Short Interruptions in Moodle in Safari on Mac and iOS Devices

[ger-moneylender]

Describe the bug

RWTH Aachen Uni uses paella for educational purposes. I'm using a Mac and Safari to watch lectures. After restarting my Mac, running Safari for the first time and watching a video on Moodle, after like 2 minutes the video starts interrupting every 10 seconds. The sound stops shortly and replays a tenth of a second of what was said before the interruption. And this keeps happening throughout the rest of the video. The same occurs on my iPad Pro and iPhone using Safari. Now the magic happens if I just use Chrome to watch the video. But I don't want to switch every time I watch or just download files between both browsers.
Speed 2x just reduces the time in-between the interruption to 5 seconds.

To Reproduce

1. Use Mac or iPad or any Device running MacOS or iPadOS or iOS.
2. Start Safari.
3. (login to Moodle)
4. Browse to a video.
5. Play and wait for aprox. 2-3 minutes.
6. The error should occur now.

Workaround (if any)

Use Chrome on same device

Environment Information

• OS: MacOS 10.14, .15 and 11, iOS 13 & 14, iPadOS 13 & 14
• Browser: Safari (14.0.1), Chrome
• Paella version: I assume the ITC keeps it up to date

Additional context

I know this bug occurred 2 years ago and I kept working around it. Watching more at home due to Covid-19 I really would like to see this fixed.
Thank you and have a good one.

Thank you for contributing!

[turro]

Hi ger-moneylender

If you put the mouse on top of the help symbol of paella, it shows the version and build number. Could you do that?

[ger-moneylender]

Hi turro,

the viewer in Moodle doesn't show the help button, as you can see below.
Is there any other way to figure it out?

[turro]

OK. When you install paella in a server you decide which buttons to show, and that button isn't active.

Anyway, solving the problem will mean to update the player, and that is not done automatically, so at the end some activity from RTWH IT is required, so I think the best would be to open a ticket with them and then they open the ticket here, so we may test directly. The kind of problems you found usually are related to how the video has been encoded, and that is also something we would need to talk with them.

To look for the version you'll need to look inside the code of the page, find the paella iframe, open in a new tab so paella is out of the iframe, and then in the javascript console write

paella.version

and you'll get that value (i.e) "6.3.0 - build: bb889ae"

[ger-moneylender]

Alright, so the version is 6.2.7. The build is not shown by the command (nor in Chrome or Safari).
Safari

Chrome

I will contact our IT service and hopefully they will talk to you.
Thank you.

[t-schroeder]

Thanks @ger-moneylender for raising this issue. We received similar reports from other users recently.

@turro At RWTH Aachen we currently use Opencast 8.7 which comes with Paella 6.2.7. We usually don't upgrade Paella independently, only when we move to a new Opencast version. For encoding we use the ffmpeg commands defined here:

https://github.com/opencast/opencast/blob/r/8.x/etc/encoding/adaptive-streaming-movies.properties

As the default streaming format we use HLS. It transfers the video data in chunks of 10s length. I also emailed you a link to a test video on our site so you can see for yourself.

We've had some issues in the last weeks with high load on our servers but if that was the issue here then why does it work in Chrome?

[TheRealKingS]

The problem still exists with Opencast 9.4 and Paella Player 6.4.3 - build: 38c757f. We are using a Wowza Streaming, which sends the streams to the Paella Player, maybe there is a misconfiguration.