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• Opencv VideoCapture always returns false on Heroku

  27 juin 2022, par Dacian Mujdar

  I'm using the following code to open a video stream :

  


  import cv2
video = cv2.VideoCapture()
video.open("some_m3u8_link")
success, image = video.read()


  


  However, even if the code works as intended locally, on Heroku success is always false.

  


  I'm using cedar-14 stack with the following buildpacks :

  


  


  heroku/python

  


  https://github.com/jonathanong/heroku-buildpack-ffmpeg-latest.git

  


  


  (I tried several buildpack options for ffmpeg)

  


  Running ffmpeg --version on heroku instance will return ffmpeg version 4.0-static https://johnvansickle.com/ffmpeg/

  


  Is there any setting/configuration I missed in order to make it work on deployment ? Thank you !

  


  Later edit : I tried several links for "some_m3u8_link" including from twitch and other streaming services (including traffic streaming li
An example for reproducing :

  


  python -c "import cv2; video=cv2.VideoCapture(); video.open('https://hddn01.skylinewebcams.com/live.m3u8?a=5tm6kfqrhqbpblan9j5d4bmua4'); success, image = video.read(); print(success)"


  


  Returns True on local machine and False on Heroku.

  


  (the link is taken from here)

  


• What video codecs work on Google Chromebook

  3 mars 2019, par MonkeyDLuffy

  I’m trying to put a show on my friends Google Chromebook but the mp4 files show up black when trying to watch them on said Chromebook, audio works fine. I found out that it is a video encoding problem but I cannot find a list of video formats that work on the Chromebook. I have ffmpeg and handbrake to try and test some things, but if someone could tell me a ffmpeg code that will convert the video files into a format that works on a Google Chromebook that would help a lot.

  What I’ve tried :

  ffmpeg -i "Game of Thrones S02E01 The North Remembers.mkv" codec mpeg "Game of Thrones S02E01 The North Remembers.mp4"

  Which gives error :

  [NULL @ 00000177196ea500] Unable to find a suitable output format for
  ’codec’ codec : Invalid argument

• ffmpeg on google app engine or other alternatives

  6 décembre 2022, par Jon Luc

  This isn’t really a problem with any specific bit of code more just a general question about how I would host a ffmpeg function within a severless function like google app engine. Basically I have a block of code that takes every n frame a video and uploads it to google cloud storage. I have tried implementing such a solution with Firebase functions but to no avail. I think the primary problem is really to do with file storage, from my undetnsdjng data should be written to the tmp folder.

  


  So if anyone can outline exactly how I could host this on app engine that would be great, please be very specific and don’t assumeI know anything because I’ve only really worked with functions :)

  


  Thanks so much

  


  
//Essentially this but on app engine or any other severless environment

try {
        const process = new ffmpeg('star_wars_film_scene.mp4');
        process.then(function(video) {
            // Callback mode
            video.fnExtractFrameToJPG('helpers/frames/', {
                every_n_frames: 500
                
            }, function(error, files) {
                if (error) {
                    console.log(error);
                    return;
                }
                ProcessFrames(files);
            });
        }, function(err) {
            console.log(err);
        });
    } catch (e) {
        console.log('Houston, we have a problem')
        console.log(e.code);
        console.log(e.msg);
    }