindows()