OpenCV – Aiharasoft BLOG

Twitter「一部の画像/動画をアップロードできません。」

OpenCV で動画を作成し、Twitterに動画を投稿しようとすると、「一部の画像/動画をアップロードできません。」のエラーが発生する。

fourcc = cv2.VideoWriter_fourcc(* ‘mp4v’)

ではなく、次のように　h264 コーデックを使用する。

fourcc = cv2.VideoWriter_fourcc(* ‘h264’)

Capturing Youtube by OpenCV

Reference

https://www.366service.com/jp/qa/ad87eecb1989830886612272067df0eb
It needs some changes.

Environment

macOS BigSur

Visual Studio Code

Python 3.8.5 64bit

Prerequisites

$ pip install cv2
$ pip install pafy

Code for macOS

import cv2
import pafy

# Tokyo Station
url = 'https://youtu.be/6YRUWrkV2R4'
video = pafy.new(url)

streams = video.streams
for i in streams:
    print(i)

# get best resolution regardless of format
best = video.getbest()

# start the video
cap = cv2.VideoCapture(best.url)
while (True):
    ret, frame = cap.read()
    cv2.imshow('frame', frame)
    if cv2.waitKey(20) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()

A beautiful sea of clouds at Chichibu, Japan.

This video has been remixed from Chichi Live Camera photos by Python + OpenCV + Visual Studio Code on mac.

import os
import time
import datetime
import urllib.error
import urllib.request
import cv2

def download_file(url, dst_path):
    try:
        with urllib.request.urlopen(url) as web_file:
            data = web_file.read()
            with open(dst_path, mode='wb') as local_file:
                local_file.write(data)
    except urllib.error.URLError as e:
        print(e)

fourcc = cv2.VideoWriter_fourcc(* 'h264')
fps = 10
out = cv2.VideoWriter('out.mp4', fourcc, fps, (H,V))

startTime = datetime.datetime(yyyy, mm, dd, HH, MM, SS)
x = duration
for interval in range(x):
    t = startTime + datetime.timedelta(minutes=interval)
    print(datetime.datetime.strftime(t, "/%Y%m%d/%H%M%S.jpg"))
    tstr = datetime.datetime.strftime(t, "/%Y%m%d/%H%M%S.jpg")
    url = 'https://*********' + tstr
    dst_path = datetime.datetime.strftime(t, "images/%Y%m%d%H%M%S.jpg")
    if os.path.exists(dst_path):
        print("skip")
    else:
        download_file(url, dst_path)
        time.sleep(10)  # Don't rush to 

    img = cv2.imread(dst_path, cv2.IMREAD_COLOR)
    # 画像の大きさを取得
    # height, width, channels = img.shape[:3]
    # print("width: " + str(width))
    # print("height: " + str(height))
    out.write(img)

out.release()

Chichibu Live Camera

You can find out beautiful photos of Chichibu Live camera from here.

https://navi.city.chichibu.lg.jp/cloudview/

Anohana: The Flower We Saw That Day

Chichibu is also famous for the animation “Anohana: The Flower We Saw That Day“. It was on air in 2011, but still may anime fans are visiting Chichibu, the place of anime scenes.

TimeLapse by mac Mini + OpenCV + Python

Environment

macOS Catalina 10.15.6

OpenCV

Python 3.8

Tyhoon HAISHEN is coming!

Source Code

import cv2

RATE = 30
cap = cv2.VideoCapture(0)
w = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
h = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
fps = cap.get(cv2.CAP_PROP_FPS)
fourcc = cv2.VideoWriter_fourcc(*'h264')
out = cv2.VideoWriter('out.mp4', fourcc, fps, (int(w), int(h)))

count = RATE
while True:
    ret, frame = cap.read()
    if ret == True:
        if count == 0:
            out.write(frame)
            count = RATE
        count -= 1
        cv2.imshow('frame', frame)
        keyboard = cv2.waitKey(30)
        if keyboard == 27:
            break
    else:
        break
cap.release()
out.release()
cv2.destroyAllWindows()

mac, VisualStudio Code, OpenCV, VideoCapture, Crash due to PRIVACY VIOLATION

現象　

mac OSで、Visual Studio Code で、次のコードを実行すると、クラッシュする。

import cv2
cap = cv2.VideoCapture(0) # ここで、Pythonがクラッシュする。
…

環境

Mac OS: Catalina 10.15.6

Visual Studio Code: 1.48.2

Python 3.8.4

原因

クラッシュレポートを見ると、次のようになっていて、

Crashed Thread: 1 Dispatch queue: com.apple.root.default-qos
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
…
Thread 1 Crashed:: Dispatch queue: com.apple.root.default-qos
…
0x00007fff71fb4411 abort_with_payload + 9 3 com.apple.TCC 0x00007fff6868559f __CRASHING_DUE_TO_PRIVACY_VIOLATION + 163
4 com.apple.TCC 0x00007fff68683531 __TCCAccessRequest_block_invoke.114 + 500
…

CRASHING_DUE_TO_PRIVACY_VIOLATION

macOS 10.15 Catalinaでは「User Consent」がさらに強化され、アプリがスクリーンキャプチャの撮影や書類、ダウンロードフォルダへのアクセスする際にユーザーの承認が必要に。

Visual Studio Code が Python を実行する段階で、Permission を取得していないのが原因と思われる。