Testing code for sequentially reading a frame from a video.

VideoStreamTest.py

from time import time

import cv2 as cv
import numpy as np
from pathlib import Path

videoPath = Path('/home/knowblesse/VCF/butter/Sample/TestVideo_Blinking.avi')

# Option 1 : OpenCV calling all frames
cap = cv.VideoCapture(str(videoPath))
startTime = time()
EOF = False
fr = 0
while not EOF:
    fr += 1
    ret, frame = cap.read()
    if not ret:
        EOF = True
print(f'Option 1 Time {time() - startTime}')

# Option 2 : ffmpeg methods

import ffmpeg

videoObject = ffmpeg.input(str(videoPath))

probe = ffmpeg.probe(str(videoPath))
info = [stream for stream in probe['streams'] if stream['codec_type'] == 'video']
info = info[0]

height = int(info['height'])
width = int(info['width'])

## Option 2-1 : ffmpeg : Directly reading bgr image from yuv420p video
# Conversion is done inside the ffmpeg side
out = (
    ffmpeg
    .input(str(videoPath))
    .output('pipe:', format='rawvideo', pix_fmt = 'bgr24')
    .global_args('-loglevel', 'error', '-hide_banner')
    .run_async(pipe_stdout=True)
)

startTime = time()
EOF = False
fr = 0
while not EOF:
    fr += 1
    frame = out.stdout.read(int(height * width * 3))
    if not len(frame):
        EOF = True
    else:
        img = np.frombuffer(frame, np.uint8).reshape([height, width, 3])

print(f'Option 2-1 Time {time() - startTime}')

# Option 2-2 : ffmpeg : Reading yuv420p video and converting from the opencv side
# Credit to roninpawn
out = (
    ffmpeg
    .input(str(videoPath))
    .output('pipe:', format='rawvideo', pix_fmt = 'yuv420p')
    .global_args('-loglevel', 'error', '-hide_banner')
    .run_async(pipe_stdout=True)
)

startTime = time()
EOF = False
fr = 0
while not EOF:
    fr += 1
    frame = out.stdout.read(int(height * width * 1.5))
    if not len(frame):
        EOF = True
    else:
        img = np.frombuffer(frame, np.uint8).reshape([height*3//2, width])
        img = cv.cvtColor(img, cv.COLOR_YUV2BGR_I420)

print(f'Option 2-2 Time {time() - startTime}')

# Option 2-3 : ffmpeg : FFdecoder
# Credit to deffcode

from deffcode import FFdecoder

decoder = FFdecoder(str(videoPath), frame_format="bgr24").formulate()
startTime = time()
fr = 0
for frame in decoder.generateFrame():
    fr += 1
    img = frame
print(f'Option 2-3 Time {time() - startTime}')