Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

playing videos in JATOS from lab.js file

Hi there!

I wrote an audiovisual experiment in lab.js.

I want to do a pilot study by using the free server of JATOS (Thank you for that! ). When I upload my study and run it, the video's are delayed. It gives no video at all, or a black screen first and then shows the video, but my audio and video are separate (and it shows synchronized in lab.js without the black screen) so audio and video are completely off when I run it in JATOS. Does anyone have experience with this or knows how to solve it?

It runs without problems in lab.js.

The videos are .mov files, but I also tried it with a .mp4 file, that doesn't change anything.

There are 20 different videos, but they are all relatively small (between 500-900kb). The videos are integrated in the .json file

I also tried to make a very basic experiment to see if I could just get a video to run. So i made a lab.js file with a start screen and then 1 video, but this has the same problems. (I wanted to upload the zipfile here, downloaded from lab.js but it gives me error 431?)

I tried to run it in chrome and Safari, both have the same problems.

It would be amazing if someone could help me with this issue! Thanks!


Liesbeth Gijbels

Comments

  • Hi Liesbeth,

    experiements.jatos.org should be able to handle your experiment as far as I can see: 20 different videos each 500-900kb is not too big.

    the video's are delayed. It gives no video at all, or a black screen first and then shows the video, but my audio and video are separate (and it shows synchronized in lab.js without the black screen) so audio and video are completely off when I run it in JATOS

    It sounds like network delay to me. As soon as you run the study in the internet those delays or other network problems can happen. What happens when you try to run your study in a local JATOS installation? Locally you won't have those internet problems.

    Btw. I guess you get the 431 error code because it's a zip file. The same happen with Gmail. There could be dangerous stuff inside a zip. One way around this is to use Google Drive or similar services.

    Best,

    Kristian

  • Hi Kristian,


    Thank you for your response.

    It works perfect when I run it locally.

    So how do I solve this? What is the best way to get my experiment out there? I made the experiment online because of COVID, so running it on my computer gives me the same problem as I had before, when I wrote it in Python. I can't share it with anyone?


    Thank you for your response


    Liesbeth

  • Hi Liesbeth,

    If you post/send the study I can have a look at it. But actually it would be better to ask someone from lab.js, since this is not so much a JATOS problem.

    Best,

    Kristian

  • Hi Kristian,


    Thank you.

    I am also talking to lab.js, but they had sent me to you.

    It would be great though if you could have a look at it: https://drive.google.com/drive/folders/1TKW3iLxrS_HkJnv280E5759fy2dFtRpX?usp=sharing


    Thank you so much

    Liesbeth

  • Hi Liesbeth,

    I see in your study that you load the audio and video files just before they are played. It would be better to pre-load them at the beginning of the study. Loading larger files like audio or video always take some time and here in your experiment likely take different times but are played right away which leads to not synchronized audio and video and lagging. If you pre-load them, they are already in your participant's browser memory and can be played right away. Unfortunately my knowledge of lab.js is not good enough to help your with pre-loading.

    Another thing that I noticed but this might be purpose: your audio files have quite some background noise. Is this maybe part of your experiment?

    And yet another thing: it would be easier if you combine your video and audio files into one file. This would make audio and video synchronization way easier. But somehow I suspect you are aware of this and just need to play them separately in different combinations in your experiment.

    Best,

    Kristian

  • Hi Kristian,


    Thank you for this!

    I will try to preload!

    It is a speech in noise task, so yes indeed the background noise is part of the experiment. And I would rather not combine them for the exact reason that I want different combinations and now it needs to load a small amount of different videos but a large amount of audio, which is "less heavy", If I combine them there will be a lot of 'heavier' video files, so I was trying to avoid that.


    Liesbeth Gijbels

Sign In or Register to comment.

agen judi bola , sportbook, casino, togel, number game, singapore, tangkas, basket, slot, poker, dominoqq, agen bola. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 50.000 ,- bonus cashback hingga 10% , diskon togel hingga 66% bisa bermain di android dan IOS kapanpun dan dimana pun. poker , bandarq , aduq, domino qq , dominobet. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 10.000 ,- bonus turnover 0.5% dan bonus referral 20%. Bonus - bonus yang dihadirkan bisa terbilang cukup tinggi dan memuaskan, anda hanya perlu memasang pada situs yang memberikan bursa pasaran terbaik yaitu http://45.77.173.118/ Bola168. Situs penyedia segala jenis permainan poker online kini semakin banyak ditemukan di Internet, salah satunya TahunQQ merupakan situs Agen Judi Domino66 Dan BandarQ Terpercaya yang mampu memberikan banyak provit bagi bettornya. Permainan Yang Di Sediakan Dewi365 Juga sangat banyak Dan menarik dan Peluang untuk memenangkan Taruhan Judi online ini juga sangat mudah . Mainkan Segera Taruhan Sportbook anda bersama Agen Judi Bola Bersama Dewi365 Kemenangan Anda Berapa pun akan Terbayarkan. Tersedia 9 macam permainan seru yang bisa kamu mainkan hanya di dalam 1 ID saja. Permainan seru yang tersedia seperti Poker, Domino QQ Dan juga BandarQ Online. Semuanya tersedia lengkap hanya di ABGQQ. Situs ABGQQ sangat mudah dimenangkan, kamu juga akan mendapatkan mega bonus dan setiap pemain berhak mendapatkan cashback mingguan. ABGQQ juga telah diakui sebagai Bandar Domino Online yang menjamin sistem FAIR PLAY disetiap permainan yang bisa dimainkan dengan deposit minimal hanya Rp.25.000. DEWI365 adalah Bandar Judi Bola Terpercaya & resmi dan terpercaya di indonesia. Situs judi bola ini menyediakan fasilitas bagi anda untuk dapat bermain memainkan permainan judi bola. Didalam situs ini memiliki berbagai permainan taruhan bola terlengkap seperti Sbobet, yang membuat DEWI365 menjadi situs judi bola terbaik dan terpercaya di Indonesia. Tentunya sebagai situs yang bertugas sebagai Bandar Poker Online pastinya akan berusaha untuk menjaga semua informasi dan keamanan yang terdapat di POKERQQ13. Kotakqq adalah situs Judi Poker Online Terpercayayang menyediakan 9 jenis permainan sakong online, dominoqq, domino99, bandarq, bandar ceme, aduq, poker online, bandar poker, balak66, perang baccarat, dan capsa susun. Dengan minimal deposit withdraw 15.000 Anda sudah bisa memainkan semua permaina pkv games di situs kami. Jackpot besar,Win rate tinggi, Fair play, PKV Games